# coding: utf-8
from __future__ import print_function, unicode_literals

import errno
import hashlib
import json
import math
import os
import re
import shutil
import stat
import subprocess as sp
import tempfile
import threading
import time
import traceback
from copy import deepcopy

from queue import Queue

from .__init__ import ANYWIN, PY2, TYPE_CHECKING, WINDOWS, E
from .authsrv import LEELOO_DALLAS, SEESLOG, VFS, AuthSrv
from .bos import bos
from .cfg import vf_bmap, vf_cmap, vf_vmap
from .fsutil import Fstab
from .mtag import MParser, MTag
from .util import (
    HAVE_SQLITE3,
    SYMTIME,
    VF_CAREFUL,
    Daemon,
    MTHash,
    Pebkac,
    ProgressPrinter,
    absreal,
    alltrace,
    atomic_move,
    db_ex_chk,
    dir_is_empty,
    djoin,
    fsenc,
    gen_filekey,
    gen_filekey_dbg,
    gzip,
    hidedir,
    humansize,
    min_ex,
    pathmod,
    quotep,
    rand_name,
    ren_open,
    rmdirs,
    rmdirs_up,
    runhook,
    runihook,
    s2hms,
    s3dec,
    s3enc,
    sanitize_fn,
    sfsenc,
    spack,
    statdir,
    ub64enc,
    unhumanize,
    vjoin,
    vsplit,
    w8b64dec,
    w8b64enc,
    wunlink,
)

try:
    from pathlib import Path
except:
    pass

if HAVE_SQLITE3:
    import sqlite3

DB_VER = 5

if True:  # pylint: disable=using-constant-test
    from typing import Any, Optional, Pattern, Union

if TYPE_CHECKING:
    from .svchub import SvcHub

zsg = "avif,avifs,bmp,gif,heic,heics,heif,heifs,ico,j2p,j2k,jp2,jpeg,jpg,jpx,png,tga,tif,tiff,webp"
ICV_EXTS = set(zsg.split(","))

zsg = "3gp,asf,av1,avc,avi,flv,m4v,mjpeg,mjpg,mkv,mov,mp4,mpeg,mpeg2,mpegts,mpg,mpg2,mts,nut,ogm,ogv,rm,vob,webm,wmv"
VCV_EXTS = set(zsg.split(","))

zsg = "nohash noidx xdev xvol"
VF_AFFECTS_INDEXING = set(zsg.split(" "))


SBUSY = "cannot receive uploads right now;\nserver busy with %s.\nPlease wait; the client will retry..."

HINT_HISTPATH = "you could try moving the database to another location (preferably an SSD or NVME drive) using either the --hist argument (global option for all volumes), or the hist volflag (just for this volume), or, if you want to keep the thumbnails in the current location and only move the database itself, then use --dbpath or volflag dbpath"


NULLSTAT = os.stat_result((0, -1, -1, 0, 0, 0, 0, 0, 0, 0))


class Dbw(object):
    def __init__(self, c: "sqlite3.Cursor", n: int, nf: int, t: float) -> None:
        self.c = c
        self.n = n
        self.nf = nf
        self.t = t


class Mpqe(object):
    """pending files to tag-scan"""

    def __init__(
        self,
        mtp: dict[str, MParser],
        entags: set[str],
        w: str,
        abspath: str,
        oth_tags: dict[str, Any],
    ):
        # mtp empty = mtag
        self.mtp = mtp
        self.entags = entags
        self.w = w
        self.abspath = abspath
        self.oth_tags = oth_tags


class Up2k(object):
    def __init__(self, hub: "SvcHub") -> None:
        self.hub = hub
        self.asrv: AuthSrv = hub.asrv
        self.args = hub.args
        self.log_func = hub.log

        self.vfs = self.asrv.vfs
        self.acct = self.asrv.acct
        self.iacct = self.asrv.iacct
        self.grps = self.asrv.grps

        self.salt = self.args.warksalt
        self.r_hash = re.compile("^[0-9a-zA-Z_-]{44}$")

        self.gid = 0
        self.gt0 = 0
        self.gt1 = 0
        self.stop = False
        self.mutex = threading.Lock()
        self.reload_mutex = threading.Lock()
        self.reload_flag = 0
        self.reloading = False
        self.blocked: Optional[str] = None
        self.pp: Optional[ProgressPrinter] = None
        self.rescan_cond = threading.Condition()
        self.need_rescan: set[str] = set()
        self.db_act = 0.0

        self.reg_mutex = threading.Lock()
        self.registry: dict[str, dict[str, dict[str, Any]]] = {}
        self.flags: dict[str, dict[str, Any]] = {}
        self.droppable: dict[str, list[str]] = {}
        self.volnfiles: dict["sqlite3.Cursor", int] = {}
        self.volsize: dict["sqlite3.Cursor", int] = {}
        self.volstate: dict[str, str] = {}
        self.vol_act: dict[str, float] = {}
        self.busy_aps: dict[str, int] = {}
        self.dupesched: dict[str, list[tuple[str, str, float]]] = {}
        self.snap_prev: dict[str, Optional[tuple[int, float]]] = {}

        self.mtag: Optional[MTag] = None
        self.entags: dict[str, set[str]] = {}
        self.mtp_parsers: dict[str, dict[str, MParser]] = {}
        self.pending_tags: list[tuple[set[str], str, str, dict[str, Any]]] = []
        self.hashq: Queue[
            tuple[str, str, dict[str, Any], str, str, str, float, str, bool]
        ] = Queue()
        self.tagq: Queue[tuple[str, str, str, str, int, str, float]] = Queue()
        self.tag_event = threading.Condition()
        self.hashq_mutex = threading.Lock()
        self.n_hashq = 0
        self.n_tagq = 0
        self.mpool_used = False

        self.xiu_ptn = re.compile(r"(?:^|,)i([0-9]+)")
        self.xiu_busy = False  # currently running hook
        self.xiu_asleep = True  # needs rescan_cond poke to schedule self
        self.fx_backlog: list[tuple[str, dict[str, str], str]] = []

        self.cur: dict[str, "sqlite3.Cursor"] = {}
        self.mem_cur = None
        self.sqlite_ver = None
        self.no_expr_idx = False
        self.timeout = int(max(self.args.srch_time, 50) * 1.2) + 1
        self.spools: set[tempfile.SpooledTemporaryFile[bytes]] = set()
        if HAVE_SQLITE3:
            # mojibake detector
            assert sqlite3  # type: ignore  # !rm
            self.mem_cur = self._orz(":memory:")
            self.mem_cur.execute(r"create table a (b text)")
            self.sqlite_ver = tuple([int(x) for x in sqlite3.sqlite_version.split(".")])
            if self.sqlite_ver < (3, 9):
                self.no_expr_idx = True
        else:
            t = "could not initialize sqlite3, will use in-memory registry only"
            self.log(t, 3)

        self.fstab = Fstab(self.log_func, self.args)
        self.gen_fk = self._gen_fk if self.args.log_fk else gen_filekey

        if self.args.hash_mt < 2:
            self.mth: Optional[MTHash] = None
        else:
            self.mth = MTHash(self.args.hash_mt)

        if self.args.no_fastboot:
            self.deferred_init()

    def init_vols(self) -> None:
        if self.args.no_fastboot:
            return

        Daemon(self.deferred_init, "up2k-deferred-init")

    def unpp(self) -> None:
        self.gt1 = time.time()
        if self.pp:
            self.pp.end = True
            self.pp = None

    def reload(self, rescan_all_vols: bool) -> None:
        n = 2 if rescan_all_vols else 1
        with self.reload_mutex:
            if self.reload_flag < n:
                self.reload_flag = n
        with self.rescan_cond:
            self.rescan_cond.notify_all()

    def _reload_thr(self) -> None:
        while self.pp:
            time.sleep(0.1)
        while True:
            with self.reload_mutex:
                if not self.reload_flag:
                    break
                rav = self.reload_flag == 2
                self.reload_flag = 0
            gt1 = self.gt1
            with self.mutex:
                self._reload(rav)
            while gt1 == self.gt1 or self.pp:
                time.sleep(0.1)

        self.reloading = False

    def _reload(self, rescan_all_vols: bool) -> None:
        """mutex(main) me"""
        self.log("reload #{} scheduled".format(self.gid + 1))
        all_vols = self.asrv.vfs.all_vols

        with self.reg_mutex:
            scan_vols = [
                k for k, v in all_vols.items() if v.realpath not in self.registry
            ]

        if rescan_all_vols:
            scan_vols = list(all_vols.keys())

        self._rescan(all_vols, scan_vols, True, False)

    def deferred_init(self) -> None:
        all_vols = self.asrv.vfs.all_vols
        have_e2d = self.init_indexes(all_vols, [], False)

        if self.stop:
            # up-mt consistency not guaranteed if init is interrupted;
            # drop caches for a full scan on next boot
            with self.mutex, self.reg_mutex:
                self._drop_caches()

            self.unpp()
            return

        if not self.pp and self.args.exit == "idx":
            return self.hub.sigterm()

        if self.hub.is_dut:
            return

        Daemon(self._snapshot, "up2k-snapshot")
        if have_e2d:
            Daemon(self._hasher, "up2k-hasher")
            Daemon(self._sched_rescan, "up2k-rescan")
            if self.mtag:
                for n in range(max(1, self.args.mtag_mt)):
                    Daemon(self._tagger, "tagger-{}".format(n))

    def log(self, msg: str, c: Union[int, str] = 0) -> None:
        if self.pp:
            msg += "\033[K"

        self.log_func("up2k", msg, c)

    def _gen_fk(self, alg: int, salt: str, fspath: str, fsize: int, inode: int) -> str:
        return gen_filekey_dbg(
            alg, salt, fspath, fsize, inode, self.log, self.args.log_fk
        )

    def _block(self, why: str) -> None:
        self.blocked = why
        self.log("uploads temporarily blocked due to " + why, 3)

    def _unblock(self) -> None:
        if self.blocked is not None:
            self.blocked = None
            if not self.stop:
                self.log("uploads are now possible", 2)

    def get_state(self, get_q: bool, uname: str) -> str:
        mtpq: Union[int, str] = 0
        ups = []
        up_en = not self.args.no_up_list
        q = "select count(w) from mt where k = 't:mtp'"
        got_lock = False if PY2 else self.mutex.acquire(timeout=0.5)
        if got_lock:
            try:
                for cur in self.cur.values() if get_q else []:
                    try:
                        mtpq += cur.execute(q).fetchone()[0]
                    except:
                        pass
                if uname and up_en:
                    ups = self._active_uploads(uname)
            finally:
                self.mutex.release()
        else:
            mtpq = "(?)"
            if up_en:
                ups = [(1, 0, 0, time.time(), "cannot show list (server too busy)")]
                if PY2:
                    ups = []

        ups.sort(reverse=True)

        ret = {
            "volstate": self.volstate,
            "scanning": bool(self.pp),
            "hashq": self.n_hashq,
            "tagq": self.n_tagq,
            "mtpq": mtpq,
            "ups": ups,
            "dbwu": "{:.2f}".format(self.db_act),
            "dbwt": "{:.2f}".format(
                min(1000 * 24 * 60 * 60 - 1, time.time() - self.db_act)
            ),
        }
        return json.dumps(ret, separators=(",\n", ": "))

    def _active_uploads(self, uname: str) -> list[tuple[float, int, int, str]]:
        ret = []
        for vtop in self.vfs.aread.get(uname) or []:
            vfs = self.vfs.all_vols.get(vtop)
            if not vfs:  # dbv only
                continue
            ptop = vfs.realpath
            tab = self.registry.get(ptop)
            if not tab:
                continue
            for job in tab.values():
                ineed = len(job["need"])
                ihash = len(job["hash"])
                if ineed == ihash or not ineed:
                    continue

                poke = job["poke"]
                zt = (
                    ineed / ihash,
                    job["size"],
                    int(job.get("t0c", poke)),
                    int(poke),
                    djoin(vtop, job["prel"], job["name"]),
                )
                ret.append(zt)
        return ret

    def find_job_by_ap(self, ptop: str, ap: str) -> str:
        try:
            if ANYWIN:
                ap = ap.replace("\\", "/")

            vp = ap[len(ptop) :].strip("/")
            dn, fn = vsplit(vp)
            with self.reg_mutex:
                tab2 = self.registry[ptop]
                for job in tab2.values():
                    if job["prel"] == dn and job["name"] == fn:
                        return json.dumps(job, separators=(",\n", ": "))
        except:
            pass

        return "{}"

    def get_unfinished_by_user(self, uname, ip) -> dict[str, Any]:
        # returns dict due to ExceptionalQueue
        if PY2 or not self.reg_mutex.acquire(timeout=2):
            return {"timeout": 1}

        ret: list[tuple[int, str, int, int, int]] = []
        userset = set([(uname or "\n"), "*"])
        n = 1000
        try:
            for ptop, tab2 in self.registry.items():
                cfg = self.flags.get(ptop, {}).get("u2abort", 1)
                if not cfg:
                    continue
                addr = (ip or "\n") if cfg in (1, 2) else ""
                user = userset if cfg in (1, 3) else None
                for job in tab2.values():
                    if (
                        "done" in job
                        or (user and job["user"] not in user)
                        or (addr and addr != job["addr"])
                    ):
                        continue
                    zt5 = (
                        int(job["t0"]),
                        djoin(job["vtop"], job["prel"], job["name"]),
                        job["size"],
                        len(job["need"]),
                        len(job["hash"]),
                    )
                    ret.append(zt5)
                    n -= 1
                    if not n:
                        break
        finally:
            self.reg_mutex.release()

        if ANYWIN:
            ret = [(x[0], x[1].replace("\\", "/"), x[2], x[3], x[4]) for x in ret]

        ret.sort(reverse=True)
        ret2 = [
            {
                "at": at,
                "vp": "/" + quotep(vp),
                "pd": 100 - ((nn * 100) // (nh or 1)),
                "sz": sz,
            }
            for (at, vp, sz, nn, nh) in ret
        ]
        return {"f": ret2}

    def get_unfinished(self) -> str:
        if PY2 or not self.reg_mutex.acquire(timeout=0.5):
            return ""

        ret: dict[str, tuple[int, int]] = {}
        try:
            for ptop, tab2 in self.registry.items():
                nbytes = 0
                nfiles = 0
                for job in tab2.values():
                    if "done" in job:
                        continue

                    nfiles += 1
                    try:
                        # close enough on average
                        nbytes += len(job["need"]) * job["size"] // len(job["hash"])
                    except:
                        pass

                ret[ptop] = (nbytes, nfiles)
        finally:
            self.reg_mutex.release()

        return json.dumps(ret, separators=(",\n", ": "))

    def get_volsize(self, ptop: str) -> tuple[int, int]:
        with self.reg_mutex:
            return self._get_volsize(ptop)

    def get_volsizes(self, ptops: list[str]) -> list[tuple[int, int]]:
        ret = []
        with self.reg_mutex:
            for ptop in ptops:
                ret.append(self._get_volsize(ptop))

        return ret

    def _get_volsize(self, ptop: str) -> tuple[int, int]:
        if "e2ds" not in self.flags.get(ptop, {}):
            return (0, 0)

        cur = self.cur[ptop]
        nbytes = self.volsize[cur]
        nfiles = self.volnfiles[cur]
        for j in list(self.registry.get(ptop, {}).values()):
            nbytes += j["size"]
            nfiles += 1

        return (nbytes, nfiles)

    def rescan(
        self, all_vols: dict[str, VFS], scan_vols: list[str], wait: bool, fscan: bool
    ) -> str:
        with self.mutex:
            return self._rescan(all_vols, scan_vols, wait, fscan)

    def _rescan(
        self, all_vols: dict[str, VFS], scan_vols: list[str], wait: bool, fscan: bool
    ) -> str:
        """mutex(main) me"""
        if not wait and self.pp:
            return "cannot initiate; scan is already in progress"

        self.gid += 1
        Daemon(
            self.init_indexes,
            "up2k-rescan-{}".format(scan_vols[0] if scan_vols else "all"),
            (all_vols, scan_vols, fscan, self.gid),
        )
        return ""

    def _sched_rescan(self) -> None:
        volage = {}
        cooldown = timeout = time.time() + 3.0
        while not self.stop:
            now = time.time()
            timeout = max(timeout, cooldown)
            wait = timeout - time.time()
            # self.log("SR in {:.2f}".format(wait), 5)
            with self.rescan_cond:
                self.rescan_cond.wait(wait)

            if self.stop:
                return

            with self.reload_mutex:
                if self.reload_flag and not self.reloading:
                    self.reloading = True
                    zs = "up2k-reload-%d" % (self.gid,)
                    Daemon(self._reload_thr, zs)

            now = time.time()
            if now < cooldown:
                # self.log("SR: cd - now = {:.2f}".format(cooldown - now), 5)
                timeout = cooldown  # wakeup means stuff to do, forget timeout
                continue

            if self.pp:
                # self.log("SR: pp; cd := 1", 5)
                cooldown = now + 1
                continue

            cooldown = now + 3
            # self.log("SR", 5)

            if self.args.no_lifetime and not self.args.shr:
                timeout = now + 9001
            else:
                # important; not deferred by db_act
                timeout = self._check_lifetimes()
                timeout = min(self._check_forget_ip(), timeout)
                try:
                    if self.args.shr:
                        timeout = min(self._check_shares(), timeout)
                except Exception as ex:
                    timeout = min(timeout, now + 60)
                    t = "could not check for expiring shares: %r"
                    self.log(t % (ex,), 1)

            try:
                timeout = min(timeout, now + self._check_xiu())
            except Exception as ex:
                if "closed cursor" in str(ex):
                    self.log("sched_rescan: lost db")
                    return
                raise

            with self.mutex:
                for vp, vol in sorted(self.vfs.all_vols.items()):
                    maxage = vol.flags.get("scan")
                    if not maxage:
                        continue

                    if vp not in volage:
                        volage[vp] = now

                    deadline = volage[vp] + maxage
                    if deadline <= now:
                        self.need_rescan.add(vp)

                    timeout = min(timeout, deadline)

            if self.db_act > now - self.args.db_act and self.need_rescan:
                # recent db activity; defer volume rescan
                act_timeout = self.db_act + self.args.db_act
                if self.need_rescan:
                    timeout = now

                if timeout < act_timeout:
                    timeout = act_timeout
                    t = "volume rescan deferred {:.1f} sec, due to database activity"
                    self.log(t.format(timeout - now))

                continue

            with self.mutex:
                vols = list(sorted(self.need_rescan))
                self.need_rescan.clear()

            if vols:
                cooldown = now + 10
                err = self.rescan(self.vfs.all_vols, vols, False, False)
                if err:
                    for v in vols:
                        self.need_rescan.add(v)

                    continue

                for v in vols:
                    volage[v] = now

    def _check_forget_ip(self) -> float:
        now = time.time()
        timeout = now + 9001
        for vp, vol in sorted(self.vfs.all_vols.items()):
            maxage = vol.flags["forget_ip"]
            if not maxage:
                continue

            cur = self.cur.get(vol.realpath)
            if not cur:
                continue

            cutoff = now - maxage * 60

            for _ in range(2):
                q = "select ip, at from up where ip > '' order by +at limit 1"
                hits = cur.execute(q).fetchall()
                if not hits:
                    break

                remains = hits[0][1] - cutoff
                if remains > 0:
                    timeout = min(timeout, now + remains)
                    break

                q = "update up set ip = '' where ip > '' and at <= %d"
                cur.execute(q % (cutoff,))
                zi = cur.rowcount
                cur.connection.commit()

                t = "forget-ip(%d) removed %d IPs from db [/%s]"
                self.log(t % (maxage, zi, vol.vpath))

            timeout = min(timeout, now + 900)

        return timeout

    def _check_lifetimes(self) -> float:
        now = time.time()
        timeout = now + 9001
        for vp, vol in sorted(self.vfs.all_vols.items()):
            lifetime = vol.flags.get("lifetime")
            if not lifetime:
                continue

            cur = self.cur.get(vol.realpath)
            if not cur:
                continue

            nrm = 0
            deadline = time.time() - lifetime
            timeout = min(timeout, now + lifetime)
            q = "select rd, fn from up where at > 0 and at < ? limit 100"
            while True:
                with self.mutex:
                    hits = cur.execute(q, (deadline,)).fetchall()

                if not hits:
                    break

                for rd, fn in hits:
                    if rd.startswith("//") or fn.startswith("//"):
                        rd, fn = s3dec(rd, fn)

                    fvp = ("%s/%s" % (rd, fn)).strip("/")
                    if vp:
                        fvp = "%s/%s" % (vp, fvp)

                    self._handle_rm(LEELOO_DALLAS, "", fvp, [], True, False)
                    nrm += 1

            if nrm:
                self.log("%d files graduated in /%s" % (nrm, vp))

            if timeout < 10:
                continue

            q = "select at from up where at > 0 order by at limit 1"
            with self.mutex:
                hits = cur.execute(q).fetchone()

            if hits:
                timeout = min(timeout, now + lifetime - (now - hits[0]))

        return timeout

    def _check_shares(self) -> float:
        assert sqlite3  # type: ignore  # !rm

        now = time.time()
        timeout = now + 9001
        maxage = self.args.shr_rt * 60
        low = now - maxage

        vn = self.vfs.nodes.get(self.args.shr.strip("/"))
        active = vn and vn.nodes

        db = sqlite3.connect(self.args.shr_db, timeout=2)
        cur = db.cursor()

        q = "select k from sh where t1 and t1 <= ?"
        rm = [x[0] for x in cur.execute(q, (now,))] if active else []
        if rm:
            assert vn and vn.nodes  # type: ignore
            # self.log("chk_shr: %d" % (len(rm),))
            zss = set(rm)
            rm = [zs for zs in vn.nodes if zs in zss]
        reload = bool(rm)
        if reload:
            self.log("disabling expired shares %s" % (rm,))

        rm = [x[0] for x in cur.execute(q, (low,))]
        if rm:
            self.log("forgetting expired shares %s" % (rm,))
            cur.executemany("delete from sh where k=?", [(x,) for x in rm])
            cur.executemany("delete from sf where k=?", [(x,) for x in rm])
            db.commit()

        if reload:
            Daemon(self.hub.reload, "sharedrop", (False, False))

        q = "select min(t1) from sh where t1 > ?"
        (earliest,) = cur.execute(q, (1,)).fetchone()
        if earliest:
            # deadline for revoking regular access
            timeout = min(timeout, earliest + maxage)

