From 293cf33702c8cad471989c1e08ce05323baadaf7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Tue, 19 Jul 2011 12:12:25 +0200 Subject: Separate message and packet handling for websockets Improves the readability of websocket handler code by having two functions: websocket_handle/3 handles the packets received from the socket, removing the tuple construct that was otherwise needed, so only websocket_handle(Data, Req, State) is needed now; websocket_info/3 handles the messages that the websocket handler process received, as websocket_info(Info, Req, State). Both functions return values are handled identically by Cowboy so nothing changes on that end. --- src/cowboy_http_websocket_handler.erl | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-) (limited to 'src/cowboy_http_websocket_handler.erl') diff --git a/src/cowboy_http_websocket_handler.erl b/src/cowboy_http_websocket_handler.erl index b02c28d..90cf7ac 100644 --- a/src/cowboy_http_websocket_handler.erl +++ b/src/cowboy_http_websocket_handler.erl @@ -14,12 +14,13 @@ %% @doc Handler for HTTP WebSocket requests. %% -%% WebSocket handlers must implement three callbacks: websocket_init/3, -%% websocket_handle/3 and websocket_terminate/3. These -%% callbacks will only be called if the connection is upgraded to WebSocket -%% in the HTTP handler's init/3 callback. They are then called in that -%% order, although websocket_handle/3 will be called multiple time, -%% one time for each message or packet received. +%% WebSocket handlers must implement four callbacks: websocket_init/3, +%% websocket_handle/3, websocket_info/3 and +%% websocket_terminate/3. These callbacks will only be called if the +%% connection is upgraded to WebSocket in the HTTP handler's init/3 +%% callback. They are then called in that order, although +%% websocket_handle/3 will be called for each packet received, +%% and websocket_info for each message received. %% %% websocket_init/3 is meant for initialization. It receives %% information about the transport and protocol used, along with the handler @@ -27,11 +28,15 @@ %% If you are going to want to compact the request, you should probably do it %% here. %% -%% websocket_handle/3 receives messages sent to the process and -%% also the data sent to the socket. In the later case the information is -%% given as a tuple {websocket, Data}. It can reply something, do -%% nothing or close the connection. You can choose to hibernate the process -%% by returning hibernate to save memory and CPU. +%% websocket_handle/3 receives the data from the socket. It can reply +%% something, do nothing or close the connection. You can choose to hibernate +%% the process by returning hibernate to save memory and CPU. +%% +%% websocket_info/3 receives messages sent to the process. It has +%% the same reply format as websocket_handle/3 described above. Note +%% that unlike in a gen_server, when websocket_info/3 +%% replies something, it is always to the socket, not to the process that +%% originated the message. %% %% websocket_terminate/3 is meant for cleaning up. It also receives %% the request and the state previously defined, along with a reason for @@ -41,9 +46,11 @@ -export([behaviour_info/1]). %% @private --spec behaviour_info(_) -> undefined | [{websocket_handle, 3} - | {websocket_init, 3} | {websocket_terminate, 3}, ...]. +-spec behaviour_info(_) + -> undefined | [{websocket_handle, 3} | {websocket_info, 3} + | {websocket_init, 3} | {websocket_terminate, 3}, ...]. behaviour_info(callbacks) -> - [{websocket_init, 3}, {websocket_handle, 3}, {websocket_terminate, 3}]; + [{websocket_init, 3}, {websocket_handle, 3}, + {websocket_info, 3}, {websocket_terminate, 3}]; behaviour_info(_Other) -> undefined. -- cgit v1.2.3