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HTML内容下载完成之前如何下载HTML资产

[英]How can HTML assets be download before HTML content has finished dowloading

原文 2017-12-04 02:51:52 2 1 html/ performance/ google-chrome/ web/ pagespeed

I am trying to improve my site load speed. 我正在尝试提高网站加载速度。 When checking on the network requests, there is something that doesn't make sense to me: 检查网络请求时，对我来说没有什么意义：

How can the content that is going to be requested (css and js files) is being download before the html content has been downloaded? 在下载html内容之前，如何下载要请求的内容（css和js文件）？ I have tried with a hard reload and empty cache from chrome, but this has happened again. 我尝试了从chrome进行重新加载并清空缓存，但是这种情况再次发生。 Morover, the files seem to be dowload from the server and not from the cache. 另外，文件似乎是从服务器下载的，而不是从缓存下载的。

Another thing I don't get, is why chrome is pating the bar chart almost all with blue, when the majority of the time is waiting for the server to respond (TTFB). 我不明白的另一件事是，为什么铬在大多数时间都在等待服务器响应（TTFB）时几乎用蓝色填充条形图。

Thanks in advance! 提前致谢！

1 个解决方案

There's a couple of possibilities: 有两种可能：

The HTML doesn't download all at once. HTML不会一次全部下载。 It's possible for the server to send part of the page, pause, then send the rest. 服务器可能会发送部分页面，暂停然后发送其余部分。 If the part that's sent first contains references to CSS, JS, image, font, or other files, the browser can start downloading those files as soon as it sees them referenced. 如果首先发送的部分包含对CSS，JS，图像，字体或其他文件的引用，则浏览器在看到被引用的文件后便可以立即开始下载这些文件。
HTTP 2.0 supports "server push", a scheme where the web server can indicate to the client through HTTP headers that it should start downloading specific other files. HTTP 2.0支持“服务器推送”，该方案是Web服务器可以通过HTTP标头向客户端指示它应该开始下载特定的其他文件的方案。 Judging from some of the file names in your network tab, you're using Cloudflare; 从“网络”标签中的某些文件名来看，您正在使用Cloudflare。 they use server push for some features, including "Rocket Loader". 他们将服务器推送功能用于某些功能，包括“火箭装载程序”。