最快的速度获取网页全部图片的长和宽

程序员文章站 1970-01-01 07:59:18

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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。



function ranger($url){
	$headers = array( "Range: bytes=0-32768" );
	$curl = curl_init($url);
	curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
	curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
	return curl_exec($curl);
	curl_close($curl);
}//curl设置

require dirname(__FILE__) . '/simple_html_dom.php'; 
//采用simple_html_dom.php分析HTML nod

$url = 'http://www.huffingtonpost.com/';

$html = file_get_html($url);
if($html->find('img')){
	foreach($html->find('img') as $element) {
		$raw = ranger($element->src);
		$im = @imagecreatefromstring($raw);
		$width = @imagesx($im);
		$height = @imagesy($im);
		if($width>=200||$height>=200){
			echo $element;//得出长大于大于200，宽大于等于200的图片
		}
	}
}

------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
------解决思路----------------------
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
http://s.huffpost.com/images/v/logos/v4/homepage.gif?v9
http://i.huffpost.com/gen/559399/thumbs/r-OLBERMANN-huge.jpg
http://s.huffpost.com/images/facebook_promo_connect.png?3
http://images.huffingtonpost.com/2012-04-04-michaeljfoxmarlo2SECOND.jpg
http://images.huffingtonpost.com/2012-04-05-Screenshot20120405at9.40.24AM.jpg
http://i.huffpost.com/gen/557914/thumbs/s-SCORSESE-large300.jpg

原循环改为

    foreach($html->find('img') as $element) {
       tenor("tenorcall.php?v=$element->src");
    }
}

tenorcall.php

function ranger($url){
    $headers = array( "Range: bytes=0-32768" );
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    return curl_exec($curl);
    curl_close($curl);
}//curl设置

        $raw = ranger($_GET['v']);
        $im = @imagecreatefromstring($raw);
        $width = @imagesx($im);
        $height = @imagesy($im);
        if($width>=200
------解决思路----------------------
$height>=200){
            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
        }

/**
 * 函数 tenor
 * 功能 启动一个url，但不等待返回
 * 参数 $page，待执行的页面程序
 * 返回 无
 **/
if(! function_exists('tenor')):
function tenor($page) {
        $host = $_SERVER["HTTP_HOST"];
        $fp = fsockopen($host, 80, $errno, $errmsg);
        if(!$fp) {
                echo "$errstr ($errno)
\n";
        } else {
                fputs($fp,"GET /$page HTTP/1.0\nHost: $host\n\n");
                fclose($fp);
        }
}
endif;

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
------解决思路----------------------
学习！是用PHP获取图片url后直接读取图片的头信息吗？
------解决思路----------------------
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')
------解决思路----------------------