            (earliest,) = cur.execute(q, (now - 2,)).fetchone()
            if earliest:
                # deadline for revival; drop entirely
                timeout = min(timeout, earliest)

        cur.close()
        db.close()

        if self.args.shr_v:
            self.log("next shr_chk = %d (%d)" % (timeout, timeout - time.time()))

        return timeout

    def _check_xiu(self) -> float:
        if self.xiu_busy:
            return 2

        ret = 9001
        for _, vol in sorted(self.vfs.all_vols.items()):
            rp = vol.realpath
            cur = self.cur.get(rp)
            if not cur:
                continue

            with self.mutex:
                q = "select distinct c from iu"
                cds = cur.execute(q).fetchall()
                if not cds:
                    continue

            run_cds: list[int] = []
            for cd in sorted([x[0] for x in cds]):
                delta = cd - (time.time() - self.vol_act[rp])
                if delta > 0:
                    ret = min(ret, delta)
                    break

                run_cds.append(cd)

            if run_cds:
                self.xiu_busy = True
                Daemon(self._run_xius, "xiu", (vol, run_cds))
                return 2

        return ret

    def _run_xius(self, vol: VFS, cds: list[int]):
        for cd in cds:
            self._run_xiu(vol, cd)

        self.xiu_busy = False
        self.xiu_asleep = True

    def _run_xiu(self, vol: VFS, cd: int):
        rp = vol.realpath
        cur = self.cur[rp]

        # t0 = time.time()
        with self.mutex:
            q = "select w,rd,fn from iu where c={} limit 80386"
            wrfs = cur.execute(q.format(cd)).fetchall()
            if not wrfs:
                return

            # dont wanna rebox so use format instead of prepared
            q = "delete from iu where w=? and +rd=? and +fn=? and +c={}"
            cur.executemany(q.format(cd), wrfs)
            cur.connection.commit()

            q = "select * from up where substr(w,1,16)=? and +rd=? and +fn=?"
            ups = []
            for wrf in wrfs:
                up = cur.execute(q, wrf).fetchone()
                if up:
                    ups.append(up)

        # t1 = time.time()
        # self.log("mapped {} warks in {:.3f} sec".format(len(wrfs), t1 - t0))
        # "mapped 10989 warks in 0.126 sec"

        cmds = self.flags[rp]["xiu"]
        for cmd in cmds:
            m = self.xiu_ptn.search(cmd)
            ccd = int(m.group(1)) if m else 5
            if ccd != cd:
                continue

            self.log("xiu: %d# %r" % (len(wrfs), cmd))
            runihook(self.log, self.args.hook_v, cmd, vol, ups)

    def _vis_job_progress(self, job: dict[str, Any]) -> str:
        perc = 100 - (len(job["need"]) * 100.0 / (len(job["hash"]) or 1))
        path = djoin(job["ptop"], job["prel"], job["name"])
        return "{:5.1f}% {}".format(perc, path)

    def _vis_reg_progress(self, reg: dict[str, dict[str, Any]]) -> list[str]:
        ret = []
        for _, job in reg.items():
            if job["need"]:
                ret.append(self._vis_job_progress(job))

        return ret

    def _expr_idx_filter(self, flags: dict[str, Any]) -> tuple[bool, dict[str, Any]]:
        if not self.no_expr_idx:
            return False, flags

        ret = {k: v for k, v in flags.items() if not k.startswith("e2t")}
        if len(ret) == len(flags):
            return False, flags

        return True, ret

    def init_indexes(
        self, all_vols: dict[str, VFS], scan_vols: list[str], fscan: bool, gid: int = 0
    ) -> bool:
        if not gid:
            with self.mutex:
                gid = self.gid

        self.gt0 = time.time()

        nspin = 0
        while True:
            nspin += 1
            if nspin > 1:
                time.sleep(0.1)

            with self.mutex:
                if gid != self.gid:
                    return False

                if self.pp:
                    continue

                self.pp = ProgressPrinter(self.log, self.args)
                if not self.hub.is_dut:
                    self.pp.start()

            break

        if gid:
            self.log("reload #%d running" % (gid,))

        self.vfs = self.asrv.vfs
        self.acct = self.asrv.acct
        self.iacct = self.asrv.iacct
        self.grps = self.asrv.grps

        have_e2d = self.args.idp_h_usr or self.args.chpw or self.args.shr
        vols = list(all_vols.values())
        t0 = time.time()

        if self.no_expr_idx:
            modified = False
            for vol in vols:
                m, f = self._expr_idx_filter(vol.flags)
                if m:
                    vol.flags = f
                    modified = True

            if modified:
                msg = "disabling -e2t because your sqlite belongs in a museum"
                self.log(msg, c=3)

        live_vols = []
        with self.mutex, self.reg_mutex:
            # only need to protect register_vpath but all in one go feels right
            for vol in vols:
                try:
                    # mkdir gonna happen at snap anyways;
                    bos.makedirs(vol.realpath, vf=vol.flags)
                    dir_is_empty(self.log_func, not self.args.no_scandir, vol.realpath)
                except Exception as ex:
                    self.volstate[vol.vpath] = "OFFLINE (cannot access folder)"
                    self.log("cannot access %s: %r" % (vol.realpath, ex), c=1)
                    continue

                if scan_vols and vol.vpath not in scan_vols:
                    continue

                if not self.register_vpath(vol.realpath, vol.flags):
                    # self.log("db not enable for {}".format(m, vol.realpath))
                    continue

                live_vols.append(vol)

                if vol.vpath not in self.volstate:
                    self.volstate[vol.vpath] = "OFFLINE (pending initialization)"

        vols = live_vols
        need_vac = {}

        need_mtag = False
        for vol in vols:
            if "e2t" in vol.flags:
                need_mtag = True

        if need_mtag and not self.mtag:
            self.mtag = MTag(self.log_func, self.args)
            if not self.mtag.usable:
                self.mtag = None

        # e2ds(a) volumes first
        if next((zv for zv in vols if "e2ds" in zv.flags), None):
            self._block("indexing")

        if self.args.re_dhash or [zv for zv in vols if "e2tsr" in zv.flags]:
            self.args.re_dhash = False
            with self.mutex, self.reg_mutex:
                self._drop_caches()

        for vol in vols:
            if self.stop or gid != self.gid:
                break

            en = set(vol.flags.get("mte", {}))
            self.entags[vol.realpath] = en

            if "e2d" in vol.flags:
                have_e2d = True

            if "e2ds" in vol.flags or fscan:
                self.volstate[vol.vpath] = "busy (hashing files)"
                _, vac = self._build_file_index(vol, list(all_vols.values()))
                if vac:
                    need_vac[vol] = True

            if "e2v" in vol.flags:
                t = "online (integrity-check pending)"
            elif "e2ts" in vol.flags:
                t = "online (tags pending)"
            else:
                t = "online, idle"

            self.volstate[vol.vpath] = t

        self._unblock()

        # file contents verification
        for vol in vols:
            if self.stop:
                break

            if "e2v" not in vol.flags:
                continue

            t = "online (verifying integrity)"
            self.volstate[vol.vpath] = t
            self.log("{} [{}]".format(t, vol.realpath))

            nmod = self._verify_integrity(vol)
            if nmod:
                self.log("modified {} entries in the db".format(nmod), 3)
                need_vac[vol] = True

            if "e2ts" in vol.flags:
                t = "online (tags pending)"
            else:
                t = "online, idle"

            self.volstate[vol.vpath] = t

        # open the rest + do any e2ts(a)
        needed_mutagen = False
        for vol in vols:
            if self.stop:
                break

            if "e2ts" not in vol.flags:
                continue

            t = "online (reading tags)"
            self.volstate[vol.vpath] = t
            self.log("{} [{}]".format(t, vol.realpath))

            nadd, nrm, success = self._build_tags_index(vol)
            if not success:
                needed_mutagen = True

            if nadd or nrm:
                need_vac[vol] = True

            self.volstate[vol.vpath] = "online (mtp soon)"

        for vol in need_vac:
            with self.mutex, self.reg_mutex:
                reg = self.register_vpath(vol.realpath, vol.flags)

            assert reg  # !rm
            cur, _ = reg
            with self.mutex:
                cur.connection.commit()
                cur.execute("vacuum")

        if self.stop:
            return False

        for vol in all_vols.values():
            if vol.flags["dbd"] == "acid":
                continue

            with self.mutex, self.reg_mutex:
                reg = self.register_vpath(vol.realpath, vol.flags)

            try:
                assert reg  # !rm
                cur, db_path = reg
                if bos.path.getsize(db_path + "-wal") < 1024 * 1024 * 5:
                    continue
            except:
                continue

            try:
                with self.mutex:
                    cur.execute("pragma wal_checkpoint(truncate)")
                    try:
                        cur.execute("commit")  # absolutely necessary! for some reason
                    except:
                        pass

                    cur.connection.commit()  # this one maybe not
            except Exception as ex:
                self.log("checkpoint failed: {}".format(ex), 3)

        if self.stop:
            return False

        self.pp.end = True

        msg = "{} volumes in {:.2f} sec"
        self.log(msg.format(len(vols), time.time() - t0))

        if needed_mutagen:
            msg = "could not read tags because no backends are available (Mutagen or FFprobe)"
            self.log(msg, c=1)

        t = "online (running mtp)" if self.mtag else "online, idle"
        for vol in vols:
            self.volstate[vol.vpath] = t

        if self.mtag:
            Daemon(self._run_all_mtp, "up2k-mtp-scan", (gid,))
        else:
            self.unpp()

        return have_e2d

    def register_vpath(
        self, ptop: str, flags: dict[str, Any]
    ) -> Optional[tuple["sqlite3.Cursor", str]]:
        """mutex(main,reg) me"""
        histpath = self.vfs.dbpaths.get(ptop)
        if not histpath:
            self.log("no dbpath for %r" % (ptop,))
            return None

        db_path = os.path.join(histpath, "up2k.db")
        if ptop in self.registry:
            try:
                return self.cur[ptop], db_path
            except:
                return None

        vpath = "?"
        for k, v in self.vfs.all_vols.items():
            if v.realpath == ptop:
                vpath = k

        _, flags = self._expr_idx_filter(flags)
        n4g = bool(flags.get("noforget"))

        ft = "\033[0;32m{}{:.0}"
        ff = "\033[0;35m{}{:.0}"
        fv = "\033[0;36m{}:\033[90m{}"
        zs = "ext_th_d html_head put_name2 mv_re_r mv_re_t rm_re_r rm_re_t srch_re_dots srch_re_nodot zipmax zipmaxn_v zipmaxs_v"
        fx = set(zs.split())
        fd = vf_bmap()
        fd.update(vf_cmap())
        fd.update(vf_vmap())
        fd = {v: k for k, v in fd.items()}
        fl = {
            k: v
            for k, v in flags.items()
            if k not in fd
            or (
                v != getattr(self.args, fd[k])
                and str(v) != str(getattr(self.args, fd[k]))
            )
        }
        for k1, k2 in vf_cmap().items():
            if k1 not in fl or k1 in fx:
                continue
            if str(fl[k1]) == str(getattr(self.args, k2)):
                del fl[k1]
            else:
                fl[k1] = ",".join(x for x in fl[k1])

        if fl["chmod_d"] == int(self.args.chmod_d, 8):
            fl.pop("chmod_d")
        try:
            if fl["chmod_f"] == int(self.args.chmod_f or "-1", 8):
                fl.pop("chmod_f")
        except:
            pass
        for k in ("chmod_f", "chmod_d"):
            try:
                fl[k] = "%o" % (fl[k])
            except:
                pass

        a = [
            (ft if v is True else ff if v is False else fv).format(k, str(v))
            for k, v in fl.items()
            if k not in fx
        ]
        if not a:
            a = ["\033[90mall-default"]

        if a:
            zs = " ".join(sorted(a))
            zs = zs.replace("90mre.compile(", "90m(")  # nohash
            self.log("/{} {}".format(vpath + ("/" if vpath else ""), zs), "35")

        reg = {}
        drp = None
        emptylist = []
        dotpart = "." if self.args.dotpart else ""
        snap = os.path.join(histpath, "up2k.snap")
        if bos.path.exists(snap):
            with gzip.GzipFile(snap, "rb") as f:
                j = f.read().decode("utf-8")

            reg2 = json.loads(j)
            try:
                drp = reg2["droppable"]
                reg2 = reg2["registry"]
            except:
                pass

            reg = reg2  # diff-golf

            if reg2 and "dwrk" not in reg2[next(iter(reg2))]:
                for job in reg2.values():
                    job["dwrk"] = job["wark"]

            rm = []
            for k, job in reg2.items():
                job["ptop"] = ptop
                is_done = "done" in job
                if is_done:
                    job["need"] = job["hash"] = emptylist
                else:
                    if "need" not in job:
                        job["need"] = []
                    if "hash" not in job:
                        job["hash"] = []

                if is_done:
                    fp = djoin(ptop, job["prel"], job["name"])
                else:
                    fp = djoin(ptop, job["prel"], dotpart + job["name"] + ".PARTIAL")

                if bos.path.exists(fp):
                    if is_done:
                        continue
                    job["poke"] = time.time()
                    job["busy"] = {}
                else:
                    self.log("ign deleted file in snap: %r" % (fp,))
                    if not n4g:
                        rm.append(k)

            for x in rm:
                del reg2[x]

            # optimize pre-1.15.4 entries
            if next((x for x in reg.values() if "done" in x and "poke" in x), None):
                zsl = "host tnam busy sprs poke t0c".split()
                for job in reg.values():
                    if "done" in job:
                        for k in zsl:
                            job.pop(k, None)

            if drp is None:
                drp = [k for k, v in reg.items() if not v["need"]]
            else:
                drp = [x for x in drp if x in reg]

            t = "loaded snap {} |{}| ({})".format(snap, len(reg.keys()), len(drp or []))
            ta = [t] + self._vis_reg_progress(reg)
            self.log("\n".join(ta))

        self.flags[ptop] = flags
        self.vol_act[ptop] = 0.0
        self.registry[ptop] = reg
        self.droppable[ptop] = drp or []
        self.regdrop(ptop, "")
        if not HAVE_SQLITE3 or "e2d" not in flags or "d2d" in flags:
            return None

        try:
            if bos.makedirs(histpath):
                hidedir(histpath)
        except Exception as ex:
            t = "failed to initialize volume '/%s': %s"
            self.log(t % (vpath, ex), 1)
            return None

        try:
            cur = self._open_db_wd(db_path)

            # speeds measured uploading 520 small files on a WD20SPZX (SMR 2.5" 5400rpm 4kb)
            dbd = flags["dbd"]
            if dbd == "acid":
                # 217.5s; python-defaults
                zs = "delete"
                sync = "full"
            elif dbd == "swal":
                # 88.0s; still 99.9% safe (can lose a bit of on OS crash)
                zs = "wal"
                sync = "full"
            elif dbd == "yolo":
                # 2.7s; may lose entire db on OS crash
                zs = "wal"
                sync = "off"
            else:
                # 4.1s; corruption-safe but more likely to lose wal
                zs = "wal"
                sync = "normal"

            try:
                amode = cur.execute("pragma journal_mode=" + zs).fetchone()[0]
                if amode.lower() != zs.lower():
                    t = "sqlite failed to set journal_mode {}; got {}"
                    raise Exception(t.format(zs, amode))
            except Exception as ex:
                if sync != "off":
                    sync = "full"
                    t = "reverting to sync={} because {}"
                    self.log(t.format(sync, ex))

            cur.execute("pragma synchronous=" + sync)
            cur.connection.commit()

            self._verify_db_cache(cur, vpath)

            self.cur[ptop] = cur
            self.volsize[cur] = 0
            self.volnfiles[cur] = 0

            return cur, db_path
        except:
            msg = "ERROR: cannot use database at [%s]:\n%s\n\033[33mhint: %s\n"
            self.log(msg % (db_path, traceback.format_exc(), HINT_HISTPATH), 1)

        return None

    def _verify_db_cache(self, cur: "sqlite3.Cursor", vpath: str) -> None:
        # check if list of intersecting volumes changed since last use; drop caches if so
        prefix = (vpath + "/").lstrip("/")
        vps = [x for x in self.vfs.all_vols if x.startswith(prefix)]
        vps.sort()
        seed = [x[len(prefix) :] for x in vps]

        # also consider volflags which affect indexing
        for vp in vps:
            vf = self.vfs.all_vols[vp].flags
            vf = {k: v for k, v in vf.items() if k in VF_AFFECTS_INDEXING}
            seed.append(str(sorted(vf.items())))

        zb = hashlib.sha1("\n".join(seed).encode("utf-8", "replace")).digest()
        vcfg = ub64enc(zb[:18]).decode("ascii")

        c = cur.execute("select v from kv where k = 'volcfg'")
        try:
            (oldcfg,) = c.fetchone()
        except:
            oldcfg = ""

        if oldcfg != vcfg:
            cur.execute("delete from kv where k = 'volcfg'")
            cur.execute("delete from dh")
            cur.execute("delete from cv")
            cur.execute("insert into kv values ('volcfg',?)", (vcfg,))
            cur.connection.commit()

    def _build_file_index(self, vol: VFS, all_vols: list[VFS]) -> tuple[bool, bool]:
        do_vac = False
        top = vol.realpath
        rei = vol.flags.get("noidx")
        reh = vol.flags.get("nohash")
        n4g = bool(vol.flags.get("noforget"))
        ffat = "fat32" in vol.flags
        cst = bos.stat(top)
        dev = cst.st_dev if vol.flags.get("xdev") else 0

        with self.mutex:
            with self.reg_mutex:
                reg = self.register_vpath(top, vol.flags)

            assert reg and self.pp  # !rm
            cur, db_path = reg

            db = Dbw(cur, 0, 0, time.time())
            self.pp.n = next(db.c.execute("select count(w) from up"))[0]

            excl = [
                vol.realpath + "/" + d.vpath[len(vol.vpath) :].lstrip("/")
                for d in all_vols
                if d != vol and (d.vpath.startswith(vol.vpath + "/") or not vol.vpath)
            ]
            excl += [absreal(x) for x in excl]
            excl += list(self.vfs.histtab.values())
            excl += list(self.vfs.dbpaths.values())
            if WINDOWS:
                excl = [x.replace("/", "\\") for x in excl]
            else:
                # ~/.wine/dosdevices/z:/ and such
                excl.extend(("/dev", "/proc", "/run", "/sys"))

            excl = list({k: 1 for k in excl})

            if self.args.re_dirsz:
                db.c.execute("delete from ds")
                db.n += 1

            rtop = absreal(top)
            n_add = n_rm = 0
            try:
                if dir_is_empty(self.log_func, not self.args.no_scandir, rtop):
                    t = "volume /%s at [%s] is empty; will not be indexed as this could be due to an offline filesystem"
                    self.log(t % (vol.vpath, rtop), 6)
                    return True, False
                if not vol.check_landmarks():
                    t = "volume /%s at [%s] will not be indexed due to bad landmarks"
                    self.log(t % (vol.vpath, rtop), 6)
                    return True, False

                n_add, _, _ = self._build_dir(
                    db,
                    top,
                    set(excl),
                    top,
                    rtop,
                    rei,
                    reh,
                    n4g,
                    ffat,
                    [],
                    cst,
                    dev,
                    bool(vol.flags.get("xvol")),
                )
                if not n4g:
                    n_rm = self._drop_lost(db.c, top, excl)
            except Exception as ex:
                t = "failed to index volume [{}]:\n{}"
                self.log(t.format(top, min_ex()), c=1)
                if db_ex_chk(self.log, ex, db_path):
                    self.hub.log_stacks()

            if db.n:
                self.log("commit %d new files; %d updates" % (db.nf, db.n))

            if self.args.no_dhash:
                if db.c.execute("select d from dh").fetchone():
                    db.c.execute("delete from dh")
                    self.log("forgetting dhashes in {}".format(top))
            elif n_add or n_rm:
                self._set_tagscan(db.c, True)

            db.c.connection.commit()

            if (
                vol.flags.get("vmaxb")
                or vol.flags.get("vmaxn")
                or (self.args.stats and not self.args.nos_vol)
            ):
                zs = "select count(sz), sum(sz) from up"
                vn, vb = db.c.execute(zs).fetchone()
                vb = vb or 0
                vb += vn * 2048
                self.volsize[db.c] = vb
                self.volnfiles[db.c] = vn
                vmaxb = unhumanize(vol.flags.get("vmaxb") or "0")
                vmaxn = unhumanize(vol.flags.get("vmaxn") or "0")
                t = "{:>5} / {:>5}  ( {:>5} / {:>5} files) in {}".format(
                    humansize(vb, True),
                    humansize(vmaxb, True),
                    humansize(vn, True).rstrip("B"),
                    humansize(vmaxn, True).rstrip("B"),
                    vol.realpath,
                )
                self.log(t)

            return True, bool(n_add or n_rm or do_vac)

    def _build_dir(
        self,
        db: Dbw,
        top: str,
        excl: set[str],
        cdir: str,
        rcdir: str,
        rei: Optional[Pattern[str]],
        reh: Optional[Pattern[str]],
        n4g: bool,
        ffat: bool,
        seen: list[str],
        cst: os.stat_result,
        dev: int,
        xvol: bool,
    ) -> tuple[int, int, int]:
        if xvol and not rcdir.startswith(top):
            self.log("skip xvol: %r -> %r" % (cdir, rcdir), 6)
            return 0, 0, 0

        if rcdir in seen:
            t = "bailing from symlink loop,\n  prev: %r\n  curr: %r\n  from: %r"
            self.log(t % (seen[-1], rcdir, cdir), 3)
            return 0, 0, 0

