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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
|
"""
fs.wrapfs.limitsizefs
=====================
An FS wrapper class for limiting the size of the underlying FS.
This module provides the class LimitSizeFS, an FS wrapper that can limit the
total size of files stored in the wrapped FS.
"""
from __future__ import with_statement
from fs.errors import *
from fs.path import *
from fs.base import FS, threading, synchronize
from fs.wrapfs import WrapFS
from fs.filelike import FileWrapper
class LimitSizeFS(WrapFS):
"""FS wrapper class to limit total size of files stored."""
def __init__(self, fs, max_size):
super(LimitSizeFS,self).__init__(fs)
if max_size < 0:
try:
max_size = fs.getmeta("total_space") + max_size
except NoMetaError:
msg = "FS doesn't report total_size; "\
"can't use negative max_size"
raise ValueError(msg)
self.max_size = max_size
self._size_lock = threading.Lock()
self._file_sizes = PathMap()
self.cur_size = self._get_cur_size()
def __getstate__(self):
state = super(LimitSizeFS,self).__getstate__()
del state["cur_size"]
del state["_size_lock"]
del state["_file_sizes"]
return state
def __setstate__(self, state):
super(LimitSizeFS,self).__setstate__(state)
self._size_lock = threading.Lock()
self._file_sizes = PathMap()
self.cur_size = self._get_cur_size()
def _get_cur_size(self,path="/"):
return sum(self.getsize(f) for f in self.walkfiles(path))
def getsyspath(self, path, allow_none=False):
# If people could grab syspaths, they could route around our
# size protection; no dice!
if not allow_none:
raise NoSysPathError(path)
return None
def open(self, path, mode='r', buffering=-1, encoding=None, errors=None, newline=None, line_buffering=False, **kwargs):
path = relpath(normpath(path))
with self._size_lock:
try:
size = self.getsize(path)
except ResourceNotFoundError:
size = 0
f = super(LimitSizeFS,self).open(path,
mode=mode,
buffering=buffering,
errors=errors,
newline=newline,
line_buffering=line_buffering,
**kwargs)
if "w" not in mode:
self._set_file_size(path,None,1)
else:
self.cur_size -= size
size = 0
self._set_file_size(path,0,1)
return LimitSizeFile(f,mode,size,self,path)
def _set_file_size(self,path,size,incrcount=None):
try:
(cursize,count) = self._file_sizes[path]
except KeyError:
count = 0
try:
cursize = self.getsize(path)
except ResourceNotFoundError:
cursize = 0
if size is None:
size = cursize
if count is not None:
count += 1
if count == 0:
del self._file_sizes[path]
else:
self._file_sizes[path] = (size,count)
def setcontents(self, path, data, chunk_size=64*1024):
f = None
try:
f = self.open(path, 'wb')
if hasattr(data, 'read'):
chunk = data.read(chunk_size)
while chunk:
f.write(chunk)
chunk = data.read(chunk_size)
else:
f.write(data)
finally:
if f is not None:
f.close()
def _file_closed(self, path):
self._set_file_size(path,None,-1)
def _ensure_file_size(self, path, size, shrink=False):
with self._size_lock:
try:
(cur_size,_) = self._file_sizes[path]
except KeyError:
try:
cur_size = self.getsize(path)
except ResourceNotFoundError:
cur_size = 0
self._set_file_size(path,cur_size,1)
diff = size - cur_size
if diff > 0:
if self.cur_size + diff > self.max_size:
raise StorageSpaceError("write")
self.cur_size += diff
self._set_file_size(path,size)
return size
elif diff < 0 and shrink:
self.cur_size += diff
self._set_file_size(path,size)
return size
else:
return cur_size
# We force use of several base FS methods,
# since they will fall back to writing out each file
# and thus will route through our size checking logic.
def copy(self, src, dst, **kwds):
FS.copy(self,src,dst,**kwds)
def copydir(self, src, dst, **kwds):
FS.copydir(self,src,dst,**kwds)
def move(self, src, dst, **kwds):
if self.getmeta("atomic.rename",False):
if kwds.get("overwrite",False) or not self.exists(dst):
try:
self.rename(src,dst)
return
except FSError:
pass
FS.move(self, src, dst, **kwds)
def movedir(self, src, dst, **kwds):
overwrite = kwds.get("overwrite",False)
if self.getmeta("atomic.rename",False):
if kwds.get("overwrite",False) or not self.exists(dst):
try:
self.rename(src,dst)
return
except FSError:
pass
FS.movedir(self,src,dst,**kwds)
def rename(self, src, dst):
if self.getmeta("atomic.rename",False):
try:
dst_size = self._get_cur_size(dst)
except ResourceNotFoundError:
dst_size = 0
super(LimitSizeFS,self).rename(src,dst)
with self._size_lock:
self.cur_size -= dst_size
self._file_sizes.pop(src,None)
else:
if self.isdir(src):
self.movedir(src,dst)
else:
self.move(src,dst)
def remove(self, path):
with self._size_lock:
try:
(size,_) = self._file_sizes[path]
except KeyError:
size = self.getsize(path)
super(LimitSizeFS,self).remove(path)
self.cur_size -= size
self._file_sizes.pop(path,None)
def removedir(self, path, recursive=False, force=False):
# Walk and remove directories by hand, so they we
# keep the size accounting precisely up to date.
for nm in self.listdir(path):
if not force:
raise DirectoryNotEmptyError(path)
cpath = pathjoin(path,nm)
try:
if self.isdir(cpath):
self.removedir(cpath,force=True)
else:
self.remove(cpath)
except ResourceNotFoundError:
pass
super(LimitSizeFS,self).removedir(path,recursive=recursive)
def getinfo(self, path):
info = super(LimitSizeFS,self).getinfo(path)
try:
info["size"] = max(self._file_sizes[path][0],info["size"])
except KeyError:
pass
return info
def getsize(self, path):
size = super(LimitSizeFS,self).getsize(path)
try:
size = max(self._file_sizes[path][0],size)
except KeyError:
pass
return size
class LimitSizeFile(FileWrapper):
"""Filelike wrapper class for use by LimitSizeFS."""
def __init__(self, file, mode, size, fs, path):
super(LimitSizeFile,self).__init__(file,mode)
self.size = size
self.fs = fs
self.path = path
self._lock = fs._lock
@synchronize
def _write(self, data, flushing=False):
pos = self.wrapped_file.tell()
new_size = self.fs._ensure_file_size(self.path, pos+len(data))
res = super(LimitSizeFile,self)._write(data, flushing)
self.size = new_size
return res
@synchronize
def _truncate(self, size):
new_size = self.fs._ensure_file_size(self.path,size,shrink=True)
res = super(LimitSizeFile,self)._truncate(size)
self.size = new_size
return res
@synchronize
def close(self):
super(LimitSizeFile,self).close()
self.fs._file_closed(self.path)
|
