用 python 实现一个多线程网页下载器

今天上来分享一下昨天实现的一个多线程网页下载器。
这是一个有着真实需求的实现，我的用途是拿它来通过 HTTP 方式向服务器提交游戏数据。把它放上来也是想大家帮忙挑刺，找找 bug，让它工作得更好。
keywords:python,http,multi-threads,thread,threading,httplib,urllib,urllib2,Queue,http pool,httppool
废话少说，上源码：
  1 # -*- coding:utf-8 -*-
  2 import urllib, httplib
  3 import thread
  4 import time
  5 from Queue import Queue, Empty, Full
  6 HEADERS = {"Content-type": "application/x-www-form-urlencoded",
  7                         'Accept-Language':'zh-cn',
  8                         'User-Agent': 'Mozilla/4.0 (compatible; MSIE 6.0;Windows NT 5.0)',
  9                         "Accept": "text/plain"}
 10 UNEXPECTED_ERROR = -1
 11 POST = 'POST'
 12 GET = 'GET'
 13 def base_log(msg):
 14     print msg
 15 def base_fail_op(task, status, log):
 16     log('fail op. task = %s, status = %d'%(str(task), status))
 17 def get_remote_data(tasks, results, fail_op = base_fail_op, log = base_log):
 18     while True:
 19         task = tasks.get()
 20         try:
 21             tid = task['id']
 22             hpt = task['conn_args'] # hpt <= host:port, timeout
 23         except KeyError, e:
 24             log(str(e))
 25             continue
 26         log('thread_%s doing task %d'%(thread.get_ident(), tid))
 27         #log('hpt = ' + str(hpt))
 28         conn = httplib.HTTPConnection(**hpt)
 29             
 30         try:
 31             params = task['params']
 32         except KeyError, e:
 33             params = {}
 34         params = urllib.urlencode(params)
 35         #log('params = ' + params)
 36         
 37         try:
 38             method = task['method']
 39         except KeyError:
 40             method = 'GET'
 41         #log('method = ' + method)
 42         
 43         try:
 44             url = task['url']
 45         except KeyError:
 46             url = '/'
 47         #log('url = ' + url)
 48         
 49         headers = HEADERS
 50         try:
 51             tmp = task['headers']
 52         except KeyError, e:
 53             tmp = {}
 54         headers.update(tmp)
 55         #log('headers = ' + str(headers))
 56         headers['Content-Length'] = len(params)
 57         
 58         try:
 59             if method == POST:
 60                 conn.request(method, url, params, headers)
 61             else:
 62                 conn.request(method, url + params)
 63             response = conn.getresponse()
 64         except Exception, e:
 65             log('request failed. method = %s, url = %s, params = %s headers = %s'%(
 66                         method, url, params, headers))
 67             log(str(e))
 68             fail_op(task, UNEXPECTED_ERROR, log)
 69             continue
 70             
 71         if response.status != httplib.OK:
 72             fail_op(task, response.status, log)
 73             continue
 74             
 75         data = response.read()
 76         results.put((tid, data), True)
 77         
 78 class HttpPool(object):
 79     def __init__(self, threads_count, fail_op, log):
 80         self._tasks = Queue()
 81         self._results = Queue()
 82         
 83         for i in xrange(threads_count):
 84             thread.start_new_thread(get_remote_data, 
 85                                                             (self._tasks, self._results, fail_op, log))
 86             
 87     def add_task(self, tid, host, url, params, headers = {}, method = 'GET', timeout = None):
 88         task = {
 89             'id' : tid,
 90             'conn_args' : {'host' : host} if timeout is None else {'host' : host, 'timeout' : timeout},
 91             'headers' : headers,
 92             'url' : url,
 93             'params' : params,
 94             'method' : method,
 95             }
 96         try:
 97             self._tasks.put_nowait(task)
 98         except Full:
 99             return False
100         return True
101         
102     def get_results(self):
103         results = []
104         while True:
105             try:
106                 res = self._results.get_nowait()
107             except Empty:
108                 break
109             results.append(res)
110         return results
111         
112 def test_google(task_count, threads_count):
113     hp = HttpPool(threads_count, base_fail_op, base_log)
114     for i in xrange(task_count):
115         if hp.add_task(i,
116                 'www.google.cn',
117                 '/search?',
118                 {'q' : 'lai'},
119 #                method = 'POST'
120                 ):
121             print 'add task successed.'
122             
123     while True:
124         results = hp.get_results()
125         if not results:
126             time.sleep(1.0 * random.random())
127         for i in results:
128             print i[0], len(i[1])
129 #            print unicode(i[1], 'gb18030')
130             
131 if __name__ == '__main__':
132     import sys, random
133     task_count, threads_count = int(sys.argv[1]), int(sys.argv[2])
134     test_google(task_count, threads_count)
from: http://blog.csdn.net/gzlaiyonghao/article/details/4083852