        # total-files-added, total-num-files, recursive-size
        tfa = tnf = rsz = 0
        seen = seen + [rcdir]
        unreg: list[str] = []
        files: list[tuple[int, int, str]] = []
        fat32 = True
        cv = vcv = ""

        th_cvd = self.args.th_coversd
        th_cvds = self.args.th_coversd_set

        assert self.pp and self.mem_cur  # !rm
        self.pp.msg = "a%d %s" % (self.pp.n, cdir)

        rd = cdir[len(top) :].strip("/")
        if WINDOWS:
            rd = rd.replace("\\", "/").strip("/")

        rds = rd + "/" if rd else ""
        cdirs = cdir + os.sep

        g = statdir(self.log_func, not self.args.no_scandir, True, cdir, False)
        gl = sorted(g)
        partials = set([x[0] for x in gl if "PARTIAL" in x[0]])
        for iname, inf in gl:
            if self.stop:
                return -1, 0, 0

            rp = rds + iname
            abspath = cdirs + iname

            if rei and rei.search(abspath):
                unreg.append(rp)
                continue

            lmod = int(inf.st_mtime)
            if stat.S_ISLNK(inf.st_mode):
                try:
                    inf = bos.stat(abspath)
                except:
                    continue

            sz = inf.st_size
            if fat32 and not ffat and inf.st_mtime % 2:
                fat32 = False

            if stat.S_ISDIR(inf.st_mode):
                rap = absreal(abspath)
                if (
                    dev
                    and inf.st_dev != dev
                    and not (ANYWIN and bos.stat(rap).st_dev == dev)
                ):
                    self.log("skip xdev %s->%s: %r" % (dev, inf.st_dev, abspath), 6)
                    continue
                if abspath in excl or rap in excl:
                    unreg.append(rp)
                    continue
                if iname == ".th" and bos.path.isdir(os.path.join(abspath, "top")):
                    # abandoned or foreign, skip
                    continue
                # self.log(" dir: {}".format(abspath))
                try:
                    i1, i2, i3 = self._build_dir(
                        db,
                        top,
                        excl,
                        abspath,
                        rap,
                        rei,
                        reh,
                        n4g,
                        fat32,
                        seen,
                        inf,
                        dev,
                        xvol,
                    )
                    tfa += i1
                    tnf += i2
                    rsz += i3
                except:
                    t = "failed to index subdir %r:\n%s"
                    self.log(t % (abspath, min_ex()), 1)
            elif not stat.S_ISREG(inf.st_mode):
                self.log("skip type-0%o file %r" % (inf.st_mode, abspath))
            else:
                # self.log("file: {}".format(abspath))
                if rp.endswith(".PARTIAL") and time.time() - lmod < 60:
                    # rescan during upload
                    continue

                if not sz and (
                    "%s.PARTIAL" % (iname,) in partials
                    or ".%s.PARTIAL" % (iname,) in partials
                ):
                    # placeholder for unfinished upload
                    continue

                rsz += sz
                files.append((sz, lmod, iname))
                if sz:
                    liname = iname.lower()
                    ext = liname.rsplit(".", 1)[-1]
                    if (
                        liname in th_cvds
                        or (not cv and ext in ICV_EXTS and not iname.startswith("."))
                    ) and (
                        not cv
                        or liname not in th_cvds
                        or cv.lower() not in th_cvds
                        or th_cvd.index(liname) < th_cvd.index(cv.lower())
                    ):
                        cv = iname
                    elif not vcv and ext in VCV_EXTS and not iname.startswith("."):
                        vcv = iname

        if not cv:
            cv = vcv

        if not self.args.no_dirsz:
            tnf += len(files)
            q = "select sz, nf from ds where rd=? limit 1"
            try:
                db_sz, db_nf = db.c.execute(q, (rd,)).fetchone() or (-1, -1)
                if rsz != db_sz or tnf != db_nf:
                    db.c.execute("delete from ds where rd=?", (rd,))
                    db.c.execute("insert into ds values (?,?,?)", (rd, rsz, tnf))
                    db.n += 1
            except:
                pass  # mojibake rd

        # folder of 1000 files = ~1 MiB RAM best-case (tiny filenames);
        # free up stuff we're done with before dhashing
        gl = []
        partials.clear()
        if not self.args.no_dhash:
            if len(files) < 9000:
                zh = hashlib.sha1(str(files).encode("utf-8", "replace"))
            else:
                zh = hashlib.sha1()
                _ = [zh.update(str(x).encode("utf-8", "replace")) for x in files]

            zh.update(cv.encode("utf-8", "replace"))
            zh.update(spack(b"<d", cst.st_mtime))
            dhash = ub64enc(zh.digest()[:12]).decode("ascii")
            sql = "select d from dh where d=? and +h=?"
            try:
                c = db.c.execute(sql, (rd, dhash))
                drd = rd
            except:
                drd = "//" + w8b64enc(rd)
                c = db.c.execute(sql, (drd, dhash))

            if c.fetchone():
                return tfa, tnf, rsz

        if cv and rd:
            # mojibake not supported (for performance / simplicity):
            try:
                q = "select * from cv where rd=? and dn=? and +fn=?"
                crd, cdn = rd.rsplit("/", 1) if "/" in rd else ("", rd)
                if not db.c.execute(q, (crd, cdn, cv)).fetchone():
                    db.c.execute("delete from cv where rd=? and dn=?", (crd, cdn))
                    db.c.execute("insert into cv values (?,?,?)", (crd, cdn, cv))
                    db.n += 1
            except Exception as ex:
                self.log("cover %r/%r failed: %s" % (rd, cv, ex), 6)

        seen_files = set([x[2] for x in files])  # for dropcheck
        for sz, lmod, fn in files:
            if self.stop:
                return -1, 0, 0

            rp = rds + fn
            abspath = cdirs + fn
            nohash = reh.search(abspath) if reh else False

            sql = "select w, mt, sz, ip, at from up where rd = ? and fn = ?"
            try:
                c = db.c.execute(sql, (rd, fn))
            except:
                c = db.c.execute(sql, s3enc(self.mem_cur, rd, fn))

            in_db = list(c.fetchall())
            if in_db:
                self.pp.n -= 1
                dw, dts, dsz, ip, at = in_db[0]
                if len(in_db) > 1:
                    t = "WARN: multiple entries: %r => %r |%d|\n%r"
                    rep_db = "\n".join([repr(x) for x in in_db])
                    self.log(t % (top, rp, len(in_db), rep_db))
                    dts = -1

                if fat32 and abs(dts - lmod) == 1:
                    dts = lmod

                if dts == lmod and dsz == sz and (nohash or dw[0] != "#" or not sz):
                    continue

                t = "reindex %r => %r mtime(%s/%s) size(%s/%s)"
                self.log(t % (top, rp, dts, lmod, dsz, sz))
                self.db_rm(db.c, rd, fn, 0)
                tfa += 1
                db.n += 1
                in_db = []
            else:
                dw = ""
                ip = ""
                at = 0

            self.pp.msg = "a%d %s" % (self.pp.n, abspath)

            if nohash or not sz:
                wark = up2k_wark_from_metadata(self.salt, sz, lmod, rd, fn)
            else:
                if sz > 1024 * 1024:
                    self.log("file: %r" % (abspath,))

                try:
                    hashes, _ = self._hashlist_from_file(
                        abspath, "a{}, ".format(self.pp.n)
                    )
                except Exception as ex:
                    self.log("hash: %r @ %r" % (ex, abspath))
                    continue

                if not hashes:
                    return -1, 0, 0

                wark = up2k_wark_from_hashlist(self.salt, sz, hashes)

            if dw and dw != wark:
                ip = ""
                at = 0

            # skip upload hooks by not providing vflags
            self.db_add(db.c, {}, rd, fn, lmod, sz, "", "", wark, wark, "", "", ip, at)
            db.n += 1
            db.nf += 1
            tfa += 1
            td = time.time() - db.t
            if db.n >= 4096 or td >= 60:
                self.log("commit %d new files; %d updates" % (db.nf, db.n))
                db.c.connection.commit()
                db.n = db.nf = 0
                db.t = time.time()

        if not self.args.no_dhash:
            db.c.execute("delete from dh where d = ?", (drd,))  # type: ignore
            db.c.execute("insert into dh values (?,?)", (drd, dhash))  # type: ignore

        if self.stop:
            return -1, 0, 0

        # drop shadowed folders
        for sh_rd in unreg:
            n = 0
            q = "select count(w) from up where (rd=? or rd like ?||'/%')"
            for sh_erd in [sh_rd, "//" + w8b64enc(sh_rd)]:
                try:
                    erd_erd = (sh_erd, sh_erd)
                    n = db.c.execute(q, erd_erd).fetchone()[0]
                    break
                except:
                    pass

            assert erd_erd  # type: ignore  # !rm

            if n:
                t = "forgetting %d shadowed autoindexed files in %r > %r"
                self.log(t % (n, top, sh_rd))

                q = "delete from dh where (d = ? or d like ?||'/%')"
                db.c.execute(q, erd_erd)

                q = "delete from up where (rd=? or rd like ?||'/%')"
                db.c.execute(q, erd_erd)
                tfa += n

            q = "delete from ds where (rd=? or rd like ?||'/%')"
            db.c.execute(q, erd_erd)

        if n4g:
            return tfa, tnf, rsz

        # drop missing files
        q = "select fn from up where rd = ?"
        try:
            c = db.c.execute(q, (rd,))
        except:
            c = db.c.execute(q, ("//" + w8b64enc(rd),))

        hits = [w8b64dec(x[2:]) if x.startswith("//") else x for (x,) in c]
        rm_files = [x for x in hits if x not in seen_files]
        n_rm = len(rm_files)
        for fn in rm_files:
            self.db_rm(db.c, rd, fn, 0)

        if n_rm:
            self.log("forgot {} deleted files".format(n_rm))

        return tfa, tnf, rsz

    def _drop_lost(self, cur: "sqlite3.Cursor", top: str, excl: list[str]) -> int:
        rm = []
        n_rm = 0
        nchecked = 0
        assert self.pp

        # `_build_dir` did all unshadowed files; first do dirs:
        ndirs = next(cur.execute("select count(distinct rd) from up"))[0]
        c = cur.execute("select distinct rd from up order by rd desc")
        for (drd,) in c:
            nchecked += 1
            if drd.startswith("//"):
                rd = w8b64dec(drd[2:])
            else:
                rd = drd

            abspath = djoin(top, rd)
            self.pp.msg = "b%d %s" % (ndirs - nchecked, abspath)
            try:
                if os.path.isdir(abspath):
                    continue
            except:
                pass

            rm.append(drd)

        if rm:
            q = "select count(w) from up where rd = ?"
            for rd in rm:
                n_rm += next(cur.execute(q, (rd,)))[0]

            self.log("forgetting {} deleted dirs, {} files".format(len(rm), n_rm))
            for rd in rm:
                cur.execute("delete from dh where d = ?", (rd,))
                cur.execute("delete from up where rd = ?", (rd,))

        # then shadowed deleted files
        n_rm2 = 0
        c2 = cur.connection.cursor()
        excl = [x[len(top) + 1 :] for x in excl if x.startswith(top + "/")]
        q = "select rd, fn from up where (rd = ? or rd like ?||'%') order by rd"
        for rd in excl:
            for erd in [rd, "//" + w8b64enc(rd)]:
                try:
                    c = cur.execute(q, (erd, erd + "/"))
                    break
                except:
                    pass

            crd = "///"
            cdc: set[str] = set()
            for drd, dfn in c:
                rd, fn = s3dec(drd, dfn)

                if crd != rd:
                    crd = rd
                    try:
                        cdc = set(os.listdir(djoin(top, rd)))
                    except:
                        cdc.clear()

                if fn not in cdc:
                    q = "delete from up where rd = ? and fn = ?"
                    c2.execute(q, (drd, dfn))
                    n_rm2 += 1

        if n_rm2:
            self.log("forgetting {} shadowed deleted files".format(n_rm2))

        c2.connection.commit()

        # then covers
        n_rm3 = 0
        qu = "select 1 from up where rd=? and fn=? limit 1"
        q = "delete from cv where rd=? and dn=? and +fn=?"
        for crd, cdn, fn in cur.execute("select * from cv"):
            urd = vjoin(crd, cdn)
            if not c2.execute(qu, (urd, fn)).fetchone():
                c2.execute(q, (crd, cdn, fn))
                n_rm3 += 1

        if n_rm3:
            self.log("forgetting {} deleted covers".format(n_rm3))

        c2.connection.commit()
        c2.close()
        return n_rm + n_rm2

    def _verify_integrity(self, vol: VFS) -> int:
        """expensive; blocks database access until finished"""
        ptop = vol.realpath
        assert self.pp

        cur = self.cur[ptop]
        rei = vol.flags.get("noidx")
        reh = vol.flags.get("nohash")
        e2vu = "e2vu" in vol.flags
        e2vp = "e2vp" in vol.flags

        excl = [
            d[len(vol.vpath) :].lstrip("/")
            for d in self.vfs.all_vols
            if d != vol.vpath and (d.startswith(vol.vpath + "/") or not vol.vpath)
        ]
        qexa: list[str] = []
        pexa: list[str] = []
        for vpath in excl:
            qexa.append("up.rd != ? and not up.rd like ?||'%'")
            pexa.extend([vpath, vpath])

        pex: tuple[Any, ...] = tuple(pexa)
        qex = " and ".join(qexa)
        if qex:
            qex = " where " + qex

        rewark: list[tuple[str, str, str, int, int]] = []
        f404: list[tuple[str, str, str]] = []

        with self.mutex:
            b_left = 0
            n_left = 0
            q = "select sz from up" + qex
            for (sz,) in cur.execute(q, pex):
                b_left += sz  # sum() can overflow according to docs
                n_left += 1

            tf, _ = self._spool_warks(cur, "select w, rd, fn from up" + qex, pex, 0)

        with gzip.GzipFile(mode="rb", fileobj=tf) as gf:
            for zb in gf:
                if self.stop:
                    return -1

                zs = zb[:-1].decode("utf-8").replace("\x00\x02", "\n")
                w, drd, dfn = zs.split("\x00\x01")
                with self.mutex:
                    q = "select mt, sz from up where rd=? and fn=? and +w=?"
                    try:
                        mt, sz = cur.execute(q, (drd, dfn, w)).fetchone()
                    except:
                        # file moved/deleted since spooling
                        continue

                n_left -= 1
                b_left -= sz
                if drd.startswith("//") or dfn.startswith("//"):
                    rd, fn = s3dec(drd, dfn)
                else:
                    rd = drd
                    fn = dfn

                abspath = djoin(ptop, rd, fn)
                if rei and rei.search(abspath):
                    continue

                nohash = reh.search(abspath) if reh else False

                pf = "v{}, {:.0f}+".format(n_left, b_left / 1024 / 1024)
                self.pp.msg = pf + abspath

                try:
                    stl = bos.lstat(abspath)
                    st = bos.stat(abspath) if stat.S_ISLNK(stl.st_mode) else stl
                except Exception as ex:
                    self.log("missing file: %r" % (abspath,), 3)
                    f404.append((drd, dfn, w))
                    continue

                mt2 = int(stl.st_mtime)
                sz2 = st.st_size

                if nohash or not sz2:
                    w2 = up2k_wark_from_metadata(self.salt, sz2, mt2, rd, fn)
                else:
                    if sz2 > 1024 * 1024 * 32:
                        self.log("file: %r" % (abspath,))

                    try:
                        hashes, _ = self._hashlist_from_file(abspath, pf)
                    except Exception as ex:
                        self.log("hash: %r @ %r" % (ex, abspath))
                        continue

                    if not hashes:
                        return -1

                    w2 = up2k_wark_from_hashlist(self.salt, sz2, hashes)

                if w == w2:
                    continue

                # symlink mtime was inconsistent before v1.9.4; check if that's it
                if st != stl and (nohash or not sz2):
                    mt2b = int(st.st_mtime)
                    w2b = up2k_wark_from_metadata(self.salt, sz2, mt2b, rd, fn)
                    if w == w2b:
                        continue

                rewark.append((drd, dfn, w2, sz2, mt2))

                t = "hash mismatch: %r\n  db: %s (%d byte, %d)\n  fs: %s (%d byte, %d)"
                self.log(t % (abspath, w, sz, mt, w2, sz2, mt2), 1)

        if e2vp and (rewark or f404):
            self.hub.retcode = 1
            Daemon(self.hub.sigterm)
            t = "in volume /%s:  %s files missing, %s files have incorrect hashes"
            t = t % (vol.vpath, len(f404), len(rewark))
            self.log(t, 1)
            raise Exception(t)

        if not e2vu or (not rewark and not f404):
            return 0

        with self.mutex:
            q = "update up set w=?, sz=?, mt=? where rd=? and fn=?"
            for rd, fn, w, sz, mt in rewark:
                cur.execute(q, (w, sz, int(mt), rd, fn))

            if f404:
                q = "delete from up where rd=? and fn=? and +w=?"
                cur.executemany(q, f404)

            cur.connection.commit()

        return len(rewark) + len(f404)

    def _build_tags_index(self, vol: VFS) -> tuple[int, int, bool]:
        ptop = vol.realpath
        with self.mutex, self.reg_mutex:
            reg = self.register_vpath(ptop, vol.flags)

        assert reg and self.pp
        cur = self.cur[ptop]

        if not self.args.no_dhash:
            with self.mutex:
                c = cur.execute("select k from kv where k = 'tagscan'")
                if not c.fetchone():
                    return 0, 0, bool(self.mtag)

        ret = self._build_tags_index_2(ptop)

        with self.mutex:
            self._set_tagscan(cur, False)
            cur.connection.commit()

        return ret

    def _drop_caches(self) -> None:
        """mutex(main,reg) me"""
        self.log("dropping caches for a full filesystem scan")
        for vol in self.vfs.all_vols.values():
            reg = self.register_vpath(vol.realpath, vol.flags)
            if not reg:
                continue

            cur, _ = reg
            self._set_tagscan(cur, True)
            cur.execute("delete from dh")
            cur.execute("delete from cv")
            cur.connection.commit()

    def _set_tagscan(self, cur: "sqlite3.Cursor", need: bool) -> bool:
        if self.args.no_dhash:
            return False

        c = cur.execute("select k from kv where k = 'tagscan'")
        if bool(c.fetchone()) == need:
            return False

        if need:
            cur.execute("insert into kv values ('tagscan',1)")
        else:
            cur.execute("delete from kv where k = 'tagscan'")

        return True

    def _build_tags_index_2(self, ptop: str) -> tuple[int, int, bool]:
        entags = self.entags[ptop]
        flags = self.flags[ptop]
        cur = self.cur[ptop]

        n_add = 0
        n_rm = 0
        if "e2tsr" in flags:
            with self.mutex:
                n_rm = cur.execute("select count(w) from mt").fetchone()[0]
                if n_rm:
                    self.log("discarding {} media tags for a full rescan".format(n_rm))
                    cur.execute("delete from mt")

