import io
import zlib
class _GzipStreamFile(object):
def __init__(self, stream):
self.stream = stream
self.decoder = None
self.restart_decoder()
###
self.unused_buffer = ''
self.closed = False
self.finished = False
def restart_decoder(self):
unused_raw = self.decoder.unused_data if self.decoder else None
self.decoder = zlib.decompressobj(16 + zlib.MAX_WBITS)
if unused_raw:
self.unused_buffer += self.decoder.decompress(unused_raw)
def read(self, size):
# TODO: Update this to use unconsumed_tail and a StringIO buffer
# http://docs.python.org/2/library/zlib.html#zlib.Decompress.unconsumed_tail
# Check if we need to start a new decoder
if self.decoder and self.decoder.unused_data:
self.restart_decoder()
# Use unused data first
if len(self.unused_buffer) > size:
part = self.unused_buffer[:size]
self.unused_buffer = self.unused_buffer[size:]
return part
# If the stream is finished and no unused raw data, return what we have
if self.stream.closed or self.finished:
self.finished = True
buf, self.unused_buffer = self.unused_buffer, ''
return buf
# Otherwise consume new data
raw = self.stream.read(io.DEFAULT_BUFFER_SIZE)
if len(raw) > 0:
self.unused_buffer += self.decoder.decompress(raw)
else:
self.finished = True
return self.read(size)
def readinto(self, b):
# Read up to len(b) bytes into bytearray b
# Sadly not as efficient as lower level
data = self.read(len(b))
if not data:
return None
b[:len(data)] = data
return len(data)
def readable(self):
# io.BufferedReader needs us to appear readable
return True
class GzipStreamFile(io.BufferedReader):
def __init__(self, stream):
self._gzipstream = _GzipStreamFile(stream)
super(GzipStreamFile, self).__init__(self._gzipstream)
def read(self, *args, **kwargs):
# Patch read to return '' instead of raise Value Error
try:
result = super(GzipStreamFile, self).read(*args, **kwargs)
return result
except ValueError:
return ''
def readline(self, *args, **kwargs):
# Patch readline to return '' instead of raise Value Error
try:
result = super(GzipStreamFile, self).readline(*args, **kwargs)
return result
except ValueError:
return ''
