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浏览器渲染引擎,提高css渲染速度。

一、渲染引擎
渲染引擎的职责是……渲染,也就是把请求的内容显示到浏览器屏幕上。
默认情况下渲染引擎可以显示HTML,

二、各种渲染引擎
我们提到的Firefox, Safari两种浏览器构建于两种渲染引擎之上:
Firefox使用Gecko —— Mozilla自家的渲染引擎;Safari 和 Chrome 都使用 Webkit。


最终决定浏览器表现出来的页面效果的差异是:渲染引擎 Rendering Engine(也叫做排版引擎),也就是我们通常所说的“浏览器内核”,负责解析网页语法(如HTML、JavaScript)并渲染、展示网页。相同的代码在不同的浏览器呈现出来的效果不一样,那么就很有可能是不同的浏览器内核导致的。

三、主要流程
渲染引擎开始于从网络层获取请求内容,一般是不超过8K的数据块。接下来就是渲染引擎的基本工作流程:
浏览器渲染引擎,提高css渲染速度。
渲染引擎的基本工作流程(解析HTML构建DOM树,渲染树构建,渲染树布局,绘制渲染树)。
1、解析HTML以重建DOM树(Parsing HTML to construct the DOM tree ):渲染引擎开始解析HTML文档,转换树中的标签到DOM节点,它被称为“内容树”。
2、构建渲染树(Render tree construction):解析CSS(包括外部CSS文件和样式元素),根据CSS选择器计算出节点的样式,创建另一个树 —- 渲染树。
3、布局渲染树(Layout of the render tree): 从根节点递归调用,计算每一个元素的大小、位置等,给每个节点所应该出现在屏幕上的精确坐标。
4、绘制渲染树(Painting the render tree) : 遍历渲染树,每个节点将使用UI后端层来绘制。

一定要理解这是一个缓慢的过程,为了更好的用户体验,渲染引擎会尝试尽快的把内容显示出来。它不会等到所有HTML都被解析完才创建并布局渲染树。它会 在处理后续内容的同时把处理过的局部内容先展示出来。

四、主要流程示例

图 2:Webkit主要流程

浏览器渲染引擎,提高css渲染速度。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.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

 

从图2和图3中可以看出,尽管Webkit与Gecko使用略微不同的术语,这个过程还是基本相同的。
Gecko里把格式化好的可视元素称做“帧树”(Frame tree)。每个元素就是一个帧(frame)。
Webkit则使用”渲染树”这个术语,渲染树由”渲染对象”组成。
Webkit里使用”layout”表示元素的布局,Gecko则称为”Reflow”。
Webkit使用”Attachment”来连接DOM节点与可视化信息以构建渲染树。
一个非语义上的小差别是Gecko在HTML与DOM树之间有一个附加的层 ,称作”content sink”,是创建DOM对象的工厂。

主要的流程就是:构建一个dom树,页面要显示的各元素都会创建到这个dom树当中,每当一个新元素加入到这个dom树当中,浏览器便会通过css引擎查遍css样式表,找到符合该元素的样式规则应用到这个元素上。

五、浏览器对CSS的匹配原理

浏览器CSS匹配是从右到左进行查找。比如之前说的DIV#divBoxpspan.red{color:red;},浏 览器 的查找顺序如下:先查找html中所有class=’red’的span元素,找到后,再查找其父辈元素中是否有p元素,再判断p的父元素中是否有id为 divBox的div元素,如果都存在则CSS匹配上。

浏览器从右到左进行查找的好处是为了尽早过滤掉一些无关的样式规则和元素。firefox称这种查 找方式为keyselector(关键字查询),所谓的关键字就是样式规则中最后(最右边)的规则,上面的key就是span.red。

 

六、优化你的CSS
1.css 命名 、书写规范。
好的代码看上去就很整齐 很有条理性这样方便日后的维护和管理。
2.避免使用通配规则。
*{}  计算次数惊人!只对需要用到的元素进行选择。
3.css优先级。
选择器权重:内联样式:1000,id选择器:100, class选择器:10,标签选择器:1 。
上一篇有总结。CSS选择器的权重与优先规则?
4.少用滤镜,少用hack,少用position:absolute;。
5.尽量少的去对标签进行选择,而是用class。
如:#nav li{},可以为li加上nav_item的类名,如下选择.nav_item{}。
6.不要去用标签限定ID或者类选择符
如:ul#nav,应该简化为#nav。
如:div.box { color: #f00; }; 直接 可以 用类名, .box { color:#f00;}  这样浏览器找到这个class后 就不用再匹配是否存在div标签.从而提高了渲染效率。当然同一级的 有不同的样式可以这样写,但是不建议这样。
7.尽量少的去使用后代选择器,降低选择器的权重值,css的层级关系不要太深 用class直接代替多余的层级元素。
后代选择器的开销是最高的,尽量将选择器的深度降到最低,最高不要超过三层,更多的使用类来关联每一个标签元素。
例如 .box .box-con .box-list li { line-height: 24px; } 这么长。。。增加代码量减小开发效率。刚也说了,css渲染是从上到下,从右到左的
所以直接这样写就可以了.box-list li { line-height: 24px; };
8.使用简写样式。
例如margin: 10px; 浏览器会解释为上下左右各有10px的外补丁。margin: 0 10px 浏览器解析为 左右有10px的外补丁。
9.平铺背景图片不要过小,影响渲染速率。
10.float使用要谨慎。
11.不要放空的class。
别放空的的class或没有的class在html代码中,这样无意义。
12.多用继承属性。
考虑继承 了解哪些属性是可以通过继承而来的,然后避免对这些属性重复指定规则。

<style>  a:link,a:visited{color:#0000FF}  a:hover,a:active{color:#FF0000}  #zishu a:link,#zishu a:visited{ font-weight:bold}  #zishu a:hover,#zishu a:active{ font-style: italic;}</style><div><a href="#">test</a><div><div id="zishu"><a href="#">jb51.net</a></div>

13.合理化布局(模块化布局)。
可以把样式划分为 基类 和扩展类 ;模块化布局 :
模块基本相同的样式写在 基类里,不同的在重新用class来定义称为扩展类 。
14.在css渲染效率中id和class的效率是基本相当的。
class在第一次载入中被缓存,在层叠中会有更加好的效果,在根部元素采用id会具有更加好(id有微妙的速度优势)。




原标题:浏览器渲染引擎,提高css渲染速度。

关键词:CSS

CSS
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