Files
serverAppConfigs/scripts/media-apply.py
T
Frank a803aa046a fix(media): a sweep carries the emptied folder's own empty subfolders
The live sweep removed 2271 husks and left 146 standing, every one a release
folder blocked by a junk subfolder (Screens/, Sample/, a BDMV leaf) that no
file ever moved out of. Eligibility was per-folder, so the blocker was never a
target and its parent could never be removed.

Proof now carries downward: inside a folder the journal shows emptied, every
empty directory qualifies. Nothing under such a folder can hold data, and every
removal is still journalled as rmdir and undone by rollback.

The new test is red against the previous revision, green now. The live sweep
touched no file: 8193 before, 8193 after.
2026-10-30 20:18:54 -07:00

422 lines
18 KiB
Python
Executable File

#!/usr/bin/env python3
"""media-apply.py — the only thing that moves movie-library files.
Reads the plan written by scripts/media-plan.py (rows: `action src dst kind`,
plus `mkdir` rows) and performs it with rename(2) — bytes are never copied, so
an interrupted run has destroyed nothing. Every run is resumable and every run
is undoable: the journal is a write-ahead log, one JSON line per intent, fsynced
BEFORE the rename it authorises. That ordering is the whole design: a crash
leaves either an intent whose move happened or an intent whose move never ran,
and both are recognised on the next run. A file that moved with no journal line
cannot have been moved by this tool, and saying so is better than guessing.
Four subcommands:
apply --plan PLAN [--root ROOT] [--journal J] [--apply]
no --apply => report only and write NOTHING, not even folders
rollback --journal J [--root ROOT] [--apply]
back to the paths the census saw; folders this run created are
removed only when empty, never anything else
verify --plan PLAN --journal J [--root ROOT]
every planned file is at its target with the journalled byte count
sweep --journal J [--root ROOT] [--apply]
removes the folders THIS RUN emptied — the journal has to show a
file that moved out of one, so a folder someone made by hand can
never be removed by this tool, and rollback puts them back
Refusals (exit 2, before the first rename, with nothing touched): a target
already occupied by a foreign file, a source that has gone, a duplicate target,
a path outside --root, a journal that was already rolled back, a move that would
cross a filesystem (rename cannot do it and a silent copy at 24 TB would not).
--force relaxes only the guards that are opinion (journal already rolled back,
paths outside --root); it never allows overwriting a file.
The journal defaults to `media-relayout.jsonl` BESIDE the library root, never
inside it: a log inside the library is a file Jellyfin will index.
"""
import argparse
import datetime
import json
import os
import sys
DEFAULT_ROOT = os.environ.get("MEDIA_ROOT", "/mnt/entropy/Movies")
class Refuse(Exception):
"""A gate the operator has to see; every refusal leaves the library alone."""
def journal_default(root):
return os.path.join(os.path.dirname(os.path.abspath(root)), "media-relayout.jsonl")
class Journal:
"""Append-only JSONL of intents. Writes are fsynced before the tool acts."""
def __init__(self, path, writing):
self.path, self.writing = path, writing
self.records = []
if os.path.exists(path):
for line in open(path):
line = line.strip()
if line:
self.records.append(json.loads(line))
self._fh = None
def already(self, dst, src):
"""An intent for this exact (src, dst) was written by an earlier run."""
return any(r.get("op") == "move" and r.get("dst") == dst
and r.get("src") == src for r in self.records)
@property
def rolled_back(self):
return any(r.get("op") == "rollback" for r in self.records)
def record(self, **fields):
self.records.append(fields)
if not self.writing:
return
if self._fh is None:
self._fh = open(self.path, "a")
self._fh.write(json.dumps(fields) + "\n")
self._fh.flush()
os.fsync(self._fh.fileno())
def close(self):
if self._fh:
self._fh.close()
def read_plan(path, root, force):
"""Plan rows: (mkdirs, keeps, moves), header dropped, all paths under root."""
