Files
am-downloader/am_deduper/exact.py
T

109 lines
3.8 KiB
Python

from __future__ import annotations
import os
from pathlib import Path
from .db import connect
from .hashing import sha256
def confirm_sha256(conn, row) -> str | None:
path = Path(row["file_path"])
try:
st = path.stat()
except (FileNotFoundError, PermissionError):
return None
if st.st_size != row["file_size"]:
return None
digest = sha256(path)
try:
st2 = path.stat()
except (FileNotFoundError, PermissionError):
return None
if st2.st_size != st.st_size or st2.st_mtime_ns != st.st_mtime_ns:
return None
conn.execute(
"UPDATE audio_tracks SET sha256=?,updated_at=CURRENT_TIMESTAMP WHERE id=?",
(digest, row["id"]),
)
return digest
def hardlink_duplicate(loser: Path, winner: Path) -> None:
"""Atomically replace loser with a hard link to winner."""
if loser.stat().st_dev != winner.stat().st_dev:
raise OSError("hard link requires both files on the same filesystem")
tmp = loser.with_name(loser.name + ".dedupe-linking")
try:
if tmp.exists():
tmp.unlink()
os.link(winner, tmp)
os.replace(tmp, loser)
finally:
if tmp.exists():
try:
tmp.unlink()
except OSError:
pass
def choose_winner(rows):
def key(r):
p = str(r["file_path"])
admin = "/admin/" in p or p.endswith("/admin")
return (0 if admin else 1, r["created_at"], p)
return min(rows, key=key)
def exact_dedupe(db_path: Path, root: Path, dry_run: bool = False) -> list[tuple[str, str]]:
actions: list[tuple[str, str]] = []
root = root.resolve()
with connect(db_path) as conn:
rows = conn.execute(
"SELECT * FROM audio_tracks WHERE status IN ('active','hardlinked')"
).fetchall()
groups: dict[tuple[int, str], list] = {}
for row in rows:
groups.setdefault((row["file_size"], row["fast_hash"]), []).append(row)
for candidates in groups.values():
if len(candidates) < 2:
continue
for row in candidates:
if not row["sha256"]:
confirm_sha256(conn, row)
ids = [row["id"] for row in candidates]
placeholders = ",".join("?" * len(ids))
refreshed = conn.execute(
f"SELECT * FROM audio_tracks WHERE id IN ({placeholders})", ids
).fetchall()
by_sha: dict[str, list] = {}
for row in refreshed:
if row["sha256"]:
by_sha.setdefault(row["sha256"], []).append(row)
for same in by_sha.values():
if len(same) < 2:
continue
winner = choose_winner(same)
wp = Path(winner["file_path"])
if not wp.exists() or not wp.is_relative_to(root):
continue
for row in same:
if row["id"] == winner["id"]:
continue
lp = Path(row["file_path"])
if not lp.exists() or not lp.is_relative_to(root):
continue
if lp.stat().st_ino != wp.stat().st_ino:
if not dry_run:
hardlink_duplicate(lp, wp)
conn.execute("INSERT INTO operations(action,file_path,winner_path,details) VALUES(?,?,?,?)", ('exact-hardlink',str(lp),str(wp),'sha256 exact duplicate'))
conn.execute(
"UPDATE audio_tracks SET status='hardlinked',updated_at=CURRENT_TIMESTAMP WHERE id=?",
(row["id"],),
)
actions.append((str(lp), str(wp)))
return actions