Common development issues with WebKit browsers

Some time ago someone asked me a simple question, how does HTML create parsing?

I told a whole bunch of what passed Documentloader, Cachedresourceloader,

Cacheresource, Resourceloaderscheduler, resourcehandle these classes.

A step-by-step cache lookup is then requested for download and so on.

Until I debug my XML parsing, I find that a lot of problems are inconsistent with understanding,

In the analysis of the source of the time only to understand the overall steps. Do you really know the details?

First, HTTP header Web header request

Requests Part (list several important ones)

Accept	Specify what types of content clients can receive	Accept:text/plain, text/html
Accept-charset	The set of character encodings that the browser can accept.	Accept-charset:iso-8859-5
Accept-encoding	Specifies that the Web server that the browser can support returns the content compression encoding type.	Accept-encoding:compress, gzip
Accept-language	Browser-acceptable language	Accept-language:en,zh
Connection	Indicates whether a persistent connection is required. (HTTP 1.1 defaults to persistent connection)	Connection:close
Cookies	When an HTTP request is sent, all cookie values stored under that request domain are sent to the Web server.	Cookie: $Version = 1; Skin=new;
Content-length	The requested content length	content-length:537
Content-type	The requested MIME information corresponding to the entity	content-type:application/x-www-form-urlencoded
Date	Date and time the request was sent	Date:tue, 15:12:31 GMT
User-agent	The content of the user-agent contains the user information that made the request	user-agent:mozilla/5.0 (Linux; X11)

Responses part

Accept-ranges	Indicates whether the server supports the specified range request and what kind of staging request	Accept-ranges:bytes
Age	Estimated time (in seconds, non-negative) from the original server to the proxy cache	Age:12
Allow	A valid request behavior for a network resource is not allowed to return 405	Allow:get, HEAD
Cache-control	Tell if all caching mechanisms can be cached and which type	Cache-control:no-cache
Content-encoding	The type of return content compression encoding supported by the Web server.	Content-encoding:gzip
Content-language	The language of the response body	Content-language:en,zh
Content-length	The length of the response body	content-length:348
Content-location	Alternate alternative address to request resource substitution	Content-location:/index.htm
Content-md5	Returns the MD5 checksum value of a resource	content-md5:q2hly2sgsw50zwdyaxr5iq==
Content-range	The byte position of this section in the entire return body	Content-range:bytes 21010-47021/47022
Content-type	Returns the MIME type of the content	content-type:text/html; Charset=utf-8
Date	Time the original server message was issued	Date:tue, 15:12:31 GMT
Location	Used to redirect the receiver to the location of the non-request URL to complete the request or identify the new resource	Location:http://www.oschina.net/u/2335812/admin

User-agent This field user information, indicating that your browser supports the standard, the server resolves the field to return different requests

(a Web page that is compatible with multiple terminals will be treated with compatibility) This is especially important in IPTV,

Many times some front-end Web page is to add some special fields to normal operation is very depressed.

The HTTP request header can convey more information.

Second, WebKit How to distinguish the creation of html,xml and other analysis

It is determined by the Content-type field in the $ OK returned by the HTTP request,

content-type:text/html; Charset=utf-8,

Describes the text type HTML, character encoding utf-8.

Determines whether the type is html,xml when CreateDocument () is created in DOMImplementation.cpp.

This type, such as video, is parsed by Content-type in the request return OK field.

Third, request redirection

Redirect is the URL returned in the Location field of the 302 found returned by the HTTP request determines the new address of the jump

Iv. Setting the load cache size

In the Loader/cache/memorycache.cpp file, the Setcapacities () function can set the cache size,

Find a balance point where a resource is loaded at a speed of memory usage

There are a lot of small details like that, and you can tell us about your problems.

Thank you for your reading and look forward to seeing you next time:

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Common development issues with WebKit browsers