• Python边学边用BT客户端实现之(三)Peer协议设计


    与peer建立tcp连接后,首先发送handshake消息进行握手

    handshake消息格式如下:

    一个字节0x19 + 一个字符串'BitTorrent protocol' + 8 byte 保留字节默认值为0(draft中对保留字节有定义)

    + 种子文件中info 部分的sha1字,大小为20个字节 + 20个自己的peer id(从tracker获取到的peer信息大多没有peerid,这个可以使用本地的peer id)

    如果handshake信息协商不上,tcp连接将被关闭。

     

    BT标准BEP-3中定义了8种peer消息:消息格式为msg_len(4个字节) + msg_type(1一个字节) + payload

    0 - choke  --发送该消息表示本段发送阻塞,对端将不能获取到piece数据,payload 为 0

    1 - unchoke  --发送该消息表示解阻塞,对端可以开始发送请求获取piece数据,payload 为 0

    2 - interested  --发送该消息,表示对对端的pieces数据有兴趣,payload 为 0

    3 - not interested  ---发送该消息,表示对对端的pieces数据没有兴趣了,payload 为 0

    4 - have       ---发送该消息,通告对端 本段拥有的pieces,payload为4个字节的piece index

    5 - bitfield  ---发送该消息,通告对端 本段拥有的pieces,为bit map的方式表示每个piece index在本端是否拥有。piece index所在bit位为1,表示拥有。

                         该消息为handshake成功后的第一个消息。

    6 - request   ---piece请求消息,payload为: index, begin, and length,都是4个字节表示,length一般实现为0x8000, 最大不能超过0x20000。

    7 - piece     ---piece  数据,payload为: index, begin,data 

    8 - cancel    ---发送该消息,表示本端取消了某个piece请求。payload为:index, begin, and length

    使用python的异步socket接口实现,为了减少处理过程被socket阻塞,使用多个线程处理每个peer。

    每个peer包括3个线程:request timeout timer ,socket send data thread, socket receive data thread,使用select 函数判断socket是否可读、可写。

    对socket读写操作时使用RLock进行保护,select阻塞进程时不加锁,避免阻塞其他线程。

    发送数据数据时先写一个队列,然后通过set threading.Event 变量出发socket send data thread发送数据,保证发送数据的线程不阻塞

    由于 python没有结束线程的接口,socket send data thread, socket receive data thread 需要依赖特殊变量的赋值,使socket处理进程结束。