        # integrity: drop tags for tracks that were deleted
        if "e2t" in flags:
            with self.mutex:
                n = 0
                c2 = cur.connection.cursor()
                up_q = "select w from up where substr(w,1,16) = ?"
                rm_q = "delete from mt where w = ?"
                for (w,) in cur.execute("select w from mt"):
                    if not c2.execute(up_q, (w,)).fetchone():
                        c2.execute(rm_q, (w[:16],))
                        n += 1

                c2.close()
                if n:
                    t = "discarded media tags for {} deleted files"
                    self.log(t.format(n))
                    n_rm += n

        with self.mutex:
            cur.connection.commit()

        # bail if a volflag disables indexing
        if "d2t" in flags or "d2d" in flags:
            return 0, n_rm, True

        # add tags for new files
        if "e2ts" in flags:
            if not self.mtag:
                return 0, n_rm, False

            nq = 0
            with self.mutex:
                tf, nq = self._spool_warks(
                    cur, "select w from up order by rd, fn", (), 1
                )

            if not nq:
                # self.log("tags ok")
                self._unspool(tf)
                return 0, n_rm, True

            if nq == -1:
                return -1, -1, True

            with gzip.GzipFile(mode="rb", fileobj=tf) as gf:
                n_add = self._e2ts_q(gf, nq, cur, ptop, entags)

            self._unspool(tf)

        return n_add, n_rm, True

    def _e2ts_q(
        self,
        qf: gzip.GzipFile,
        nq: int,
        cur: "sqlite3.Cursor",
        ptop: str,
        entags: set[str],
    ) -> int:
        assert self.pp and self.mtag

        flags = self.flags[ptop]
        mpool: Optional[Queue[Mpqe]] = None
        if self.mtag.prefer_mt and self.args.mtag_mt > 1:
            mpool = self._start_mpool()

        n_add = 0
        n_buf = 0
        last_write = time.time()
        for bw in qf:
            if self.stop:
                return -1

            w = bw[:-1].decode("ascii")
            w16 = w[:16]

            with self.mutex:
                try:
                    q = "select rd, fn, ip, at from up where substr(w,1,16)=? and +w=?"
                    rd, fn, ip, at = cur.execute(q, (w16, w)).fetchone()
                except:
                    # file modified/deleted since spooling
                    continue

                if rd.startswith("//") or fn.startswith("//"):
                    rd, fn = s3dec(rd, fn)

                if "mtp" in flags:
                    q = "select 1 from mt where w=? and +k='t:mtp' limit 1"
                    if cur.execute(q, (w16,)).fetchone():
                        continue

                    q = "insert into mt values (?,'t:mtp','a')"
                    cur.execute(q, (w16,))

            abspath = djoin(ptop, rd, fn)
            self.pp.msg = "c%d %s" % (nq, abspath)
            if not mpool:
                n_tags = self._tagscan_file(cur, entags, w, abspath, ip, at)
            else:
                if ip:
                    oth_tags = {"up_ip": ip, "up_at": at}
                else:
                    oth_tags = {}

                mpool.put(Mpqe({}, entags, w, abspath, oth_tags))
                with self.mutex:
                    n_tags = len(self._flush_mpool(cur))

            n_add += n_tags
            n_buf += n_tags
            nq -= 1

            td = time.time() - last_write
            if n_buf >= 4096 or td >= self.timeout / 2:
                self.log("commit {} new tags".format(n_buf))
                with self.mutex:
                    cur.connection.commit()

                last_write = time.time()
                n_buf = 0

        if mpool:
            self._stop_mpool(mpool)
            with self.mutex:
                n_add += len(self._flush_mpool(cur))

        with self.mutex:
            cur.connection.commit()

        return n_add

    def _spool_warks(
        self,
        cur: "sqlite3.Cursor",
        q: str,
        params: tuple[Any, ...],
        flt: int,
    ) -> tuple[tempfile.SpooledTemporaryFile[bytes], int]:
        """mutex(main) me"""
        n = 0
        c2 = cur.connection.cursor()
        tf = tempfile.SpooledTemporaryFile(1024 * 1024 * 8, "w+b", prefix="cpp-tq-")
        with gzip.GzipFile(mode="wb", fileobj=tf) as gf:
            for row in cur.execute(q, params):
                if self.stop:
                    return tf, -1

                if flt == 1:
                    q = "select 1 from mt where w=? and +k != 't:mtp'"
                    if c2.execute(q, (row[0][:16],)).fetchone():
                        continue

                zs = "\x00\x01".join(row).replace("\n", "\x00\x02")
                gf.write((zs + "\n").encode("utf-8"))
                n += 1

        c2.close()
        tf.seek(0)
        self.spools.add(tf)
        return tf, n

    def _unspool(self, tf: tempfile.SpooledTemporaryFile[bytes]) -> None:
        try:
            self.spools.remove(tf)
        except:
            return

        try:
            tf.close()
        except Exception as ex:
            self.log("failed to delete spool: {}".format(ex), 3)

    def _flush_mpool(self, wcur: "sqlite3.Cursor") -> list[str]:
        ret = []
        for x in self.pending_tags:
            self._tag_file(wcur, *x)
            ret.append(x[1])

        self.pending_tags = []
        return ret

    def _run_all_mtp(self, gid: int) -> None:
        t0 = time.time()
        for ptop, flags in self.flags.items():
            if "mtp" in flags:
                if ptop not in self.entags:
                    t = "skipping mtp for unavailable volume {}"
                    self.log(t.format(ptop), 1)
                else:
                    self._run_one_mtp(ptop, gid)

            vtop = "\n"
            for vol in self.vfs.all_vols.values():
                if vol.realpath == ptop:
                    vtop = vol.vpath
            if "running mtp" in self.volstate.get(vtop, ""):
                self.volstate[vtop] = "online, idle"

        td = time.time() - t0
        msg = "mtp finished in {:.2f} sec ({})"
        self.log(msg.format(td, s2hms(td, True)))

        self.unpp()
        if self.args.exit == "idx":
            self.hub.sigterm()

    def _run_one_mtp(self, ptop: str, gid: int) -> None:
        if gid != self.gid:
            return

        entags = self.entags[ptop]

        parsers = {}
        for parser in self.flags[ptop]["mtp"]:
            try:
                parser = MParser(parser)
            except:
                self.log("invalid argument (could not find program): " + parser, 1)
                return

            for tag in entags:
                if tag in parser.tags:
                    parsers[parser.tag] = parser

        if self.args.mtag_vv:
            t = "parsers for {}: \033[0m{}"
            self.log(t.format(ptop, list(parsers.keys())), "90")

        self.mtp_parsers[ptop] = parsers

        q = "select count(w) from mt where k = 't:mtp'"
        with self.mutex:
            cur = self.cur[ptop]
            cur = cur.connection.cursor()
            wcur = cur.connection.cursor()
            n_left = cur.execute(q).fetchone()[0]

        mpool = self._start_mpool()
        batch_sz = mpool.maxsize * 3
        t_prev = time.time()
        n_prev = n_left
        n_done = 0
        to_delete = {}
        in_progress = {}
        while True:
            did_nothing = True
            with self.mutex:
                if gid != self.gid:
                    break

                q = "select w from mt where k = 't:mtp' limit ?"
                zq = cur.execute(q, (batch_sz,)).fetchall()
                warks = [str(x[0]) for x in zq]
                jobs = []
                for w in warks:
                    if w in in_progress:
                        continue

                    q = "select rd, fn, ip, at from up where substr(w,1,16)=? limit 1"
                    rd, fn, ip, at = cur.execute(q, (w,)).fetchone()
                    rd, fn = s3dec(rd, fn)
                    abspath = djoin(ptop, rd, fn)

                    q = "select k from mt where w = ?"
                    zq = cur.execute(q, (w,)).fetchall()
                    have: dict[str, Union[str, float]] = {x[0]: 1 for x in zq}

                    did_nothing = False
                    parsers = self._get_parsers(ptop, have, abspath)
                    if not parsers:
                        to_delete[w] = True
                        n_left -= 1
                        continue

                    if next((x for x in parsers.values() if x.pri), None):
                        q = "select k, v from mt where w = ?"
                        zq2 = cur.execute(q, (w,)).fetchall()
                        oth_tags = {str(k): v for k, v in zq2}
                    else:
                        oth_tags = {}

                    if ip:
                        oth_tags["up_ip"] = ip
                        oth_tags["up_at"] = at

                    jobs.append(Mpqe(parsers, set(), w, abspath, oth_tags))
                    in_progress[w] = True

            with self.mutex:
                done = self._flush_mpool(wcur)
                for w in done:
                    to_delete[w] = True
                    did_nothing = False
                    in_progress.pop(w)
                    n_done += 1

                for w in to_delete:
                    q = "delete from mt where w = ? and +k = 't:mtp'"
                    cur.execute(q, (w,))

                to_delete = {}

            if not warks:
                break

            if did_nothing:
                with self.tag_event:
                    self.tag_event.wait(0.2)

            if not jobs:
                continue

            try:
                now = time.time()
                s = ((now - t_prev) / (n_prev - n_left)) * n_left
                h, s = divmod(s, 3600)
                m, s = divmod(s, 60)
                n_prev = n_left
                t_prev = now
            except:
                h = 1
                m = 1

            msg = "mtp: {} done, {} left, eta {}h {:02d}m"
            with self.mutex:
                msg = msg.format(n_done, n_left, int(h), int(m))
                self.log(msg, c=6)

            for j in jobs:
                n_left -= 1
                mpool.put(j)

            with self.mutex:
                cur.connection.commit()

        self._stop_mpool(mpool)
        with self.mutex:
            done = self._flush_mpool(wcur)
            for w in done:
                q = "delete from mt where w = ? and +k = 't:mtp'"
                cur.execute(q, (w,))

            cur.connection.commit()
            if n_done:
                self.log("mtp: scanned {} files in {}".format(n_done, ptop), c=6)
                cur.execute("vacuum")

            wcur.close()
            cur.close()

    def _get_parsers(
        self, ptop: str, have: dict[str, Union[str, float]], abspath: str
    ) -> dict[str, MParser]:
        try:
            all_parsers = self.mtp_parsers[ptop]
        except:
            if self.args.mtag_vv:
                self.log("no mtp defined for {}".format(ptop), "90")
            return {}

        entags = self.entags[ptop]
        parsers = {}
        for k, v in all_parsers.items():
            if "ac" in entags or ".aq" in entags:
                if "ac" in have or ".aq" in have:
                    # is audio, require non-audio?
                    if v.audio == "n":
                        if self.args.mtag_vv:
                            t = "skip mtp {}; want no-audio, got audio"
                            self.log(t.format(k), "90")
                        continue
                # is not audio, require audio?
                elif v.audio == "y":
                    if self.args.mtag_vv:
                        t = "skip mtp {}; want audio, got no-audio"
                        self.log(t.format(k), "90")
                    continue

            if v.ext:
                match = False
                for ext in v.ext:
                    if abspath.lower().endswith("." + ext):
                        match = True
                        break

                if not match:
                    if self.args.mtag_vv:
                        t = "skip mtp {}; want file-ext {}, got {}"
                        self.log(t.format(k, v.ext, abspath.rsplit(".")[-1]), "90")
                    continue

            parsers[k] = v

        parsers = {k: v for k, v in parsers.items() if v.force or k not in have}
        return parsers

    def _start_mpool(self) -> Queue[Mpqe]:
        # mp.pool.ThreadPool and concurrent.futures.ThreadPoolExecutor
        # both do crazy runahead so lets reinvent another wheel
        nw = max(1, self.args.mtag_mt)
        assert self.mtag  # !rm
        if not self.mpool_used:
            self.mpool_used = True
            self.log("using {}x {}".format(nw, self.mtag.backend))

        mpool: Queue[Mpqe] = Queue(nw)
        for _ in range(nw):
            Daemon(self._tag_thr, "up2k-mpool", (mpool,))

        return mpool

    def _stop_mpool(self, mpool: Queue[Mpqe]) -> None:
        if not mpool:
            return

        for _ in range(mpool.maxsize):
            mpool.put(Mpqe({}, set(), "", "", {}))

        mpool.join()

    def _tag_thr(self, q: Queue[Mpqe]) -> None:
        assert self.mtag
        while True:
            qe = q.get()
            if not qe.w:
                q.task_done()
                return

            try:
                st = bos.stat(qe.abspath)
                if not qe.mtp:
                    if self.args.mtag_vv:
                        t = "tag-thr: {}({})"
                        self.log(t.format(self.mtag.backend, qe.abspath), "90")

                    tags = self.mtag.get(qe.abspath) if st.st_size else {}
                else:
                    if self.args.mtag_vv:
                        t = "tag-thr: {}({})"
                        self.log(t.format(list(qe.mtp.keys()), qe.abspath), "90")

                    tags = self.mtag.get_bin(qe.mtp, qe.abspath, qe.oth_tags)
                    vtags = [
                        "\033[36m{} \033[33m{}".format(k, v) for k, v in tags.items()
                    ]
                    if vtags:
                        self.log("{}\033[0m [{}]".format(" ".join(vtags), qe.abspath))

                with self.mutex:
                    self.pending_tags.append((qe.entags, qe.w, qe.abspath, tags))
            except:
                ex = traceback.format_exc()
                self._log_tag_err(qe.mtp or self.mtag.backend, qe.abspath, ex)
            finally:
                if qe.mtp:
                    with self.tag_event:
                        self.tag_event.notify_all()

            q.task_done()

    def _log_tag_err(self, parser: Any, abspath: str, ex: Any) -> None:
        msg = "%s failed to read tags from %r:\n%s" % (parser, abspath, ex)
        self.log(msg.lstrip(), c=1 if "<Signals.SIG" in msg else 3)

    def _tagscan_file(
        self,
        write_cur: "sqlite3.Cursor",
        entags: set[str],
        wark: str,
        abspath: str,
        ip: str,
        at: float,
    ) -> int:
        """will mutex(main)"""
        assert self.mtag  # !rm

        try:
            st = bos.stat(abspath)
        except:
            return 0

        if not stat.S_ISREG(st.st_mode):
            return 0

        try:
            tags = self.mtag.get(abspath) if st.st_size else {}
        except Exception as ex:
            self._log_tag_err("", abspath, ex)
            return 0

        if ip:
            tags["up_ip"] = ip
            tags["up_at"] = at

        with self.mutex:
            return self._tag_file(write_cur, entags, wark, abspath, tags)

    def _tag_file(
        self,
        write_cur: "sqlite3.Cursor",
        entags: set[str],
        wark: str,
        abspath: str,
        tags: dict[str, Union[str, float]],
    ) -> int:
        """mutex(main) me"""
        assert self.mtag  # !rm

        if not bos.path.isfile(abspath):
            return 0

        if entags:
            tags = {k: v for k, v in tags.items() if k in entags}
            if not tags:
                # indicate scanned without tags
                tags = {"x": 0}

        if not tags:
            return 0

        for k in tags.keys():
            q = "delete from mt where w = ? and ({})".format(
                " or ".join(["+k = ?"] * len(tags))
            )
            args = [wark[:16]] + list(tags.keys())
            write_cur.execute(q, tuple(args))

        ret = 0
        for k, v in tags.items():
            q = "insert into mt values (?,?,?)"
            write_cur.execute(q, (wark[:16], k, v))
            ret += 1

        self._set_tagscan(write_cur, True)
        return ret

    def _trace(self, msg: str) -> None:
        self.log("ST: {}".format(msg))

    def _open_db_wd(self, db_path: str) -> "sqlite3.Cursor":
        ok: list[int] = []
        if not self.hub.is_dut:
            Daemon(self._open_db_timeout, "opendb_watchdog", [db_path, ok])

        try:
            return self._open_db(db_path)
        finally:
            ok.append(1)

    def _open_db_timeout(self, db_path, ok: list[int]) -> None:
        # give it plenty of time due to the count statement (and wisdom from byte's box)
        for _ in range(60):
            time.sleep(1)
            if ok:
                return

        t = "WARNING:\n\n  initializing an up2k database is taking longer than one minute; something has probably gone wrong:\n\n"
        self._log_sqlite_incompat(db_path, t)

    def _log_sqlite_incompat(self, db_path, t0) -> None:
        txt = t0 or ""
        digest = hashlib.sha512(db_path.encode("utf-8", "replace")).digest()
        stackname = ub64enc(digest[:9]).decode("ascii")
        stackpath = os.path.join(E.cfg, "stack-%s.txt" % (stackname,))

        t = "  the filesystem at %s may not support locking, or is otherwise incompatible with sqlite\n\n  %s\n\n"
        t += "  PS: if you think this is a bug and wish to report it, please include your configuration + the following file: %s\n"
        txt += t % (db_path, HINT_HISTPATH, stackpath)
        self.log(txt, 3)

        try:
            stk = alltrace()
            with open(stackpath, "wb") as f:
                f.write(stk.encode("utf-8", "replace"))
        except Exception as ex:
            self.log("warning: failed to write %s: %s" % (stackpath, ex), 3)

        if self.args.q:
            t = "-" * 72
            raise Exception("%s\n%s\n%s" % (t, txt, t))

    def _orz(self, db_path: str) -> "sqlite3.Cursor":
        assert sqlite3  # type: ignore  # !rm
        c = sqlite3.connect(
            db_path, timeout=self.timeout, check_same_thread=False
        ).cursor()
        # c.connection.set_trace_callback(self._trace)
        return c

    def _open_db(self, db_path: str) -> "sqlite3.Cursor":
        existed = bos.path.exists(db_path)
        cur = self._orz(db_path)
        ver = self._read_ver(cur)
        if not existed and ver is None:
            return self._try_create_db(db_path, cur)

        if ver == 4:
            try:
                t = "creating backup before upgrade: "
                cur = self._backup_db(db_path, cur, ver, t)
                self._upgrade_v4(cur)
                ver = 5
            except:
                self.log("WARN: failed to upgrade from v4", 3)

        if ver == DB_VER:
            self._add_dhash_tab(cur)
            self._add_xiu_tab(cur)
            self._add_cv_tab(cur)
            self._add_idx_up_vp(cur, db_path)
            self._add_ds_tab(cur)

            try:
                nfiles = next(cur.execute("select count(w) from up"))[0]
                self.log("  {} |{}|".format(db_path, nfiles), "90")
                return cur
            except:
                self.log("WARN: could not list files; DB corrupt?\n" + min_ex())

        if (ver or 0) > DB_VER:
            t = "database is version {}, this copyparty only supports versions <= {}"
            raise Exception(t.format(ver, DB_VER))

        msg = "creating new DB (old is bad); backup: "
        if ver:
            msg = "creating new DB (too old to upgrade); backup: "

        cur = self._backup_db(db_path, cur, ver, msg)
        db = cur.connection
        cur.close()
        db.close()
        self._delete_db(db_path)
        return self._try_create_db(db_path, None)

    def _delete_db(self, db_path: str):
        for suf in ("", "-shm", "-wal", "-journal"):
            try:
                bos.unlink(db_path + suf)
            except:
                if not suf:
                    raise

    def _backup_db(
        self, db_path: str, cur: "sqlite3.Cursor", ver: Optional[int], msg: str
    ) -> "sqlite3.Cursor":
        assert sqlite3  # type: ignore  # !rm
        bak = "{}.bak.{:x}.v{}".format(db_path, int(time.time()), ver)
        self.log(msg + bak)
        try:
            c2 = sqlite3.connect(bak)
            with c2:
                cur.connection.backup(c2)
            return cur
        except:
            t = "native sqlite3 backup failed; using fallback method:\n"
            self.log(t + min_ex())
        finally:
            c2.close()  # type: ignore

        db = cur.connection
        cur.close()
        db.close()

        shutil.copy2(fsenc(db_path), fsenc(bak))
        return self._orz(db_path)

    def _read_ver(self, cur: "sqlite3.Cursor") -> Optional[int]:
        for tab in ["ki", "kv"]:
            try:
                c = cur.execute(r"select v from {} where k = 'sver'".format(tab))
            except:
                continue

            rows = c.fetchall()
            if rows:
                return int(rows[0][0])
        return None

    def _try_create_db(
        self, db_path: str, cur: Optional["sqlite3.Cursor"]
    ) -> "sqlite3.Cursor":
        try:
            return self._create_db(db_path, cur)
        except:
            try:
                self._delete_db(db_path)
            except:
                pass
            raise

    def _create_db(
        self, db_path: str, cur: Optional["sqlite3.Cursor"]
    ) -> "sqlite3.Cursor":
        """
        collision in 2^(n/2) files where n = bits (6 bits/ch)
          10*6/2 = 2^30 =       1'073'741'824, 24.1mb idx  1<<(3*10)
          12*6/2 = 2^36 =      68'719'476'736, 24.8mb idx
          16*6/2 = 2^48 = 281'474'976'710'656, 26.1mb idx
        """
        if not cur:
            cur = self._orz(db_path)

        idx = r"create index up_w on up(substr(w,1,16))"
        if self.no_expr_idx:
            idx = r"create index up_w on up(w)"

