Merge pull request #1088 from arsenetar/as/remove-shelve
feat: Remove shelve picture cachepull/1049/head
commit
a5e31f15f0
@ -1,141 +0,0 @@
|
||||
# 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
|
Loading…
Reference in New Issue