    使用同步调用来触发下载过程运转,尽量不使用timer轮询的方式,可以降低cpu使用率并加快下载过程。

    但是,多线程间的同步调用由于锁的存在,会导致性能下降并容易引入信号量死锁的问题。需要仔细设计好多线程的运行轨迹避免死锁。

    draft BEP中定义的功能暂未实现,peer的上传流控未实现,peer质量分级未实现。

    PeerConnect
      1 '''
      2 Created on 2012-10-3
      3 
      4 @author: ddt
      5 '''
      6 from socket import *
      7 import threading
      8 import log_info
      9 import select
     10 
     11 class PeerConnect(object):
     12     '''
     13     TODO: upload flow control
     14     TODO: peer quality management
     15     '''
     16     def __init__(self, ip, port, task_info):
     17         '''
     18         Constructor
     19         '''
     20         self.__ip = ip
     21         self.__port = port
     22         
     23         self.__info_hash = task_info.get_info_hash()
     24         self.__local_id = task_info.get_local_id()
     25         self.__task_info = task_info
     26         
     27         leading_string = chr(19)+'BitTorrent protocol'
     28         reserved_string = chr(0)*8
     29         self.__handshake_info = leading_string + reserved_string 
     30         self.__handshake_info += self.__info_hash + self.__local_id
     31     
     32         self.__request_piece_len = 0x4000
     33         self.__receive_data_len = 0x8000
     34         
     35         self.__tcp_con = None
     36         self.__tcp_connect_timeout = 60
     37         
     38         self.__tcp_handshake_timeout = 60
     39         
     40         self.__keepalive_timer = None
     41         self.__sck_send_thread = None
     42         
     43         self.__retry_timer = None
     44         self.__retry_intvl = 2 # second
     45         self.__retry_times = 0
     46         self.__max_retrys = 10
     47         
     48         self.__local_choked = True
     49         self.__peer_choked = True
     50         self.__local_interested = False
     51         self.__peer_interested = False
     52         
     53         self.__peer_have_pieces = []
     54 
     55     
     56         self.__local_requesting = False;
     57         self.__local_requesting_pieces = []
     58         self.__local_max_requesting = 10
     59         self.__local_requesting_timer = None
     60         self.__local_requesting_timeout_intvl = 30
     61             
     62         self.__receiving_cache = ''
     63     
     64         self.__peer_pending_request = []
     65         self.__local_pending_request = []
     66         
     67         self.__local_pending_request_less = 10
     68         self.__peer_have_pieces_pending = []
     69         
     70         self.__local_sending_queue = None
     71         self.__rlock_sck_send = threading.RLock() 
     72         self.__local_sending_event = threading.Event()
     73         self.__min_sck_send_msg = 0x1000
     74         
     75         self.__rlock_common = threading.RLock()
     76         
     77         self.__peer_started = False
     78         
     79         self.__peer_choked_timer = None
     80         self.__peer_choked_timeout_intvl = 180
     81         
     82         self.__dispatch_timer = None
     83         self.__dispatch_timeout = 5
     84 
     85     def start(self):
     86         with self.__rlock_common:
     87             if not self.__peer_started:
     88                 self.__retry_times = 0
     89                 self.__startup_thread = threading.Thread(target=PeerConnect.__connect,args=(self,))
     90                 self.__peer_started = True
     91                 self.__startup_thread.start()
     92     
     93     def stop(self):
     94         with self.__rlock_common:
     95             if self.__peer_started:
     96                 self.__retry_times = self.__max_retrys
     97                 self.__disconnect()
     98                 self.__peer_started = False
     99         pass
    100 
    101     def dispatch_pieces(self,pieces, piece_len):
    102         
    103         with self.__rlock_common:
    104         
    105             self.__write_log(str(pieces))
    106             self.__write_log(str(self.__peer_have_pieces))
    107             
    108             if len(pieces) == 0:
    109                 return False
    110             
    111             for piece_index in pieces:
    112                 if piece_index not in self.__peer_have_pieces:
    113                     return False 
    114                  
    115             for piece_index in pieces:       
    116                 for offset in range(0, piece_len, self.__request_piece_len):
    117                     length = self.__request_piece_len
    118                     if offset+length > piece_len:
    119                         length = piece_len - offset
    120                     piece = (piece_index, offset, length)
    121                     if piece not in self.__local_pending_request:
    122                         self.__local_pending_request.append(piece)
    123             
    124             if self.__dispatch_timer != None:
    125                 self.__dispatch_timer.cancel()
    126             
    127             self.__check_local_request()
    128             
