• preload似乎是当今最好的异步加载机制... 一些不错的读物： 用npm安装 npm install @digitalkaoz/preload-polyfill 用法 该Polyfill支持以下类型： js CSS 字形 图像 音频（未经良好测试） 文件（未经良好...



展开全文

参考资料：

<link>元素的 rel 属性的属性值preload能够让你在你的HTML页面中<head>元素内部书写一些声明式的资源获取请求，可以指明哪些资源是在页面加载完成后即刻需要的。

试想我们网站使用了一种特殊字体，我们在css里面定义了字体的url。那么直到浏览器开始解析CSS了才会识别出来需要加载这个资源。
如果我们提前让浏览器下载好这个资源呢？那么执行CSS的时候就可以直接用了。就像这样：
<link rel="preload" href="fonts/cicle_fina-webfont.woff" as="font" type="font/woff" crossorigin="anonymous">
复制代码
如上所示，我们使用这样的语法：

preload is a declarative fetch, allowing you to force the browser to make a request for a resource without blocking the document’s onload event. preload是声明式获取，促使浏览器请求资源但不阻塞document的onload事件。

响应式预加载
<link rel="preload" href="bg-image-narrow.png" as="image" media="(max-width: 600px)">
复制代码
prefetch

Prefetch is a hint to the browser that a resource might be needed, but delegates deciding whether and when loading it is a good idea or not to the browser. prefetch是对浏览器的暗示，暗示将来可能需要某些资源，但由代理决定是否加载以及什么时候加载这些资源。

场景：用户正在登陆页面，登陆成功之后会跳转到首页。我是否可以在登陆页面就去请求首页的资源呢？
<link rel="prefetch" href="main.js">

复制代码
preloadPrefetch语法<link rel="preload" href="bg-image-narrow.png"><link rel="prefetch" href="bg-image-narrow.png" />适用场景本页面接下来大概率要使用的资源下个页面的资源。下个页面很可能会去访问浏览器支持情况一般较高加载时间立即加载（一般而言，跟as有关）浏览器闲置的时候才会加载（一般而言）
浏览器支持如何？
prefetch
可以看到除了safari和Opera Mini，其他浏览器都有较好地支持（全球80.12%，中国66.57%）。

webpack中的应用
import(/* webpackPreload: true */ 'ChartingLibrary');
复制代码
使用prefetch
import(/* webpackPrefetch: true */ 'LoginModal');
复制代码
下面是webpack官方文档对这两种用法的总结：
A preloaded chunk starts loading in parallel to the parent chunk. A prefetched chunk starts after the parent chunk finish.A preloaded chunk has medium priority and instantly downloaded. A prefetched chunk is downloaded in browser idle time.A preloaded chunk should be instantly requested by the parent chunk. A prefetched chunk can be used anytime in the future.Browser support is different.

展开全文
• 1. What is bearing preload? The pre-tightening of a rolling bearing refers to a certain initial pressure and pre-deformation between the bearing rolling element and the inner and outer rings when the...
1. What is bearing preload?
The pre-tightening of a rolling bearing refers to a certain initial pressure and pre-deformation between the bearing rolling element and the inner and outer rings when the bearing is installed, so as to keep the inner and outer rings of the bearing in a compressed state, so that the bearing is under working load. Operate in a state of negative clearance.
2. What is the purpose of bearing preload?
The purpose of bearing pre-tightening is to increase the stiffness of the bearing; make the rotating shaft position correctly in the axial and radial directions, improve the rotation accuracy of the shaft; reduce the vibration and noise of the shaft, and reduce the rolling element relative to the inner part caused by the moment of inertia. , The sliding of the outer ring raceway; to compensate for changes in the internal clearance of the bearing caused by wear; to extend the life of the bearing.
3. What are the bearing preload directions?
Positioning preload refers to an axial preload method in which the axial position of the bearing remains unchanged during use. As shown in Figure 1 below, a certain preload can be obtained by adjusting the width of the spacer between the two bearings the amount.

展开全文
LD_PRELOAD含义
If you set LD_PRELOAD to the path of a shared object, that file will be loaded before any other library (including the C runtime, libc.so). So to run ls with your special malloc() implementation, do this:
\$ LD_PRELOAD=/path/to/my/malloc.so /bin/ls

展开全文
• 使用 Gulp 为 OPENUI5/SAPUI5 构建 Component-preload.js。 预加载仅组合您想要的文件（主页、搜索、登录页面等），因此您可以使更大的应用程序依赖于初始加载。 请相应地配置 gulpfile（视图目录、预加载目标和命名...
• import { preload } from '@osome/redux-preload' const SimpleComponent = ( props ) => ( < div> Simple component < / div > ) const MyComponent = preload ( users : { action : action . loadUsers , ...
• 本文主要介绍 preload 的使用，以及与 prefetch 的区别。然后会聊聊浏览器的加载优先级，大家一定要认真看完

千次阅读 2018-06-03 10:08:33

千次阅读 2019-05-16 22:38:39
• LD_PRELOAD顾名思义，就是重新加载链接库。 一般用于链接库的重定向，例如linux测试lockdep的测试代码，就使用了此功能。 进入源码中的 cd linux-stable-rt-4.19/tools/lib/lockdep cat lockdep #!/bin/bash LD_...

千次阅读 2016-01-06 10:38:00

千次阅读 2019-03-12 15:48:46
• <div><p>The preload IDL attribute is defined to reflect the content attribute. However, preload="auto" or even preload="metadata" isn't appropriate on all platforms, and ...