def openPersistenceFile(fileName, flags):
"""This function opens the given persistence file. When O_CREAT
was specified, the function will attempt to create the directories
too."""
if isinstance(fileName, str):
fileName = fileName.encode()
try:
fd = SecureOSFunctions.secureOpenFile(fileName, flags)
return fd
except OSError as openOsError:
if ((flags&os.O_CREAT) == 0) or (openOsError.errno != errno.ENOENT):
raise openOsError
# Find out, which directory is missing by stating our way up.
dirNameLength = fileName.rfind(b'/')
if dirNameLength > 0:
os.makedirs(fileName[:dirNameLength])
return SecureOSFunctions.secureOpenFile(fileName, flags)
def open(self, reopenFlag=False):
"""Open the given resource.
@param reopenFlag when True, attempt to reopen the same resource
and check if it differs from the previously opened one.
@raise Exception if valid logStreamFd was already provided,
is still open and reopenFlag is False.
@raise OSError when opening failed with unexpected error.
@return True if the resource was really opened or False if
opening was not yet possible but should be attempted again."""
if not reopenFlag and (self.logFileFd != -1):
raise Exception(
'Cannot reopen stream still open when not instructed to do so')
logFileFd = -1
statData = None
try:
logFileFd = SecureOSFunctions.secureOpenFile(
self.logResourceName[7:], os.O_RDONLY)
statData = os.fstat(logFileFd)
except OSError as openOsError:
if logFileFd != -1:
os.close(logFileFd)
if openOsError.errno == errno.ENOENT:
return False
raise
if not stat.S_ISREG(statData.st_mode):
os.close(logFileFd)
raise Exception('Attempting to open non-regular file %s ' \
'as file' % encodeByteStringAsString(self.logResourceName))
if (reopenFlag and (self.statData != None)
and (statData.st_ino == self.statData.st_ino)
and (statData.st_dev == self.statData.st_dev)):
# Reopening was requested, but we would reopen the file already
# opened, which is of no use.
os.close(logFileFd)
return False
# This is a new file or a successful reopen attempt.
self.logFileFd = logFileFd
self.statData = statData
return True