    129             if self.__peer_choked:
    130                 if self.__peer_choked_timer == None or not self.__peer_choked_timer.is_alive():
    131                     self.__peer_choked_timer = threading.Timer(self.__peer_choked_timeout_intvl, PeerConnect.__peer_choked_timeout, [self,])
    132                     self.__peer_choked_timer.start()
    133         
    134             
    135         return True
    136     
    137     def cancel_pieces(self, pieces):
    138         with self.__rlock_common:
    139             for piece in self.__local_pending_request:
    140                 if piece[0] in pieces:
    141                     self.__local_pending_request.remove(piece)
    142                     
    143             if self.__local_requesting:
    144                 for piece in self.__local_requesting_pieces:
    145                     if piece[0] in pieces:
    146                         self.__send_cancel(piece)
    147                         self.__local_requesting_pieces.remove(piece)
    148                 if len(self.__local_requesting_pieces) == 0:
    149                     self.__local_requesting = False
    150                     if self.__local_requesting_timer != None:
    151                         self.__local_requesting_timer.cancel()       
    152                 self.__check_local_request()
    153 
    154         
    155     def set_choke_state(self, choked):
    156         with self.__rlock_common:
    157             if self.__local_choked != choked:
    158                 if choked:
    159                     self.__send_choked()
    160                 else:
    161                     self.__send_unchoked()
    162                     self.__check_peer_request()
    163             pass
    164         
    165     def get_peer_have_pieces(self):
    166         with self.__rlock_common:
    167             return self.__peer_have_pieces
    168     
    169     def notify_local_have_pieces(self, pieces):
    170         with self.__rlock_common:
    171             self.__send_have(pieces)
    172          
    173     def is_dead_peer(self):
    174         with self.__rlock_common:
    175             return  self.__retry_times > self.__max_retrys
    176     
    177     def get_local_pending_pieces(self):
    178         with self.__rlock_common:
    179             pieces_index = []
    180             for piece in self.__local_pending_request:
    181                 if piece[0] not in pieces_index:
    182                     pieces_index.append(piece[0])
    183             if self.__local_requesting:
    184                 for piece in self.__local_requesting_pieces: 
    185                     if piece[0] not in pieces_index:
    186                         pieces_index.append(piece[0])
    187 
    188         return pieces_index
    189     
    190     def get_peer_addr(self):
    191         return (self.__ip, self.__port)
    192         
    193     def __connect(self):
    194 
    195         self.__tcp_con = socket(AF_INET, SOCK_STREAM)
    196         self.__tcp_con.settimeout(self.__tcp_connect_timeout)
    197 
    198         try:
    199             self.__tcp_con.connect((self.__ip,self.__port))
    200         except error , e:
    201             self.__write_log('peer connect error: %s, retry' %e)
    202             self.__retry_connect()
    203             return
    204         
    205         self.__tcp_con.settimeout(None)
    206         
    207         self.__start_send_proc()
    208 
    209         if not self.__handshake():
    210             self.__retry_connect()
    211             return
    212         
    213         self.__send_bitfield()
    214         self.__send_unchoked()
    215         self.__start_keepalive_timer()      
    216 
    217         self.__recv_loop()
    218     pass
    219 
    220     def __disconnect(self):
    221         self.__write_log('__disconnect:begin')
    222         
    223         if self.__retry_timer != None:
    224             self.__retry_timer.cancel()
    225         
    226         if self.__keepalive_timer != None:
    227             self.__keepalive_timer.cancel()
    228             
    229         if self.__local_sending_queue != None:
    230             self.__local_sending_queue = None
    231             self.__local_sending_event.set()
    232             
    233         if self.__peer_choked_timer != None:
    234             self.__peer_choked_timer.cancel()
    235             
    236         if self.__dispatch_timer != None:
    237             self.__dispatch_timer.cancel()    
    238 
    239         
    240         if self.__local_requesting:
    241             self.__local_requesting = False
    242             self.__local_pending_request = self.__local_requesting_pieces + self.__local_pending_request
    243             self.__local_requesting_pieces = []
    244             if self.__local_requesting_timer != None:
    245                 self.__local_requesting_timer.cancel()
    246         
    247         self.__tcp_con.close()
    248         self.__write_log('__disconnect: self.__tcp_con.closed')
