Python3标准库：zlib GNUzlib压缩(3)

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Python3标准库：zlib GNUzlib压缩(3)

			 
			# Connect to the server as a client

			logger.info('Contacting server on %s:%s', ip, port)

			s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

			s.connect((ip, port))

			# Ask for a file

			requested_file = 'lorem.txt'

			logger.debug('sending filename: %r', requested_file)

			len_sent = s.send(requested_file.encode('utf-8'))

			# Receive a response

			buffer = BytesIO()

			decompressor = zlib.decompressobj()

			while True:

			response = s.recv(BLOCK_SIZE)

			if not response:

			break

			logger.debug('READ %r', binascii.hexlify(response))

			# Include any unconsumed data when

			# feeding the decompressor.

			to_decompress = decompressor.unconsumed_tail + response

			while to_decompress:

			decompressed = decompressor.decompress(to_decompress)

			if decompressed:

			logger.debug('DECOMPRESSED %r', decompressed)

			buffer.write(decompressed)

			# Look for unconsumed data due to buffer overflow

			to_decompress = decompressor.unconsumed_tail

			else:

			logger.debug('BUFFERING')

			to_decompress = None

			# deal with data reamining inside the decompressor buffer

			remainder = decompressor.flush()

			if remainder:

			logger.debug('FLUSHED %r', remainder)

			buffer.write(remainder)

			full_response = buffer.getvalue()

			lorem = open('lorem.txt', 'rb').read()

			logger.debug('response matches file contents: %s',

			full_response == lorem)

			# Clean up

			s.close()

			server.socket.close()

我们人为的将这个代码清单做了一些划分，以展示缓冲行为，如果将数据传递到compress()或decompress()，但没有得到完整的压缩或未压缩输出块，此时便会进行缓冲。

客户连接到套接字，并请求一个文件。然后循环，接收压缩数据块。由于一个块可能未包含足够多的信息来完全解压缩，所以之前接收的剩余数据将与新数据结合，并且传递到解压缩器。解压缩数据时，会把它追加到一个缓冲区，处理循环结束时将与文件内容进行比较。

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