import struct import zlib class GzipDecompressor(object): """An interface to gzip which is similar to bz2.BZ2Decompressor and lzma.LZMADecompressor.""" def __init__(self): self.inbuffer = b"" self.decompressor = None def decompress(self, data): """ @raises ValueError: if no gzip magic is found @raises zlib.error: from zlib invocations """ while True: if self.decompressor: data = self.decompressor.decompress(data) unused_data = self.decompressor.unused_data if not unused_data: return data self.decompressor = None return data + self.decompress(unused_data) self.inbuffer += data skip = 10 if len(self.inbuffer) < skip: return b"" if not self.inbuffer.startswith(b"\037\213\010"): raise ValueError("gzip magic not found") flag = ord(self.inbuffer[3]) if flag & 4: if len(self.inbuffer) < skip + 2: return b"" length, = struct.unpack("= length: ret = self.buff[:length] self.buff = self.buff[length:] return ret elif not data: # read EOF in last iteration ret = self.buff self.buff = b"" return ret data = self.fileobj.read(self.blocksize) if data: self.buff += self.decompressor.decompress(data) else: self.buff += self.decompressor.flush()