【发布时间】：2015-09-22 06:08:01
【问题描述】：
在处理了 inlineCallbacks 和 twisted/txredisapi 的 yield 之后，我可以将数据保存到 redis 中。感谢 txredisapi 的作者。现在我遇到了一个新问题，套接字服务器在保存到数据库之前/之后不会发送回客户端。
Twisted 提供如下简单的套接字服务器：
from twisted.internet import protocol, reactor
class Echo(protocol.Protocol):
def dataReceived(self, data):
self.transport.write(data) ### write back
class EchoFactory(protocol.Factory):
def buildProtocol(self, addr):
return Echo()
reactor.listenTCP(8000, EchoFactory)
recctor.run()
我的代码是类似的，只是有额外的数据库操作。
#!/usr/bin/env python
import time
import binascii
import txredisapi
from twisted.internet import defer
from twisted.internet import protocol, reactor
from twisted.internet.protocol import Factory
from twisted.enterprise import adbapi
from twisted.python import log
from dmpack import Dmpack
from dmdb import Dmdb
from dmconfig import DmConf
dm = Dmpack()
conf = DmConf().loadConf()
rcs = txredisapi.lazyConnection(password=conf['RedisPassword'])
dbpool = adbapi.ConnectionPool("MySQLdb",db=conf['DbName'],user=conf['DbAccount'],\
passwd=conf['DbPassword'],host=conf['DbHost'],\
use_unicode=True,charset=conf['DbCharset'])
def getDataParsed(data):
realtime = None
period = None
self.snrCode = dm.snrToAscii(data[2:7])
realtime = data[7:167] # save it into redis
period = data[167:-2] # save it into SQL
return (snrCode, realtime, period)
class PlainTCP(protocol.Protocol):
def __init__(self, factory):
self.factory = factory
self.factory.numConnections = 0
self.snrCode = None
self.rData = None
self.pData = None
self.err = None
def connectionMade(self):
self.factory.numConnections += 1
print "Nr. of connections: %d\n" %(self.factory.numConnections)
self.transport.write("Hello remote\r\n") # it only prints very 5 connections.
def connectionLost(self, reason):
self.factory.numConnections -= 1
print "Nr. of connections: %d\n" %(self.factory.numConnections)
@defer.inlineCallbacks
def dataReceived(self, data):
global dbpool, rcs
(self.snrCode,rDat,pDat) = getDataParsed(data)
if self.snrCode == None or rDat == None or pDat == None:
err = "Bad format"
else:
err = "OK"
print "err:%s"%(err) # debug print to show flow control
self.err = err
self.transport.write(self.snrCode)
self.transport.write(self.err)
self.transport.write(rDat)
self.transport.write(pDat)
self.transport.loseConnection()
if self.snrCode != None and rDat != None and pDat != None:
res = yield self.saveRealTimeData(rcs, rDat)
res = yield self.savePeriodData(dbpool, pDat, conf)
print "err2:%s"%(err) # debug print to show flow control
@defer.inlineCallbacks
def saveRealTimeData(self, rc, dat):
key = "somekey"
val = "somedata"
yield rc.set(key,val)
yield rc.expire(key,30)
@defer.inlineCallbacks
def savePeriodData(self,rc,dat,conf):
query = "some SQL statement"
yield rc.runQuery(query)
class PlainTCPFactory(protocol.Factory):
def buildProtocol(self, addr):
return PlainTCP(self)
def main():
dmdb = Dmdb()
if not dmdb.detectDb():
print "Please run MySQL RDBS first."
sys.exit()
log.startLogging(sys.stdout)
reactor.listenTCP(8080, PlainTCPFactory())
reactor.run()
if __name__ == "__main__":
main()
还有我的客户的剪辑，这是一个简单的客户：
def connectSend(host="127.0.0.1",port=8080):
global packet
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
s.connect((host, port))
s.sendall(''.join(packet))
data = s.recv(1024)
s.close()
print 'Received', repr(data)
except socket.error, err:
print "Remote socket is not available: %s"%str(err)
sys.exit(1)
目前的状态是：
- 如果禁用 @defer.inlineCallbacks 和 dataReceived() 的 yield 操作，connectionMode() 和 dataReceived() 内部的 self.transport.write() 和 dataReceived() 都可以向客户端输出数据。
- 如果我们启用了@defer.inlineCallbacks 和 SQL/Redis 的两个 yield DB 操作，那么 connectionMode() 内部的 self.transport.write() 会每 5 个连接打印一次，而 dataReceived() 将不会向客户端输出任何数据。
- 不管@defer.inlineCallbacks 无论如何，调试打印语句都会打印在日志上。
有人告诉我 dataReceived() 不应该是 @defer.inlineCallbacks。但如果我去掉那个装饰，它不会改变任何东西。
我正在考虑 gevent 是否可以帮助我摆脱这种无法预料的行为。我被扭曲成无尽的龙卷风，旋风......
哪位有类似经历的，请帮帮我。谢谢。
【问题讨论】：