Dieser Artikel stellt hauptsächlich die von PHP und Python implementierte Thread-Pool-Multi-Thread-Crawler-Funktion vor und analysiert die vollständige Implementierungsmethode des Thread-Pool-Multi-Thread-Crawlers in Form von Beispielen it
Multithread-Crawler können zum Crawlen von Inhalten verwendet werden. Dies kann die Leistung verbessern. Hier sehen wir uns Beispiele für Multithread-Crawler in PHP- und Python-Thread-Pools an:
PHP-Beispiel
<?php class Connect extends Worker //worker模式 { public function __construct() { } public function getConnection() { if (!self::$ch) { self::$ch = curl_init(); curl_setopt(self::$ch, CURLOPT_TIMEOUT, 2); curl_setopt(self::$ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt(self::$ch, CURLOPT_HEADER, 0); curl_setopt(self::$ch, CURLOPT_NOSIGNAL, true); curl_setopt(self::$ch, CURLOPT_USERAGENT, "Firefox"); curl_setopt(self::$ch, CURLOPT_FOLLOWLOCATION, 1); } /* do some exception/error stuff here maybe */ return self::$ch; } public function closeConnection() { curl_close(self::$ch); } /** * Note that the link is stored statically, which for pthreads, means thread local * */ protected static $ch; } class Query extends Threaded { public function __construct($url) { $this->url = $url; } public function run() { $ch = $this->worker->getConnection(); curl_setopt($ch, CURLOPT_URL, $this->url); $page = curl_exec($ch); $info = curl_getinfo($ch); $error = curl_error($ch); $this->deal_data($this->url, $page, $info, $error); $this->result = $page; } function deal_data($url, $page, $info, $error) { $parts = explode(".", $url); $id = $parts[1]; if ($info['http_code'] != 200) { $this->show_msg($id, $error); } else { $this->show_msg($id, "OK"); } } function show_msg($id, $msg) { echo $id."\t$msg\n"; } public function getResult() { return $this->result; } protected $url; protected $result; } function check_urls_multi_pthreads() { global $check_urls; //定义抓取的连接 $check_urls = array( 'http://xxx.com' => "xx网",); $pool = new Pool(10, "Connect", array()); //建立10个线程池 foreach ($check_urls as $url => $name) { $pool->submit(new Query($url)); } $pool->shutdown(); } check_urls_multi_pthreads(); python 多线程 def handle(sid)://这个方法内执行爬虫数据处理 pass class MyThread(Thread): """docstring for ClassName""" def __init__(self, sid): Thread.__init__(self) self.sid = sid def run(): handle(self.sid) threads = [] for i in xrange(1,11): t = MyThread(i) threads.append(t) t.start() for t in threads: t.join()
Python-Thread-Pool-Crawler:
from queue import Queue from threading import Thread, Lock import urllib.parse import socket import re import time seen_urls = set(['/']) lock = Lock() class Fetcher(Thread): def __init__(self, tasks): Thread.__init__(self) self.tasks = tasks self.daemon = True self.start() def run(self): while True: url = self.tasks.get() print(url) sock = socket.socket() sock.connect(('localhost', 3000)) get = 'GET {} HTTP/1.0\r\nHost: localhost\r\n\r\n'.format(url) sock.send(get.encode('ascii')) response = b'' chunk = sock.recv(4096) while chunk: response += chunk chunk = sock.recv(4096) links = self.parse_links(url, response) lock.acquire() for link in links.difference(seen_urls): self.tasks.put(link) seen_urls.update(links) lock.release() self.tasks.task_done() def parse_links(self, fetched_url, response): if not response: print('error: {}'.format(fetched_url)) return set() if not self._is_html(response): return set() urls = set(re.findall(r'''(?i)href=["']?([^\s"'<>]+)''', self.body(response))) links = set() for url in urls: normalized = urllib.parse.urljoin(fetched_url, url) parts = urllib.parse.urlparse(normalized) if parts.scheme not in ('', 'http', 'https'): continue host, port = urllib.parse.splitport(parts.netloc) if host and host.lower() not in ('localhost'): continue defragmented, frag = urllib.parse.urldefrag(parts.path) links.add(defragmented) return links def body(self, response): body = response.split(b'\r\n\r\n', 1)[1] return body.decode('utf-8') def _is_html(self, response): head, body = response.split(b'\r\n\r\n', 1) headers = dict(h.split(': ') for h in head.decode().split('\r\n')[1:]) return headers.get('Content-Type', '').startswith('text/html') class ThreadPool: def __init__(self, num_threads): self.tasks = Queue() for _ in range(num_threads): Fetcher(self.tasks) def add_task(self, url): self.tasks.put(url) def wait_completion(self): self.tasks.join() if __name__ == '__main__': start = time.time() pool = ThreadPool(4) pool.add_task("/") pool.wait_completion() print('{} URLs fetched in {:.1f} seconds'.format(len(seen_urls),time.time() - start))
Zusammenfassung: Das ist es. Der gesamte Inhalt dieses Artikels soll für das Studium aller hilfreich sein.
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