# encoding_chunked, amitp@cs.stanford.edu, March 2000## Deal with Transfer-encoding: chunked [HTTP/1.1]# TEST CASE:#    http://www.apache.org/from proxy4_base import *class UnchunkStream:    # States:    #   if bytes_remaining is None:    #      we're in the "need chunk size" state    #   else:    #      we're reading up to bytes_remaining elements of data    def __init__(self):        self.buffer = ''        self.bytes_remaining = None        self.closed = 0            def decode(self, string):        self.buffer = self.buffer + string        string = ''        while self.buffer and not self.closed:            # Keep looking for alternating chunk lengths and chunk content                        if self.bytes_remaining is None:                # We want to find a chunk length                i = find(self.buffer, '\n')                if i >= 0:                    # We have a line; let's hope it's a chunk length                    line = strip(self.buffer[:i])                    # Remove this line from the buffer                    self.buffer = self.buffer[i+1:]                    if line:                        # NOTE: chunklen can be followed by r";.*"                        self.bytes_remaining = atoi(line, 16) # chunklen is hex                        print 'chunk len:', color(2, self.bytes_remaining)                        if self.bytes_remaining == 0:                            # End of stream                            self.closed = 1                            # NOTE: at this point, we should read                             # footers until we get to a blank line                else:                    break                            if self.bytes_remaining is not None:                # We know how many bytes we need                data = self.buffer[:self.bytes_remaining]                string = string + data                self.buffer = self.buffer[self.bytes_remaining:]                self.bytes_remaining = self.bytes_remaining - len(data)                assert self.bytes_remaining >= 0                if self.bytes_remaining == 0:                    # We reached the end of the chunk                    self.bytes_remaining = None                            return string    def flush(self):        string = self.buffer        self.buffer = ''        return string