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
对

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

又，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,…]
0: "http://s.huffpost.com/images/v/logos/v4/homepage.gif?v9"
1: "http://s.huffpost.com/images/v/logos/v4/tagline.gif"
2: "http://s.huffpost.com/images/splash/t_mini-a.png"
3: "http://s.huffpost.com/images/splash/t_mini-a.png"
4: "http://s.huffpost.com/images/splash/t_mini-a.png"
5: "http://s.huffpost.com/images/splash/t_mini-a.png"
6: "http://s.huffpost.com/images/splash/t_mini-a.png"
7: "http://s.huffpost.com/images/splash/t_mini-a.png"
8: "http://s.huffpost.com/images/splash/t_mini-a.png"
9: "http://s.huffpost.com/images/splash/t_mini-a.png"
10: "http://s.huffpost.com/images/splash/t_mini-a.png"
11: "http://s.huffpost.com/images/splash/t_mini-a.png"
12: "http://s.huffpost.com/images/splash/t_mini-a.png"
13: "http://s.huffpost.com/images/splash/t_mini-a.png"
14: "http://s.huffpost.com/images/splash/t_mini-a.png"
15: "http://s.huffpost.com/images/splash/t_mini-a.png"
16: "http://s.huffpost.com/images/splash/t_mini-a.png"
17: "http://i.huffpost.com/gen/560770/thumbs/r-GSA-LAS-VEGAS-VIDEO-huge.jpg"
18: "http://s.huffpost.com/images/webslice12x12.png"
19: "http://s.huffpost.com/images/v/blog_column.png"
20: "http://s.huffpost.com/contributors/gary-hart/headshot.jpg"
21: "http://www.huffingtonpost.com/images/trans.gif"
22: "http://www.huffingtonpost.com/images/trans.gif"
23: "http://www.huffingtonpost.com/images/trans.gif"
24: "http://images.huffingtonpost.com/2012-04-06-campbellguitar.jpg"
25: "http://www.huffingtonpost.com/images/trans.gif"
26: "http://www.huffingtonpost.com/images/trans.gif"
27: "http://www.huffingtonpost.com/images/trans.gif"
28: "http://www.huffingtonpost.com/images/trans.gif"
29: "http://www.huffingtonpost.com/images/trans.gif"
30: "http://www.huffingtonpost.com/images/trans.gif"
31: "http://images.huffingtonpost.com/2012-04-06-Screenshot20120406at7.09.17PM.jpg"
32: "http://www.huffingtonpost.com/images/trans.gif"
33: "http://www.huffingtonpost.com/images/trans.gif"
34: "http://www.huffingtonpost.com/images/trans.gif"
35: "http://www.huffingtonpost.com/images/trans.gif"
36: "http://www.huffingtonpost.com/images/trans.gif"
37: "http://www.huffingtonpost.com/images/trans.gif"
38: "http://www.huffingtonpost.com/images/trans.gif"
39: "http://www.huffingtonpost.com/images/trans.gif"
40: "http://www.huffingtonpost.com/images/trans.gif"
41: "http://www.huffingtonpost.com/images/trans.gif"
42: "http://www.huffingtonpost.com/images/trans.gif"
43: "http://www.huffingtonpost.com/images/trans.gif"
44: "http://www.huffingtonpost.com/images/trans.gif"
45: "http://www.huffingtonpost.com/images/trans.gif"
46: "http://www.huffingtonpost.com/images/trans.gif"
47: "http://www.huffingtonpost.com/images/trans.gif"
48: "http://www.huffingtonpost.com/images/trans.gif"
49: "http://www.huffingtonpost.com/images/trans.gif"
50: "http://www.huffingtonpost.com/images/trans.gif"
51: "http://www.huffingtonpost.com/images/trans.gif"
52: "http://www.huffingtonpost.com/images/trans.gif"
53: "http://www.huffingtonpost.com/images/trans.gif"
54: "http://www.huffingtonpost.com/images/trans.gif"
55: "http://www.huffingtonpost.com/images/trans.gif"
56: "http://www.huffingtonpost.com/images/trans.gif"
57: "http://www.huffingtonpost.com/images/trans.gif"
58: "http://www.huffingtonpost.com/images/trans.gif"
59: "http://www.huffingtonpost.com/images/trans.gif"
60: "http://www.huffingtonpost.com/images/trans.gif"
61: "http://www.huffingtonpost.com/images/trans.gif"
62: "http://www.huffingtonpost.com/images/trans.gif"
63: "http://www.huffingtonpost.com/images/trans.gif"
64: "http://www.huffingtonpost.com/images/trans.gif"
65: "http://www.huffingtonpost.com/images/trans.gif"
66: "http://www.huffingtonpost.com/images/trans.gif"
67: "http://www.huffingtonpost.com/images/trans.gif"
68: "http://www.huffingtonpost.com/images/trans.gif"
69: "http://www.huffingtonpost.com/images/trans.gif"
70: "http://www.huffingtonpost.com/images/trans.gif"
71: "http://www.huffingtonpost.com/images/trans.gif"
