1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
# -*- Mode: Python -*-
# GObject-Introspection - a framework for introspecting GObject libraries
# Copyright (C) 2008-2010 Johan Dahlin
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
#
import errno
import glob
import hashlib
import os
import shutil
import sys
import tempfile
import pickle
import giscanner
from . import utils
_CACHE_VERSION_FILENAME = '.cache-version'
def _get_versionhash():
toplevel = os.path.dirname(giscanner.__file__)
sources = glob.glob(os.path.join(toplevel, '*.py'))
sources.append(sys.argv[0])
# Using mtimes is a bit (5x) faster than hashing the file contents
mtimes = (str(os.stat(source).st_mtime) for source in sources)
# ASCII encoding is sufficient since we are only dealing with numbers.
return hashlib.sha1(''.join(mtimes).encode('ascii')).hexdigest()
class CacheStore(object):
def __init__(self):
self._directory = self._get_cachedir()
self._check_cache_version()
def _get_cachedir(self):
if 'GI_SCANNER_DISABLE_CACHE' in os.environ:
return None
else:
cachedir = utils.get_user_cache_dir('g-ir-scanner')
return cachedir
def _check_cache_version(self):
if self._directory is None:
return
current_hash = _get_versionhash()
version = os.path.join(self._directory, _CACHE_VERSION_FILENAME)
try:
with open(version, 'r', encoding='utf-8') as version_file:
cache_hash = version_file.read()
except (IOError, OSError) as e:
# File does not exist
if e.errno == errno.ENOENT:
cache_hash = 0
else:
raise
if current_hash == cache_hash:
return
self._clean()
tmp_fd, tmp_filename = tempfile.mkstemp(prefix='g-ir-scanner-cache-version-')
try:
with os.fdopen(tmp_fd, 'w', encoding='utf-8') as tmp_file:
tmp_file.write(current_hash)
# On Unix, this would just be os.rename() but Windows
# doesn't allow that.
shutil.move(tmp_filename, version)
except (IOError, OSError) as e:
# Permission denied
if e.errno == errno.EACCES:
return
else:
raise
def _get_filename(self, filename):
# If we couldn't create the directory we're probably
# on a read only home directory where we just disable
# the cache all together.
if self._directory is None:
return
# Assume UTF-8 encoding for the filenames. This doesn't matter so much
# as long as the results of this method always produce the same hash.
hexdigest = hashlib.sha1(filename.encode('utf-8')).hexdigest()
return os.path.join(self._directory, hexdigest)
def _cache_is_valid(self, store_filename, filename):
try:
store_mtime = os.stat(store_filename).st_mtime
except FileNotFoundError:
return False
return store_mtime >= os.stat(filename).st_mtime
def _remove_filename(self, filename):
try:
os.unlink(filename)
except (IOError, OSError) as e:
# Ignore "permission denied", "file does not exist"
if e.errno in (errno.EACCES, errno.ENOENT):
return
else:
raise
def _clean(self):
for filename in os.listdir(self._directory):
if filename == _CACHE_VERSION_FILENAME:
continue
self._remove_filename(os.path.join(self._directory, filename))
def store(self, filename, data):
store_filename = self._get_filename(filename)
if store_filename is None:
return
if self._cache_is_valid(store_filename, filename):
return None
tmp_fd, tmp_filename = tempfile.mkstemp(prefix='g-ir-scanner-cache-')
try:
with os.fdopen(tmp_fd, 'wb') as tmp_file:
pickle.dump(data, tmp_file)
except (IOError, OSError) as e:
# No space left on device
if e.errno == errno.ENOSPC:
self._remove_filename(tmp_filename)
return
else:
raise
try:
shutil.move(tmp_filename, store_filename)
except (IOError, OSError) as e:
# Permission denied
if e.errno == errno.EACCES:
self._remove_filename(tmp_filename)
else:
raise
def load(self, filename):
store_filename = self._get_filename(filename)
if store_filename is None:
return
try:
fd = open(store_filename, 'rb')
except (IOError, OSError) as e:
if e.errno == errno.ENOENT:
return None
else:
raise
with fd:
if not self._cache_is_valid(store_filename, filename):
return None
try:
data = pickle.load(fd)
except Exception:
# Broken cache entry, remove it
self._remove_filename(store_filename)
data = None
return data
|
