8 files changed, 336 insertions, 326 deletions

diff --git a/doc/src/manual/cowboy_handler.ezdoc b/doc/src/manual/cowboy_handler.ezdoc
index 0495f28..b440b60 100644
--- a/doc/src/manual/cowboy_handler.ezdoc
+++ b/doc/src/manual/cowboy_handler.ezdoc
@@ -15,10 +15,96 @@ Environment output:
 
 * result = ok
 
+This module also defines the `cowboy_handler` behaviour that
+defines the basic interface for handlers. All Cowboy handlers
+implement at least the `init/2` callback, and may implement
+the `terminate/3` callback optionally.
+
 :: Types
 
 None.
 
+:: Terminate reasons
+
+The following values may be received as the terminate reason
+in the optional `terminate/3` callback. Different handler types
+may define additional terminate reasons.
+
+: normal
+
+The connection was closed normally.
+
+: {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.
+
+:: Callbacks
+
+: init(Req, Opts)
+	-> {ok, Req, State}
+	| {Module, Req, State}
+	| {Module, Req, State, hibernate}
+	| {Module, Req, State, Timeout}
+	| {Module, Req, State, Timeout, hibernate}
+
+Types:
+
+* Req = cowboy_req:req()
+* Opts = any()
+* State = any()
+* Module = module()
+* Timeout = timeout()
+
+Process the request.
+
+This function can be used to switch to an alternate handler
+type by returning the name of the module to be used, along
+with a few options.
+
+For basic handlers this is the function where the response
+should be sent. If no response is sent, Cowboy will ensure
+that a `204 No Content` response is sent.
+
+A crash in this callback will result in `terminate/3` being
+called if it is defined, with the `State` argument set to
+the value of `Opts` originally given to the `init/2` callback.
+
+: terminate(Reason, Req, State) -> ok
+
+Types:
+
+* Reason = any()
+* Req = cowboy_req:req()
+* State = any()
+
+Perform any necessary cleanup of the state.
+
+This callback should release any resource currently in use,
+clear any active timer and reset the process to its original
+state, as it might be reused for future requests sent on the
+same connection. Typical plain HTTP handlers rarely need to
+use it.
+
+A crash in this callback or an invalid return value will
+result in the closing of the connection and the termination
+of the process.
+
 :: Exports
 
