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最快的速度获取网页全部图片的长和宽

WBOY
Release: 2016-06-13 12:08:55
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最快的速度获取网页所有图片的长和宽。
不知道大家有没有玩过 http://pinterest.com ?注册后,它有一个 add a pin, 当你提交一个网站的URL后,按Find Images时,它可以查找你提交网页上所有图片的(并进行长和宽条件的筛选),整个过程一般在10秒左右。

最近想模仿它,做一个小功能组件。已经摒弃掉万恶的 getimagesize() (需要48.64秒),换用 imagecreatefromstring()(还是需要26.13秒),和它10秒左右的成绩,简直是天壤之别。

要考虑 TCP 连接数,要做到服务器资源最省化,还要考虑执行时间最少化。求助万能的大虾们,如何继续优化代码?可以跑的更快些。

<br /><br />function ranger($url){<br />	$headers = array( "Range: bytes=0-32768" );<br />	$curl = curl_init($url);<br />	curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);<br />	curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);<br />	return curl_exec($curl);<br />	curl_close($curl);<br />}//curl设置<br /><br />require dirname(__FILE__) . '/simple_html_dom.php'; <br />//采用simple_html_dom.php分析HTML nod<br /><br />$url = 'http://www.huffingtonpost.com/';<br /><br />$html = file_get_html($url);<br />if($html->find('img')){<br />	foreach($html->find('img') as $element) {<br />		$raw = ranger($element->src);<br />		$im = @imagecreatefromstring($raw);<br />		$width = @imagesx($im);<br />		$height = @imagesy($im);<br />		if($width>=200||$height>=200){<br />			echo $element;//得出长大于大于200,宽大于等于200的图片<br />		}<br />	}<br />}<br /><br />
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------解决思路----------------------
也许能走个弯路,减轻服务器网络压力。
服务器负责解析HTML数据,统计image标签信息,最后将收集的文本数据送回客户端。
加载图片由客户端来完成,只需读取width,height属性,就完全可以获取图片的原始大小。
好处多多,不过可能的麻烦是防盗链
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顶楼上
PHP获取资源
javascript 取图片长和宽
------解决思路----------------------
读取并解析 2.8秒
读取图片(138个) 27秒
找到 7 个

仅从优化代码出发,应该油水不大
可考虑多路并发
------解决思路----------------------
读取并解析 3.6秒
启动读取图片进程(138个) 1.3秒
结果文件中记录数 7 个
http://s.huffpost.com/images/v/logos/v4/tagline.gif<br />http://s.huffpost.com/images/v/logos/v4/homepage.gif?v9<br />http://i.huffpost.com/gen/559399/thumbs/r-OLBERMANN-huge.jpg<br />http://s.huffpost.com/images/facebook_promo_connect.png?3<br />http://images.huffingtonpost.com/2012-04-04-michaeljfoxmarlo2SECOND.jpg<br />http://images.huffingtonpost.com/2012-04-05-Screenshot20120405at9.40.24AM.jpg<br />http://i.huffpost.com/gen/557914/thumbs/s-SCORSESE-large300.jpg<br />
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原循环改为
    foreach($html->find('img') as $element) {<br />       tenor("tenorcall.php?v=$element->src");<br />    }<br />}<br />
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tenorcall.php
function ranger($url){<br />    $headers = array( "Range: bytes=0-32768" );<br />    $curl = curl_init($url);<br />    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);<br />    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);<br />    return curl_exec($curl);<br />    curl_close($curl);<br />}//curl设置<br /><br />        $raw = ranger($_GET['v']);<br />        $im = @imagecreatefromstring($raw);<br />        $width = @imagesx($im);<br />        $height = @imagesy($im);<br />        if($width>=200<br><font color='#FF8000'>------解决思路----------------------</font><br>$height>=200){<br />            file_put_contents('tenorcall.txt', $_GET['v'].PHP_EOL, FILE_APPEND );//得出长大于大于200,宽大于等于200的图片<br />        }<br />
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/**<br /> * 函数 tenor<br /> * 功能 启动一个url,但不等待返回<br /> * 参数 $page,待执行的页面程序<br /> * 返回 无<br /> **/<br />if(! function_exists('tenor')):<br />function tenor($page) {<br />        $host = $_SERVER["HTTP_HOST"];<br />        $fp = fsockopen($host, 80, $errno, $errmsg);<br />        if(!$fp) {<br />                echo "$errstr ($errno)<br>\n";<br />        } else {<br />                fputs($fp,"GET /$page HTTP/1.0\nHost: $host\n\n");<br />                fclose($fp);<br />        }<br />}<br />endif;<br />
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代码还是原代码,非但没减少,反而增加了
但因为是并发,所以速度明显提高

