我实现了一个循环的分布式哈希表,每个对等体知道它的直接后继并与其后继者建立TCP连接,例如,1-> 3-> 4-> 5-> 8- > 1
用户将输入一个4位数字,我们使用我们编写的散列函数将其转换为某个值。例如,用户输入3456,对应的散列值是128.对等3获得来自用户的输入,并将散列值传递给其后继者(4),询问他是否大于散列值。如果没有,后继者将把哈希值传递给它的后继者(5)。重复此操作,直到找到合适的同伴。 (这里,因为8< 128,我们说对等1是我们想要的那个)
现在,我们知道对等体1是我们想要的对等体。然后我们让对等体1与请求对等体3建立TCP连接,并发送3" FIND1,3456,3"当对等体3收到此消息时,它应该打印出来#34;对等体1具有值"
我遇到的问题是,在我发现对等体1是我想要的对象之后,我的对等体1客户端与对等体3服务器建立TCP连接(对等体1客户端表示已建立连接),但是对等体3没有&#39 ; t从对等方1获取任何消息,它有什么问题?
我该如何解决?
感谢您耐心阅读这些内容,请随时询问是否有任何含糊不清的内容:)
#!/usr/bin/python2.7
import sys
import socket
import time
import threading
import re
from collections import defaultdict
successor = defaultdict(dict)
peer = int(sys.argv[1])
successor[1] = int(sys.argv[2])
successor[2] = int(sys.argv[3])
serverName = 'localhost'
peerPort = 50000 + int(peer)
address = (serverName,peerPort)
#-------------proceed input string---------------------------
def getFileNum(name):
fileValid = re.match('^request ([0-9]{4})$',name)
if fileValid is None:
print 'invalid file!'
return
else:
hashName = fileValid.group(1)
return hashName
#----------------get request input--------------------------------
def getRequestInput(clientSocketTCP):
while flag == 0:
fileName = raw_input()
hashname = getFileNum(fileName)
if hashname is not None:
hashname = re.sub('^(0)*','',hashname)
hashnum = int(hashname) % 256
info = 'FILE_REQUEST'+str(hashname) + ','+ str(hashnum) + ','+ str(peer) + ',1'
clientSocketTCP.send(info)
print 'File request message for '+ str(hashname) + ' has been sent to my successor.'
clientSocketTCP.close()
#-------------------send file to successor---------------------------
def sendRequestToS(clientSocketTCP):
global important
while flag == 0:
if important:
an = re.match('^FILE_REQUEST([0-9]{4}),',important)
if an:
hashname = an.group(1)
clientSocketTCP.send(important)
print 'File request message for '+ str(hashname) + ' has been sent to my successor.'
important = ''
clientSocketTCP.close()
#-----------------------find file-------------------------------------
def findF():
global flag
global important
while flag == 0:
if re.match('^FIND',important):
obj = re.match('^FIND[0-9]{1,3},([0-9]{4}),([0-9]{1,3})',important)
n = int(obj.group(2))
info = important
ff = threading.Thread(target=clientTCPTemp,args=(n,info))
ff.start()
ff.join()
important = ''
#--------------------set up client temporary---------------------------
def clientTCPTemp(n,info):
global flag
clientConn = False
clientSocketTCP = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serverPortTCP = 50000 + n
print serverPortTCP
while not clientConn:
try:
clientSocketTCP.connect((serverName,serverPortTCP))
clientConn = True
print "Now client connection works!!!!!"
except:
print "fail"
clientSocketTCP.send(info)
print info
print 'A response message, destined for peer '+ str(n) +', has been sent.'
clientSocketTCP.close()
#--------------------TCP server---------------------------------------
def serverTCP():
global flag
global serverSetUp
global important
serverSocketTCP = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serverConn = False
while not serverConn:
try:
serverSocketTCP.bind((serverName,peerPort))
serverConn = True
serverSocketTCP.listen(2)
serverSetUp = 0
print 'The server is ready to receive'
except:
pass
while flag == 0:
connectionSocket, addr = serverSocketTCP.accept()
print 'connect by'+ str(addr)
threeinfo = connectionSocket.recv(1024)
print threeinfo
if re.match('^FILE_REQUEST',threeinfo):
obj = re.match('^FILE_REQUEST([0-9]{4}),([0-9]{1,3}),([0-9]{1,3}),([01])$',threeinfo)
if obj is not None:
filename = obj.group(1)
hashn = int(obj.group(2))
peerID = int(obj.group(3))
endCircle = int(obj.group(4))
if peer < hashn and endCircle:
print 'File ' +filename +' is not stored here. '
important = threeinfo
if peer > successor[1]:
important = re.sub('1$','0',threeinfo)
else:
print 'File '+ filename+' is here.'
important = 'FIND'+str(peer)+','+ filename +','+ str(peerID)
elif re.match('^FIND',threeinfo):
dest = re.match('^FIND([0-9]{1,3}),([0-9]{4})','',threeinfo)
fromP = dest.group(1)
fileP = dest.group(2)
print 'Received a response message from peer '+fromP+', which has the file '+fileP
connectionSocket.send('i receive from you------------------------')
print sen
connectionSocket.send('can you hear me?')
connectionSocket.close()
#--------------------TCP client----------------------------------------
def clientTCP(n):
global flag
global serverSetUp
global important
clientConn = False
# while serverSetUp == 1:
# pass
clientSocketTCP = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serverPortTCP = 50000 + n
while not clientConn:
try:
clientSocketTCP.connect((serverName,serverPortTCP))
clientConn = True
print "Now client connection works!!!!!"
except:
pass
try:
rt = threading.Thread(target=getRequestInput,args=(clientSocketTCP,))
sr = threading.Thread(target=sendRequestToS,args=(clientSocketTCP,))
ff = threading.Thread(target=findF,args=())
rt.start()
sr.start()
ff.start()
except:
print 'thread failed'
sen = raw_input()
clientSocketTCP.send(sen)
m = clientSocketTCP.recv(1024)
print m
clientSocketTCP.close()
#----------------start thread---------------------------------
#------adapt from https://www.tutorialspoint.com/python/python_multithreading.html --------
flag = 0
serverSetUp = 1
important = ''
findFile = False
try:
serTCP = threading.Thread(target=serverTCP,args=())
cliTCP = threading.Thread(target=clientTCP,args=(successor[1],))
serTCP.start()
cliTCP.start()
except:
print "thread can not be set up"
while flag == 0:
try:
pass
except KeyboardInterrupt:
flag = 1