    249         
    250         self.__receiving_cache = ''
    251         
    252         self.__local_choked = True
    253         self.__peer_choked = True
    254         self.__local_interested = False
    255         self.__peer_interested = False
    256         self.__local_requesting_pieces = []
    257         self.__peer_pending_request = []
    258         self.__peer_have_pieces = []
    259         self.__peer_have_pieces_pending = []
    260         pass
    261     
    262     def __start_keepalive_timer(self):
    263         if self.__keepalive_timer != None:
    264             self.__keepalive_timer.cancel()
    265         self.__keepalive_timer = threading.Timer(120,PeerConnect.__send_keepalive_timeout,[self,])
    266         self.__keepalive_timer.start()
    267         
    268     def __send_keepalive_timeout(self):
    269         
    270         with self.__rlock_common:
    271             self.__send_keepalive()
    272             self.__start_keepalive_timer()
    273         
    274     def __recv_loop(self):
    275         self.__tcp_con.setblocking(False)
    276         while True:
    277             ready_r, ready_w, in_err = select.select([self.__tcp_con,], [], [self.__tcp_con,], 600)
    278             
    279             with self.__rlock_common:
    280                 if self.__tcp_con in in_err:
    281                     self.__write_log('__recv_loop: socket in error select result:%s' %str(in_err))
    282                     self.__retry_connect()
    283                     break
    284                 
    285                 if self.__tcp_con not in ready_r:
    286                     self.__write_log('__recv_loop: unexpected select result!')
    287                     continue 
    288                 
    289                 try:
    290                     received_data = self.__tcp_con.recv(self.__receive_data_len)
    291                         
    292                 except error, e:
    293                     self.__write_log("receive data failed, error:%s, retry" %e)
    294                     self.__retry_connect()
    295                     break
    296             
    297                 if len(received_data) == 0:
    298                     self.__write_log("have received null data")
    299                     self.__retry_connect()
    300                     break
    301             
    302                 self.__reveived_data(received_data)
    303         pass
    304     
    305     def __start_send_proc(self):
    306         with self.__rlock_sck_send:
    307             self.__local_sending_queue = ''
    308         self.__sck_send_thread = threading.Thread(target=PeerConnect.__proc_sending, args=(self,))
    309         self.__sck_send_thread.start()
    310         
    311     def __proc_sending(self):
    312         while self.__local_sending_queue != None:
    313                         
    314             ready_r, ready_w, in_err = select.select([], [self.__tcp_con,], [self.__tcp_con,])
    315             
    316             self.__local_sending_event.wait()
    317 
    318             with self.__rlock_common:
    319                 
    320                 if self.__tcp_con  in in_err:
    321                     self.__tcp_con.close()
    322                     break
    323                 
    324                 if self.__tcp_con not in ready_w:
    325                     self.__write_log('__proc_sending: unexpected select result!')
    326                     continue
    327                 
    328                 if self.__local_sending_queue == None:
    329                     break
    330                 
    331                 try:
    332                     sent_len = self.__tcp_con.send(self.__local_sending_queue)
    333                     self.__local_sending_queue = self.__local_sending_queue[sent_len:]
    334                     
    335                 except error,e:
    336                     self.__tcp_con.close()
    337                     self.__write_log('__proc_sending failed! error:%s' %str(e))
    338                     break
    339                     
    340                 if len(self.__local_sending_queue) == 0:
    341                     self.__local_sending_event.clear()
    342         pass
    343     
    344     def __check_peer_request(self):
    345         if self.__peer_interested and not self.__local_choked:
    346             while len(self.__peer_pending_request) > 0:
    347                 piece = self.__peer_pending_request.pop(0)
    348                 piece_index, offset, length = piece
    349                 if self.__local_have(piece_index):
    350                     data = self.__read_piecedata(piece_index,offset, length)
    351                     self.__send_piece(piece_index, offset, data)
    352                 else:
    353                     self.__write_log('peer request piece:%d not have.' %piece_index)
    354         pass
    355 
    356     def __check_local_request(self): 
    357         with self.__rlock_common:
    358             self.__check_interested() 
    359             