-None.
+: terminate(Reason, Req, State, Handler) -> ok
+
+Types:
+
+* Reason = any()
+* Req = cowboy_req:req()
+* State = any()
+* Handler = module()
+
+Call the optional `terminate/3` callback if it exists.
+
+This function should always be called at the end of the execution
+of a handler, to give it a chance to clean up or perform
+miscellaneous operations.
diff --git a/doc/src/manual/cowboy_http_handler.ezdoc b/doc/src/manual/cowboy_http_handler.ezdoc
deleted file mode 100644
index 6776598..0000000
--- a/doc/src/manual/cowboy_http_handler.ezdoc
+++ /dev/null
@@ -1,57 +0,0 @@
-::: cowboy_http_handler
-
-The `cowboy_http_handler` behaviour defines the interface used
-by plain HTTP handlers.
-
-Unless noted otherwise, the callbacks will be executed sequentially.
-
-:: Types
-
-None.
-
-:: Callbacks
-
-: init({TransportName, ProtocolName}, Req, Opts)
-	-> {ok, Req, State} | {shutdown, Req, State}
-
-Types:
-
-* TransportName = tcp | ssl | atom()
-* ProtocolName = http | atom()
-* Req = cowboy_req:req()
-* Opts = any()
-* State = any()
-
-Initialize the state for this request.
-
-The `shutdown` return value can be used to skip the `handle/2`
-call entirely.
-
-: handle(Req, State) -> {ok, Req, State}
-
-Types:
-
-* Req = cowboy_req:req()
-* State = any()
-
-Handle the request.
-
-This callback is where the request is handled and a response
-should be sent. If a response is not sent, Cowboy will send
-a `204 No Content` response automatically.
-
-: terminate(Reason, Req, State) -> ok
-
-Types:
-
-* Reason = {normal, shutdown} | {error, atom()}
-* Req = cowboy_req:req()
-* State = any()
-
-Perform any necessary cleanup of the state.
-
-This callback should release any resource currently in use,
-clear any active timer and reset the process to its original
-state, as it might be reused for future requests sent on the
-same connection. Typical plain HTTP handlers rarely need to
-use it.
diff --git a/doc/src/manual/cowboy_loop.ezdoc b/doc/src/manual/cowboy_loop.ezdoc
new file mode 100644
index 0000000..1f3ab9e
--- /dev/null
+++ b/doc/src/manual/cowboy_loop.ezdoc
@@ -0,0 +1,100 @@
+::: cowboy_loop
+
+The `cowboy_loop` module implements a handler interface for
+long running HTTP connections. It is the recommended interface
+for long polling and server-sent events, amongst others.
+
+This module is a sub protocol that defines three callbacks to
+be implemented by handlers. The `init/2` and `terminate/3`
+callbacks are common to all handler types and are documented
+in the manual for the ^cowboy_handler module.
+
+The `info/3` callback is specific to loop handlers and will be
+called as many times as necessary until a reply is sent.
+
+It is highly recommended to return a timeout value from the
+`init/2` callback to ensure that the process is terminated
+when no data has been received during that timespan. The
+default timeout is `infinity`, which should only be used if
+you have alternate means of ending inactive connections.
+
+:: Types
+
+None.
+
+:: Terminate reasons
+
+The following values may be received as the terminate reason
+in the optional `terminate/3` callback.
+
+: normal
+
+The connection was closed normally before switching to the
+loop sub protocol. This typically happens if an `ok` tuple is
+returned from the `init/2` callback.
+
+: shutdown
+
+The handler requested to close the connection by returning
+a `shutdown` 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.
+
+:: Callbacks
+
+: info(Info, Req, State)
+	-> {ok, Req, State}
+	| {ok, Req, State, hibernate}
+	| {shutdown, Req, State}
+
+Types:
+
+* Info = any()
+* Req = cowboy_req:req()
+* State = any()
+
+Handle the Erlang message received.
+
+This function will be called every time an Erlang message
+has been received. The message can be any Erlang term.
+
+The `shutdown` return value can be used to stop the receive loop,
+typically because a response has been sent.
+
+The `hibernate` option will hibernate the process until
+it receives another message.
+
+:: Exports
+
+None.
diff --git a/doc/src/manual/cowboy_loop_handler.ezdoc b/doc/src/manual/cowboy_loop_handler.ezdoc
deleted file mode 100644
index 0811a9a..0000000
--- a/doc/src/manual/cowboy_loop_handler.ezdoc
+++ /dev/null
@@ -1,91 +0,0 @@
-::: cowboy_loop_handler
-
-The `cowboy_loop_handler` behaviour defines the interface used
-by HTTP handlers that do not send a response directly, instead
-requiring a receive loop to process Erlang messages.
-
-This interface is best fit for long-polling types of requests.
-
-The `init/3` callback will always be called, followed by zero
-or more calls to `info/3`. The `terminate/3` callback will
-always be called last.
-
-:: Types
-
-None.
-
-:: Callbacks
-
-: init({TransportName, ProtocolName}, Req, Opts)
-	-> {loop, Req, State}
-	| {loop, Req, State, hibernate}
-	| {loop, Req, State, Timeout}
-	| {loop, Req, State, Timeout, hibernate}
-	| {shutdown, Req, State}
-
-Types:
-
-* TransportName = tcp | ssl | atom()
-* ProtocolName = http | atom()
-* Req = cowboy_req:req()
-* Opts = any()
-* State = any()
-* Timeout = timeout()
-
-Initialize the state for this request.
-
-This callback will typically be used to register this process
-to an event manager or a message queue in order to receive
-the messages the handler wants to process.
-
-The receive loop will run for a duration of up to `Timeout`
-milliseconds after it last received data from the socket,
-at which point it will stop and send a `204 No Content` reply.
-By default this value is set to `infinity`. It is recommended
-to either set this value or ensure by any other mechanism
-that the handler will be closed after a certain period of
-inactivity.
-
-The `hibernate` option will hibernate the process until it
-starts receiving messages.
-
-The `shutdown` return value can be used to skip the receive
-loop entirely.
-
-: info(Info, Req, State) -> {ok, Req, State} | {loop, Req, State}
-	| {loop, Req, State, hibernate}
-
-Types:
-
-* Info = any()
-* Req = cowboy_req:req()
-* State = any()
-
-Handle the Erlang message received.
-
-This function will be called every time an Erlang message
-has been received. The message can be any Erlang term.
-
-The `ok` return value can be used to stop the receive loop,
-typically because a response has been sent.
-
-The `hibernate` option will hibernate the process until
-it receives another message.
-
-: terminate(Reason, Req, State) -> ok
-
-Types:
-
-* Reason = {normal, shutdown} | {normal, timeout} | {error, closed} | {error, overflow} | {error, atom()}
-* Req = cowboy_req:req()
-* State = any()
-
-Perform any necessary cleanup of the state.
-
-This callback will typically unregister from any event manager
-or message queue it registered to in `init/3`.
-
-This callback should release any resource currently in use,
-clear any active timer and reset the process to its original
-state, as it might be reused for future requests sent on the
-same connection.
diff --git a/doc/src/manual/cowboy_rest.ezdoc b/doc/src/manual/cowboy_rest.ezdoc
index 9fe5c77..f128a22 100644
--- a/doc/src/manual/cowboy_rest.ezdoc
+++ b/doc/src/manual/cowboy_rest.ezdoc
@@ -3,12 +3,13 @@
 The `cowboy_rest` module implements REST semantics on top of
 the HTTP protocol.
 
