def load(filename, gzip=False, lock=None, timeout=None):
"""
Unpickle an object from filename
@param filename: Filename pickled object
@param gzip: Use gzip to uncompress the file
@type gzip: Boolean
@param lock: Use a lockfile to restrict access
@return: Python object unpickled from file
"""
## file locked?
filename = os.path.expanduser(filename)
if lock is not None:
lockdir = filename + '.lock'
if timeout is not None and timeout > 0:
end_time = timeout + time.time()
while True:
try:
os.mkdir(lockdir)
except OSError as e:
# File is already locked
if e.errno == errno.EEXIST:
if timeout is not None and time.time() > end_time:
raise IOError("Failed to acquire Lock")
else:
raise IOError("Failed to acquire Lock")
else:
break
if gzip:
import gzip
stream = gzip.GzipFile(filename)
try:
stream.readline()
stream.seek(0)
except:
stream.close()
raise
else:
stream = open(filename, 'rb')
try:
this = Pickle.load(stream)
except:
stream.close()
import Numeric #@UnresolvedImport
try:
stream = gzip.GzipFile(filename)
except:
stream = open(filename, 'rb')
try:
unpickler = Numeric.Unpickler(stream)
this = unpickler.load()
except:
stream.close()
raise
stream.close()
if lock is not None:
## release lock
try:
os.rmdir(lockdir)
except:
raise IOError('missing lockfile {0}'.format(lockdir))
return this