    360             if self.__local_requesting and len(self.__local_requesting_pieces) >= self.__local_max_requesting:
    361                 return
    362             
    363             if len(self.__local_pending_request) != 0:
    364                 if not self.__local_interested:
    365                     self.__send_interested()
    366             else:
    367                 if len(self.__peer_have_pieces) != 0:
    368                     if self.__dispatch_timer != None:
    369                         self.__dispatch_timer.cancel()
    370                         
    371                     self.__dispatch_timer = threading.Timer(self.__dispatch_timeout,PeerConnect.__check_local_request ,[self,])
    372                     self.__dispatch_timer.start()
    373                     self.__local_interested = False
    374                     self.__notify_pieces_completed()
    375                 return
    376             
    377             if self.__peer_choked:
    378                 return
    379         
    380             adding_piece = self.__local_pending_request.pop(0)
    381             if adding_piece[0] not in self.__peer_have_pieces:
    382                 for piece in self.__local_pending_request:
    383                     if piece[0] == adding_piece[0]:
    384                         self.__local_pending_request.remove(piece)
    385                 self.__notify_pieces_canceled([adding_piece[0],])
    386                 self.__check_local_request()
    387             else:
    388                 self.__local_requesting = True
    389                 self.__local_requesting_pieces.append(adding_piece)    
    390                 self.__send_request(adding_piece)
    391                 self.__check_local_request()
    392                 
    393                 if self.__local_requesting_timer == None or not self.__local_requesting_timer.is_alive():
    394                     self.__local_requesting_timer = threading.Timer(self.__local_requesting_timeout_intvl, PeerConnect.__local_requesting_timeout, [self,])
    395                     self.__local_requesting_timer.start()
    396             pass
    397     
    398     def __local_requesting_timeout(self):
    399         with self.__rlock_common:
    400             if self.__local_requesting:
    401                 self.__local_requesting = False
    402                 self.__local_pending_request = self.__local_requesting_pieces + self.__local_pending_request
    403                 self.__local_requesting_pieces = []
    404                 self.__local_interested = False
    405                 self.__check_local_request()
    406 
    407         pass
    408     
    409     def __peer_choked_timeout(self):
    410         with self.__rlock_common:
    411             if self.__peer_choked:
    412                 pending_pieces = []
    413                 for piece in self.__local_pending_request:
    414                     if piece[0] not in pending_pieces:
    415                         pending_pieces.append(piece[0])
    416                 if len(pending_pieces) != 0:
    417                     self.__notify_pieces_canceled(pending_pieces)
    418                     self.__local_pending_request = []
    419         
    420                     
    421     
    422     def __check_interested(self):
    423         if not self.__local_requesting:
    424             if len(self.__local_pending_request) != 0 and not self.__local_interested:
    425                 self.__send_interested()
    426                 
    427         if not self.__local_requesting and len(self.__local_pending_request) == 0:
    428             if self.__local_interested:
    429                 self.__send_notintrested()
    430         pass
    431                 
    432     def __retry_connect(self):
    433         
    434         self.__write_log('__retry_connect')
    435         pending_pieces = []
    436         peer_dead = False
    437          
    438         with self.__rlock_common:
    439             self.__disconnect()
    440             
    441             for piece in self.__local_pending_request:
    442                 if piece[0] not in pending_pieces:
    443                     pending_pieces.append(piece[0])
    444                     
    445             self.__retry_times += 1
    446             if self.__retry_times > self.__max_retrys:
    447                 peer_dead = True
    448 
    449             else:
    450                 self.__retry_timer = threading.Timer(self.__retry_intvl**self.__retry_times, PeerConnect.__connect, [self,])
    451                 self.__retry_timer.start()
    452                 
    453         if peer_dead == True:        
    454             self.__notify_peer_dead()
    455             
    456         if len(pending_pieces) != 0:
    457             self.__notify_pieces_canceled(pending_pieces)
    458             self.__local_pending_request = []
    459 
    460     def __reveived_data(self, data):
    461         self.__receiving_cache += data
    462             
    463         while len(self.__receiving_cache) >= 4:
    464             msg_len = _str_ntohl(self.__receiving_cache[0:4])
