协议打包
# -*- coding:utf-8 -*-import structdef pack(command_id, sequence, session_id, body): """ 网络传输 @param command_id: 协议编号 @param sequence: 序列号 @param session_id: @param body: 包体,str类型 @return: 二进制串 """ header_size, header_data = pack_header(command_id, sequence, session_id) body_size, body_data = pack_body(body) size = header_size + body_size data = struct.pack('!I', size) + header_data + body_data return datadef pack_header(command_id, sequence, session_id): """ 包头 """ if isinstance(session_id, unicode): session_id.encode('utf-8') fmt = '!IIB%ds' % len(session_id) header_size = struct.calcsize(fmt) data = struct.pack(fmt, command_id, sequence, len(session_id), session_id) return header_size, datadef pack_body(body): """ 包体 """ fmt = '!H%ds' % len(body) body_size = struct.calcsize(fmt) data = struct.pack(fmt, len(body), body) return body_size, data def unpack(data): """ 解包 """ command_id, sequence, session_id, data = unpack_header(data) body = unpack_body(data) return command_id, sequence, session_id, bodydef unpack_size(data): """ 总长度 """ (size,) = struct.unpack('!i', data) return sizedef unpack_header(data): """ 包头 """ (command_id,), data = struct.unpack('!I', data[:4]), data[4:] (sequence,), data = struct.unpack('!I', data[:4]), data[4:] (session_size,), data = struct.unpack('!B', data[:1]), data[1:] (session_id,), data = struct.unpack('!%ds' % (session_size), data[:session_size]), data[session_size:] return command_id, sequence, session_id, datadef unpack_body(data): """ 包体 """ (body_size,), data = struct.unpack('!H', data[:2]), data[2:] (body,) = struct.unpack('!%ds' % (body_size,), data) if isinstance(body, unicode): body.encode('utf-8') return body?