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
|
"""Temporary files and filenames."""
# XXX This tries to be not UNIX specific, but I don't know beans about
# how to choose a temp directory or filename on MS-DOS or other
# systems so it may have to be changed...
import os
__all__ = ["mktemp", "TemporaryFile", "tempdir", "gettempprefix"]
# Parameters that the caller may set to override the defaults
tempdir = None
template = None
def gettempdir():
"""Function to calculate the directory to use."""
global tempdir
if tempdir is not None:
return tempdir
try:
pwd = os.getcwd()
except (AttributeError, os.error):
pwd = os.curdir
attempdirs = ['/tmp', '/var/tmp', '/usr/tmp', pwd]
if os.name == 'nt':
attempdirs.insert(0, 'C:\\TEMP')
attempdirs.insert(0, '\\TEMP')
elif os.name == 'mac':
import macfs, MACFS
try:
refnum, dirid = macfs.FindFolder(MACFS.kOnSystemDisk,
MACFS.kTemporaryFolderType, 1)
dirname = macfs.FSSpec((refnum, dirid, '')).as_pathname()
attempdirs.insert(0, dirname)
except macfs.error:
pass
for envname in 'TMPDIR', 'TEMP', 'TMP':
if os.environ.has_key(envname):
attempdirs.insert(0, os.environ[envname])
testfile = gettempprefix() + 'test'
for dir in attempdirs:
try:
filename = os.path.join(dir, testfile)
if os.name == 'posix':
try:
fd = os.open(filename,
os.O_RDWR | os.O_CREAT | os.O_EXCL, 0700)
except OSError:
pass
else:
fp = os.fdopen(fd, 'w')
fp.write('blat')
fp.close()
os.unlink(filename)
del fp, fd
tempdir = dir
break
else:
fp = open(filename, 'w')
fp.write('blat')
fp.close()
os.unlink(filename)
tempdir = dir
break
except IOError:
pass
if tempdir is None:
msg = "Can't find a usable temporary directory amongst " + `attempdirs`
raise IOError, msg
return tempdir
# template caches the result of gettempprefix, for speed, when possible.
# XXX unclear why this isn't "_template"; left it "template" for backward
# compatibility.
if os.name == "posix":
# We don't try to cache the template on posix: the pid may change on us
# between calls due to a fork, and on Linux the pid changes even for
# another thread in the same process. Since any attempt to keep the
# cache in synch would have to call os.getpid() anyway in order to make
# sure the pid hasn't changed between calls, a cache wouldn't save any
# time. In addition, a cache is difficult to keep correct with the pid
# changing willy-nilly, and earlier attempts proved buggy (races).
template = None
# Else the pid never changes, so gettempprefix always returns the same
# string.
elif os.name == "nt":
template = '~' + `os.getpid()` + '-'
elif os.name == 'mac':
template = 'Python-Tmp-'
else:
template = 'tmp' # XXX might choose a better one
def gettempprefix():
"""Function to calculate a prefix of the filename to use.
This incorporates the current process id on systems that support such a
notion, so that concurrent processes don't generate the same prefix.
"""
global template
if template is None:
return '@' + `os.getpid()` + '.'
else:
return template
def mktemp(suffix=""):
"""User-callable function to return a unique temporary file name."""
dir = gettempdir()
pre = gettempprefix()
while 1:
i = _counter.get_next()
file = os.path.join(dir, pre + str(i) + suffix)
if not os.path.exists(file):
return file
class TemporaryFileWrapper:
"""Temporary file wrapper
This class provides a wrapper around files opened for temporary use.
In particular, it seeks to automatically remove the file when it is
no longer needed.
"""
def __init__(self, file, path):
self.file = file
self.path = path
def close(self):
self.file.close()
os.unlink(self.path)
def __del__(self):
try: self.close()
except: pass
def __getattr__(self, name):
file = self.__dict__['file']
a = getattr(file, name)
if type(a) != type(0):
setattr(self, name, a)
return a
def TemporaryFile(mode='w+b', bufsize=-1, suffix=""):
"""Create and return a temporary file (opened read-write by default)."""
name = mktemp(suffix)
if os.name == 'posix':
# Unix -- be very careful
fd = os.open(name, os.O_RDWR|os.O_CREAT|os.O_EXCL, 0700)
try:
os.unlink(name)
return os.fdopen(fd, mode, bufsize)
except:
os.close(fd)
raise
else:
# Non-unix -- can't unlink file that's still open, use wrapper
file = open(name, mode, bufsize)
return TemporaryFileWrapper(file, name)
# In order to generate unique names, mktemp() uses _counter.get_next().
# This returns a unique integer on each call, in a threadsafe way (i.e.,
# multiple threads will never see the same integer). The integer will
# usually be a Python int, but if _counter.get_next() is called often
# enough, it will become a Python long.
# Note that the only name that survives this next block of code
# is "_counter".
class _ThreadSafeCounter:
def __init__(self, mutex, initialvalue=0):
self.mutex = mutex
self.i = initialvalue
def get_next(self):
self.mutex.acquire()
result = self.i
try:
newi = result + 1
except OverflowError:
newi = long(result) + 1
self.i = newi
self.mutex.release()
return result
try:
import thread
except ImportError:
class _DummyMutex:
def acquire(self):
pass
release = acquire
_counter = _ThreadSafeCounter(_DummyMutex())
del _DummyMutex
else:
_counter = _ThreadSafeCounter(thread.allocate_lock())
del thread
del _ThreadSafeCounter
|