    465             
    466             if (len(self.__receiving_cache)-4) >= msg_len:
    467                 self.__proc_msg(self.__receiving_cache[4:(4+msg_len)])
    468                 self.__receiving_cache = data[4+msg_len:]
    469             else:
    470                 break
    471                     
    472                 
    473     def __proc_msg(self, msg):
    474         with self.__rlock_common:
    475             if len(msg) == 0:
    476                 self.__received_keepalive()
    477             else: 
    478                 msg_type = msg[0]
    479                 if msg_type == chr(0):
    480                     self.__received_choked()
    481                 elif msg_type == chr(1):
    482                     self.__received_unchoked()
    483                 elif msg_type == chr(2):
    484                     self.__received_interested()
    485                 elif msg_type == chr(3):
    486                     self.__received_notinterested()
    487                 elif msg_type == chr(4):
    488                     self.__received_have(msg[1:])                                
    489                 elif msg_type == chr(5):
    490                     self.__received_bitfield(msg[1:])
    491                 elif msg_type == chr(6):
    492                     self.__received_request(msg[1:])             
    493                 elif msg_type == chr(7):
    494                     self.__received_piece(msg[1:])
    495                 elif msg_type == chr(8):
    496                     self.__received_cancel(msg[1:]) 
    497                 else:
    498                     self.__write_log('received unknown msg :%s' %list(msg))
    499     
    500     def  __handshake(self):
    501         self.__write_log('send handshake: %s' %list(self.__handshake_info))
    502         self.__tcp_con.sendall(self.__handshake_info)
    503         
    504         try:
    505             self.__tcp_con.settimeout(self.__tcp_handshake_timeout)
    506             rsp = self.__tcp_con.recv(68)
    507             
    508             if len(rsp) != 68:
    509                 return False
    510             
    511             self.__tcp_con.settimeout(None)
    512             self.__write_log('recived handshake rsp: %s' %list(rsp))
    513             self.__peer_id = rsp[47:67]
    514             self.__write_log('peer_id:%s' %self.__peer_id)
    515             
    516         except (error,timeout), e:
    517             self.__write_log('handshake failed, error:%s' %e)
    518             return False
    519         return True
    520     
    521     def __received_keepalive(self):
    522         self.__write_log('received keepalive')
    523         #self.__send_keepalive()
    524         pass
    525             
    526     def __received_choked(self):
    527 
    528         self.__peer_choked = True
    529         
    530         if self.__local_requesting:
    531             self.__local_requesting = False
    532             self.__local_pending_request =  self.__local_requesting_pieces + self.__local_pending_request
    533             self.__local_requesting_pieces = []
    534             
    535         self.__notify_peer_choked()
    536         
    537         if len(self.__local_pending_request) != 0:
    538             pending_pieces = []
    539             for piece in self.__local_pending_request:
    540                 if piece[0] not in pending_pieces:
    541                     pending_pieces.append(piece[0])
    542             self.__notify_pieces_canceled(pending_pieces)
    543             self.__local_pending_request = []
    544             self.__local_interested = False
    545             
    546         self.__write_log('received choked')
    547         
    548     def __received_unchoked(self):
    549         self.__peer_choked = False
    550         
    551         self.__notify_peer_unchoked()
    552         
    553         #if len(self.__local_pending_request) < self.__local_pending_request_less:
    554         self.__check_local_request()
    555         
    556         if self.__peer_choked_timer != None:
    557             self.__peer_choked_timer.cancel()
    558             
    559         self.__write_log('received unchoked')
    560         
    561     
    562     def __received_interested(self):
    563         self.__peer_interested = True
    564         #self.__send_unchoked()
    565         self.__write_log('received interested')
    566         
    567     def __received_notinterested(self):
    568         self.__peer_interested = False
    569         self.__peer_pending_request = [] 
    570         self.__write_log('received notinterested')
    571         
    572     def __received_have(self, data):
    573         '''
    574         TODO:Notify peer have pieces changed
    575         '''
    576         piece_index = _str_ntohl(data[0:4])
    577         if piece_index not in self.__peer_have_pieces:
    578             self.__peer_have_pieces.append(piece_index)
    579             self.__peer_have_pieces_pending.append(piece_index)
