mirror of
https://github.com/arsenetar/dupeguru.git
synced 2024-11-18 13:09:02 +00:00
142 lines
4.1 KiB
Python
142 lines
4.1 KiB
Python
# Copyright 2016 Virgil Dupras
|
|
#
|
|
# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
|
|
# which should be included with this package. The terms are also available at
|
|
# http://www.gnu.org/licenses/gpl-3.0.html
|
|
|
|
import os
|
|
import os.path as op
|
|
import shelve
|
|
import tempfile
|
|
from collections import namedtuple
|
|
|
|
from core.pe.cache import string_to_colors, colors_to_string
|
|
|
|
|
|
def wrap_path(path):
|
|
return f"path:{path}"
|
|
|
|
|
|
def unwrap_path(key):
|
|
return key[5:]
|
|
|
|
|
|
def wrap_id(path):
|
|
return f"id:{path}"
|
|
|
|
|
|
def unwrap_id(key):
|
|
return int(key[3:])
|
|
|
|
|
|
CacheRow = namedtuple("CacheRow", "id path blocks mtime")
|
|
|
|
|
|
class ShelveCache:
|
|
"""A class to cache picture blocks in a shelve backend."""
|
|
|
|
def __init__(self, db=None, readonly=False):
|
|
self.istmp = db is None
|
|
if self.istmp:
|
|
self.dtmp = tempfile.mkdtemp()
|
|
self.ftmp = db = op.join(self.dtmp, "tmpdb")
|
|
flag = "r" if readonly else "c"
|
|
self.shelve = shelve.open(db, flag)
|
|
self.maxid = self._compute_maxid()
|
|
|
|
def __contains__(self, key):
|
|
return wrap_path(key) in self.shelve
|
|
|
|
def __delitem__(self, key):
|
|
row = self.shelve[wrap_path(key)]
|
|
del self.shelve[wrap_path(key)]
|
|
del self.shelve[wrap_id(row.id)]
|
|
|
|
def __getitem__(self, key):
|
|
if isinstance(key, int):
|
|
skey = self.shelve[wrap_id(key)]
|
|
else:
|
|
skey = wrap_path(key)
|
|
return string_to_colors(self.shelve[skey].blocks)
|
|
|
|
def __iter__(self):
|
|
return (unwrap_path(k) for k in self.shelve if k.startswith("path:"))
|
|
|
|
def __len__(self):
|
|
return sum(1 for k in self.shelve if k.startswith("path:"))
|
|
|
|
def __setitem__(self, path_str, blocks):
|
|
blocks = colors_to_string(blocks)
|
|
if op.exists(path_str):
|
|
mtime = int(os.stat(path_str).st_mtime)
|
|
else:
|
|
mtime = 0
|
|
if path_str in self:
|
|
rowid = self.shelve[wrap_path(path_str)].id
|
|
else:
|
|
rowid = self._get_new_id()
|
|
row = CacheRow(rowid, path_str, blocks, mtime)
|
|
self.shelve[wrap_path(path_str)] = row
|
|
self.shelve[wrap_id(rowid)] = wrap_path(path_str)
|
|
|
|
def _compute_maxid(self):
|
|
return max((unwrap_id(k) for k in self.shelve if k.startswith("id:")), default=1)
|
|
|
|
def _get_new_id(self):
|
|
self.maxid += 1
|
|
return self.maxid
|
|
|
|
def clear(self):
|
|
self.shelve.clear()
|
|
|
|
def close(self):
|
|
if self.shelve is not None:
|
|
self.shelve.close()
|
|
if self.istmp:
|
|
os.remove(self.ftmp)
|
|
os.rmdir(self.dtmp)
|
|
self.shelve = None
|
|
|
|
def filter(self, func):
|
|
to_delete = [key for key in self if not func(key)]
|
|
for key in to_delete:
|
|
del self[key]
|
|
|
|
def get_id(self, path):
|
|
if path in self:
|
|
return self.shelve[wrap_path(path)].id
|
|
else:
|
|
raise ValueError(path)
|
|
|
|
def get_multiple(self, rowids):
|
|
for rowid in rowids:
|
|
try:
|
|
skey = self.shelve[wrap_id(rowid)]
|
|
except KeyError:
|
|
continue
|
|
yield (rowid, string_to_colors(self.shelve[skey].blocks))
|
|
|
|
def purge_outdated(self):
|
|
"""Go through the cache and purge outdated records.
|
|
|
|
A record is outdated if the picture doesn't exist or if its mtime is greater than the one in
|
|
the db.
|
|
"""
|
|
todelete = []
|
|
for path in self:
|
|
row = self.shelve[wrap_path(path)]
|
|
if row.mtime and op.exists(path):
|
|
picture_mtime = os.stat(path).st_mtime
|
|
if int(picture_mtime) <= row.mtime:
|
|
# not outdated
|
|
continue
|
|
todelete.append(path)
|
|
for path in todelete:
|
|
try:
|
|
del self[path]
|
|
except KeyError:
|
|
# I have no idea why a KeyError sometimes happen, but it does, as we can see in
|
|
# #402 and #439. I don't think it hurts to silently ignore the error, so that's
|
|
# what we do
|
|
pass
|