        for cmd in [
            r"create table up (w text, mt int, sz int, rd text, fn text, ip text, at int)",
            r"create index up_vp on up(rd, fn)",
            r"create index up_fn on up(fn)",
            r"create index up_ip on up(ip)",
            r"create index up_at on up(at)",
            idx,
            r"create table mt (w text, k text, v int)",
            r"create index mt_w on mt(w)",
            r"create index mt_k on mt(k)",
            r"create index mt_v on mt(v)",
            r"create table kv (k text, v int)",
            r"insert into kv values ('sver', {})".format(DB_VER),
        ]:
            cur.execute(cmd)

        self._add_dhash_tab(cur)
        self._add_xiu_tab(cur)
        self._add_cv_tab(cur)
        self._add_ds_tab(cur)
        self.log("created DB at {}".format(db_path))
        return cur

    def _upgrade_v4(self, cur: "sqlite3.Cursor") -> None:
        for cmd in [
            r"alter table up add column ip text",
            r"alter table up add column at int",
            r"create index up_ip on up(ip)",
            r"update kv set v=5 where k='sver'",
        ]:
            cur.execute(cmd)

        cur.connection.commit()

    def _add_dhash_tab(self, cur: "sqlite3.Cursor") -> None:
        # v5 -> v5a
        try:
            cur.execute("select d, h from dh limit 1").fetchone()
            return
        except:
            pass

        for cmd in [
            r"create table dh (d text, h text)",
            r"create index dh_d on dh(d)",
            r"insert into kv values ('tagscan',1)",
        ]:
            cur.execute(cmd)

        cur.connection.commit()

    def _add_xiu_tab(self, cur: "sqlite3.Cursor") -> None:
        # v5a -> v5b
        # store rd+fn rather than warks to support nohash vols
        try:
            cur.execute("select c, w, rd, fn from iu limit 1").fetchone()
            return
        except:
            pass

        try:
            cur.execute("drop table iu")
        except:
            pass

        for cmd in [
            r"create table iu (c int, w text, rd text, fn text)",
            r"create index iu_c on iu(c)",
            r"create index iu_w on iu(w)",
        ]:
            cur.execute(cmd)

        cur.connection.commit()

    def _add_cv_tab(self, cur: "sqlite3.Cursor") -> None:
        # v5b -> v5c
        try:
            cur.execute("select rd, dn, fn from cv limit 1").fetchone()
            return
        except:
            pass

        for cmd in [
            r"create table cv (rd text, dn text, fn text)",
            r"create index cv_i on cv(rd, dn)",
        ]:
            cur.execute(cmd)

        try:
            cur.execute("delete from dh")
        except:
            pass

        cur.connection.commit()

    def _add_idx_up_vp(self, cur: "sqlite3.Cursor", db_path: str) -> None:
        # v5c -> v5d
        try:
            cur.execute("drop index up_rd")
        except:
            return

        for cmd in [
            r"create index up_vp on up(rd, fn)",
            r"create index up_at on up(at)",
        ]:
            self.log("upgrading db [%s]: %s" % (db_path, cmd[:18]))
            cur.execute(cmd)

        self.log("upgrading db [%s]: writing to disk..." % (db_path,))
        cur.connection.commit()
        cur.execute("vacuum")

    def _add_ds_tab(self, cur: "sqlite3.Cursor") -> None:
        # v5d -> v5e
        try:
            cur.execute("select rd, sz from ds limit 1").fetchone()
            return
        except:
            pass

        for cmd in [
            r"create table ds (rd text, sz int, nf int)",
            r"create index ds_rd on ds(rd)",
        ]:
            cur.execute(cmd)

        cur.connection.commit()

    def wake_rescanner(self):
        with self.rescan_cond:
            self.rescan_cond.notify_all()

    def handle_json(
        self, cj: dict[str, Any], busy_aps: dict[str, int]
    ) -> dict[str, Any]:
        # busy_aps is u2fh (always undefined if -j0) so this is safe
        self.busy_aps = busy_aps
        if self.reload_flag or self.reloading:
            raise Pebkac(503, SBUSY % ("fs-reload",))

        got_lock = False
        try:
            # bit expensive; 3.9=10x 3.11=2x
            if self.mutex.acquire(timeout=10):
                got_lock = True
                with self.reg_mutex:
                    ret = self._handle_json(cj)
            else:
                raise Pebkac(503, SBUSY % (self.blocked or "[unknown]",))
        except TypeError:
            if not PY2:
                raise
            with self.mutex, self.reg_mutex:
                ret = self._handle_json(cj)
        finally:
            if got_lock:
                self.mutex.release()

        if self.fx_backlog:
            self.do_fx_backlog()

        return ret

    def _handle_json(self, cj: dict[str, Any], depth: int = 1) -> dict[str, Any]:
        if depth > 16:
            raise Pebkac(500, "too many xbu relocs, giving up")

        ptop = cj["ptop"]
        if not self.register_vpath(ptop, cj["vcfg"]):
            if ptop not in self.registry:
                raise Pebkac(410, "location unavailable")

        cj["poke"] = now = self.db_act = self.vol_act[ptop] = time.time()
        wark = dwark = self._get_wark(cj)
        job = None
        pdir = djoin(ptop, cj["prel"])
        inc_ap = djoin(pdir, cj["name"])
        try:
            dev = bos.stat(pdir).st_dev
        except:
            dev = 0

        # check if filesystem supports sparse files;
        # refuse out-of-order / multithreaded uploading if sprs False
        sprs = self.fstab.get(pdir) != "ng"

        if True:
            jcur = self.cur.get(ptop)
            reg = self.registry[ptop]
            vfs = self.vfs.all_vols[cj["vtop"]]
            n4g = bool(vfs.flags.get("noforget"))
            noclone = bool(vfs.flags.get("noclone"))
            rand = vfs.flags.get("rand") or cj.get("rand")
            lost: list[tuple["sqlite3.Cursor", str, str]] = []

            safe_dedup = vfs.flags.get("safededup") or 50
            data_ok = safe_dedup < 10 or n4g

            vols = [(ptop, jcur)] if jcur else []
            if vfs.flags.get("xlink"):
                vols += [(k, v) for k, v in self.cur.items() if k != ptop]

            if noclone:
                wark = up2k_wark_from_metadata(
                    self.salt, cj["size"], cj["lmod"], cj["prel"], cj["name"]
                )

            zi = cj["lmod"]
            bad_mt = zi <= 0 or zi > 0xAAAAAAAA
            if bad_mt or vfs.flags.get("up_ts", "") == "fu":
                # force upload time rather than last-modified
                cj["lmod"] = int(time.time())
                if zi and bad_mt:
                    t = "ignoring impossible last-modified time from client: %s"
                    self.log(t % (zi,), 6)

            alts: list[tuple[int, int, dict[str, Any], "sqlite3.Cursor", str, str]] = []
            for ptop, cur in vols:
                allv = self.vfs.all_vols
                cvfs = next((v for v in allv.values() if v.realpath == ptop), vfs)
                vtop = cj["vtop"] if cur == jcur else cvfs.vpath

                if self.no_expr_idx:
                    q = r"select * from up where w = ?"
                    argv = [dwark]
                else:
                    q = r"select * from up where substr(w,1,16)=? and +w=?"
                    argv = [dwark[:16], dwark]

                c2 = cur.execute(q, tuple(argv))
                for _, dtime, dsize, dp_dir, dp_fn, ip, at in c2:
                    if dp_dir.startswith("//") or dp_fn.startswith("//"):
                        dp_dir, dp_fn = s3dec(dp_dir, dp_fn)

                    dp_abs = djoin(ptop, dp_dir, dp_fn)
                    if noclone and dp_abs != inc_ap:
                        continue

                    try:
                        st = bos.stat(dp_abs)
                        if stat.S_ISLNK(st.st_mode):
                            # broken symlink
                            raise Exception()
                        if st.st_size != dsize:
                            t = "candidate ignored (db/fs desync): {}, size fs={} db={}, mtime fs={} db={}, file: {}"
                            t = t.format(
                                dwark, st.st_size, dsize, st.st_mtime, dtime, dp_abs
                            )
                            self.log(t)
                            raise Exception()
                    except Exception as ex:
                        if n4g:
                            st = NULLSTAT
                        else:
                            lost.append((cur, dp_dir, dp_fn))
                            continue

                    j = {
                        "name": dp_fn,
                        "prel": dp_dir,
                        "vtop": vtop,
                        "ptop": ptop,
                        "sprs": sprs,  # dontcare; finished anyways
                        "size": dsize,
                        "lmod": dtime,
                        "host": cj["host"],
                        "user": cj["user"],
                        "addr": ip,
                        "at": at,
                    }
                    for k in ["life"]:
                        if k in cj:
                            j[k] = cj[k]

                    # offset of 1st diff in vpaths
                    zig = (
                        n + 1
                        for n, (c1, c2) in enumerate(
                            zip(dp_dir + "\r", cj["prel"] + "\n")
                        )
                        if c1 != c2
                    )
                    score = (
                        (6969 if st.st_dev == dev else 0)
                        + (3210 if dp_dir == cj["prel"] else next(zig))
                        + (1 if dp_fn == cj["name"] else 0)
                    )
                    alts.append((score, -len(alts), j, cur, dp_dir, dp_fn))

            job = None
            for dupe in sorted(alts, reverse=True):
                rj = dupe[2]
                orig_ap = djoin(rj["ptop"], rj["prel"], rj["name"])
                if data_ok or inc_ap == orig_ap:
                    data_ok = True
                    job = rj
                    break
                else:
                    self.log("asserting contents of %r" % (orig_ap,))
                    hashes2, st = self._hashlist_from_file(orig_ap)
                    wark2 = up2k_wark_from_hashlist(self.salt, st.st_size, hashes2)
                    if dwark != wark2:
                        t = "will not dedup (fs index desync): fs=%s, db=%s, file: %r\n%s"
                        self.log(t % (wark2, dwark, orig_ap, rj))
                        lost.append(dupe[3:])
                        continue
                    data_ok = True
                    job = rj
                    break

            if job:
                if wark in reg:
                    del reg[wark]
                job["hash"] = job["need"] = []
                job["done"] = 1
                job["busy"] = {}

            if lost:
                c2 = None
                for cur, dp_dir, dp_fn in lost:
                    t = "forgetting desynced db entry: %r"
                    self.log(t % ("/" + vjoin(vjoin(vfs.vpath, dp_dir), dp_fn)))
                    self.db_rm(cur, dp_dir, dp_fn, cj["size"])
                    if c2 and c2 != cur:
                        c2.connection.commit()

                    c2 = cur

                assert c2  # !rm
                c2.connection.commit()

            cur = jcur
            ptop = None  # use cj or job as appropriate

            if not job and wark in reg:
                # ensure the files haven't been edited or deleted
                path = ""
                st = None
                rj = reg[wark]
                names = [rj[x] for x in ["name", "tnam"] if x in rj]
                for fn in names:
                    path = djoin(rj["ptop"], rj["prel"], fn)
                    try:
                        st = bos.stat(path)
                        if st.st_size > 0 or "done" in rj:
                            # upload completed or both present
                            break
                    except:
                        # missing; restart
                        if not self.args.nw and not n4g:
                            t = "forgetting deleted partial upload at %r"
                            self.log(t % (path,))
                            del reg[wark]
                        break

                inc_ap = djoin(cj["ptop"], cj["prel"], cj["name"])
                orig_ap = djoin(rj["ptop"], rj["prel"], rj["name"])

                if self.args.nw or n4g or not st or "done" not in rj:
                    pass

                elif st.st_size != rj["size"]:
                    t = "will not dedup (fs index desync): %s, size fs=%d db=%d, mtime fs=%d db=%d, file: %r\n%s"
                    t = t % (
                        wark,
                        st.st_size,
                        rj["size"],
                        st.st_mtime,
                        rj["lmod"],
                        path,
                        rj,
                    )
                    self.log(t)
                    del reg[wark]

                elif inc_ap != orig_ap and not data_ok and "done" in reg[wark]:
                    self.log("asserting contents of %r" % (orig_ap,))
                    hashes2, _ = self._hashlist_from_file(orig_ap)
                    wark2 = up2k_wark_from_hashlist(self.salt, st.st_size, hashes2)
                    if wark != wark2:
                        t = "will not dedup (fs index desync): fs=%s, idx=%s, file: %r\n%s"
                        self.log(t % (wark2, wark, orig_ap, rj))
                        del reg[wark]

            if job or wark in reg:
                job = job or reg[wark]
                if (
                    job["ptop"] != cj["ptop"]
                    or job["prel"] != cj["prel"]
                    or job["name"] != cj["name"]
                ):
                    # file contents match, but not the path
                    src = djoin(job["ptop"], job["prel"], job["name"])
                    dst = djoin(cj["ptop"], cj["prel"], cj["name"])
                    vsrc = djoin(job["vtop"], job["prel"], job["name"])
                    vsrc = vsrc.replace("\\", "/")  # just for prints anyways
                    if "done" not in job:
                        self.log("unfinished:\n  %r\n  %r" % (src, dst))
                        err = "partial upload exists at a different location; please resume uploading here instead:\n"
                        err += "/" + quotep(vsrc) + " "

                        # registry is size-constrained + can only contain one unique wark;
                        # let want_recheck trigger symlink (if still in reg) or reupload
                        if cur:
                            dupe = (cj["prel"], cj["name"], cj["lmod"])
                            try:
                                if dupe not in self.dupesched[src]:
                                    self.dupesched[src].append(dupe)
                            except:
                                self.dupesched[src] = [dupe]

                        raise Pebkac(422, err)

                    elif "nodupe" in vfs.flags:
                        self.log("dupe-reject:\n  %r\n  %r" % (src, dst))
                        err = "upload rejected, file already exists:\n"
                        err += "/" + quotep(vsrc) + " "
                        raise Pebkac(409, err)
                    else:
                        # symlink to the client-provided name,
                        # returning the previous upload info
                        psrc = src + ".PARTIAL"
                        if self.args.dotpart:
                            m = re.match(r"(.*[\\/])(.*)", psrc)
                            if m:  # always true but...
                                zs1, zs2 = m.groups()
                                psrc = zs1 + "." + zs2

                        if (
                            src in self.busy_aps
                            or psrc in self.busy_aps
                            or (wark in reg and "done" not in reg[wark])
                        ):
                            raise Pebkac(
                                422, "source file busy; please try again later"
                            )

                        job = deepcopy(job)
                        job["wark"] = wark
                        job["dwrk"] = dwark
                        job["at"] = cj.get("at") or now
                        zs = "vtop ptop prel name lmod host user addr poke"
                        for k in zs.split():
                            job[k] = cj.get(k) or ""
                        for k in ("life", "replace"):
                            if k in cj:
                                job[k] = cj[k]

                        pdir = djoin(cj["ptop"], cj["prel"])
                        if rand:
                            job["name"] = rand_name(
                                pdir, cj["name"], vfs.flags["nrand"]
                            )

                        dst = djoin(job["ptop"], job["prel"], job["name"])
                        xbu = vfs.flags.get("xbu")
                        if xbu:
                            vp = djoin(job["vtop"], job["prel"], job["name"])
                            hr = runhook(
                                self.log,
                                None,
                                self,
                                "xbu.up2k.dupe",
                                xbu,  # type: ignore
                                dst,
                                vp,
                                job["host"],
                                job["user"],
                                self.vfs.get_perms(job["vtop"], job["user"]),
                                job["lmod"],
                                job["size"],
                                job["addr"],
                                job["at"],
                                "",
                            )
                            if not hr:
                                t = "upload blocked by xbu server config: %r" % (dst,)
                                self.log(t, 1)
                                raise Pebkac(403, t)
                            if hr.get("reloc"):
                                x = pathmod(self.vfs, dst, vp, hr["reloc"])
                                if x:
                                    ud1 = (vfs.vpath, job["prel"], job["name"])
                                    pdir, _, job["name"], (vfs, rem) = x
                                    dst = os.path.join(pdir, job["name"])
                                    job["vcfg"] = vfs.flags
                                    job["ptop"] = vfs.realpath
                                    job["vtop"] = vfs.vpath
                                    job["prel"] = rem
                                    job["name"] = sanitize_fn(job["name"], "")
                                    ud2 = (vfs.vpath, job["prel"], job["name"])
                                    if ud1 != ud2:
                                        # print(json.dumps(job, sort_keys=True, indent=4))
                                        job["hash"] = cj["hash"]
                                        self.log("xbu reloc1:%d..." % (depth,), 6)
                                        return self._handle_json(job, depth + 1)

                        job["name"] = self._untaken(pdir, job, now)
                        dst = djoin(job["ptop"], job["prel"], job["name"])

                        if not self.args.nw:
                            dvf: dict[str, Any] = vfs.flags
                            try:
                                dvf = self.flags[job["ptop"]]
                                self._symlink(src, dst, dvf, lmod=cj["lmod"], rm=True)
                            except:
                                if bos.path.exists(dst):
                                    wunlink(self.log, dst, dvf)
                                if not n4g:
                                    raise

                        if cur and not self.args.nw:
                            zs = "prel name lmod size ptop vtop wark dwrk host user addr at"
                            a = [job[x] for x in zs.split()]
                            self.db_add(cur, vfs.flags, *a)
                            cur.connection.commit()
                elif wark in reg:
                    # checks out, but client may have hopped IPs
                    job["addr"] = cj["addr"]

            if not job:
                ap1 = djoin(cj["ptop"], cj["prel"])
                if rand:
                    cj["name"] = rand_name(ap1, cj["name"], vfs.flags["nrand"])

                if vfs.lim:
                    ap2, cj["prel"] = vfs.lim.all(
                        cj["addr"],
                        cj["prel"],
                        cj["size"],
                        cj["ptop"],
                        ap1,
                        self.hub.broker,
                        reg,
                        "up2k._get_volsize",
                    )
                    bos.makedirs(ap2, vf=vfs.flags)
                    vfs.lim.nup(cj["addr"])
                    vfs.lim.bup(cj["addr"], cj["size"])

                job = {
                    "wark": wark,
                    "dwrk": dwark,
                    "t0": now,
                    "sprs": sprs,
                    "hash": deepcopy(cj["hash"]),
                    "need": [],
                    "busy": {},
                }
                # client-provided, sanitized by _get_wark: name, size, lmod
                zs = "vtop ptop prel name size lmod host user addr poke"
                for k in zs.split():
                    job[k] = cj[k]

                for k in ["life", "replace"]:
                    if k in cj:
                        job[k] = cj[k]

