zip-stream.py

import zlib


class ZipStream(object):
    GZIP_MAGIC = 32 + zlib.MAX_WBITS
    CHUNK_SIZE = 4 * 4096

    def __init__(self, f):
        self.decompress = zlib.decompressobj(self.GZIP_MAGIC)
        self.file = f
        self.buffer = ""

    def read(self, bytes):

        # fill decompress obj
        while len(self.buffer) < bytes:
            chunk = self.file.read(self.CHUNK_SIZE)
            if not chunk:
                self.buffer += self.decompress.flush()
                break
            self.buffer += self.decompress(chunk)

        rv = self.buffer[:bytes]
        self.buffer = self.buffer[bytes:]

        return rv