import time
import shutil
import os
-import types
import __builtin__
-_open = __builtin__.open # avoid name clash
-
keep_all_files = 00000
ignore_corrupt_dbfiles = 0
-if hasattr(types, 'UnicodeType'):
+def corruption_warning(filename):
+ print "Warning: Discarding corrupt database:", filename
+
+try: unicode
+except NameError:
def is_string(s):
- t = type(s)
- return t is types.StringType or t is types.UnicodeType
+ return isinstance(s, str)
else:
def is_string(s):
- return type(s) is types.StringType
+ return type(s) in (str, unicode)
try:
unicode('a')
except NameError:
def unicode(s): return s
+dblite_suffix = '.dblite'
+tmp_suffix = '.tmp'
+
class dblite:
+ # Squirrel away references to the functions in various modules
+ # that we'll use when our __del__() method calls our sync() method
+ # during shutdown. We might get destroyed when Python is in the midst
+ # of tearing down the different modules we import in an essentially
+ # arbitrary order, and some of the various modules's global attributes
+ # may already be wiped out from under us.
+ #
+ # See the discussion at:
+ # http://mail.python.org/pipermail/python-bugs-list/2003-March/016877.html
+
+ _open = __builtin__.open
+ _cPickle_dump = cPickle.dump
+ _os_chmod = os.chmod
+ try:
+ _os_chown = os.chown
+ except AttributeError:
+ _os_chown = None
+ _os_rename = os.rename
+ _os_unlink = os.unlink
+ _shutil_copyfile = shutil.copyfile
+ _time_time = time.time
+
def __init__(self, file_base_name, flag, mode):
assert flag in (None, "r", "w", "c", "n")
if (flag is None): flag = "r"
- if file_base_name[-7:] != '.dblite':
- file_base_name = file_base_name + '.dblite'
- self._file_name = file_base_name
+ base, ext = os.path.splitext(file_base_name)
+ if ext == dblite_suffix:
+ # There's already a suffix on the file name, don't add one.
+ self._file_name = file_base_name
+ self._tmp_name = base + tmp_suffix
+ else:
+ self._file_name = file_base_name + dblite_suffix
+ self._tmp_name = file_base_name + tmp_suffix
self._flag = flag
self._mode = mode
self._dict = {}
self._needs_sync = 00000
+ if self._os_chown is not None and (os.geteuid()==0 or os.getuid()==0):
+ # running as root; chown back to current owner/group when done
+ try:
+ statinfo = os.stat(self._file_name)
+ self._chown_to = statinfo.st_uid
+ self._chgrp_to = statinfo.st_gid
+ except OSError, e:
+ # db file doesn't exist yet.
+ # Check os.environ for SUDO_UID, use if set
+ self._chown_to = int(os.environ.get('SUDO_UID', -1))
+ self._chgrp_to = int(os.environ.get('SUDO_GID', -1))
+ else:
+ self._chown_to = -1 # don't chown
+ self._chgrp_to = -1 # don't chgrp
if (self._flag == "n"):
- _open(self._file_name, "wb", self._mode)
+ self._open(self._file_name, "wb", self._mode)
else:
try:
- f = _open(self._file_name, "rb")
+ f = self._open(self._file_name, "rb")
except IOError, e:
if (self._flag != "c"):
raise e
- _open(self._file_name, "wb", self._mode)
+ self._open(self._file_name, "wb", self._mode)
else:
p = f.read()
if (len(p) > 0):
try:
self._dict = cPickle.loads(p)
- except:
+ except (cPickle.UnpicklingError, EOFError):
if (ignore_corrupt_dbfiles == 0): raise
if (ignore_corrupt_dbfiles == 1):
- print "Warning: Discarding corrupt database:", self._file_name
+ corruption_warning(self._file_name)
def __del__(self):
if (self._needs_sync):
def sync(self):
self._check_writable()
- f = _open(self._file_name, "wb", self._mode)
- cPickle.dump(self._dict, f, 1)
+ f = self._open(self._tmp_name, "wb", self._mode)
+ self._cPickle_dump(self._dict, f, 1)
f.close()
+ # Windows doesn't allow renaming if the file exists, so unlink
+ # it first, chmod'ing it to make sure we can do so. On UNIX, we
+ # may not be able to chmod the file if it's owned by someone else
+ # (e.g. from a previous run as root). We should still be able to
+ # unlink() the file if the directory's writable, though, so ignore
+ # any OSError exception thrown by the chmod() call.
+ try: self._os_chmod(self._file_name, 0777)
+ except OSError: pass
+ self._os_unlink(self._file_name)
+ self._os_rename(self._tmp_name, self._file_name)
+ if self._os_chown is not None and self._chown_to > 0: # don't chown to root or -1
+ try:
+ self._os_chown(self._file_name, self._chown_to, self._chgrp_to)
+ except OSError:
+ pass
self._needs_sync = 00000
if (keep_all_files):
- shutil.copyfile(
+ self._shutil_copyfile(
self._file_name,
- self._file_name + "_" + str(int(time.time())))
+ self._file_name + "_" + str(int(self._time_time())))
def _check_writable(self):
if (self._flag == "r"):
if (__name__ == "__main__"):
_exercise()
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
projects / scons.git / blobdiff