mkdirs, keeps, moves = [], [], []
with open(path) as fh:
header = fh.readline()
if not header.startswith("action\t"):
raise Refuse(f"{path} is not a plan (first column is "
f"{header.split(chr(9))[0]!r}, expected 'action') —"
" regenerate it with scripts/media-plan.py")
for line in fh:
f = line.rstrip("\n").split("\t")
if f[0] == "mkdir":
mkdirs.append(f[2])
elif f[0] == "keep":
keeps.append(f[1])
elif f[0] == "move":
moves.append((f[1], f[2], f[3] if len(f) > 3 else ""))
if not force:
for p in mkdirs + keeps + [p for m in moves for p in m[:2]]:
if p and not (p == root or p.startswith(root + os.sep)):
raise Refuse(f"{p} is outside --root {root}"
" (a plan built for another library?)")
return mkdirs, keeps, moves
def do_apply(args, root, journal, mkdirs, keeps, moves):
"""Preflight everything, then folders, then renames. Never a partial start."""
problems = []
for p in keeps:
if not os.path.exists(p):
problems.append(f"missing: keep row source is gone: {p}")
seen = {}
for src, dst, _kind in moves:
if src == dst:
problems.append(f"no-op: move row whose target is its source: {src}")
if dst in seen:
problems.append(f"double-claim: {dst} claimed by {seen[dst]} and {src}")
seen[dst] = src
if journal.already(dst, src) and os.path.exists(dst) and not os.path.exists(src):
continue # this intent already ran
if not os.path.exists(src):
if os.path.exists(dst):
problems.append(f"missing: {src} is gone and {dst} carries no journal"
" line — it moved outside this tool, refusing to guess")
else:
problems.append(f"missing: {src} is gone and {dst} is not there either")
continue
if os.path.exists(dst):
problems.append(f"occupied: target already holds another file: {dst}")
if problems:
print(f"refusing: {len(problems)} problem(s), nothing moved")
for p in sorted(problems)[:20]:
print(" " + p)
if len(problems) > 20:
print(f" ... and {len(problems) - 20} more")
return 2
if not args.apply:
print(f"dry run: {len(moves)} moves, {len(mkdirs)} folders, {len(keeps)} files stay"
" — nothing written (pass --apply to run)")
for src, dst, _k in moves[:5]:
print(f" would move {src} -> {dst}")
return 0
made = {r.get("dst") for r in journal.records if r.get("op") == "mkdir"}
dirs_new = 0
for d in sorted(mkdirs, key=lambda q: q.count(os.sep)):
if d in made or os.path.isdir(d):
continue
journal.record(op="mkdir", dst=d)
os.makedirs(d, exist_ok=True)
dirs_new += 1
# same-filesystem gate: rename cannot cross a device, and a silent copy of a
# library this size is not an option anyone would choose.
cross = []
for src, dst, _k in moves:
if journal.already(dst, src) and os.path.exists(dst) and not os.path.exists(src):
continue
parent = os.path.dirname(dst)
if os.path.exists(parent) and os.stat(parent).st_dev != os.stat(src).st_dev:
cross.append(dst)
if cross:
print(f"refusing: {len(cross)} moves would cross a filesystem"
f" (first: {cross[0]}) — this tool only renames")
return 2
moved = done = 0
for src, dst, _kind in moves:
if journal.already(dst, src):
if os.path.exists(dst) and not os.path.exists(src):
done += 1
continue
if os.path.exists(src) and not os.path.exists(dst):
os.rename(src, dst) # the intent ran, the move did not
moved += 1
continue
st = os.stat(src)
journal.record(op="move", src=src, dst=dst, bytes=st.st_size, mode=st.st_mode,
mtime=st.st_mtime, ino=st.st_ino, dev=st.st_dev)
os.rename(src, dst)
moved += 1
print(f"applied: {moved} moved, {done} already done in an earlier run,"
f" {dirs_new} folders created, {len(keeps)} files stayed put")
print(f"journal: {journal.path} — undo with: media-apply.py rollback"
f" --journal {journal.path} --root {root} --apply")
return 0
def do_verify(root, journal, moves, keeps):
"""Every planned file sits at its target carrying the journalled bytes."""