    580             if len(self.__local_pending_request) < self.__local_pending_request_less:
    581                 self.__notify_pieces_have(self.__peer_have_pieces_pending)
    582                 self.__peer_have_pieces_pending = []
    583             
    584             
    585         self.__write_log('received have piece:%d' %piece_index)
    586 
    587     def __received_bitfield(self, data):
    588         '''
    589         '''
    590         bitfield_len = len(data)
    591         for i in range(0,bitfield_len):
    592             byte = data[i]
    593             for j in range(0,8):
    594                 byte_mask = 1<<(7-j)
    595                 piece_index = i*8+j
    596                 have = ord(byte)&byte_mask
    597                 if have != 0:
    598                     if piece_index not in self.__peer_have_pieces:
    599                         self.__peer_have_pieces.append(piece_index)
    600                         
    601         self.__notify_pieces_have(self.__peer_have_pieces)
    602 
    603         self.__write_log('received bitfield ,peer have pieces:%s' %self.__peer_have_pieces)
    604 
    605     def __received_request(self, data):
    606         piece_index = _str_ntohl(data[0:4])
    607         offset      = _str_ntohl(data[4:8])
    608         data_len    = _str_ntohl(data[8:12])
    609         if self.__peer_interested:
    610                 self.__peer_pending_request.append((piece_index, offset, data_len))
    611         else:
    612             self.__write_log("received request piece:%d , but peer not interested" %piece_index)
    613         
    614         self.__check_peer_request()
    615         self.__write_log("received request piece:%d " %piece_index)
    616     
    617     def __received_piece(self, data):
    618         piece_index = _str_ntohl(data[0:4])
    619         offset      = _str_ntohl(data[4:8])
    620         piece = (piece_index, offset, len(data)-8)
    621         
    622         if self.__local_requesting:
    623             if piece in self.__local_requesting_pieces:
    624                 self.__write_piecedata(piece_index, offset, data[8:])
    625                 self.__local_requesting_pieces.remove(piece)
    626                 
    627             if self.__local_requesting_timer != None:
    628                 self.__local_requesting_timer.cancel()
    629                 
    630             if len(self.__local_requesting_pieces) == 0:  
    631                 self.__local_requesting = False
    632                 
    633             self.__check_local_request()
    634             self.__write_log("received  piece: %s" %str((piece_index, offset, len(data)-8)))
    635         else:
    636             self.__write_log("received unexpected piece: %s" %str((piece_index, offset, len(data)-8)))
    637 
    638     def __received_cancel(self, data):
    639         piece_index = _str_ntohl(data[0:4])
    640         offset      = _str_ntohl(data[4:8])
    641         data_len    = _str_ntohl(data[8:12])
    642         request = (piece_index, offset, data_len)
    643         if request in self.__peer_pending_request:
    644             self.__peer_pending_request.remove(request)
    645         self.__check_peer_request()
    646         self.__write_log("received cancel: %s" %str((piece_index,offset,data_len)))
    647             
    648     def __send_keepalive(self):
    649         msg_len = 0
    650         msg = _htonl_str(msg_len)
    651         self.__write_log('send keepalive: %s' %list(msg))
    652         self.__sck_send(msg)
    653         
    654     def __send_choked(self):
    655         self.__local_choked = True
    656         msg_type = chr(0)
    657         msg_len = 1
    658         msg = _htonl_str(msg_len) + msg_type
    659         self.__write_log('send choked: %s' %list(msg))
    660         self.__sck_send(msg)
    661         
    662     def __send_unchoked(self):
    663         self.__local_choked = False
    664         msg_type = chr(1)
    665         msg_len = 1
    666         msg = _htonl_str(msg_len) + msg_type
    667         self.__write_log('send unchoked: %s' %list(msg))
    668         self.__sck_send(msg)    
    669         
    670     def __send_interested(self):
    671         self.__local_interested = True
    672         msg_type = chr(2)
    673         msg_len = 1
    674         msg = _htonl_str(msg_len) + msg_type
    675         self.__write_log('send intrested: %s' %list(msg))
    676         self.__sck_send(msg)
    677         
    678     def __send_notintrested(self):
    679         self.__local_interested = False
    680         msg_type = chr(3)
    681         msg_len = 1
    682         msg = _htonl_str(msg_len) + msg_type
    683         self.__write_log('send notintrested: %s' %list(msg))
    684         self.__sck_send(msg)
    685         
    686     def __send_have(self,pieces):
    687         msg = ''
    688         msg_type = chr(4)
    689         msg_len = 5
    690         for piece_index in pieces:
    691             msg += _htonl_str(msg_len) + msg_type +  _htonl_str(piece_index)
