Add cowboy_decompress_h stream handler

doc/src/guide/streams.asciidoc

@@ -65,6 +65,11 @@ automatically compress responses when possible. It is not
 enabled by default. It is a good example for writing your
 own handlers that will modify responses.
 
+link:man:cowboy_decompress_h(3)[cowboy_decompress_h] will
+automatically decompress requests when possible. It is not
+enabled by default. It is a good example for writing your
+own handlers that will modify requests.
+
 link:man:cowboy_metrics_h(3)[cowboy_metrics_h] gathers
 metrics about a stream then passes them to a configurable
 function. It is not enabled by default.

doc/src/manual/cowboy_compress_h.asciidoc

@@ -63,6 +63,7 @@ The compress stream handler does not produce any event.
 
 link:man:cowboy(7)[cowboy(7)],
 link:man:cowboy_stream(3)[cowboy_stream(3)],
+link:man:cowboy_decompress_h(3)[cowboy_decompress_h(3)],
 link:man:cowboy_metrics_h(3)[cowboy_metrics_h(3)],
 link:man:cowboy_stream_h(3)[cowboy_stream_h(3)],
 link:man:cowboy_tracer_h(3)[cowboy_tracer_h(3)]

doc/src/manual/cowboy_decompress_h.asciidoc

@@ -0,0 +1,58 @@
+= cowboy_decompress_h(3)
+
+== Name
+
+cowboy_decompress_h - Decompress stream handler
+
+== Description
+
+The module `cowboy_decompress_h` decompresses request bodies
+automatically when the server supports it. Requests will
+only be decompressed when their compression ratio is lower
+than the configured limit. Mismatch of the content and
+`content-encoding` is rejected with `400 Bad Request`.
+
+== Options
+
+[source,erlang]
+----
+opts() :: #{
+	decompress_ratio_limit => non_neg_integer(),
+	decompress_ignore => boolean()
+}
+----
+
+Configuration for the decompress stream handler.
+
+The default value is given next to the option name:
+
+decompress_ratio_limit (20)::
+The max ratio of the compressed and decompressed body
+before it is rejected with `413 Payload Too Large`.
++
+This option can be updated at any time using the
+`set_options` stream handler command.
+
+decompress_ignore (false)::
+
+Whether the handler will be ignored.
++
+This option can be updated at any time using the
+`set_options` stream handler command.
+
+== Events
+
+The decompress stream handler does not produce any event.
+
+== Changelog
+
+* *2.11*: Module introduced.
+
+== See also
+
+link:man:cowboy(7)[cowboy(7)],
+link:man:cowboy_stream(3)[cowboy_stream(3)],
+link:man:cowboy_compress_h(3)[cowboy_compress_h(3)],
+link:man:cowboy_metrics_h(3)[cowboy_metrics_h(3)],
+link:man:cowboy_stream_h(3)[cowboy_stream_h(3)],
+link:man:cowboy_tracer_h(3)[cowboy_tracer_h(3)]

doc/src/manual/cowboy_metrics_h.asciidoc

@@ -160,5 +160,6 @@ The metrics stream handler does not produce any event.
 link:man:cowboy(7)[cowboy(7)],
 link:man:cowboy_stream(3)[cowboy_stream(3)],
 link:man:cowboy_compress_h(3)[cowboy_compress_h(3)],
+link:man:cowboy_decompress_h(3)[cowboy_decompress_h(3)],
 link:man:cowboy_stream_h(3)[cowboy_stream_h(3)],
 link:man:cowboy_tracer_h(3)[cowboy_tracer_h(3)]

doc/src/manual/cowboy_stream_h.asciidoc

@@ -69,5 +69,6 @@ may not work properly if they are executed
 link:man:cowboy(7)[cowboy(7)],
 link:man:cowboy_stream(3)[cowboy_stream(3)],
 link:man:cowboy_compress_h(3)[cowboy_compress_h(3)],
+link:man:cowboy_decompress_h(3)[cowboy_decompress_h(3)],
 link:man:cowboy_metrics_h(3)[cowboy_metrics_h(3)],
 link:man:cowboy_tracer_h(3)[cowboy_tracer_h(3)]

doc/src/manual/cowboy_tracer_h.asciidoc

@@ -84,5 +84,6 @@ The tracer stream handler does not produce any event.
 link:man:cowboy(7)[cowboy(7)],
 link:man:cowboy_stream(3)[cowboy_stream(3)],
 link:man:cowboy_compress_h(3)[cowboy_compress_h(3)],
+link:man:cowboy_decompress_h(3)[cowboy_decompress_h(3)],
 link:man:cowboy_metrics_h(3)[cowboy_metrics_h(3)],
 link:man:cowboy_stream_h(3)[cowboy_stream_h(3)]