mochiweb 不一定每个请求是一个新的process(转)

转:http://approach.javaeye.com/blog/547638

mochiweb 不一定每个请求是一个新的process

文章分类:综合技术 关键字: mochiweb

今天试了一下mochiweb，这个东东的文档实在是少的可怜，推荐一个不错的tutorial：

http://erlang-china.org/start/mochiweb_intro.html

做了一个简单的comet测试，在firefox下浏览时发现每个http请求处理的process id固定在2个，而且进程字典的数据也可以跨请求共享，找了下mochiweb的源码，发现其在http请求结束时，支持tcp连接复用（http1.1），代码如下：

mochiweb_http.erl

Erlang代码

1. after_response(Body, Req) ->
2. Socket = Req:get(socket),
3. case Req:should_close() of
4. true ->
5. gen_tcp:close(Socket),
6. exit(normal);
7. false ->
8. Req:cleanup(),
9. ?MODULE:loop(Socket, Body)
10. end.

mochiweb_request.erl

Erlang代码

1. %% @spec should_close() -> bool()
2. %% @doc Return true if the connection must be closed. If false, using
3. %% Keep-Alive should be safe.
4. should_close() ->
5. ForceClose = erlang:get(mochiweb_request_force_close) =/= undefined,
6. DidNotRecv = erlang:get(mochiweb_request_recv) =:= undefined,
7. ForceClose orelse Version < {1, 0}
8. %% Connection: close
9. orelse get_header_value("connection") =:= "close"
10. %% HTTP 1.0 requires Connection: Keep-Alive
11. orelse (Version =:= {1, 0}
12. andalso get_header_value("connection") =/= "Keep-Alive")
13. %% unread data left on the socket, can't safely continue
14. orelse (DidNotRecv
15. andalso get_header_value("content-length") =/= undefined
16. andalso list_to_integer(get_header_value("content-length")) > 0)
17. orelse (DidNotRecv
18. andalso get_header_value("transfer-encoding") =:= "chunked").

So, it's clear now.