journalled = {(r["src"], r["dst"]): r for r in journal.records
if r.get("op") == "move"}
todo = moves or [(r["src"], r["dst"], "") for r in journal.records
if r.get("op") == "move"]
bad, missing, bytes_total = [], [], 0
for src, dst, _kind in todo:
rec = journalled.get((src, dst))
if not os.path.exists(dst):
missing.append(dst)
continue
size = os.path.getsize(dst)
bytes_total += size
if rec and rec.get("bytes") not in (None, size):
bad.append(f"{dst}: {size} bytes on disk, {rec['bytes']} at move time")
if os.path.exists(src) and src != dst:
bad.append(f"{src}: still in place as well as at {dst}")
missing += [p for p in keeps if not os.path.exists(p)]
if bad or missing:
print(f"verify FAILED: {len(missing)} absent, {len(bad)} wrong")
for line in (missing + bad)[:20]:
print(" " + line)
return 2
empty = [r["dst"] for r in journal.records
if r.get("op") == "mkdir" and os.path.isdir(r["dst"])
and not os.listdir(r["dst"])]
print(f"verified: {len(todo)} files at their targets"
f" ({bytes_total / 2**40:.2f} TiB), {len(keeps)} kept")
if empty:
print(f"note: {len(empty)} folders are empty (left in place — see the trash law)")
return 0
def sweep_targets(root, journal):
"""The folders this run emptied, deepest first — never one it did not touch.
Eligibility is evidence, not appearance. A folder is a target only when the
journal shows a file moved out of it or out of something beneath it, it holds
nothing but empty directories now, it is not a folder this run created, and no
journalled destination lives under it. A symlink anywhere inside disqualifies
the whole subtree: this tool never follows a link, and deleting the folder
that holds one would delete someone's mount point.
Proof carries downward: once a folder qualifies, every empty directory inside
it qualifies too. A release's junk (``Screens/``, ``Sample/``) is never itself
a move source, so without that rule it holds its emptied parent on disk
forever — the parent can never be removed while the child stands.
"""
moves = [r for r in journal.records if r.get("op") == "move"]
made = {r["dst"] for r in journal.records if r.get("op") == "mkdir"}
gone = {r["path"] for r in journal.records if r.get("op") == "rmdir"}
dsts = [r["dst"] for r in moves]
marked = set()
for r in moves:
d = os.path.dirname(r["src"])
while d.startswith(root + os.sep):
marked.add(d)
d = os.path.dirname(d)
def removable(d):
if d in made or d in gone or os.path.islink(d):
return False
if any(p == d or p.startswith(d + os.sep) for p in dsts):
return False
try:
entries = os.listdir(d)
except OSError:
return False
for e in entries:
c = os.path.join(d, e)
if os.path.islink(c) or not os.path.isdir(c) or not removable(c):
return False
return True
roots = [d for d in marked if removable(d)]
targets = set(roots)
for d in roots:
for dirpath, dirnames, _ in os.walk(d):
for c in dirnames:
p = os.path.join(dirpath, c)
if removable(p):
targets.add(p)
return sorted(targets, key=lambda q: (-q.count(os.sep), q))
def do_sweep(args, root, journal):
"""Remove the empty husks an apply left standing at the library root."""
moves = [r for r in journal.records if r.get("op") == "move"]
if not moves:
raise Refuse("the journal holds no moves — a sweep follows an apply, it"
" does not guess at emptiness")
outside = sorted({p for r in moves for p in (r["src"], r["dst"])
if not (p == root or p.startswith(root + os.sep))})
if outside and not args.force:
raise Refuse(f"{len(outside)} journalled paths are outside --root {root}"
f" (first: {outside[0]}) — this journal belongs to another"
" library")
targets = sweep_targets(root, journal)
if not targets:
print("swept: 0 folders — nothing this run emptied is still standing empty")
return 0
if not args.apply:
print(f"dry run: {len(targets)} folders this run emptied would be removed"
" (pass --apply to run)")
for d in targets[:5]:
print(f" would remove {d}")
return 0
removed = 0
for d in targets:
journal.record(op="rmdir", path=d)
try:
os.rmdir(d)
except OSError as e:
print(f"left in place: {d} ({e})")
continue
removed += 1
print(f"swept: {removed} folders removed, {len(targets) - removed} left in place")
print(f"journal: {journal.path} — rollback recreates them with their files")
return 0
def do_rollback(args, root, journal):
"""Undo every journalled move, newest first, after a full preflight."""
