They are now cowboy:start_clear/3 and cowboy:start_tls/3.
The NumAcceptors argument can be specified via the
num_acceptor transport option. Ranch has been updated
to 1.4.0 to that effect.
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.
This change simplifies a little more the sub protocols mechanism.
Aliases have been removed. The renaming of loop handlers as long
polling handlers has been reverted.
Plain HTTP handlers now simply do their work in the init/2
callback. There is no specific code for them.
Loop handlers now follow the same return value as Websocket,
they use ok to continue and shutdown to stop.
Terminate reasons for all handler types have been documented.
The terminate callback is now appropriately called in all cases
(or should be).
Behaviors for all handler types have been moved in the module
that implement them. This means that cowboy_handler replaces
the cowboy_http_handler behavior, and similarly cowboy_loop
replaces cowboy_loop_handler, cowboy_websocket replaces
cowboy_websocket_handler. Finally cowboy_rest now has the
start of a behavior in it and will have the full list of
optional callbacks defined once Erlang 18.0 gets released.
The guide has been reorganized and should be easier to follow.
This set of changes is the first step to simplify the
writing of handlers, by removing some extraneous
callbacks and making others optional.
init/3 is now init/2, its first argument being removed.
rest_init/2 and rest_terminate/2 have been removed.
websocket_init/3 and websocket_terminate/3 have been removed.
terminate/3 is now optional. It is called regardless of
the type of handler, including rest and websocket.
The return value of init/2 changed. It now returns
{Mod, Req, Opts} with Mod being either one of the four
handler type or a custom module. It can also return extra
timeout and hibernate options.
The signature for sub protocols has changed, they now
receive these extra timeout and hibernate options.
Loop handlers are now implemented in cowboy_long_polling,
and will be renamed throughout the project in a future commit.
Simplify the interface for most cowboy_req functions. They all return
a single value except the four body reading functions. The reply functions
now only return a Req value.
Access functions do not return a Req anymore.
Functions that used to cache results do not have a cache anymore.
The interface for accessing query string and cookies has therefore
been changed.
There are now three query string functions: qs/1 provides access
to the raw query string value; parse_qs/1 returns the query string
as a list of key/values; match_qs/2 returns a map containing the
values requested in the second argument, after applying constraints
and default value.
Similarly, there are two cookie functions: parse_cookies/1 and
match_cookies/2. More match functions will be added in future commits.
None of the functions return an error tuple anymore. It either works
or crashes. Cowboy will attempt to provide an appropriate status code
in the response of crashed handlers.
As a result, the content decode function has its return value changed
to a simple binary, and the body reading functions only return on success.
Changes include:
* Much simplified route configuration.
* Etag generation is now enabled by default.
* Web mimetypes are now detected by default. A bigger list of
mimetypes can be detected without any additional library.
* Mimetypes can no longer be specified as a list. Copying this
list for new connections is too costy. You can easily convert
it into a function and pass that function to the handler instead.
* You can however specify a single hardcoded mimetype. Mostly
useful when serving a single file, like an index.html file,
to avoid extra operations.
* Specifying a path as a list of tokens is not possible anymore.
Use either a binary or a string.
* Using a private directory will not work if the application
was not started properly. Cowboy will not attempt to find
the location of this directory if the VM doesn't know it,
as this caused issues in some setups.
* Overall the code has been much simplified and clarified,
and of course has now been documented.