值得注意的是:tenor 函数在某些web服务器中不能稳定的运行(比如iis6)原因不明
------解决思路----------------------
我觉得,让客户端加载的方案是可行的,

客户端再将符合要求的图片信息提交给服务器,服务器端再验证一次后保存。。。


另外32768是怎么得来的?1-200不够吗
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学习! 是用PHP获取图片url后直接读取图片的头信息吗?
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pinterest那个pin功能创意很好,而且技术很简单,就是书签一串js代码,然后你点这个书签就相当于往当前页面文档append入一个js文件,这个js文件怎么写,就很简单了,主要就是遍历document.getElementsByTagName('img')
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本帖最后由 xuzuning 于 2012-04-06 15:25:06 编辑

138个照片并发,是不是就消耗了138个连接数


是否需要修改php.ini,增加连接数
否,连接是向外的,如果要改,也是对方改

CPU和内存开销如何
这个不太好测试

,关于使用 js 判断的问题,由于他们没有给出代码,无法测试
自己写了两个方案都不理想,也就作罢了

用JS并发和直接PHP并发,2者从资源消耗角度来比,哪个会更少
资源消耗角度来比 都一样,都要完整的加载图片
不过前者是消耗客户端资源,后者是消耗服务器端资源
另外浏览器的机制不很了解,是否真的是并发也未可知
------解决思路----------------------
这段代码在我这里大约 1.8秒,不计算 file_get_html ( $url ) 时间

$res [] = $url ;//$temp;
这样就是网络地址了

他是保存为本地文件后用 getimagesize 获取尺寸的

他应该是通过 curl 并发的,这个机制我不太了解
------解决思路----------------------
但是 if(in_array($absUrl, $visited))continue; 这行报错。 Warning: in_array() expects parameter 2 to be array, null。

他的代码中并没有你说的出错的代码
应该是 file_get_html 在报错吧
file_get_html 使用 file_get_contents 读取 url 成功率较低
经常要刷两三次才可独到数据
------解决思路----------------------
JS可以通过获取图片的头部信息,而直接获取到图片的高度,
这种方式比用图片加载完成以后在获取他的搞定效率至少快10倍以上,
之前记得有在一个播客里面看到过这么个帖子来着,
没收藏,这一时半会的找不到了,郁闷啊~

