使用file_get_content系列函數和使用curl系列函數來擷取圖片的效能對比

　　由於公司的一個汽車網站的後台的汽車內容都是主要是來自與汽車之家的，編輯的同事們必須天天手動去對著汽車之家來添加汽車，實在是太蛋疼了。於是乎，為了改變這個狀況，身為一個開發碼農，我的任務就來了。 。 。那就是準備做一個功能，只要貼上對應的汽車之家的網址url就能對這些數據進行自動填充到我們後台的表單中，目前基本的填充都實現了，但是還是沒有能夠把對應的汽車相冊採集進來。

　　採集圖片的功能我以前也做過，但是汽車之家大部分的汽車都有挺多圖片的，開始的時候，我打算使用以前的採集圖片的辦法，也就是使用file_get_content獲取url對應的內容，然後再配對到圖片的位址，再使用file_get_content取得這些圖片url的內容，再載入到本地去，程式碼如下：

<?<span>php
</span><span>header</span>('Content-type:text/html;charset=utf-8'<span>);
</span><span>set_time_limit</span>(0<span>);

</span><span>class</span><span> runtime  
{  
    </span><span>var</span> <span>$StartTime</span> = 0<span>;  
    </span><span>var</span> <span>$StopTime</span> = 0<span>;  
   
    </span><span>function</span><span> get_microtime()  
    {  
        </span><span>list</span>(<span>$usec</span>, <span>$sec</span>) = <span>explode</span>(' ', <span>microtime</span><span>());  
        </span><span>return</span> ((<span>float</span>)<span>$usec</span> + (<span>float</span>)<span>$sec</span><span>);  
    }  
   
    </span><span>function</span><span> start()  
    {  
        </span><span>$this</span>->StartTime = <span>$this</span>-><span>get_microtime();  
    }  
   
    </span><span>function</span><span> stop()  
    {  
        </span><span>$this</span>->StopTime = <span>$this</span>-><span>get_microtime();  
    }  
   
    </span><span>function</span><span> spent()  
    {  
        </span><span>return</span> <span>round</span>((<span>$this</span>->StopTime - <span>$this</span>->StartTime) * 1000, 1<span>);  
    }  
   
}  

</span><span>$runtime</span>= <span>new</span><span> runtime();  
</span><span>$runtime</span>-><span>start();  

</span><span>$url</span> = 'http://car.autohome.com.cn/pic/series-s15306/289.html#pvareaid=102177'<span>;
</span><span>$rs</span> = <span>file_get_contents</span>(<span>$url</span><span>);
</span><span>//</span><span> echo $rs;exit;</span>
<span>preg_match_all</span>('/(\/pic\/series-s15306\/289-\d+\.html)/', <span>$rs</span>, <span>$urlArr</span><span>);

</span><span>$avalie</span> = <span>array_unique</span>(<span>$urlArr</span>[0<span>]);
</span><span>$count</span> = <span>array</span><span>();
</span><span>foreach</span> (<span>$avalie</span> <span>as</span> <span>$key</span> => <span>$ul</span><span>) {
   </span><span>$pattern</span> = '/<img src="(http:\/\/car1\.autoimg\.cn\/upload\/\d+\/\d+\/\d+\/.*?\.jpg)"/'<span>;
   </span><span>preg_match_all</span>(<span>$pattern</span>, <span>file_get_contents</span>('http://car.autohome.com.cn'.<span>$ul</span>), <span>$imgSrc</span><span>);
   </span><span>$count</span> = <span>array_merge</span>(<span>$count</span>, <span>$imgSrc</span>[1<span>]);
}


</span><span>foreach</span>(<span>$count</span> <span>as</span> <span>$k</span>=><span>$v</span><span>) {
  </span><span>$data</span>[<span>$k</span>] = <span>file_get_contents</span>(<span>$v</span><span>);
}

</span><span>foreach</span>(<span>$data</span> <span>as</span> <span>$k</span>=><span>$v</span><span>) {
  </span><span>file_put_contents</span>('./pic2/'.<span>time</span>().'_'.<span>rand</span>(1, 10000).'.jpg', <span>$v</span><span>);
}

</span><span>$runtime</span>-><span>stop();  
</span><span>echo</span> "页面执行时间: ".<span>$runtime</span>->spent()." 毫秒"; 

　　結果發現，這種方法少圖片還好，圖片多了，那是相當的卡。 。就本地測試也比較難跑，更不如說到時候上線了。百度之後，我採用了curl的辦法來下載圖片，經過測試後的確有所改善，但是感覺還是有點慢，要是php有多線程那有多好。 。 。

　　又經過一番折騰和找資料，發現php的curl庫其實還是可以模擬多線程的，那就是使用curl_multi_*系列的函數，經過改寫，程式碼又變成了這樣：

　　

<?<span>php
</span><span>header</span>('Content-type:text/html;charset=utf-8'<span>);
</span><span>set_time_limit</span>(0<span>);

</span><span>class</span><span> runtime  
{  
    </span><span>var</span> <span>$StartTime</span> = 0<span>;  
    </span><span>var</span> <span>$StopTime</span> = 0<span>;  
   
    </span><span>function</span><span> get_microtime()  
    {  
        </span><span>list</span>(<span>$usec</span>, <span>$sec</span>) = <span>explode</span>(' ', <span>microtime</span><span>());  
        </span><span>return</span> ((<span>float</span>)<span>$usec</span> + (<span>float</span>)<span>$sec</span><span>);  
    }  
   