    692         self.__write_log('send have: %s' %str(list(msg)))
    693         self.__sck_send(msg)
    694         
    695     def __send_bitfield(self):
    696         bitfield = self.__get_local_bitfield()
    697         msg_type = chr(5)
    698         msg_len = 1 + len(bitfield)
    699         msg = _htonl_str(msg_len) + msg_type + bitfield
    700         self.__sck_send(msg)
    701         self.__write_log('send bitfield: %s' %list(msg))
    702         
    703     def __send_request(self, piece):
    704         msg = ''
    705         msg_type = chr(6)
    706         msg_len = 13
    707         (piece_index, begin, length) = piece
    708         msg += _htonl_str(msg_len) + msg_type + _htonl_str(piece_index) + _htonl_str(begin) + _htonl_str(length)
    709         self.__write_log('send request: %s' %list(msg))
    710         self.__sck_send(msg)
    711     
    712     def __send_piece(self, piece_index, offset, data):
    713         msg = ''
    714         msg_type = chr(7)
    715         data_len = len(data)
    716         msg_len = 1 + 4 + 4 + data_len
    717         msg += _htonl_str(msg_len) + msg_type + _htonl_str(piece_index) + _htonl_str(offset)
    718         msg += data
    719         self.__write_log('send piece (%d,%d)' %(piece_index, offset))
    720         self.__sck_send(msg)
    721         
    722     def __send_cancel(self, piece_index, offset, length):
    723         msg = ''
    724         msg_type = chr(8)
    725         msg_len = 13
    726         msg += _htonl_str(msg_len) + msg_type + _htonl_str(piece_index) + _htonl_str(offset) + _htonl_str(length)
    727         self.__write_log('send cancel: %s' %list(msg))
    728         self.__sck_send(msg)
    729             
    730     def __sck_send(self, msg):
    731         with self.__rlock_common:
    732             if self.__local_sending_queue == None:
    733                 self.__write_log('sck send msg failed, because queue is none!')
    734                 return
    735             
    736             self.__local_sending_queue += msg
    737             self.__local_sending_event.set()
    738             #self.__tcp_con.sendall(msg)
    739 
    740         
    741     def __local_have(self,piece_index):
    742         pieces = self.__task_info.get_local_have_pieces()
    743         if piece_index in pieces:
    744             return True
    745         else:
    746             return False
    747 
    748     def __read_piecedata(self, piece_index, offset, data_len):
    749         return self.__task_info.read_piecedata(piece_index, offset, data_len)
    750     
    751     def __write_piecedata(self, piece_index, offset, data):
    752         self.__task_info.write_piecedata(piece_index, offset, data)
    753     
    754     def __notify_pieces_canceled(self, pieces):
    755         self.__write_log('notify taskinfo canceled pieces')
    756         self.__task_info.peer_pieces_canceled(self, pieces)
    757     
    758     def __notify_pieces_have(self, pieces):
    759         self.__write_log('notify taskinfo peeer have pieces')
    760         self.__task_info.peer_have_pieces(self, pieces)
    761         
    762     def __notify_pieces_completed(self):
    763         self.__task_info.peer_pieces_completed(self)
    764     
    765     def __notify_peer_choked(self):
    766         self.__task_info.peer_choked(self)
    767         
    768     def __notify_peer_unchoked(self):
    769         self.__task_info.peer_unchoked(self)
    770         
    771     def __notify_peer_dead(self):
    772         self.__task_info.peer_dead(self)
    773     
    774     def __get_local_bitfield(self):
    775         pieces_num = self.__task_info.get_pieces_num()
    776         bitfield_len = pieces_num/8
    777         if pieces_num%8 != 0:
    778             bitfield_len += 1
    779         bitfield = [chr(0),]*bitfield_len
    780         
    781         pieces = self.__task_info.get_local_have_pieces()
    782         for index in pieces:
    783             bit_filed_index = index / 8
    784             bit_field_offset = index % 8
    785             byte_mask = 1<<bit_field_offset
    786             byte = ord(bitfield[bit_filed_index])
    787             byte |= byte_mask
    788             bitfield[bit_filed_index] = chr(byte)
    789         return ''.join(bitfield)
    790     
    791     def __write_log(self, info):
    792         log_info.write_log('#peer_connect[%s]# '  %self.__ip + info)
    793         pass
    794          
    795 def _htonl_str(integer):
    796     msg = ''
    797     msg += chr((integer>>24)%0x100)
    798     msg += chr((integer>>16)%0x100)
    799     msg += chr((integer>>8)%0x100)
    800     msg += chr(integer%0x100)
    801     return msg
    802 
    803 def _str_ntohl(msg):
    804     integer = 0
    805     integer += ord(msg[0])<<24
    806     integer += ord(msg[1])<<16
    807     integer += ord(msg[2])<<8
    808     integer += ord(msg[3])
    809     return integer
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  • 原文地址:https://www.cnblogs.com/piaoliu/p/2714598.html
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