-This module cannot be described as a behaviour due to most of
-the callbacks it defines being optional. It has the same
-semantics as a behaviour otherwise.
+This module is a sub protocol that defines many callbacks
+be implemented by handlers. The `init/2` and `terminate/3`
+callbacks are common to all handler types and are documented
+in the manual for the ^cowboy_handler module.
 
-The only mandatory callback is `init/3`, needed to perform
-the protocol upgrade.
+All other callbacks are optional, though some may become
+required depending on the return value of previous callbacks.
 
 :: Types
 
@@ -43,46 +44,23 @@ The media-type is the content-type, excluding the charset.
 This value is always defined after the call to
 `content_types_provided/2`.
 
-:: Callbacks
-
-: init({TransportName, ProtocolName}, Req, Opts)
-	-> {upgrade, protocol, cowboy_rest}
-	| {upgrade, protocol, cowboy_rest, Req, Opts}
-
-Types:
-
-* TransportName = tcp | ssl | atom()
-* ProtocolName = http | atom()
-* Req = cowboy_req:req()
-* Opts = any()
-
-Upgrade the protocol to `cowboy_rest`.
-
-This is the only mandatory callback.
-
-: rest_init(Req, Opts) -> {ok, Req, State}
+:: Terminate reasons
 
-Types:
+The following values may be received as the terminate reason
+in the optional `terminate/3` callback.
 
-* Req = cowboy_req:req()
-* Opts = any()
-* State = any()
+: normal
 
-Initialize the state for this request.
+The connection was closed normally.
 
-: rest_terminate(Req, State) -> ok
+: {crash, Class, Reason}
 
-Types:
+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.
 
-* Req = cowboy_req:req()
-* State = any()
-
-Perform any necessary cleanup of the state.
-
-This callback should release any resource currently in use,
-clear any active timer and reset the process to its original
-state, as it might be reused for future requests sent on the
-same connection.
+:: Callbacks
 
 : Callback(Req, State) -> {Value, Req, State} | {halt, Req, State}
 
diff --git a/doc/src/manual/cowboy_websocket.ezdoc b/doc/src/manual/cowboy_websocket.ezdoc
index 59a6248..889ddd7 100644
--- a/doc/src/manual/cowboy_websocket.ezdoc
+++ b/doc/src/manual/cowboy_websocket.ezdoc
@@ -2,8 +2,25 @@
 
 The `cowboy_websocket` module implements the Websocket protocol.
 
-The callbacks for websocket handlers are defined in the manual
-for the `cowboy_websocket_handler` behaviour.
+This module is a sub protocol that defines four callbacks to
+be implemented by handlers. The `init/2` and `terminate/3`
+callbacks are common to all handler types and are documented
+in the manual for the ^cowboy_handler module.
+
+The `websocket_handle/3` and `websocket_info/3` callbacks are
+specific to Websocket handlers and will be called as many times
+as necessary until the Websocket connection is closed.
+
+The `init/2` callback can be used to negotiate Websocket protocol
+extensions with the client. It is highly recommended to return a
+timeout value from this callback to ensure that the process is
+terminated when no data has been received during that timespan.
+The default timeout is `infinity`, which should only be used if
+you have alternate means of ending inactive connections.
+
+Cowboy will terminate the process right after closing the
+Websocket connection. This means that there is no real need to
+perform any cleanup in the optional `terminate/3` callback.
 