                # one chunk may occur multiple times in a file;
                # filter to unique values for the list of missing chunks
                # (preserve order to reduce disk thrashing)
                lut = set()
                for k in cj["hash"]:
                    if k not in lut:
                        job["need"].append(k)
                        lut.add(k)

                try:
                    ret = self._new_upload(job, vfs, depth)
                    if ret:
                        return ret  # xbu recursed
                except:
                    self.registry[job["ptop"]].pop(job["wark"], None)
                    raise

            purl = "{}/{}".format(job["vtop"], job["prel"]).strip("/")
            purl = "/{}/".format(purl) if purl else "/"

            ret = {
                "name": job["name"],
                "purl": purl,
                "size": job["size"],
                "lmod": job["lmod"],
                "sprs": job.get("sprs", sprs),
                "hash": job["need"],
                "dwrk": dwark,
                "wark": wark,
            }

            if (
                not ret["hash"]
                and "fk" in vfs.flags
                and not self.args.nw
                and (cj["user"] in vfs.axs.uread or cj["user"] in vfs.axs.upget)
            ):
                alg = 2 if "fka" in vfs.flags else 1
                ap = absreal(djoin(job["ptop"], job["prel"], job["name"]))
                ino = 0 if ANYWIN else bos.stat(ap).st_ino
                fk = self.gen_fk(alg, self.args.fk_salt, ap, job["size"], ino)
                ret["fk"] = fk[: vfs.flags["fk"]]

            if (
                not ret["hash"]
                and cur
                and cj.get("umod")
                and int(cj["lmod"]) != int(job["lmod"])
                and not self.args.nw
                and cj["user"] in vfs.axs.uwrite
                and cj["user"] in vfs.axs.udel
            ):
                sql = "update up set mt=? where substr(w,1,16)=? and +rd=? and +fn=?"
                try:
                    cur.execute(sql, (cj["lmod"], dwark[:16], job["prel"], job["name"]))
                    cur.connection.commit()

                    ap = djoin(job["ptop"], job["prel"], job["name"])
                    times = (int(time.time()), int(cj["lmod"]))
                    bos.utime(ap, times, False)

                    self.log("touched %r from %d to %d" % (ap, job["lmod"], cj["lmod"]))
                except Exception as ex:
                    self.log("umod failed, %r" % (ex,), 3)

            return ret

    def _untaken(self, fdir: str, job: dict[str, Any], ts: float) -> str:
        fname = job["name"]
        ip = job["addr"]

        if self.args.nw:
            return fname

        fp = djoin(fdir, fname)

        ow = job.get("replace") and bos.path.exists(fp)
        if ow and "mt" in str(job["replace"]).lower():
            mts = bos.stat(fp).st_mtime
            mtc = job["lmod"]
            if mtc < mts:
                t = "will not overwrite; server %d sec newer than client; %d > %d %r"
                self.log(t % (mts - mtc, mts, mtc, fp))
                ow = False

        ptop = job["ptop"]
        vf = self.flags.get(ptop) or {}
        if ow:
            self.log("replacing existing file at %r" % (fp,))
            cur = None
            st = bos.stat(fp)
            try:
                vrel = vjoin(job["prel"], fname)
                xlink = bool(vf.get("xlink"))
                cur, wark, _, _, _, _ = self._find_from_vpath(ptop, vrel)
                self._forget_file(ptop, vrel, cur, wark, True, st.st_size, xlink)
            except Exception as ex:
                self.log("skipping replace-relink: %r" % (ex,))
            finally:
                if cur:
                    cur.connection.commit()

            wunlink(self.log, fp, vf)

        if self.args.plain_ip:
            dip = ip.replace(":", ".")
        else:
            dip = self.hub.iphash.s(ip)

        f, ret = ren_open(
            fname,
            "wb",
            fdir=fdir,
            suffix="-%.6f-%s" % (ts, dip),
            vf=vf,
        )
        f.close()
        return ret

    def _symlink(
        self,
        src: str,
        dst: str,
        flags: dict[str, Any],
        verbose: bool = True,
        rm: bool = False,
        lmod: float = 0,
        fsrc: Optional[str] = None,
        is_mv: bool = False,
    ) -> None:
        if src == dst or (fsrc and fsrc == dst):
            t = "symlinking a file to itself?? orig(%s) fsrc(%s) link(%s)"
            raise Exception(t % (src, fsrc, dst))

        if verbose:
            t = "linking dupe:\n  point-to: {0!r}\n  link-loc: {1!r}"
            if fsrc:
                t += "\n  data-src: {2!r}"
            self.log(t.format(src, dst, fsrc))

        if self.args.nw:
            return

        linked = False
        try:
            if "reflink" in flags:
                raise Exception("reflink")
            if not is_mv and not flags.get("dedup"):
                raise Exception("dedup is disabled in config")

            lsrc = src
            ldst = dst
            fs1 = bos.stat(os.path.dirname(src)).st_dev
            fs2 = bos.stat(os.path.dirname(dst)).st_dev
            if fs1 == 0 or fs2 == 0:
                # py2 on winxp or other unsupported combination
                raise OSError(errno.ENOSYS, "filesystem does not have st_dev")
            elif fs1 == fs2:
                # same fs; make symlink as relative as possible
                spl = r"[\\/]" if WINDOWS else "/"
                nsrc = re.split(spl, src)
                ndst = re.split(spl, dst)
                nc = 0
                for a, b in zip(nsrc, ndst):
                    if a != b:
                        break
                    nc += 1
                if nc > 1:
                    zsl = nsrc[nc:]
                    hops = len(ndst[nc:]) - 1
                    lsrc = "../" * hops + "/".join(zsl)

            if WINDOWS:
                lsrc = lsrc.replace("/", "\\")
                ldst = ldst.replace("/", "\\")

            if rm and bos.path.exists(dst):
                wunlink(self.log, dst, flags)

            try:
                if "hardlink" in flags:
                    os.link(fsenc(absreal(src)), fsenc(dst))
                    linked = True
            except Exception as ex:
                self.log("cannot hardlink: " + repr(ex))
                if "hardlinkonly" in flags:
                    raise Exception("symlink-fallback disabled in cfg")

            if not linked:
                if ANYWIN:
                    Path(ldst).symlink_to(lsrc)
                    if not bos.path.exists(dst):
                        try:
                            wunlink(self.log, dst, flags)
                        except:
                            pass
                        t = "the created symlink [%s] did not resolve to [%s]"
                        raise Exception(t % (ldst, lsrc))
                else:
                    os.symlink(fsenc(lsrc), fsenc(ldst))

                linked = True
        except Exception as ex:
            if str(ex) != "reflink":
                self.log("cannot link; creating copy: " + repr(ex))
            if bos.path.isfile(src):
                csrc = src
            elif fsrc and bos.path.isfile(fsrc):
                csrc = fsrc
            else:
                t = "BUG: no valid sources to link from! orig(%r) fsrc(%r) link(%r)"
                self.log(t, 1)
                raise Exception(t % (src, fsrc, dst))
            shutil.copy2(fsenc(csrc), fsenc(dst))

        if lmod and (not linked or SYMTIME):
            times = (int(time.time()), int(lmod))
            bos.utime(dst, times, False)

    def handle_chunks(
        self, ptop: str, wark: str, chashes: list[str]
    ) -> tuple[list[str], int, list[list[int]], str, float, int, bool]:
        with self.mutex, self.reg_mutex:
            self.db_act = self.vol_act[ptop] = time.time()
            job = self.registry[ptop].get(wark)
            if not job:
                known = " ".join([x for x in self.registry[ptop].keys()])
                self.log("unknown wark [{}], known: {}".format(wark, known))
                raise Pebkac(400, "unknown wark" + SEESLOG)

            if "t0c" not in job:
                job["t0c"] = time.time()

            if len(chashes) > 1 and len(chashes[1]) < 44:
                # first hash is full-length; expand remaining ones
                uniq = []
                lut = set()
                for chash in job["hash"]:
                    if chash not in lut:
                        uniq.append(chash)
                        lut.add(chash)
                try:
                    nchunk = uniq.index(chashes[0])
                except:
                    raise Pebkac(400, "unknown chunk0 [%s]" % (chashes[0],))
                expanded = [chashes[0]]
                for prefix in chashes[1:]:
                    nchunk += 1
                    chash = uniq[nchunk]
                    if not chash.startswith(prefix):
                        t = "next sibling chunk does not start with expected prefix [%s]: [%s]"
                        raise Pebkac(400, t % (prefix, chash))
                    expanded.append(chash)
                chashes = expanded

            for chash in chashes:
                if chash not in job["need"]:
                    msg = "chash = {} , need:\n".format(chash)
                    msg += "\n".join(job["need"])
                    self.log(msg)
                    t = "already got that (%s) but thanks??"
                    if chash not in job["hash"]:
                        t = "unknown chunk wtf: %s"
                    raise Pebkac(400, t % (chash,))

                if chash in job["busy"]:
                    nh = len(job["hash"])
                    idx = job["hash"].index(chash)
                    t = "that chunk is already being written to:\n  {}\n  {} {}/{}\n  {}"
                    raise Pebkac(400, t.format(wark, chash, idx, nh, job["name"]))

            assert chash  # type: ignore  # !rm
            chunksize = up2k_chunksize(job["size"])

            coffsets = []
            nchunks = []
            for chash in chashes:
                nchunk = [n for n, v in enumerate(job["hash"]) if v == chash]
                if not nchunk:
                    raise Pebkac(400, "unknown chunk %s" % (chash,))

                ofs = [chunksize * x for x in nchunk]
                coffsets.append(ofs)
                nchunks.append(nchunk)

            for ofs1, ofs2 in zip(coffsets, coffsets[1:]):
                gap = (ofs2[0] - ofs1[0]) - chunksize
                if gap:
                    t = "only sibling chunks can be stitched; gap of %d bytes between offsets %d and %d in %s"
                    raise Pebkac(400, t % (gap, ofs1[0], ofs2[0], job["name"]))

            path = djoin(job["ptop"], job["prel"], job["tnam"])

            if not job["sprs"]:
                cur_sz = bos.path.getsize(path)
                if coffsets[0][0] > cur_sz:
                    t = "please upload sequentially using one thread;\nserver filesystem does not support sparse files.\n  file: {}\n  chunk: {}\n  cofs: {}\n  flen: {}"
                    t = t.format(job["name"], nchunks[0][0], coffsets[0][0], cur_sz)
                    raise Pebkac(400, t)

            job["busy"][chash] = 1

        job["poke"] = time.time()

        return chashes, chunksize, coffsets, path, job["lmod"], job["size"], job["sprs"]

    def fast_confirm_chunks(
        self, ptop: str, wark: str, chashes: list[str]
    ) -> tuple[int, str]:
        if not self.mutex.acquire(False):
            return -1, ""
        if not self.reg_mutex.acquire(False):
            self.mutex.release()
            return -1, ""
        try:
            return self._confirm_chunks(ptop, wark, chashes, chashes)
        finally:
            self.reg_mutex.release()
            self.mutex.release()

    def confirm_chunks(
        self, ptop: str, wark: str, written: list[str], locked: list[str]
    ) -> tuple[int, str]:
        with self.mutex, self.reg_mutex:
            return self._confirm_chunks(ptop, wark, written, locked)

    def _confirm_chunks(
        self, ptop: str, wark: str, written: list[str], locked: list[str]
    ) -> tuple[int, str]:
        if True:
            self.db_act = self.vol_act[ptop] = time.time()
            try:
                job = self.registry[ptop][wark]
                pdir = djoin(job["ptop"], job["prel"])
                src = djoin(pdir, job["tnam"])
                dst = djoin(pdir, job["name"])
            except Exception as ex:
                return -2, "confirm_chunk, wark(%r)" % (ex,)  # type: ignore

            for chash in locked:
                job["busy"].pop(chash, None)

            try:
                for chash in written:
                    job["need"].remove(chash)
            except Exception as ex:
                # dead tcp connections can get here by timeout (OK)
                return -2, "confirm_chunk, chash(%s) %r" % (chash, ex)  # type: ignore

            ret = len(job["need"])
            if ret > 0:
                return ret, src

            if self.args.nw:
                self.regdrop(ptop, wark)

        return ret, dst

    def finish_upload(self, ptop: str, wark: str, busy_aps: dict[str, int]) -> None:
        self.busy_aps = busy_aps
        with self.mutex, self.reg_mutex:
            self._finish_upload(ptop, wark)

        if self.fx_backlog:
            self.do_fx_backlog()

    def _finish_upload(self, ptop: str, wark: str) -> None:
        """mutex(main,reg) me"""
        try:
            job = self.registry[ptop][wark]
            pdir = djoin(job["ptop"], job["prel"])
            src = djoin(pdir, job["tnam"])
            dst = djoin(pdir, job["name"])
        except Exception as ex:
            self.log(min_ex(), 1)
            raise Pebkac(500, "finish_upload, wark, %r%s" % (ex, SEESLOG))

        if job["need"]:
            self.log(min_ex(), 1)
            t = "finish_upload %s with remaining chunks %s%s"
            raise Pebkac(500, t % (wark, job["need"], SEESLOG))

        upt = job.get("at") or time.time()
        vflags = self.flags[ptop]

        atomic_move(self.log, src, dst, vflags)

        times = (int(time.time()), int(job["lmod"]))
        t = "no more chunks, setting times %s (%d) on %r"
        self.log(t % (times, bos.path.getsize(dst), dst))
        try:
            bos.utime(dst, times)
        except:
            self.log("failed to utime (%r, %s)" % (dst, times))

        zs = "prel name lmod size ptop vtop wark dwrk host user addr"
        z2 = [job[x] for x in zs.split()]
        wake_sr = False
        try:
            flt = job["life"]
            vfs = self.vfs.all_vols[job["vtop"]]
            vlt = vfs.flags["lifetime"]
            if vlt and flt > 1 and flt < vlt:
                upt -= vlt - flt
                wake_sr = True
                t = "using client lifetime; at={:.0f} ({}-{})"
                self.log(t.format(upt, vlt, flt))
        except:
            pass

        z2.append(upt)
        if self.idx_wark(vflags, *z2):
            del self.registry[ptop][wark]
        else:
            for k in "host tnam busy sprs poke".split():
                del job[k]
            job.pop("t0c", None)
            job["t0"] = int(job["t0"])
            job["hash"] = []
            job["done"] = 1
            self.regdrop(ptop, wark)

        if wake_sr:
            with self.rescan_cond:
                self.rescan_cond.notify_all()

        dupes = self.dupesched.pop(dst, [])
        if not dupes:
            return

        cur = self.cur.get(ptop)
        for rd, fn, lmod in dupes:
            d2 = djoin(ptop, rd, fn)
            if os.path.exists(d2):
                continue

            self._symlink(dst, d2, self.flags[ptop], lmod=lmod)
            if cur:
                self.db_add(cur, vflags, rd, fn, lmod, *z2[3:])

        if cur:
            cur.connection.commit()

    def regdrop(self, ptop: str, wark: str) -> None:
        """mutex(main,reg) me"""
        olds = self.droppable[ptop]
        if wark:
            olds.append(wark)

        if len(olds) <= self.args.reg_cap:
            return

        n = len(olds) - int(self.args.reg_cap / 2)
        t = "up2k-registry [{}] has {} droppables; discarding {}"
        self.log(t.format(ptop, len(olds), n))
        for k in olds[:n]:
            self.registry[ptop].pop(k, None)
        self.droppable[ptop] = olds[n:]

    def idx_wark(
        self,
        vflags: dict[str, Any],
        rd: str,
        fn: str,
        lmod: float,
        sz: int,
        ptop: str,
        vtop: str,
        wark: str,
        dwark: str,
        host: str,
        usr: str,
        ip: str,
        at: float,
        skip_xau: bool = False,
    ) -> bool:
        cur = self.cur.get(ptop)
        if not cur:
            return False

        self.db_act = self.vol_act[ptop] = time.time()
        try:
            self.db_add(
                cur,
                vflags,
                rd,
                fn,
                lmod,
                sz,
                ptop,
                vtop,
                wark,
                dwark,
                host,
                usr,
                ip,
                at,
                skip_xau,
            )
            cur.connection.commit()
        except Exception as ex:
            x = self.register_vpath(ptop, {})
            assert x  # !rm
            db_ex_chk(self.log, ex, x[1])
            raise

        if "e2t" in self.flags[ptop]:
            self.tagq.put((ptop, dwark, rd, fn, sz, ip, at))
            self.n_tagq += 1

        return True

    def db_rm(self, db: "sqlite3.Cursor", rd: str, fn: str, sz: int) -> None:
        sql = "delete from up where rd = ? and fn = ?"
        try:
            r = db.execute(sql, (rd, fn))
        except:
            assert self.mem_cur  # !rm
            r = db.execute(sql, s3enc(self.mem_cur, rd, fn))

        if r.rowcount:
            self.volsize[db] -= sz
            self.volnfiles[db] -= 1

    def db_add(
        self,
        db: "sqlite3.Cursor",
        vflags: dict[str, Any],
        rd: str,
        fn: str,
        ts: float,
        sz: int,
        ptop: str,
        vtop: str,
        wark: str,
        dwark: str,
        host: str,
        usr: str,
        ip: str,
        at: float,
        skip_xau: bool = False,
    ) -> None:
        """mutex(main) me"""
        self.db_rm(db, rd, fn, sz)

        if not ip:
            db_ip = ""
        else:
            # plugins may expect this to look like an actual IP
            db_ip = "1.1.1.1" if "no_db_ip" in vflags else ip

        sql = "insert into up values (?,?,?,?,?,?,?)"
        v = (dwark, int(ts), sz, rd, fn, db_ip, int(at or 0))
        try:
            db.execute(sql, v)
        except:
            assert self.mem_cur  # !rm
            rd, fn = s3enc(self.mem_cur, rd, fn)
            v = (dwark, int(ts), sz, rd, fn, db_ip, int(at or 0))
            db.execute(sql, v)

        self.volsize[db] += sz
        self.volnfiles[db] += 1

        xau = False if skip_xau else vflags.get("xau")
        dst = djoin(ptop, rd, fn)
        if xau:
            hr = runhook(
                self.log,
                None,
                self,
                "xau.up2k",
                xau,
                dst,
                djoin(vtop, rd, fn),
                host,
                usr,
                self.vfs.get_perms(djoin(vtop, rd, fn), usr),
                ts,
                sz,
                ip,
                at or time.time(),
                "",
            )
            if not hr:
                t = "upload blocked by xau server config"
                self.log(t, 1)
                wunlink(self.log, dst, vflags)
                self.registry[ptop].pop(wark, None)
                raise Pebkac(403, t)

        xiu = vflags.get("xiu")
        if xiu:
            cds: set[int] = set()
            for cmd in xiu:
                m = self.xiu_ptn.search(cmd)
                cds.add(int(m.group(1)) if m else 5)

            q = "insert into iu values (?,?,?,?)"
            for cd in cds:
                # one for each unique cooldown duration
                try:
                    db.execute(q, (cd, dwark[:16], rd, fn))
                except:
                    assert self.mem_cur  # !rm
                    rd, fn = s3enc(self.mem_cur, rd, fn)
                    db.execute(q, (cd, dwark[:16], rd, fn))

            if self.xiu_asleep:
                self.xiu_asleep = False
                with self.rescan_cond:
                    self.rescan_cond.notify_all()

        if rd and sz and fn.lower() in self.args.th_coversd_set:
            # wasteful; db_add will re-index actual covers
            # but that won't catch existing files
            crd, cdn = rd.rsplit("/", 1) if "/" in rd else ("", rd)
            try:
                q = "select fn from cv where rd=? and dn=?"
                db_cv = db.execute(q, (crd, cdn)).fetchone()[0]
                db_lcv = db_cv.lower()
                if db_lcv in self.args.th_coversd_set:
                    idx_db = self.args.th_coversd.index(db_lcv)
                    idx_fn = self.args.th_coversd.index(fn.lower())
                    add_cv = idx_fn < idx_db
                else:
                    add_cv = True
            except:
                add_cv = True

            if add_cv:
                try:
                    db.execute("delete from cv where rd=? and dn=?", (crd, cdn))
                    db.execute("insert into cv values (?,?,?)", (crd, cdn, fn))
                except:
                    pass

        if "nodirsz" not in vflags:
            try:
                q = "update ds set nf=nf+1, sz=sz+? where rd=?"
                q2 = "insert into ds values(?,?,1)"
                while True:
                    if not db.execute(q, (sz, rd)).rowcount:
                        db.execute(q2, (rd, sz))
                    if not rd:
                        break
                    rd = rd.rsplit("/", 1)[0] if "/" in rd else ""
            except:
                pass

    def handle_rm(
        self,
        uname: str,
        ip: str,
        vpaths: list[str],
        lim: list[int],
        rm_up: bool,
        unpost: bool,
    ) -> str:
        n_files = 0
        ok = {}
        ng = {}
        for vp in vpaths:
            if lim and lim[0] <= 0:
                self.log("hit delete limit of {} files".format(lim[1]), 3)
                break

            a, b, c = self._handle_rm(uname, ip, vp, lim, rm_up, unpost)
            n_files += a
            for k in b:
                ok[k] = 1
            for k in c:
                ng[k] = 1

        ng = {k: 1 for k in ng if k not in ok}
        iok = len(ok)
        ing = len(ng)

        return "deleted {} files (and {}/{} folders)".format(n_files, iok, iok + ing)

    def _handle_rm(
        self, uname: str, ip: str, vpath: str, lim: list[int], rm_up: bool, unpost: bool
    ) -> tuple[int, list[str], list[str]]:
        self.db_act = time.time()
        partial = ""
        if not unpost:
            permsets = [[True, False, False, True]]
            vn0, rem0 = self.vfs.get(vpath, uname, *permsets[0])
            vn, rem = vn0.get_dbv(rem0)
        else:
            # unpost with missing permissions? verify with db
            permsets = [[False, True]]
            vn0, rem0 = self.vfs.get(vpath, uname, *permsets[0])
            vn, rem = vn0.get_dbv(rem0)
            ptop = vn.realpath
            with self.mutex, self.reg_mutex:
                abrt_cfg = self.flags.get(ptop, {}).get("u2abort", 1)
                addr = (ip or "\n") if abrt_cfg in (1, 2) else ""
                user = ((uname or "\n"), "*") if abrt_cfg in (1, 3) else None
                reg = self.registry.get(ptop, {}) if abrt_cfg else {}
                for wark, job in reg.items():
                    if (addr and addr != job["addr"]) or (
                        user and job["user"] not in user
                    ):
                        continue
                    jrem = djoin(job["prel"], job["name"])
                    if ANYWIN:
                        jrem = jrem.replace("\\", "/")
                    if jrem == rem:
                        if job["ptop"] != ptop:
                            t = "job.ptop [%s] != vol.ptop [%s] ??"
                            raise Exception(t % (job["ptop"], ptop))
                        partial = vn.canonical(vjoin(job["prel"], job["tnam"]))
                        break
                if partial:
                    dip = ip
                    dat = time.time()
                else:
                    if not self.args.unpost:
                        t = "the unpost feature is disabled in server config"
                        raise Pebkac(400, t)

                    _, _, _, _, dip, dat = self._find_from_vpath(ptop, rem)

            t = "you cannot delete this: "
            if not dip:
                t += "file not found"
            elif dip != ip:
                t += "not uploaded by (You)"
            elif dat < time.time() - self.args.unpost:
                t += "uploaded too long ago"
            else:
                t = ""

            if t:
                raise Pebkac(400, t)

        ptop = vn.realpath
        atop = vn.canonical(rem, False)
        self.vol_act[ptop] = self.db_act
        adir, fn = os.path.split(atop)
        try:
            st = bos.lstat(atop)
            is_dir = stat.S_ISDIR(st.st_mode)
        except:
            raise Pebkac(400, "file not found on disk (already deleted?)")

