cowboy源码分析(一)

时间:2023-03-09 16:39:04
cowboy源码分析(一)

前段时间导读了ranch的源码,具体见ranch 源码分析(一)

现在整理了下ranch框架下经典应用cowboy。

源码地方:https://github.com/ninenines/cowboy目前使用的是cowboy-1.0.4版本

还是找其中最简单的例子来入手,那就选这个static_world吧~~

cowboy源码分析(一)

首先我们来看static_world_app.erl

[root@erlang004 src]# cat static_world_app.erl
%% Feel free to use, reuse and abuse the code in this file. %% @private
-module(static_world_app).
-behaviour(application). %% API.
-export([start/2]).
-export([stop/1]). %% API. start(_Type, _Args) ->
Dispatch = cowboy_router:compile([
{'_', [
{"/", cowboy_static, {priv_file, static_world, "index.html"}},
{"/[...]", cowboy_static, {priv_dir, static_world, "",
[{mimetypes, cow_mimetypes, all}]}}
]}
]),
{ok, _} = cowboy:start_http(http, 100, [{port, 8080}], [
{env, [{dispatch, Dispatch}]}
]),
static_world_sup:start_link(). stop(_State) ->
ok.

cowboy_router.erl是路径路由设置,我们就不看这个源码,直接看一下结果

1> cowboy_router:compile([
1> {'_', [
1> {"/", cowboy_static, {priv_file, static_world, "index.html"}},
1> {"/[...]", cowboy_static, {priv_dir, static_world, "",
1> [{mimetypes, cow_mimetypes, all}]}}
1> ]}
1> ]).
[{'_',[],
[{[],[],cowboy_static,{priv_file,static_world,"index.html"}},
{['...'],
[],cowboy_static,
{priv_dir,static_world,[],
[{mimetypes,cow_mimetypes,all}]}}]}]

其实这个路由的意思是如果请求的是/,就路由在priv目录的index.html下面,

否则就直接读取请求的文件。

然后我们开始看cowboy:start_http/4,就是应用启动的主进程,

-module(cowboy).

-export([start_http/4]).
-export([start_https/4]).
-export([start_spdy/4]).
-export([stop_listener/1]).
-export([set_env/3]). %%省略若干行 -spec start_http(ranch:ref(), non_neg_integer(), ranch_tcp:opts(),
cowboy_protocol:opts()) -> {ok, pid()} | {error, any()}.
start_http(Ref, NbAcceptors, TransOpts, ProtoOpts)
when is_integer(NbAcceptors), NbAcceptors > 0 ->
ranch:start_listener
(Ref, NbAcceptors,
ranch_tcp, TransOpts, cowboy_protocol, ProtoOpts). -spec start_https(ranch:ref(), non_neg_integer(), ranch_ssl:opts(),
cowboy_protocol:opts()) -> {ok, pid()} | {error, any()}.
start_https(Ref, NbAcceptors, TransOpts, ProtoOpts)
when is_integer(NbAcceptors), NbAcceptors > 0 ->
ranch:start_listener(Ref, NbAcceptors,
%%省略若干行
 

可以看到这里启动ranch,而cowboy_protocol就是定义的用户进程,根据ranch源码(忘记了的参见ranch源码分析)理解,我们知道会启动cowboy_protocol:start_link/4来处理用户的应用数据请求

下面我们就进入cowboy的代码世界,从cowboy_protocol:start_link/4开始

(未完待续~)