moves = [r for r in journal.records if r.get("op") == "move"]
made = [r["dst"] for r in journal.records if r.get("op") == "mkdir"]
swept = [r["path"] for r in journal.records if r.get("op") == "rmdir"]
problems = []
for r in reversed(moves):
src, dst = r["src"], r["dst"]
if not args.force and not (src.startswith(root + os.sep)
or dst.startswith(root + os.sep)):
problems.append(f"outside --root: {dst}")
continue
if os.path.exists(dst) and os.path.exists(src):
problems.append(f"occupied: both paths exist, refusing to choose:"
f" {src} | {dst}")
elif os.path.exists(dst):
pass
elif os.path.exists(src):
continue # already undone
else:
problems.append(f"missing: {dst} is gone and {src} never came back")
if problems:
print(f"refusing: {len(problems)} problem(s), nothing moved back")
for p in problems[:20]:
print(" " + p)
return 2
if not args.apply:
print(f"dry run: would move {len(moves)} files back to their census paths"
f" and recreate {len(set(swept))} swept folders (pass --apply)")
return 0
undone = 0
recreated = 0
for d in sorted(set(swept), key=lambda q: q.count(os.sep)):
if not os.path.isdir(d):
os.makedirs(d, exist_ok=True)
recreated += 1
for r in reversed(moves):
if os.path.exists(r["dst"]) and not os.path.exists(r["src"]):
os.makedirs(os.path.dirname(r["src"]), exist_ok=True)
os.rename(r["dst"], r["src"])
undone += 1
dirs_gone = 0
for d in sorted(set(made), key=lambda q: -q.count(os.sep)):
if d == root or not os.path.isdir(d) or os.listdir(d):
continue
try:
os.rmdir(d)
dirs_gone += 1
except OSError as e:
print(f"left in place: {d} ({e})")
journal.record(op="rollback", undone=undone, dirs_removed=dirs_gone,
t=datetime.datetime.now(datetime.timezone.utc).isoformat())
print(f"rolled back: {undone} files back where the census found them,"
f" {dirs_gone} empty folders removed, {recreated} swept folders recreated")
return 0
def main():
ap = argparse.ArgumentParser(description="apply or undo a media relayout plan")
ap.add_argument("cmd", choices=["apply", "rollback", "verify", "sweep"])
ap.add_argument("--plan")
ap.add_argument("--root", default=DEFAULT_ROOT)
ap.add_argument("--journal")
ap.add_argument("--apply", action="store_true", help="actually change the library")
ap.add_argument("--force", action="store_true", help="relax the opinion guards")
args = ap.parse_args()
root = os.path.abspath(args.root)
if not os.path.isdir(root):
raise Refuse(f"no library at {root}")
journal_path = args.journal or journal_default(root)
journal = Journal(journal_path, args.apply)
try:
if args.cmd in ("rollback", "verify", "sweep") and not os.path.exists(journal_path):
raise Refuse(f"no journal at {journal_path} — nothing to {args.cmd}")
if args.cmd in ("rollback", "sweep") and not args.force and journal.rolled_back:
raise Refuse("this journal has already been rolled back"
" (--force to replay it)")
if args.cmd in ("apply", "verify") and not args.plan:
raise Refuse(f"{args.cmd} needs --plan")
mkdirs, keeps, moves = (read_plan(args.plan, root, args.force)
if args.plan else ([], [], []))
if args.cmd == "apply":
return do_apply(args, root, journal, mkdirs, keeps, moves)
if args.cmd == "verify":
return do_verify(root, journal, moves, keeps)
if args.cmd == "sweep":
return do_sweep(args, root, journal)
return do_rollback(args, root, journal)
finally:
journal.close()
if __name__ == "__main__":
try:
sys.exit(main())
except Refuse as r:
print(f"refusing: {r}")
sys.exit(2)