        scandir = not self.args.no_scandir
        if is_dir:
            # note: deletion inside shares would require a rewrite here;
            #   shares necessitate get_dbv which is incompatible with walk
            g = vn0.walk("", rem0, [], uname, permsets, 2, scandir, True)
            if unpost:
                raise Pebkac(400, "cannot unpost folders")
        elif stat.S_ISLNK(st.st_mode) or stat.S_ISREG(st.st_mode):
            voldir = vsplit(rem)[0]
            vpath_dir = vsplit(vpath)[0]
            g = [(vn, voldir, vpath_dir, adir, [(fn, 0)], [], {})]  # type: ignore
        else:
            self.log("rm: skip type-0%o file %r" % (st.st_mode, atop))
            return 0, [], []

        xbd = vn.flags.get("xbd")
        xad = vn.flags.get("xad")
        n_files = 0
        for dbv, vrem, _, adir, files, rd, vd in g:
            for fn in [x[0] for x in files]:
                if lim:
                    lim[0] -= 1
                    if lim[0] < 0:
                        self.log("hit delete limit of {} files".format(lim[1]), 3)
                        break

                abspath = djoin(adir, fn)
                st = stl = bos.lstat(abspath)
                if stat.S_ISLNK(st.st_mode):
                    try:
                        st = bos.stat(abspath)
                    except:
                        pass

                volpath = ("%s/%s" % (vrem, fn)).strip("/")
                vpath = ("%s/%s" % (dbv.vpath, volpath)).strip("/")
                self.log("rm %r\n  %r" % (vpath, abspath))
                if not unpost:
                    # recursion-only sanchk
                    _ = dbv.get(volpath, uname, *permsets[0])

                if xbd:
                    if not runhook(
                        self.log,
                        None,
                        self,
                        "xbd",
                        xbd,
                        abspath,
                        vpath,
                        "",
                        uname,
                        self.vfs.get_perms(vpath, uname),
                        stl.st_mtime,
                        st.st_size,
                        ip,
                        time.time(),
                        "",
                    ):
                        t = "delete blocked by xbd server config: %r"
                        self.log(t % (abspath,), 1)
                        continue

                n_files += 1
                with self.mutex, self.reg_mutex:
                    cur = None
                    try:
                        ptop = dbv.realpath
                        xlink = bool(dbv.flags.get("xlink"))
                        cur, wark, _, _, _, _ = self._find_from_vpath(ptop, volpath)
                        self._forget_file(
                            ptop, volpath, cur, wark, True, st.st_size, xlink
                        )
                    finally:
                        if cur:
                            cur.connection.commit()

                wunlink(self.log, abspath, dbv.flags)
                if partial:
                    wunlink(self.log, partial, dbv.flags)
                    partial = ""
                if xad:
                    runhook(
                        self.log,
                        None,
                        self,
                        "xad",
                        xad,
                        abspath,
                        vpath,
                        "",
                        uname,
                        self.vfs.get_perms(vpath, uname),
                        stl.st_mtime,
                        st.st_size,
                        ip,
                        time.time(),
                        "",
                    )

        if is_dir:
            ok, ng = rmdirs(self.log_func, scandir, True, atop, 1)
        else:
            ok = ng = []

        if rm_up:
            ok2, ng2 = rmdirs_up(os.path.dirname(atop), ptop)
        else:
            ok2 = ng2 = []

        return n_files, ok + ok2, ng + ng2

    def handle_cp(self, uname: str, ip: str, svp: str, dvp: str) -> str:
        if svp == dvp or dvp.startswith(svp + "/"):
            raise Pebkac(400, "cp: cannot copy parent into subfolder")

        svn, srem = self.vfs.get(svp, uname, True, False)
        dvn, drem = self.vfs.get(dvp, uname, False, True)
        svn_dbv, _ = svn.get_dbv(srem)
        sabs = svn.canonical(srem, False)
        curs: set["sqlite3.Cursor"] = set()
        self.db_act = self.vol_act[svn_dbv.realpath] = time.time()

        st = bos.stat(sabs)
        if stat.S_ISREG(st.st_mode) or stat.S_ISLNK(st.st_mode):
            with self.mutex:
                try:
                    ret = self._cp_file(uname, ip, svp, dvp, curs)
                finally:
                    for v in curs:
                        v.connection.commit()

                return ret

        if not stat.S_ISDIR(st.st_mode):
            raise Pebkac(400, "cannot copy type-0%o file" % (st.st_mode,))

        permsets = [[True, False]]
        scandir = not self.args.no_scandir

        # if user can see dotfiles in target volume, only include
        # dots from source vols where user also has the dot perm
        dots = 1 if uname in dvn.axs.udot else 2

        # don't use svn_dbv; would skip subvols due to _ls `if not rem:`
        g = svn.walk("", srem, [], uname, permsets, dots, scandir, True)
        with self.mutex:
            try:
                for dbv, vrem, _, atop, files, rd, vd in g:
                    for fn in files:
                        self.db_act = self.vol_act[dbv.realpath] = time.time()
                        svpf = "/".join(x for x in [dbv.vpath, vrem, fn[0]] if x)
                        if not svpf.startswith(svp + "/"):  # assert
                            self.log(min_ex(), 1)
                            t = "cp: bug at %r, top %r%s"
                            raise Pebkac(500, t % (svpf, svp, SEESLOG))

                        dvpf = dvp + svpf[len(svp) :]
                        self._cp_file(uname, ip, svpf, dvpf, curs)

                    for v in curs:
                        v.connection.commit()
                    curs.clear()
            finally:
                for v in curs:
                    v.connection.commit()

        return "k"

    def _cp_file(
        self, uname: str, ip: str, svp: str, dvp: str, curs: set["sqlite3.Cursor"]
    ) -> str:
        """mutex(main) me;  will mutex(reg)"""
        svn, srem = self.vfs.get(svp, uname, True, False)
        svn_dbv, srem_dbv = svn.get_dbv(srem)

        dvn, drem = self.vfs.get(dvp, uname, False, True)
        dvn, drem = dvn.get_dbv(drem)

        sabs = svn.canonical(srem, False)
        dabs = dvn.canonical(drem)
        drd, dfn = vsplit(drem)

        if bos.path.exists(dabs):
            raise Pebkac(400, "cp2: target file exists")

        st = stl = bos.lstat(sabs)
        if stat.S_ISLNK(stl.st_mode):
            is_link = True
            try:
                st = bos.stat(sabs)
            except:
                pass  # broken symlink; keep as-is
        elif not stat.S_ISREG(st.st_mode):
            self.log("skipping type-0%o file %r" % (st.st_mode, sabs))
            return ""
        else:
            is_link = False

        ftime = stl.st_mtime
        fsize = st.st_size

        xbc = svn.flags.get("xbc")
        xac = dvn.flags.get("xac")
        if xbc:
            if not runhook(
                self.log,
                None,
                self,
                "xbc",
                xbc,
                sabs,
                svp,
                "",
                uname,
                self.vfs.get_perms(svp, uname),
                ftime,
                fsize,
                ip,
                time.time(),
                "",
            ):
                t = "copy blocked by xbr server config: %r" % (svp,)
                self.log(t, 1)
                raise Pebkac(405, t)

        bos.makedirs(os.path.dirname(dabs), vf=dvn.flags)

        c1, w, ftime_, fsize_, ip, at = self._find_from_vpath(
            svn_dbv.realpath, srem_dbv
        )
        c2 = self.cur.get(dvn.realpath)

        if w:
            assert c1  # !rm
            if c2 and c2 != c1:
                self._copy_tags(c1, c2, w)

            curs.add(c1)

            if c2:
                self.db_add(
                    c2,
                    {},  # skip upload hooks
                    drd,
                    dfn,
                    ftime,
                    fsize,
                    dvn.realpath,
                    dvn.vpath,
                    w,
                    w,
                    "",
                    "",
                    ip or "",
                    at or 0,
                )
                curs.add(c2)
        else:
            self.log("not found in src db: %r" % (svp,))

        try:
            if is_link and st != stl:
                # relink non-broken symlinks to still work after the move,
                # but only resolve 1st level to maintain relativity
                dlink = bos.readlink(sabs)
                dlink = os.path.join(os.path.dirname(sabs), dlink)
                dlink = bos.path.abspath(dlink)
                self._symlink(dlink, dabs, dvn.flags, lmod=ftime)
            else:
                self._symlink(sabs, dabs, dvn.flags, lmod=ftime)

        except OSError as ex:
            if ex.errno != errno.EXDEV:
                raise

            self.log("using plain copy (%s):\n  %r\n  %r" % (ex.strerror, sabs, dabs))
            b1, b2 = fsenc(sabs), fsenc(dabs)
            is_link = os.path.islink(b1)  # due to _relink
            try:
                shutil.copy2(b1, b2)
            except:
                try:
                    wunlink(self.log, dabs, dvn.flags)
                except:
                    pass

                if not is_link:
                    raise

                # broken symlink? keep it as-is
                try:
                    zb = os.readlink(b1)
                    os.symlink(zb, b2)
                except:
                    wunlink(self.log, dabs, dvn.flags)
                    raise

            if is_link:
                try:
                    times = (int(time.time()), int(ftime))
                    bos.utime(dabs, times, False)
                except:
                    pass

        if xac:
            runhook(
                self.log,
                None,
                self,
                "xac",
                xac,
                dabs,
                dvp,
                "",
                uname,
                self.vfs.get_perms(dvp, uname),
                ftime,
                fsize,
                ip,
                time.time(),
                "",
            )

        return "k"

    def handle_mv(self, uname: str, ip: str, svp: str, dvp: str) -> str:
        if svp == dvp or dvp.startswith(svp + "/"):
            raise Pebkac(400, "mv: cannot move parent into subfolder")

        svn, srem = self.vfs.get(svp, uname, True, False, True)
        jail, jail_rem = svn.get_dbv(srem)
        sabs = svn.canonical(srem, False)
        curs: set["sqlite3.Cursor"] = set()
        self.db_act = self.vol_act[jail.realpath] = time.time()

        if not jail_rem:
            raise Pebkac(400, "mv: cannot move a mountpoint")

        st = bos.lstat(sabs)
        if stat.S_ISREG(st.st_mode) or stat.S_ISLNK(st.st_mode):
            with self.mutex:
                try:
                    ret = self._mv_file(uname, ip, svp, dvp, curs)
                finally:
                    for v in curs:
                        v.connection.commit()

                return ret

        if not stat.S_ISDIR(st.st_mode):
            raise Pebkac(400, "cannot move type-0%o file" % (st.st_mode,))

        permsets = [[True, False, True]]
        scandir = not self.args.no_scandir

        # following symlinks is too scary
        g = svn.walk("", srem, [], uname, permsets, 2, scandir, True)
        for dbv, vrem, _, atop, files, rd, vd in g:
            if dbv != jail:
                # fail early (prevent partial moves)
                raise Pebkac(400, "mv: source folder contains other volumes")

        g = svn.walk("", srem, [], uname, permsets, 2, scandir, True)
        with self.mutex:
            try:
                for dbv, vrem, _, atop, files, rd, vd in g:
                    if dbv != jail:
                        # the actual check (avoid toctou)
                        raise Pebkac(400, "mv: source folder contains other volumes")

                    for fn in files:
                        self.db_act = self.vol_act[dbv.realpath] = time.time()
                        svpf = "/".join(x for x in [dbv.vpath, vrem, fn[0]] if x)
                        if not svpf.startswith(svp + "/"):  # assert
                            self.log(min_ex(), 1)
                            t = "mv: bug at %r, top %r%s"
                            raise Pebkac(500, t % (svpf, svp, SEESLOG))

                        dvpf = dvp + svpf[len(svp) :]
                        self._mv_file(uname, ip, svpf, dvpf, curs)

                    for v in curs:
                        v.connection.commit()
                    curs.clear()
            finally:
                for v in curs:
                    v.connection.commit()

        rm_ok, rm_ng = rmdirs(self.log_func, scandir, True, sabs, 1)

        for zsl in (rm_ok, rm_ng):
            for ap in reversed(zsl):
                if not ap.startswith(sabs):
                    self.log(min_ex(), 1)
                    t = "mv_d: bug at %r, top %r%s"
                    raise Pebkac(500, t % (ap, sabs, SEESLOG))

                rem = ap[len(sabs) :].replace(os.sep, "/").lstrip("/")
                vp = vjoin(dvp, rem)
                try:
                    dvn, drem = self.vfs.get(vp, uname, False, True)
                    dap = dvn.canonical(drem)
                    bos.mkdir(dap, dvn.flags["chmod_d"])
                    if "chown" in dvn.flags:
                        bos.chown(dap, dvn.flags["uid"], dvn.flags["gid"])
                except:
                    pass

        return "k"

    def _mv_file(
        self, uname: str, ip: str, svp: str, dvp: str, curs: set["sqlite3.Cursor"]
    ) -> str:
        """mutex(main) me;  will mutex(reg)"""
        svn, srem = self.vfs.get(svp, uname, True, False, True)
        svn, srem = svn.get_dbv(srem)

        dvn, drem = self.vfs.get(dvp, uname, False, True)
        dvn, drem = dvn.get_dbv(drem)

        sabs = svn.canonical(srem, False)
        dabs = dvn.canonical(drem)
        drd, dfn = vsplit(drem)

        n1 = svp.split("/")[-1]
        n2 = dvp.split("/")[-1]
        if n1.startswith(".") or n2.startswith("."):
            if self.args.no_dot_mv:
                raise Pebkac(400, "moving dotfiles is disabled in server config")
            elif self.args.no_dot_ren and n1 != n2:
                raise Pebkac(400, "renaming dotfiles is disabled in server config")

        if bos.path.exists(dabs):
            raise Pebkac(400, "mv2: target file exists")

        is_link = is_dirlink = False
        st = stl = bos.lstat(sabs)
        if stat.S_ISLNK(stl.st_mode):
            is_link = True
            try:
                st = bos.stat(sabs)
                is_dirlink = stat.S_ISDIR(st.st_mode)
            except:
                pass  # broken symlink; keep as-is

        ftime = stl.st_mtime
        fsize = st.st_size

        xbr = svn.flags.get("xbr")
        xar = dvn.flags.get("xar")
        if xbr:
            if not runhook(
                self.log,
                None,
                self,
                "xbr",
                xbr,
                sabs,
                svp,
                "",
                uname,
                self.vfs.get_perms(svp, uname),
                ftime,
                fsize,
                ip,
                time.time(),
                "",
            ):
                t = "move blocked by xbr server config: %r" % (svp,)
                self.log(t, 1)
                raise Pebkac(405, t)

        is_xvol = svn.realpath != dvn.realpath

        bos.makedirs(os.path.dirname(dabs), vf=dvn.flags)

        if is_dirlink:
            dlabs = absreal(sabs)
            t = "moving symlink from %r to %r, target %r"
            self.log(t % (sabs, dabs, dlabs))
            mt = bos.path.getmtime(sabs, False)
            wunlink(self.log, sabs, svn.flags)
            self._symlink(dlabs, dabs, dvn.flags, False, lmod=mt)

            # folders are too scary, schedule rescan of both vols
            self.need_rescan.add(svn.vpath)
            self.need_rescan.add(dvn.vpath)
            with self.rescan_cond:
                self.rescan_cond.notify_all()

            if xar:
                runhook(
                    self.log,
                    None,
                    self,
                    "xar.ln",
                    xar,
                    dabs,
                    dvp,
                    "",
                    uname,
                    self.vfs.get_perms(dvp, uname),
                    ftime,
                    fsize,
                    ip,
                    time.time(),
                    "",
                )

            return "k"

        c1, w, ftime_, fsize_, ip, at = self._find_from_vpath(svn.realpath, srem)
        c2 = self.cur.get(dvn.realpath)

        has_dupes = False
        if w:
            assert c1  # !rm
            if c2 and c2 != c1:
                self._copy_tags(c1, c2, w)

            xlink = bool(svn.flags.get("xlink"))

            with self.reg_mutex:
                has_dupes = self._forget_file(
                    svn.realpath, srem, c1, w, is_xvol, fsize_ or fsize, xlink
                )

            if not is_xvol:
                has_dupes = self._relink(w, svn.realpath, srem, dabs, c1, xlink)

            curs.add(c1)

            if c2:
                self.db_add(
                    c2,
                    {},  # skip upload hooks
                    drd,
                    dfn,
                    ftime,
                    fsize,
                    dvn.realpath,
                    dvn.vpath,
                    w,
                    w,
                    "",
                    "",
                    ip or "",
                    at or 0,
                )
                curs.add(c2)
        else:
            self.log("not found in src db: %r" % (svp,))

        try:
            if is_xvol and has_dupes:
                raise OSError(errno.EXDEV, "src is symlink")

            if is_link and st != stl:
                # relink non-broken symlinks to still work after the move,
                # but only resolve 1st level to maintain relativity
                dlink = bos.readlink(sabs)
                dlink = os.path.join(os.path.dirname(sabs), dlink)
                dlink = bos.path.abspath(dlink)
                self._symlink(dlink, dabs, dvn.flags, lmod=ftime, is_mv=True)
                wunlink(self.log, sabs, svn.flags)
            else:
                atomic_move(self.log, sabs, dabs, svn.flags)

        except OSError as ex:
            if ex.errno != errno.EXDEV:
                raise

            self.log("using copy+delete (%s):\n  %r\n  %r" % (ex.strerror, sabs, dabs))
            b1, b2 = fsenc(sabs), fsenc(dabs)
            is_link = os.path.islink(b1)  # due to _relink
            try:
                shutil.copy2(b1, b2)
            except:
                try:
                    wunlink(self.log, dabs, dvn.flags)
                except:
                    pass

                if not is_link:
                    raise

                # broken symlink? keep it as-is
                try:
                    zb = os.readlink(b1)
                    os.symlink(zb, b2)
                except:
                    wunlink(self.log, dabs, dvn.flags)
                    raise

            if is_link:
                try:
                    times = (int(time.time()), int(ftime))
                    bos.utime(dabs, times, False)
                except:
                    pass

            wunlink(self.log, sabs, svn.flags)

        if xar:
            runhook(
                self.log,
                None,
                self,
                "xar.mv",
                xar,
                dabs,
                dvp,
                "",
                uname,
                self.vfs.get_perms(dvp, uname),
                ftime,
                fsize,
                ip,
                time.time(),
                "",
            )

        return "k"

    def _copy_tags(
        self, csrc: "sqlite3.Cursor", cdst: "sqlite3.Cursor", wark: str
    ) -> None:
        """copy all tags for wark from src-db to dst-db"""
        w = wark[:16]

        if cdst.execute("select * from mt where w=? limit 1", (w,)).fetchone():
            return  # existing tags in dest db

        for _, k, v in csrc.execute("select * from mt where w=?", (w,)):
            cdst.execute("insert into mt values(?,?,?)", (w, k, v))

    def _find_from_vpath(
        self, ptop: str, vrem: str
    ) -> tuple[
        Optional["sqlite3.Cursor"],
        Optional[str],
        Optional[int],
        Optional[int],
        str,
        Optional[int],
    ]:
        cur = self.cur.get(ptop)
        if not cur:
            return None, None, None, None, "", None

        rd, fn = vsplit(vrem)
        q = "select w, mt, sz, ip, at from up where rd=? and fn=? limit 1"
        try:
            c = cur.execute(q, (rd, fn))
        except:
            assert self.mem_cur  # !rm
            c = cur.execute(q, s3enc(self.mem_cur, rd, fn))

        hit = c.fetchone()
        if hit:
            wark, ftime, fsize, ip, at = hit
            return cur, wark, ftime, fsize, ip, at
        return cur, None, None, None, "", None

    def _forget_file(
        self,
        ptop: str,
        vrem: str,
        cur: Optional["sqlite3.Cursor"],
        wark: Optional[str],
        drop_tags: bool,
        sz: int,
        xlink: bool,
    ) -> bool:
        """
        mutex(main,reg) me
        forgets file in db, fixes symlinks, does not delete
        """
        srd, sfn = vsplit(vrem)
        has_dupes = False
        self.log("forgetting %r" % (vrem,))
        if wark and cur:
            self.log("found {} in db".format(wark))
            if drop_tags:
                if self._relink(wark, ptop, vrem, "", cur, xlink):
                    has_dupes = True
                    drop_tags = False

            if drop_tags:
                q = "delete from mt where w=?"
                cur.execute(q, (wark[:16],))

            self.db_rm(cur, srd, sfn, sz)

        reg = self.registry.get(ptop)
        if reg:
            vdir = vsplit(vrem)[0]
            wark = wark or next(
                (
                    x
                    for x, y in reg.items()
                    if sfn in [y["name"], y.get("tnam")] and y["prel"] == vdir
                ),
                "",
            )
            job = reg.get(wark) if wark else None
            if job:
                if job["need"]:
                    t = "forgetting partial upload {} ({})"
                    p = self._vis_job_progress(job)
                    self.log(t.format(wark, p))

                src = djoin(ptop, vrem)
                zi = len(self.dupesched.pop(src, []))
                if zi:
                    t = "...and forgetting %d links in dupesched"
                    self.log(t % (zi,))

                assert wark
                del reg[wark]

        return has_dupes

    def _relink(
        self,
        wark: str,
        sptop: str,
        srem: str,
        dabs: str,
        vcur: Optional["sqlite3.Cursor"],
        xlink: bool,
    ) -> int:
        """
        update symlinks from file at svn/srem to dabs (rename),
        or to first remaining full if no dabs (delete)
        """
        dupes = []
        sabs = djoin(sptop, srem)

        if self.no_expr_idx:
            q = r"select rd, fn from up where w = ?"
            argv = (wark,)
        else:
            q = r"select rd, fn from up where substr(w,1,16)=? and +w=?"
            argv = (wark[:16], wark)

        for ptop, cur in self.cur.items():
            if not xlink and cur and cur != vcur:
                continue
            for rd, fn in cur.execute(q, argv):
                if rd.startswith("//") or fn.startswith("//"):
                    rd, fn = s3dec(rd, fn)

                dvrem = vjoin(rd, fn).strip("/")
                if ptop != sptop or srem != dvrem:
                    dupes.append([ptop, dvrem])
                    self.log("found %s dupe: %r %r" % (wark, ptop, dvrem))

        if not dupes:
            return 0

        full: dict[str, tuple[str, str]] = {}
        links: dict[str, tuple[str, str]] = {}
        for ptop, vp in dupes:
            ap = djoin(ptop, vp)
            try:
                d = links if bos.path.islink(ap) else full
                d[ap] = (ptop, vp)
            except:
                self.log("relink: not found: %r" % (ap,))