 :: Types
 
@@ -31,6 +48,118 @@ Type: 7 | 8 | 13
 
 The version of the Websocket protocol being used.
 
+:: Terminate reasons
+
+The following values may be received as the terminate reason
+in the optional `terminate/3` callback.
+
+: normal
+
+The connection was closed normally before establishing a Websocket
+connection. This typically happens if an `ok` tuple is returned
+from the `init/2` callback.
+
+: remote
+
+The remote endpoint closed the connection without giving any
+further details.
+
+: {remote, Code, Payload}
+
+The remote endpoint closed the connection with the given
+`Code` and `Payload` as the reason.
+
+: shutdown
+
+The handler requested to close the connection, either by returning
+a `shutdown` tuple or by sending a `close` frame.
+
+: timeout
+
+The connection has been closed due to inactivity. The timeout
+value can be configured from `init/2`.
+
+: {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, badencoding}
+
+A text frame was sent by the client with invalid encoding. All
+text frames must be valid UTF-8.
+
+: {error, badframe}
+
+A protocol error has been detected.
+
+: {error, closed}
+
+The socket has been closed brutally without a close frame being
+received first.
+
+: {error, Reason}
+
+A socket error ocurred.
+
+:: Callbacks
+
+: websocket_handle(InFrame, Req, State)
+	-> {ok, Req, State}
+	| {ok, Req, State, hibernate}
+	| {reply, OutFrame | [OutFrame], Req, State}
+	| {reply, OutFrame | [OutFrame], Req, State, hibernate}
+	| {shutdown, Req, State}
+
+Types:
+
+* InFrame = {text | binary | ping | pong, binary()}
+* Req = cowboy_req:req()
+* State = any()
+* OutFrame = frame()
+
+Handle the data received from the Websocket connection.
+
+This function will be called every time data is received
+from the Websocket connection.
+
+The `shutdown` return value can be used to close the
+connection. A close reply will also result in the connection
+being closed.
+
+The `hibernate` option will hibernate the process until
+it receives new data from the Websocket connection or an
+Erlang message.
+
+: websocket_info(Info, Req, State)
+	-> {ok, Req, State}
+	| {ok, Req, State, hibernate}
+	| {reply, OutFrame | [OutFrame], Req, State}
+	| {reply, OutFrame | [OutFrame], Req, State, hibernate}
+	| {shutdown, Req, State}
+
+Types:
+
+* Info = any()
+* Req = cowboy_req:req()
+* State = any()
+* OutFrame = frame()
+
+Handle the Erlang message received.
+
+This function will be called every time an Erlang message
+has been received. The message can be any Erlang term.
+
+The `shutdown` return value can be used to close the
+connection. A close reply will also result in the connection
+being closed.
+
+The `hibernate` option will hibernate the process until
+it receives another message or new data from the Websocket
+connection.
+
 :: Exports
 
