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Diffstat (limited to 'docs/en/cowboy/2.0/guide/streams.asciidoc')
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diff --git a/docs/en/cowboy/2.0/guide/streams.asciidoc b/docs/en/cowboy/2.0/guide/streams.asciidoc deleted file mode 100644 index 841a9712..00000000 --- a/docs/en/cowboy/2.0/guide/streams.asciidoc +++ /dev/null @@ -1,65 +0,0 @@ -[[streams]] -== Streams - -A stream is the set of messages that form an HTTP -request/response pair. - -The term stream comes from HTTP/2. In Cowboy, it is -also used when talking about HTTP/1.1 or HTTP/1.0. -It should not be confused with streaming the request -or response body. - -All versions of HTTP allow clients to initiate -streams. HTTP/2 is the only one also allowing servers, -through its server push feature. Both client and -server-initiated streams go through the same process -in Cowboy. - -=== Stream handlers - -Stream handlers must implement five different callbacks. -Four of them are directly related; one is special. - -All callbacks receives the stream ID as first argument. - -Most of them can return a list of commands to be executed -by Cowboy. When callbacks are chained, it is possible to -intercept and modify these commands. This can be useful -for modifying responses for example. - -The `init/3` callback is invoked when a new request -comes in. It receives the Req object and the protocol options -for this listener. - -The `data/4` callback is invoked when data from the request -body is received. It receives both this data and a flag -indicating whether more is to be expected. - -The `info/3` callback is invoked when an Erlang message is -received for this stream. They will typically be messages -sent by the request process. - -Finally the `terminate/3` callback is invoked with the -terminate reason for the stream. The return value is ignored. -Note that as with all terminate callbacks in Erlang, there -is no strong guarantee that it will be called. - -The special callback `early_error/5` is called when an error -occurs before the request headers were fully received and -Cowboy is sending a response. It receives the partial Req -object, the error reason, the protocol options and the response -Cowboy will send. This response must be returned, possibly -modified. - -=== Built-in handlers - -Cowboy comes with two handlers. - -`cowboy_stream_h` is the default stream handler. -It is the core of much of the functionality of Cowboy. -All chains of stream handlers should call it last. - -`cowboy_compress_h` will 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. |