        # self.log("full:\n" + "\n".join("  {:90}: {}".format(*x) for x in full.items()))
        # self.log("links:\n" + "\n".join("  {:90}: {}".format(*x) for x in links.items()))
        if not dabs and not full and links:
            # deleting final remaining full copy; swap it with a symlink
            slabs = list(sorted(links.keys()))[0]
            ptop, rem = links.pop(slabs)
            self.log("linkswap %r and %r" % (sabs, slabs))
            mt = bos.path.getmtime(slabs, False)
            flags = self.flags.get(ptop) or {}
            atomic_move(self.log, sabs, slabs, flags)
            bos.utime(slabs, (int(time.time()), int(mt)), False)
            self._symlink(slabs, sabs, flags, False, is_mv=True)
            full[slabs] = (ptop, rem)
            sabs = slabs

        if not dabs:
            dabs = list(sorted(full.keys()))[0]

        for alink, parts in links.items():
            lmod = 0.0
            try:
                faulty = False
                ldst = alink
                try:
                    for n in range(40):  # MAXSYMLINKS
                        zs = bos.readlink(ldst)
                        ldst = os.path.join(os.path.dirname(ldst), zs)
                        ldst = bos.path.abspath(ldst)
                        if not bos.path.islink(ldst):
                            break

                        if ldst == sabs:
                            t = "relink because level %d would break:"
                            self.log(t % (n,), 6)
                            faulty = True
                except Exception as ex:
                    self.log("relink because walk failed: %s; %r" % (ex, ex), 3)
                    faulty = True

                zs = absreal(alink)
                if ldst != zs:
                    t = "relink because computed != actual destination:\n  %r\n  %r"
                    self.log(t % (ldst, zs), 3)
                    ldst = zs
                    faulty = True

                if bos.path.islink(ldst):
                    raise Exception("broken symlink: %s" % (alink,))

                if alink != sabs and ldst != sabs and not faulty:
                    continue  # original symlink OK; leave it be

            except Exception as ex:
                t = "relink because symlink verification failed: %s; %r"
                self.log(t % (ex, ex), 3)

            self.log("relinking %r to %r" % (alink, dabs))
            flags = self.flags.get(parts[0]) or {}
            try:
                lmod = bos.path.getmtime(alink, False)
                wunlink(self.log, alink, flags)
            except:
                pass

            # this creates a link pointing from dabs to alink; alink may
            # not exist yet, which becomes problematic if the symlinking
            # fails and it has to fall back on hardlinking/copying files
            # (for example a volume with symlinked dupes but no --dedup);
            # fsrc=sabs is then a source that currently resolves to copy

            self._symlink(
                dabs, alink, flags, False, lmod=lmod or 0, fsrc=sabs, is_mv=True
            )

        return len(full) + len(links)

    def _get_wark(self, cj: dict[str, Any]) -> str:
        if len(cj["name"]) > 1024 or len(cj["hash"]) > 512 * 1024:  # 16TiB
            raise Pebkac(400, "name or numchunks not according to spec")

        for k in cj["hash"]:
            if not self.r_hash.match(k):
                raise Pebkac(
                    400, "at least one hash is not according to spec: {}".format(k)
                )

        # try to use client-provided timestamp, don't care if it fails somehow
        try:
            cj["lmod"] = int(cj["lmod"])
        except:
            cj["lmod"] = int(time.time())

        if cj["hash"]:
            wark = up2k_wark_from_hashlist(self.salt, cj["size"], cj["hash"])
        else:
            wark = up2k_wark_from_metadata(
                self.salt, cj["size"], cj["lmod"], cj["prel"], cj["name"]
            )

        return wark

    def _hashlist_from_file(
        self, path: str, prefix: str = ""
    ) -> tuple[list[str], os.stat_result]:
        st = bos.stat(path)
        fsz = st.st_size
        csz = up2k_chunksize(fsz)
        ret = []
        suffix = " MB, {}".format(path)
        with open(fsenc(path), "rb", self.args.iobuf) as f:
            if self.mth and fsz >= 1024 * 512:
                tlt = self.mth.hash(f, fsz, csz, self.pp, prefix, suffix)
                ret = [x[0] for x in tlt]
                fsz = 0

            while fsz > 0:
                # same as `hash_at` except for `imutex` / bufsz
                if self.stop:
                    return [], st

                if self.pp:
                    mb = fsz // (1024 * 1024)
                    self.pp.msg = prefix + str(mb) + suffix

                hashobj = hashlib.sha512()
                rem = min(csz, fsz)
                fsz -= rem
                while rem > 0:
                    buf = f.read(min(rem, 64 * 1024))
                    if not buf:
                        raise Exception("EOF at " + str(f.tell()))

                    hashobj.update(buf)
                    rem -= len(buf)

                digest = hashobj.digest()[:33]
                ret.append(ub64enc(digest).decode("ascii"))

        return ret, st

    def _new_upload(self, job: dict[str, Any], vfs: VFS, depth: int) -> dict[str, str]:
        pdir = djoin(job["ptop"], job["prel"])
        if not job["size"]:
            try:
                inf = bos.stat(djoin(pdir, job["name"]))
                if stat.S_ISREG(inf.st_mode):
                    job["lmod"] = inf.st_size
                    return {}
            except:
                pass

        vf = self.flags[job["ptop"]]
        xbu = vf.get("xbu")
        ap_chk = djoin(pdir, job["name"])
        vp_chk = djoin(job["vtop"], job["prel"], job["name"])
        if xbu:
            hr = runhook(
                self.log,
                None,
                self,
                "xbu.up2k",
                xbu,
                ap_chk,
                vp_chk,
                job["host"],
                job["user"],
                self.vfs.get_perms(vp_chk, job["user"]),
                job["lmod"],
                job["size"],
                job["addr"],
                job["t0"],
                "",
            )
            if not hr:
                t = "upload blocked by xbu server config: %r" % (vp_chk,)
                self.log(t, 1)
                raise Pebkac(403, t)
            if hr.get("reloc"):
                x = pathmod(self.vfs, ap_chk, vp_chk, hr["reloc"])
                if x:
                    ud1 = (vfs.vpath, job["prel"], job["name"])
                    pdir, _, job["name"], (vfs, rem) = x
                    job["vcfg"] = vf = vfs.flags
                    job["ptop"] = vfs.realpath
                    job["vtop"] = vfs.vpath
                    job["prel"] = rem
                    job["name"] = sanitize_fn(job["name"], "")
                    ud2 = (vfs.vpath, job["prel"], job["name"])
                    if ud1 != ud2:
                        self.log("xbu reloc2:%d..." % (depth,), 6)
                        return self._handle_json(job, depth + 1)

        job["name"] = self._untaken(pdir, job, job["t0"])
        self.registry[job["ptop"]][job["wark"]] = job

        tnam = job["name"] + ".PARTIAL"
        if self.args.dotpart:
            tnam = "." + tnam

        if self.args.nw:
            job["tnam"] = tnam
            if not job["hash"]:
                del self.registry[job["ptop"]][job["wark"]]
            return {}

        if self.args.plain_ip:
            dip = job["addr"].replace(":", ".")
        else:
            dip = self.hub.iphash.s(job["addr"])

        f, job["tnam"] = ren_open(
            tnam,
            "wb",
            fdir=pdir,
            suffix="-%.6f-%s" % (job["t0"], dip),
            vf=vf,
        )
        try:
            abspath = djoin(pdir, job["tnam"])
            sprs = job["sprs"]
            sz = job["size"]
            relabel = False
            if (
                ANYWIN
                and sprs
                and self.args.sparse
                and self.args.sparse * 1024 * 1024 <= sz
            ):
                try:
                    sp.check_call(["fsutil", "sparse", "setflag", abspath])
                except:
                    self.log("could not sparse %r" % (abspath,), 3)
                    relabel = True
                    sprs = False

            if not ANYWIN and sprs and sz > 1024 * 1024:
                fs = self.fstab.get(pdir)
                if fs == "ok":
                    pass
                elif "nosparse" in vf:
                    t = "volflag 'nosparse' is preventing creation of sparse files for uploads to [%s]"
                    self.log(t % (job["ptop"],))
                    relabel = True
                    sprs = False
                elif "sparse" in vf:
                    t = "volflag 'sparse' is forcing creation of sparse files for uploads to [%s]"
                    self.log(t % (job["ptop"],))
                    relabel = True
                else:
                    relabel = True
                    f.seek(1024 * 1024 - 1)
                    f.write(b"e")
                    f.flush()
                    try:
                        nblk = bos.stat(abspath).st_blocks
                        sprs = nblk < 2048
                    except:
                        sprs = False

            if relabel:
                t = "sparse files {} on {} filesystem at {}"
                nv = "ok" if sprs else "ng"
                self.log(t.format(nv, self.fstab.get(pdir), pdir))
                self.fstab.relabel(pdir, nv)
                job["sprs"] = sprs

            if job["hash"] and sprs:
                f.seek(sz - 1)
                f.write(b"e")
        finally:
            f.close()

        if not job["hash"]:
            self._finish_upload(job["ptop"], job["wark"])

        return {}

    def _snapshot(self) -> None:
        slp = self.args.snap_wri
        if not slp or self.args.no_snap:
            return

        while True:
            time.sleep(slp)
            if self.pp:
                slp = 5
            else:
                slp = self.args.snap_wri
                self.do_snapshot()

    def do_snapshot(self) -> None:
        with self.mutex, self.reg_mutex:
            for k, reg in self.registry.items():
                self._snap_reg(k, reg)

    def _snap_reg(self, ptop: str, reg: dict[str, dict[str, Any]]) -> None:
        now = time.time()
        histpath = self.vfs.dbpaths.get(ptop)
        if not histpath:
            return

        idrop = self.args.snap_drop * 60
        rm = [x for x in reg.values() if x["need"] and now - x["poke"] >= idrop]

        if self.args.nw:
            lost = []
        else:
            lost = [
                x
                for x in reg.values()
                if x["need"]
                and not bos.path.exists(djoin(x["ptop"], x["prel"], x["name"]))
            ]

        if rm or lost:
            t = "dropping {} abandoned, {} deleted uploads in {}"
            t = t.format(len(rm), len(lost), ptop)
            rm.extend(lost)
            vis = [self._vis_job_progress(x) for x in rm]
            self.log("\n".join([t] + vis))
            for job in rm:
                del reg[job["wark"]]
                try:
                    # remove the filename reservation
                    path = djoin(job["ptop"], job["prel"], job["name"])
                    if bos.path.getsize(path) == 0:
                        bos.unlink(path)
                except:
                    pass

                try:
                    if len(job["hash"]) == len(job["need"]):
                        # PARTIAL is empty, delete that too
                        path = djoin(job["ptop"], job["prel"], job["tnam"])
                        bos.unlink(path)
                except:
                    pass

        if self.args.nw or self.args.no_snap:
            return

        path = os.path.join(histpath, "up2k.snap")
        if not reg:
            if ptop not in self.snap_prev or self.snap_prev[ptop] is not None:
                self.snap_prev[ptop] = None
                if bos.path.exists(path):
                    bos.unlink(path)
            return

        newest = float(
            max(x["t0"] if "done" in x else x["poke"] for _, x in reg.items())
            if reg
            else 0
        )
        etag = (len(reg), newest)
        if etag == self.snap_prev.get(ptop):
            return

        if bos.makedirs(histpath):
            hidedir(histpath)

        path2 = "{}.{}".format(path, os.getpid())
        body = {"droppable": self.droppable[ptop], "registry": reg}
        j = json.dumps(body, sort_keys=True, separators=(",\n", ": ")).encode("utf-8")
        # j = re.sub(r'"(need|hash)": \[\],\n', "", j)  # bytes=slow, utf8=hungry
        j = j.replace(b'"need": [],\n', b"")  # surprisingly optimal
        j = j.replace(b'"hash": [],\n', b"")
        with gzip.GzipFile(path2, "wb") as f:
            f.write(j)

        atomic_move(self.log, path2, path, VF_CAREFUL)

        self.log("snap: %s |%d| %.2fs" % (path, len(reg), time.time() - now))
        self.snap_prev[ptop] = etag

    def _tagger(self) -> None:
        with self.mutex:
            self.n_tagq += 1

        assert self.mtag
        while True:
            with self.mutex:
                self.n_tagq -= 1

            ptop, wark, rd, fn, sz, ip, at = self.tagq.get()
            if "e2t" not in self.flags[ptop]:
                continue

            # self.log("\n  " + repr([ptop, rd, fn]))
            abspath = djoin(ptop, rd, fn)
            try:
                tags = self.mtag.get(abspath) if sz else {}
                ntags1 = len(tags)
                parsers = self._get_parsers(ptop, tags, abspath)
                if self.args.mtag_vv:
                    t = "parsers({}): {}\n{} {} tags: {}".format(
                        ptop, list(parsers.keys()), ntags1, self.mtag.backend, tags
                    )
                    self.log(t)

                if parsers:
                    tags["up_ip"] = ip
                    tags["up_at"] = at
                    tags.update(self.mtag.get_bin(parsers, abspath, tags))
            except Exception as ex:
                self._log_tag_err("", abspath, ex)
                continue

            with self.mutex:
                cur = self.cur[ptop]
                if not cur:
                    self.log("no cursor to write tags with??", c=1)
                    continue

                # TODO is undef if vol 404 on startup
                entags = self.entags.get(ptop)
                if not entags:
                    self.log("no entags okay.jpg", c=3)
                    continue

                self._tag_file(cur, entags, wark, abspath, tags)
                cur.connection.commit()

            self.log("tagged %r (%d+%d)" % (abspath, ntags1, len(tags) - ntags1))

    def _hasher(self) -> None:
        with self.hashq_mutex:
            self.n_hashq += 1

        while True:
            with self.hashq_mutex:
                self.n_hashq -= 1
            # self.log("hashq {}".format(self.n_hashq))

            task = self.hashq.get()
            if len(task) != 9:
                raise Exception("invalid hash task")

            try:
                if not self._hash_t(task) and self.stop:
                    return
            except Exception as ex:
                self.log("failed to hash %r: %s" % (task, ex), 1)

    def _hash_t(
        self, task: tuple[str, str, dict[str, Any], str, str, str, float, str, bool]
    ) -> bool:
        ptop, vtop, flags, rd, fn, ip, at, usr, skip_xau = task
        # self.log("hashq {} pop {}/{}/{}".format(self.n_hashq, ptop, rd, fn))
        with self.mutex, self.reg_mutex:
            if not self.register_vpath(ptop, flags):
                return True

        abspath = djoin(ptop, rd, fn)
        self.log("hashing %r" % (abspath,))
        inf = bos.stat(abspath)
        if not inf.st_size:
            wark = up2k_wark_from_metadata(
                self.salt, inf.st_size, int(inf.st_mtime), rd, fn
            )
        else:
            hashes, _ = self._hashlist_from_file(abspath)
            if not hashes:
                return False

            wark = up2k_wark_from_hashlist(self.salt, inf.st_size, hashes)

        with self.mutex, self.reg_mutex:
            self.idx_wark(
                self.flags[ptop],
                rd,
                fn,
                inf.st_mtime,
                inf.st_size,
                ptop,
                vtop,
                wark,
                wark,
                "",
                usr,
                ip,
                at,
                skip_xau,
            )

        if at and time.time() - at > 30:
            with self.rescan_cond:
                self.rescan_cond.notify_all()

        if self.fx_backlog:
            self.do_fx_backlog()

        return True

    def hash_file(
        self,
        ptop: str,
        vtop: str,
        flags: dict[str, Any],
        rd: str,
        fn: str,
        ip: str,
        at: float,
        usr: str,
        skip_xau: bool = False,
    ) -> None:
        if "e2d" not in flags:
            return

        if self.n_hashq > 1024:
            t = "%d files in hashq; taking a nap"
            self.log(t % (self.n_hashq,), 6)

            for _ in range(self.n_hashq // 1024):
                time.sleep(0.1)
                if self.n_hashq < 1024:
                    break

        zt = (ptop, vtop, flags, rd, fn, ip, at, usr, skip_xau)
        with self.hashq_mutex:
            self.hashq.put(zt)
            self.n_hashq += 1

    def do_fx_backlog(self):
        with self.mutex, self.reg_mutex:
            todo = self.fx_backlog
            self.fx_backlog = []
        for act, hr, req_vp in todo:
            self.hook_fx(act, hr, req_vp)

    def hook_fx(self, act: str, hr: dict[str, str], req_vp: str) -> None:
        bad = [k for k in hr if k != "vp"]
        if bad:
            t = "got unsupported key in %s from hook: %s"
            raise Exception(t % (act, bad))

        for fvp in hr.get("vp") or []:
            # expect vpath including filename; either absolute
            # or relative to the client's vpath (request url)
            if fvp.startswith("/"):
                fvp, fn = vsplit(fvp[1:])
                fvp = "/" + fvp
            else:
                fvp, fn = vsplit(fvp)

            x = pathmod(self.vfs, "", req_vp, {"vp": fvp, "fn": fn})
            if not x:
                t = "hook_fx(%s): failed to resolve %r based on %r"
                self.log(t % (act, fvp, req_vp))
                continue

            ap, rd, fn, (vn, rem) = x
            vp = vjoin(rd, fn)
            if not vp:
                raise Exception("hook_fx: blank vp from pathmod")

            if act == "idx":
                rd = rd[len(vn.vpath) :].strip("/")
                self.hash_file(
                    vn.realpath, vn.vpath, vn.flags, rd, fn, "", time.time(), "", True
                )

            if act == "del":
                self._handle_rm(LEELOO_DALLAS, "", vp, [], False, False)

    def shutdown(self) -> None:
        self.stop = True

        if self.mth:
            self.mth.stop = True

        # in case we're killed early
        for x in list(self.spools):
            self._unspool(x)

        if not self.args.no_snap:
            self.log("writing snapshot")
            self.do_snapshot()

        t0 = time.time()
        while self.pp:
            time.sleep(0.1)
            if time.time() - t0 >= 1:
                break

        # if there is time
        for x in list(self.spools):
            self._unspool(x)

        for cur in self.cur.values():
            db = cur.connection
            try:
                db.interrupt()
            except:
                pass

            cur.close()
            db.close()

        if self.mem_cur:
            db = self.mem_cur.connection
            self.mem_cur.close()
            db.close()

        self.registry = {}


def up2k_chunksize(filesize: int) -> int:
    chunksize = 1024 * 1024
    stepsize = 512 * 1024
    while True:
        for mul in [1, 2]:
            nchunks = math.ceil(filesize * 1.0 / chunksize)
            if nchunks <= 256 or (chunksize >= 32 * 1024 * 1024 and nchunks <= 4096):
                return chunksize

            chunksize += stepsize
            stepsize *= mul


def up2k_wark_from_hashlist(salt: str, filesize: int, hashes: list[str]) -> str:
    """server-reproducible file identifier, independent of name or location"""
    values = [salt, str(filesize)] + hashes
    vstr = "\n".join(values)

    wark = hashlib.sha512(vstr.encode("utf-8")).digest()[:33]
    return ub64enc(wark).decode("ascii")


def up2k_wark_from_metadata(salt: str, sz: int, lastmod: int, rd: str, fn: str) -> str:
    ret = sfsenc("%s\n%d\n%d\n%s\n%s" % (salt, lastmod, sz, rd, fn))
    ret = ub64enc(hashlib.sha512(ret).digest())
    return ("#%s" % (ret.decode("ascii"),))[:44]
