From a45813c60f0f983a24ea29d491b37f0590fdd087 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Sat, 18 Feb 2017 18:26:20 +0100 Subject: Allow passing options to sub protocols Before this commit we had an issue where configuring a Websocket connection was simply not possible without doing magic, adding callbacks or extra return values. The init/2 function only allowed setting hibernate and timeout options. After this commit, when switching to a different type of handler you can either return {module, Req, State} or {module, Req, State, Opts} where Opts is any value (as far as the sub protocol interface is concerned) and is ultimately checked by the custom handlers. A large protocol like Websocket would accept only a map there, with many different options, while a small interface like loop handlers would allow passing hibernate and nothing else. For Websocket, hibernate must be set from the websocket_init/1 callback, because init/2 executes in a separate process. Sub protocols now have two callbacks: one with the Opts value, one without. The loop handler code was largely reworked and simplified. It does not need to manage a timeout or read from the socket anymore, it's the job of the protocol code. A lot of unnecessary stuff was therefore removed. Websocket compression must now be enabled from the handler options instead of per listener. This means that a project can have two separate Websocket handlers with different options. Compression is still disabled by default, and the idle_timeout value was changed from inifnity to 60000 (60 seconds), as that's safer and is also a good value for mobile devices. --- doc/src/manual/cowboy_app.asciidoc | 2 - doc/src/manual/cowboy_loop.asciidoc | 28 +------------- doc/src/manual/cowboy_rest.asciidoc | 3 -- doc/src/manual/cowboy_websocket.asciidoc | 66 ++++++++++++++++++-------------- 4 files changed, 40 insertions(+), 59 deletions(-) (limited to 'doc/src/manual') diff --git a/doc/src/manual/cowboy_app.asciidoc b/doc/src/manual/cowboy_app.asciidoc index 42c03e4..29c4497 100644 --- a/doc/src/manual/cowboy_app.asciidoc +++ b/doc/src/manual/cowboy_app.asciidoc @@ -59,8 +59,6 @@ Middlewares: * ssl - Secure communication over sockets * crypto - Crypto functions -// @todo Explicitly depend on ssl. - All these applications must be started before the `cowboy` application. To start Cowboy and all dependencies at once: diff --git a/doc/src/manual/cowboy_loop.asciidoc b/doc/src/manual/cowboy_loop.asciidoc index 3f4cfed..605e265 100644 --- a/doc/src/manual/cowboy_loop.asciidoc +++ b/doc/src/manual/cowboy_loop.asciidoc @@ -29,8 +29,6 @@ Loop handlers implement the following interface: init(Req, State) -> {cowboy_loop, Req, State} | {cowboy_loop, Req, State, hibernate} - | {cowboy_loop, Req, State, timeout()} - | {cowboy_loop, Req, State, timeout(), hibernate} info(Info, Req, State) -> {ok, Req, State} @@ -42,7 +40,7 @@ terminate(Reason, Req, State) -> ok %% optional Req :: cowboy_req:req() State :: any() Info :: any() -Reason :: stop | timeout +Reason :: stop | {crash, error | exit | throw, any()} ---- @@ -65,37 +63,15 @@ stop:: The handler requested to close the connection by returning a `stop` tuple. -timeout:: - The connection has been closed due to inactivity. The timeout - value can be configured from `init/2`. The response sent when - this happens is a `204 No Content`. - {crash, Class, Reason}:: A crash occurred in the handler. `Class` and `Reason` can be used to obtain more information about the crash. The function `erlang:get_stacktrace/0` can also be called to obtain the stacktrace of the process when the crash occurred. -//{error, overflow}:: -// The connection is being closed and the process terminated -// because the buffer Cowboy uses to keep data sent by the -// client has reached its maximum. The buffer size can be -// configured through the environment value `loop_max_buffer` -// and defaults to 5000 bytes. -// + -// If the long running request comes with a body it is recommended -// to process this body before switching to the loop sub protocol. -// -//{error, closed}:: -// The socket has been closed brutally without a close frame being -// received first. -// -//{error, Reason}:: -// A socket error ocurred. - == Changelog -* *2.0*: Cowboy temporarily no longer checks the socket for data with HTTP/1.1. +* *2.0*: Loop handlers no longer need to handle overflow/timeouts. * *1.0*: Behavior introduced. == See also diff --git a/doc/src/manual/cowboy_rest.asciidoc b/doc/src/manual/cowboy_rest.asciidoc index 26515fb..73adb23 100644 --- a/doc/src/manual/cowboy_rest.asciidoc +++ b/doc/src/manual/cowboy_rest.asciidoc @@ -21,9 +21,6 @@ REST handlers implement the following interface: ---- init(Req, State) -> {cowboy_rest, Req, State} - | {cowboy_rest, Req, State, hibernate} - | {cowboy_rest, Req, State, timeout()} - | {cowboy_rest, Req, State, timeout(), hibernate} Callback(Req, State) -> {Result, Req, State} diff --git a/doc/src/manual/cowboy_websocket.asciidoc b/doc/src/manual/cowboy_websocket.asciidoc index 73f5e72..b728edf 100644 --- a/doc/src/manual/cowboy_websocket.asciidoc +++ b/doc/src/manual/cowboy_websocket.asciidoc @@ -10,31 +10,6 @@ The module `cowboy_websocket` implements Websocket as a Ranch protocol. It also defines a callback interface for handling Websocket connections. -== Options - -[source,erlang] ----- -opts() :: #{ - websocket_compress := boolean() -} ----- - -Configuration for the Websocket protocol. - -This configuration is passed to Cowboy when starting listeners -using `cowboy:start_clear/4` or `cowboy:start_tls/4` functions. - -It can be updated without restarting listeners using the -Ranch functions `ranch:get_protocol_options/1` and -`ranch:set_protocol_options/2`. - -The default value is given next to the option name: - -websocket_compress (false):: - Whether to enable the Websocket frame compression - extension. Frames will only be compressed for the - clients that support this extension. - == Callbacks Websocket handlers must implement the following callback @@ -44,9 +19,7 @@ interface: ---- init(Req, State) -> {cowboy_websocket, Req, State} - | {cowboy_websocket, Req, State, hibernate} - | {cowboy_websocket, Req, State, timeout()} - | {cowboy_websocket, Req, State, timeout(), hibernate} + | {cowboy_websocket, Req, State, Opts} websocket_init(State) -> CallResult %% optional websocket_handle(InFrame, State) -> CallResult @@ -56,6 +29,7 @@ terminate(Reason, undefined, State) -> ok %% optional Req :: cowboy_req:req() State :: any() +Opts :: cowboy_websocket:opts() InFrame :: {text | binary | ping | pong, binary()} OutFrame :: cow_ws:frame() Info :: any() @@ -152,6 +126,42 @@ timeout:: {error, Reason}:: A socket error ocurred. +== Types + +=== opts() + +[source,erlang] +---- +opts() :: #{ + compress => boolean(), + idle_timeout => timeout() +} +---- + +Websocket handler options. + +This configuration is passed to Cowboy from the `init/2` +function: + +[source,erlang] +---- +init(Req, State) -> + Opts = #{compress => true}, + {cowboy_websocket, Req, State, Opts}. +---- + +The default value is given next to the option name: + +compress (false):: + Whether to enable the Websocket frame compression + extension. Frames will only be compressed for the + clients that support this extension. + +idle_timeout (60000):: + Time in milliseconds that Cowboy will keep the + connection open without receiving anything from + the client. + == Changelog * *2.0*: The Req object is no longer passed to Websocket callbacks. -- cgit v1.2.3