72: "http://www.huffingtonpost.com/images/trans.gif"
73: "http://www.huffingtonpost.com/images/trans.gif"
74: "http://www.huffingtonpost.com/images/trans.gif"
75: "http://s.huffpost.com/images/blank.gif"
76: "http://s.huffpost.com/images/blank.gif"
77: "http://s.huffpost.com/images/blank.gif"
78: "http://s.huffpost.com/images/blank.gif"
79: "http://s.huffpost.com/images/blank.gif"
80: "http://s.huffpost.com/images/blank.gif"
81: "http://s.huffpost.com/images/blank.gif"
82: "http://s.huffpost.com/images/facebook_promo_connect.png?3"
83: "http://s.huffpost.com/images/loader.gif"
84: "http://www.huffingtonpost.com/images/trans.gif"
85: "http://www.huffingtonpost.com/images/trans.gif"
86: "http://www.huffingtonpost.com/images/trans.gif"
87: "http://www.huffingtonpost.com/images/trans.gif"
88: "http://www.huffingtonpost.com/images/trans.gif"
89: "http://www.huffingtonpost.com/images/trans.gif"
90: "http://s.huffpost.com/contributors/gary-hart/headshot.jpg"
91: "http://s.huffpost.com/contributors/mike-campbell/headshot.jpg"
92: "http://s.huffpost.com/contributors/roma-downey/headshot.jpg"
93: "http://s.huffpost.com/contributors/gavin-newsom/headshot.jpg"
94: "http://s.huffpost.com/contributors/sarah-shourd/headshot.jpg"
95: "http://s.huffpost.com/contributors/jacqueline-novogratz/headshot.jpg"
96: "http://s.huffpost.com/contributors/peggy-drexler/headshot.jpg"
97: "http://s.huffpost.com/contributors/mohamed-a-elerian/headshot.jpg"
98: "http://s.huffpost.com/contributors/bill-mckibben/headshot.jpg"
99: "http://s.huffpost.com/contributors/marlo-thomas/headshot.jpg"
100: "http://www.huffingtonpost.com/images/v/something_to_say_button.png"
101: "http://www.huffingtonpost.com/images/trans.gif"
102: "http://www.huffingtonpost.com/images/trans.gif"
103: "http://www.huffingtonpost.com/images/trans.gif"
104: "http://www.huffingtonpost.com/images/trans.gif"
105: "http://www.huffingtonpost.com/images/trans.gif"
106: "http://www.huffingtonpost.com/images/trans.gif"
107: "http://www.huffingtonpost.com/images/trans.gif"
108: "http://www.huffingtonpost.com/images/trans.gif"
109: "http://www.huffingtonpost.com/images/trans.gif"
110: "http://www.huffingtonpost.com/images/trans.gif"
111: "http://www.huffingtonpost.com/images/trans.gif"
112: "http://www.huffingtonpost.com/images/trans.gif"
113: "http://www.huffingtonpost.com/images/trans.gif"
114: "http://www.huffingtonpost.com/images/trans.gif"
115: "http://www.huffingtonpost.com/images/trans.gif"
116: "http://www.huffingtonpost.com/images/trans.gif"
117: "http://www.huffingtonpost.com/images/trans.gif"
118: "http://www.huffingtonpost.com/images/trans.gif"
119: "http://www.huffingtonpost.com/images/trans.gif"
120: "http://www.huffingtonpost.com/images/trans.gif"
121: "http://www.huffingtonpost.com/images/trans.gif"
122: "http://www.huffingtonpost.com/images/trans.gif"
123: "http://www.huffingtonpost.com/images/trans.gif"
124: "http://www.huffingtonpost.com/images/trans.gif"
125: "http://www.huffingtonpost.com/images/trans.gif"
126: "http://www.huffingtonpost.com/images/trans.gif"
127: "http://www.huffingtonpost.com/images/trans.gif"
128: "http://www.huffingtonpost.com/images/trans.gif"
129: "http://www.huffingtonpost.com/images/trans.gif"
130: "http://www.huffingtonpost.com/images/trans.gif"
131: "http://www.huffingtonpost.com/images/trans.gif"
132: "http://www.huffingtonpost.com/images/trans.gif"
133: "http://www.huffingtonpost.com/images/trans.gif"
134: "http://b.scorecardresearch.com/p?c1=2&c2=6723616&c3=&c4=&c5=front&c6=&c15=&cj=1"
135: "http://www.huffingtonpost.com//secure-us.imrworldwide.com/cgi-bin/m?ci=us-703240h&cg=0&cc=1&ts=noscript"
136: "http://vertical-stats.huffpost.com/?-1&&"
137: "http://www.huffingtonpost.com//pixel.quantserve.com/pixel/p-6fTutip1SMLM2.gif?labels=Home"
images_count: 138
redirected: false
status: "success"
title: "Breaking News and Opinion on The Huffington Post"
type: "text/html; charset=utf-8"

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。
最快的速度获取网页全部图片的长和宽

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。