 None.
diff --git a/doc/src/manual/cowboy_websocket_handler.ezdoc b/doc/src/manual/cowboy_websocket_handler.ezdoc
deleted file mode 100644
index 0d31a54..0000000
--- a/doc/src/manual/cowboy_websocket_handler.ezdoc
+++ /dev/null
@@ -1,133 +0,0 @@
-::: cowboy_websocket_handler
-
-The `cowboy_websocket_handler` behaviour defines the interface used
-by Websocket handlers.
-
-The `init/3` and `websocket_init/3` callbacks will always be called,
-followed by zero or more calls to `websocket_handle/3` and
-`websocket_info/3`. The `websocket_terminate/3` will always
-be called last.
-
-:: Types
-
-None.
-
-:: Callbacks
-
-: init({TransportName, ProtocolName}, Req, Opts)
-	-> {upgrade, protocol, cowboy_websocket}
-	| {upgrade, protocol, cowboy_websocket, Req, Opts}
-
-Types:
-
-* TransportName = tcp | ssl | atom()
-* ProtocolName = http | atom()
-* Req = cowboy_req:req()
-* Opts = any()
-
-Upgrade the protocol to `cowboy_websocket`.
-
-: websocket_init(TransportName, Req, Opts)
-	-> {ok, Req, State}
-	| {ok, Req, State, hibernate}
-	| {ok, Req, State, Timeout}
-	| {ok, Req, State, Timeout, hibernate}
-	| {shutdown, Req}
-
-Types:
-
-* TransportName = tcp | ssl | atom()
-* Req = cowboy_req:req()
-* Opts = any()
-* State = any()
-* Timeout = timeout()
-
-Initialize the state for this session.
-
-This function is called before the upgrade to Websocket occurs.
-It can be used to negotiate Websocket protocol extensions
-with the client. It will typically be used to register this process
-to an event manager or a message queue in order to receive
-the messages the handler wants to process.
-
-The connection will stay up for a duration of up to `Timeout`
-milliseconds after it last received data from the socket,
-at which point it will stop and close the connection.
-By default this value is set to `infinity`. It is recommended
-to either set this value or ensure by any other mechanism
-that the handler will be closed after a certain period of
-inactivity.
-
-The `hibernate` option will hibernate the process until it
-starts receiving either data from the Websocket connection
-or Erlang messages.
-
-The `shutdown` return value can be used to close the connection
-before upgrading to Websocket.
-
-: websocket_handle(InFrame, Req, State)
-	-> {ok, Req, State}
-	| {ok, Req, State, hibernate}
-	| {reply, OutFrame | [OutFrame], Req, State}
-	| {reply, OutFrame | [OutFrame], Req, State, hibernate}
-	| {shutdown, Req, State}
-
-Types:
-
-* InFrame = {text | binary | ping | pong, binary()}
-* Req = cowboy_req:req()
-* State = any()
-* OutFrame = cowboy_websocket:frame()
-
-Handle the data received from the Websocket connection.
-
-This function will be called every time data is received
-from the Websocket connection.
-
-The `shutdown` return value can be used to close the
-connection. A close reply will also result in the connection
-being closed.
-
-The `hibernate` option will hibernate the process until
-it receives new data from the Websocket connection or an
-Erlang message.
-
-: websocket_info(Info, Req, State)
-	-> {ok, Req, State}
-	| {ok, Req, State, hibernate}
-	| {reply, OutFrame | [OutFrame], Req, State}
-	| {reply, OutFrame | [OutFrame], Req, State, hibernate}
-	| {shutdown, Req, State}
-
-Types:
-
-* Info = any()
-* Req = cowboy_req:req()
-* State = any()
-* OutFrame = cowboy_websocket:frame()
-
-Handle the Erlang message received.
-
-This function will be called every time an Erlang message
-has been received. The message can be any Erlang term.
-
-The `shutdown` return value can be used to close the
-connection. A close reply will also result in the connection
-being closed.
-
-The `hibernate` option will hibernate the process until
-it receives another message or new data from the Websocket
-connection.
-
-: websocket_terminate(Reason, Req, State) -> ok
-
-Types:
-
-* Reason = {normal, shutdown | timeout} | {remote, closed} | {remote, cowboy_websocket:close_code(), binary()} | {error, badencoding | badframe | closed | atom()}
-* Req = cowboy_req:req()
-* State = any()
-
-Perform any necessary cleanup of the state.
-
-The connection will be closed and the process stopped right
-after this call.
diff --git a/doc/src/manual/index.ezdoc b/doc/src/manual/index.ezdoc
index e364e90..133a341 100644
--- a/doc/src/manual/index.ezdoc
+++ b/doc/src/manual/index.ezdoc
@@ -5,8 +5,7 @@ The function reference documents the public interface of Cowboy.
 * ^"The Cowboy Application^cowboy_app
 * ^cowboy
 * ^cowboy_handler
-* ^cowboy_http_handler
-* ^cowboy_loop_handler
+* ^cowboy_loop
 * ^cowboy_middleware
 * ^cowboy_protocol
 * ^cowboy_req
@@ -16,5 +15,4 @@ The function reference documents the public interface of Cowboy.
 * ^cowboy_static
 * ^cowboy_sub_protocol
 * ^cowboy_websocket
-* ^cowboy_websocket_handler
 * ^"HTTP status codes^http_status_codes