    </span><span>function</span><span> start()  
    {  
        </span><span>$this</span>->StartTime = <span>$this</span>-><span>get_microtime();  
    }  
   
    </span><span>function</span><span> stop()  
    {  
        </span><span>$this</span>->StopTime = <span>$this</span>-><span>get_microtime();  
    }  
   
    </span><span>function</span><span> spent()  
    {  
        </span><span>return</span> <span>round</span>((<span>$this</span>->StopTime - <span>$this</span>->StartTime) * 1000, 1<span>);  
    }  
   
}  

</span><span>$runtime</span>= <span>new</span><span> runtime();  
</span><span>$runtime</span>-><span>start();  


</span><span>$url</span> = 'http://car.autohome.com.cn/pic/series-s15306/289.html#pvareaid=102177'<span>;
</span><span>$rs</span> = <span>file_get_contents</span>(<span>$url</span><span>);
</span><span>preg_match_all</span>('/(\/pic\/series-s15306\/289-\d+\.html)/', <span>$rs</span>, <span>$urlArr</span><span>);

</span><span>$avalie</span> = <span>array_unique</span>(<span>$urlArr</span>[0<span>]);
</span><span>$count</span> = <span>array</span><span>();
</span><span>foreach</span> (<span>$avalie</span> <span>as</span> <span>$key</span> => <span>$ul</span><span>) {
   </span><span>$pattern</span> = '/<img src="(http:\/\/car1\.autoimg\.cn\/upload\/\d+\/\d+\/\d+\/.*?\.jpg)"/'<span>;
   </span><span>preg_match_all</span>(<span>$pattern</span>, <span>file_get_contents</span>('http://car.autohome.com.cn'.<span>$ul</span>), <span>$imgSrc</span><span>);
   </span><span>$count</span> = <span>array_merge</span>(<span>$count</span>, <span>$imgSrc</span>[1<span>]);
}

</span><span>$handle</span> =<span> curl_multi_init();

</span><span>foreach</span>(<span>$count</span> <span>as</span> <span>$k</span> => <span>$v</span><span>) {
  </span><span>$curl</span>[<span>$k</span>] = curl_init(<span>$v</span><span>);
  curl_setopt(</span><span>$curl</span>[<span>$k</span>], CURLOPT_RETURNTRANSFER, 1<span>);
  curl_setopt(</span><span>$curl</span>[<span>$k</span>], CURLOPT_HEADER, 0<span>);
  curl_setopt(</span><span>$curl</span>[<span>$k</span>], CURLOPT_TIMEOUT, 30<span>);
  curl_multi_add_handle (</span><span>$handle</span>, <span>$curl</span>[<span>$k</span><span>]);
}

</span><span>$active</span> = <span>null</span><span>;

</span><span>do</span><span> {
    </span><span>$mrc</span> = curl_multi_exec(<span>$handle</span>, <span>$active</span><span>);
} </span><span>while</span> (<span>$mrc</span> ==<span> CURLM_CALL_MULTI_PERFORM);

</span><span>while</span> (<span>$active</span> && <span>$mrc</span> ==<span> CURLM_OK) {
    // 这句在php5.3以后的版本很关键，因为没有这句，可能curl_multi_select可能会永远返回-1，这样就永远死在循环里了
    </span><span>while</span> (curl_multi_exec(<span>$handle</span>, <span>$active</span>) ===<span> CURLM_CALL_MULTI_PERFORM);

    </span><span>if</span> (curl_multi_select(<span>$handle</span>) != -1<span>) {
        </span><span>do</span><span> {
            </span><span>$mrc</span> = curl_multi_exec(<span>$handle</span>, <span>$active</span><span>);
        } </span><span>while</span> (<span>$mrc</span> ==<span> CURLM_CALL_MULTI_PERFORM);
    }
}

</span><span>foreach</span> (<span>$curl</span> <span>as</span> <span>$k</span> => <span>$v</span><span>) {
    </span><span>if</span> (curl_error(<span>$curl</span>[<span>$k</span>]) == ""<span>) {
        </span><span>$data</span>[<span>$k</span>] = curl_multi_getcontent(<span>$curl</span>[<span>$k</span><span>]);
    }
    curl_multi_remove_handle(</span><span>$handle</span>, <span>$curl</span>[<span>$k</span><span>]);
    curl_close(</span><span>$curl</span>[<span>$k</span><span>]);
}

</span><span>foreach</span>(<span>$data</span> <span>as</span> <span>$k</span>=><span>$v</span><span>) {
    </span><span>$file</span> = <span>time</span>().'_'.<span>rand</span>(1000, 9999).'.jpg'<span>;
    </span><span>file_put_contents</span>('./pic3/'.<span>$file</span>, <span>$v</span><span>); 
}

curl_multi_close(</span><span>$handle</span><span>);

</span><span>$runtime</span>-><span>stop();  
</span><span>echo</span> "页面执行时间: ".<span>$runtime</span>->spent()." 毫秒"; 

　　好了，多線程的採集真是非常酸爽，然後通過一系列的測試和對比，5次測試，curl多線程有4次是快於file_get_content的，而且時間還是file_get_content的3～5倍，總結起來，以後採集都盡量使用這種辦法，提高效率不在話下。

以上就介紹了使用file_get_content系列函數和使用curl系列函數來擷取圖片的效能對比，包括了方面的內容，希望對PHP教學有興趣的朋友有所幫助。