file function but found a head bug

mswp.py

@@ -1,6 +1,3 @@
-from config import jsondata
-
-
 class Datapack:
     def __init__(self, method='post', app='all', version='msw/1.0', head={}, body=b'', check_head=True):
         self.method = method
@@ -22,6 +19,7 @@ class Datapack:
         self.encode_data = first_line + b'\n' + heads + b'\n' + self.body
 
     def decode(self, only_head=False):
+        self.head = {}
         index = self.encode_data.index(b'\n\n')
         upper = self.encode_data[:index]
         if not only_head:
@@ -37,10 +35,3 @@ class Datapack:
             self.head[i] = ii
         if only_head:
             return self.encode_data[index+2:]
-
-        
-def split_dp_data(data):
-    pass
-
-
-

plugins/net.py

@@ -1,7 +1,7 @@
 import threading
 import socket
 import queue
-import time
+import copy
 from mswp import Datapack
 from forwarder import receive_queues, send_queue
 from config import jsondata
@@ -72,7 +72,7 @@ class Netrecv:
         data = b''
         while True:
             new_data = conn.recv(RECV_BUFF)
-            if not new_data:
+            if not new_data and not data:
                 conn.close()
                 print('return 1')
                 return
@@ -81,11 +81,13 @@ class Netrecv:
             while True:
 
                 # try unpack #
-                dp = Datapack(check_head=False)
+                dp = copy.copy(Datapack(check_head=False))
                 dp.encode_data = data
+                print('data', data)
                 try:
                     if data:
                         data = dp.decode(only_head=True)
+                        print('decode success')
                     else:
                         print('Null data')
                         break
@@ -95,8 +97,48 @@ class Netrecv:
                 # try unpack #
 
                 if dp.method == 'file':
-                    pass
-                else:
+                    length = int(dp.head['length'])
+                    data_length = len(data)
+
+                    # 3 condition
+                    if length == data_length:
+                        file = open(dp.head['filename'], 'wb')
+                        file.write(data)
+                        data = b''
+                        # return package needed
+
+                    elif length > data_length:
+                        file = open(dp.head['filename'], 'wb')
+                        aleady_write_down = 0
+                        file.write(data)
+                        aleady_write_down += len(data)
+                        data = b''
+
+                        while aleady_write_down < length:
+                            new_data = conn.recv(RECV_BUFF)
+                            if not new_data:
+                                print('return 22')
+                                return
+
+                            new_data_size = len(new_data)
+                            still_need = length - aleady_write_down
+                            print(still_need)
+
+                            if new_data_size == still_need:  # 3 condition of new_data
+                                print('right')
+                                file.write(new_data)
+                                aleady_write_down += new_data_size
+
+                            elif new_data_size < still_need:
+                                file.write(new_data)
+                                aleady_write_down += new_data_size
+
+                            elif new_data_size > still_need:
+                                file.write(new_data[:still_need])
+                                aleady_write_down += still_need
+                                data = new_data[still_need:]
+
+                else:  # dp.method is not 'file'
                     length = int(dp.head['length'])
                     data_length = len(data)
 
@@ -146,41 +188,6 @@ class Netrecv:
                     dp.encode()
                     print('###############\n' + dp.encode_data.decode() + '\n###############')
 
-    def _process_connection(self, conn, addr):
-        print('Connection accpet %s' % str(addr))
-        data = b''
-        need_data = False
-        while True:
-            new_data = conn.recv(RECV_BUFF)  # here needs to check whether the package is continued
-            if not new_data:
-                conn.close()
-                return
-            data += new_data
-            while True:  # process sticky package
-                if not data:
-                    break
-                dp = Datapack(check_head=False)
-                dp.encode_data = data
-                try:
-                    if not need_data:
-                        data = dp.decode(only_head=True)
-                except Exception as e:  # check head
-                    print('Decode error %s: %s' % (type(e), str(e)))
-                    print('Stop and start to receive more data')
-                    break
-                length = int(dp.head['length'])
-                data_length = len(data)
-                if length < data_length:
-                    dp.body = data[:length]
-                    data = data[length:]
-                    need_data = False
-                    continue
-                elif length > data_length:
-                    need_data = True
-
-                dp.encode()
-                print('---------------\n'+dp.encode_data.decode()+'\n---------------')
-
 
 class Netlist:  # contain net list and network controller
     def __init__(self):

test_file.py

@@ -4,14 +4,15 @@ import time
 data = '''post log msw/1.0
 from: network
 flag: abcdefgh
+filename: download.txt
 num: 1/1
-length: 9
+length: 5
 
-12345'''
+123'''
 
-data2 = '''678'''
+data2 = '''4'''
 
-data3 = '''9'''
+data3 = '''5'''
 
 data4 = '''post log msw/1.1
 from: network
@@ -21,7 +22,7 @@ length: 3
 
 abc'''
 
-data_list = [data, data2, data3, data4]
+data_list = [data,data2,data3,data4]
 code_list = []
 for i in data_list:
     code_list.append(i.encode())