------解决思路----------------------
刚注册了http://pinterest.com。 它的做法就是用客户端来加载
点击Add 选择Pin ,贴上网址 http://www.huffingtonpost.com/
在chrome的Network中可以看到有一个请求
GET /pin/create/find_images/?url=http%253A%2F%2Fwww.huffingtonpost.com HTTP/1.1
返回的信息是一个json对象:
images: [http://s.huffpost.com/images/v/logos/v4/homepage.gif?v9,…]<br />0: "http://s.huffpost.com/images/v/logos/v4/homepage.gif?v9"<br />1: "http://s.huffpost.com/images/v/logos/v4/tagline.gif"<br />2: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />3: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />4: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />5: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />6: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />7: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />8: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />9: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />10: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />11: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />12: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />13: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />14: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />15: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />16: "http://s.huffpost.com/images/splash/t_mini-a.png"<br />17: "http://i.huffpost.com/gen/560770/thumbs/r-GSA-LAS-VEGAS-VIDEO-huge.jpg"<br />18: "http://s.huffpost.com/images/webslice12x12.png"<br />19: "http://s.huffpost.com/images/v/blog_column.png"<br />20: "http://s.huffpost.com/contributors/gary-hart/headshot.jpg"<br />21: "http://www.huffingtonpost.com/images/trans.gif"<br />22: "http://www.huffingtonpost.com/images/trans.gif"<br />23: "http://www.huffingtonpost.com/images/trans.gif"<br />24: "http://images.huffingtonpost.com/2012-04-06-campbellguitar.jpg"<br />25: "http://www.huffingtonpost.com/images/trans.gif"<br />26: "http://www.huffingtonpost.com/images/trans.gif"<br />27: "http://www.huffingtonpost.com/images/trans.gif"<br />28: "http://www.huffingtonpost.com/images/trans.gif"<br />29: "http://www.huffingtonpost.com/images/trans.gif"<br />30: "http://www.huffingtonpost.com/images/trans.gif"<br />31: "http://images.huffingtonpost.com/2012-04-06-Screenshot20120406at7.09.17PM.jpg"<br />32: "http://www.huffingtonpost.com/images/trans.gif"<br />33: "http://www.huffingtonpost.com/images/trans.gif"<br />34: "http://www.huffingtonpost.com/images/trans.gif"<br />35: "http://www.huffingtonpost.com/images/trans.gif"<br />36: "http://www.huffingtonpost.com/images/trans.gif"<br />37: "http://www.huffingtonpost.com/images/trans.gif"<br />38: "http://www.huffingtonpost.com/images/trans.gif"<br />39: "http://www.huffingtonpost.com/images/trans.gif"<br />40: "http://www.huffingtonpost.com/images/trans.gif"<br />41: "http://www.huffingtonpost.com/images/trans.gif"<br />42: "http://www.huffingtonpost.com/images/trans.gif"<br />43: "http://www.huffingtonpost.com/images/trans.gif"<br />44: "http://www.huffingtonpost.com/images/trans.gif"<br />45: "http://www.huffingtonpost.com/images/trans.gif"<br />46: "http://www.huffingtonpost.com/images/trans.gif"<br />47: "http://www.huffingtonpost.com/images/trans.gif"<br />48: "http://www.huffingtonpost.com/images/trans.gif"<br />49: "http://www.huffingtonpost.com/images/trans.gif"<br />50: "http://www.huffingtonpost.com/images/trans.gif"<br />51: "http://www.huffingtonpost.com/images/trans.gif"<br />52: "http://www.huffingtonpost.com/images/trans.gif"<br />53: "http://www.huffingtonpost.com/images/trans.gif"<br />54: "http://www.huffingtonpost.com/images/trans.gif"<br />55: "http://www.huffingtonpost.com/images/trans.gif"<br />56: "http://www.huffingtonpost.com/images/trans.gif"<br />57: "http://www.huffingtonpost.com/images/trans.gif"<br />58: "http://www.huffingtonpost.com/images/trans.gif"<br />59: "http://www.huffingtonpost.com/images/trans.gif"<br />60: "http://www.huffingtonpost.com/images/trans.gif"<br />61: "http://www.huffingtonpost.com/images/trans.gif"<br />62: "http://www.huffingtonpost.com/images/trans.gif"<br />63: "http://www.huffingtonpost.com/images/trans.gif"<br />64: "http://www.huffingtonpost.com/images/trans.gif"<br />65: "http://www.huffingtonpost.com/images/trans.gif"<br />66: "http://www.huffingtonpost.com/images/trans.gif"<br />67: "http://www.huffingtonpost.com/images/trans.gif"<br />68: "http://www.huffingtonpost.com/images/trans.gif"<br />69: "http://www.huffingtonpost.com/images/trans.gif"<br />70: "http://www.huffingtonpost.com/images/trans.gif"<br />71: "http://www.huffingtonpost.com/images/trans.gif"<br />72: "http://www.huffingtonpost.com/images/trans.gif"<br />73: "http://www.huffingtonpost.com/images/trans.gif"<br />74: "http://www.huffingtonpost.com/images/trans.gif"<br />75: "http://s.huffpost.com/images/blank.gif"<br />76: "http://s.huffpost.com/images/blank.gif"<br />77: "http://s.huffpost.com/images/blank.gif"<br />78: "http://s.huffpost.com/images/blank.gif"<br />79: "http://s.huffpost.com/images/blank.gif"<br />80: "http://s.huffpost.com/images/blank.gif"<br />81: "http://s.huffpost.com/images/blank.gif"<br />82: "http://s.huffpost.com/images/facebook_promo_connect.png?3"<br />83: "http://s.huffpost.com/images/loader.gif"<br />84: "http://www.huffingtonpost.com/images/trans.gif"<br />85: "http://www.huffingtonpost.com/images/trans.gif"<br />86: "http://www.huffingtonpost.com/images/trans.gif"<br />87: "http://www.huffingtonpost.com/images/trans.gif"<br />88: "http://www.huffingtonpost.com/images/trans.gif"<br />89: "http://www.huffingtonpost.com/images/trans.gif"<br />90: "http://s.huffpost.com/contributors/gary-hart/headshot.jpg"<br />91: "http://s.huffpost.com/contributors/mike-campbell/headshot.jpg"<br />92: "http://s.huffpost.com/contributors/roma-downey/headshot.jpg"<br />93: "http://s.huffpost.com/contributors/gavin-newsom/headshot.jpg"<br />94: "http://s.huffpost.com/contributors/sarah-shourd/headshot.jpg"<br />95: "http://s.huffpost.com/contributors/jacqueline-novogratz/headshot.jpg"<br />96: "http://s.huffpost.com/contributors/peggy-drexler/headshot.jpg"<br />97: "http://s.huffpost.com/contributors/mohamed-a-elerian/headshot.jpg"<br />98: "http://s.huffpost.com/contributors/bill-mckibben/headshot.jpg"<br />99: "http://s.huffpost.com/contributors/marlo-thomas/headshot.jpg"<br />100: "http://www.huffingtonpost.com/images/v/something_to_say_button.png"<br />101: "http://www.huffingtonpost.com/images/trans.gif"<br />102: "http://www.huffingtonpost.com/images/trans.gif"<br />103: "http://www.huffingtonpost.com/images/trans.gif"<br />104: "http://www.huffingtonpost.com/images/trans.gif"<br />105: "http://www.huffingtonpost.com/images/trans.gif"<br />106: "http://www.huffingtonpost.com/images/trans.gif"<br />107: "http://www.huffingtonpost.com/images/trans.gif"<br />108: "http://www.huffingtonpost.com/images/trans.gif"<br />109: "http://www.huffingtonpost.com/images/trans.gif"<br />110: "http://www.huffingtonpost.com/images/trans.gif"<br />111: "http://www.huffingtonpost.com/images/trans.gif"<br />112: "http://www.huffingtonpost.com/images/trans.gif"<br />113: "http://www.huffingtonpost.com/images/trans.gif"<br />114: "http://www.huffingtonpost.com/images/trans.gif"<br />115: "http://www.huffingtonpost.com/images/trans.gif"<br />116: "http://www.huffingtonpost.com/images/trans.gif"<br />117: "http://www.huffingtonpost.com/images/trans.gif"<br />118: "http://www.huffingtonpost.com/images/trans.gif"<br />119: "http://www.huffingtonpost.com/images/trans.gif"<br />120: "http://www.huffingtonpost.com/images/trans.gif"<br />121: "http://www.huffingtonpost.com/images/trans.gif"<br />122: "http://www.huffingtonpost.com/images/trans.gif"<br />123: "http://www.huffingtonpost.com/images/trans.gif"<br />124: "http://www.huffingtonpost.com/images/trans.gif"<br />125: "http://www.huffingtonpost.com/images/trans.gif"<br />126: "http://www.huffingtonpost.com/images/trans.gif"<br />127: "http://www.huffingtonpost.com/images/trans.gif"<br />128: "http://www.huffingtonpost.com/images/trans.gif"<br />129: "http://www.huffingtonpost.com/images/trans.gif"<br />130: "http://www.huffingtonpost.com/images/trans.gif"<br />131: "http://www.huffingtonpost.com/images/trans.gif"<br />132: "http://www.huffingtonpost.com/images/trans.gif"<br />133: "http://www.huffingtonpost.com/images/trans.gif"<br />134: "http://b.scorecardresearch.com/p?c1=2&c2=6723616&c3=&c4=&c5=front&c6=&c15=&cj=1"<br />135: "http://www.huffingtonpost.com//secure-us.imrworldwide.com/cgi-bin/m?ci=us-703240h&cg=0&cc=1&ts=noscript"<br />136: "http://vertical-stats.huffpost.com/?-1&&"<br />137: "http://www.huffingtonpost.com//pixel.quantserve.com/pixel/p-6fTutip1SMLM2.gif?labels=Home"<br />images_count: 138<br />redirected: false<br />status: "success"<br />title: "Breaking News and Opinion on The Huffington Post"<br />type: "text/html; charset=utf-8"
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几乎是服务器返回的同时,浏览器开始加载图片。chrome监控如下。黄色的那个线表示提交url获取图片资源,后面的就都是加载图片了,加载的速度还是取决于我这儿的网络。

由于http://pinterest.com/的JS代码经过压缩,且使用了JQuery,所以找起来特别费劲。其实具体怎么干就很简单,谁都能想到。遍历json数据,创建img标签对象,设置src属性,保存对象。剩下的浏览器就会自己完成。
------解决思路----------------------

引用:
引用:

刚注册了http://pinterest.com。 它的做法就是用客户端来加载
点击Add 选择Pin ,贴上网址 http://www.huffingtonpost.com/
在chrome的Network中可以看到有一个请求
GET /pin/create/find_images/?url=http%253A%2F%2Fwww.huffingtonpo……

什么对象? 
你是说服务器返回的image链接的数据吗?不用保存呀。收到ajax请求后解析返回数据就完了
另外,浏览器加载外部资源都是异步。也就是说,不管是不是用的JQuery,都是异步加载的,相互不会影响。和老大写的php端的差不多。
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