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author | Loïc Hoguin <[email protected]> | 2018-06-13 09:54:12 +0200 |
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committer | Loïc Hoguin <[email protected]> | 2018-06-13 09:54:12 +0200 |
commit | 92b54aacc0de5446dd5497c39897b0bbff72e626 (patch) | |
tree | c3a98cfec636d1271f5804e5c19b35b208bba00d /docs/en/cowboy/2.0/manual/cowboy_stream/index.html | |
parent | 8b5c3dc972b99f174750123c9e4abc96259c34a9 (diff) | |
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diff --git a/docs/en/cowboy/2.0/manual/cowboy_stream/index.html b/docs/en/cowboy/2.0/manual/cowboy_stream/index.html index 488e5d87..095b0831 100644 --- a/docs/en/cowboy/2.0/manual/cowboy_stream/index.html +++ b/docs/en/cowboy/2.0/manual/cowboy_stream/index.html @@ -62,411 +62,282 @@ <h1 class="lined-header"><span>cowboy_stream(3)</span></h1> -<div class="sect1"> <h2 id="_name">Name</h2> -<div class="sectionbody"> -<div class="paragraph"><p>cowboy_handler - Stream handlers</p></div> -</div> -</div> -<div class="sect1"> +<p>cowboy_handler - Stream handlers</p> <h2 id="_description">Description</h2> -<div class="sectionbody"> -<div class="paragraph"><p>The module <code>cowboy_stream</code> defines a callback interface -and a protocol for handling HTTP streams.</p></div> -<div class="paragraph"><p>An HTTP request and its associated response is called -a stream. A connection may have many streams. In HTTP/1.1 -they are executed sequentially, while in HTTP/2 they are -executed concurrently.</p></div> -<div class="paragraph"><p>Cowboy calls the stream handler for nearly all events -related to a stream. Exceptions vary depending on the -protocol.</p></div> -<div class="paragraph"><p>Extra care must be taken when implementing stream handlers -to ensure compatibility. While some modification of the -events and commands is allowed, it is generally not a good -idea to completely omit them.</p></div> -</div> -</div> -<div class="sect1"> +<p>The module <code>cowboy_stream</code> defines a callback interface and a protocol for handling HTTP streams.</p> +<p>An HTTP request and its associated response is called a stream. A connection may have many streams. In HTTP/1.1 they are executed sequentially, while in HTTP/2 they are executed concurrently.</p> +<p>Cowboy calls the stream handler for nearly all events related to a stream. Exceptions vary depending on the protocol.</p> +<p>Extra care must be taken when implementing stream handlers to ensure compatibility. While some modification of the events and commands is allowed, it is generally not a good idea to completely omit them.</p> <h2 id="_callbacks">Callbacks</h2> -<div class="sectionbody"> -<div class="paragraph"><p>Stream handlers must implement the following interface:</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Stream handlers must implement the following interface:</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">init</span></span>(<span style="color: #009900">StreamID</span>, <span style="color: #009900">Req</span>, <span style="color: #009900">Opts</span>) <span style="color: #990000">-></span> {<span style="color: #009900">Commands</span>, <span style="color: #009900">State</span>} -<span style="font-weight: bold"><span style="color: #000000">data</span></span>(<span style="color: #009900">StreamID</span>, <span style="color: #009900">IsFin</span>, <span style="color: #009900">Data</span>, <span style="color: #009900">State</span>) <span style="color: #990000">-></span> {<span style="color: #009900">Commands</span>, <span style="color: #009900">State</span>} -<span style="font-weight: bold"><span style="color: #000000">info</span></span>(<span style="color: #009900">StreamID</span>, <span style="color: #009900">Info</span>, <span style="color: #009900">State</span>) <span style="color: #990000">-></span> {<span style="color: #009900">Commands</span>, <span style="color: #009900">State</span>} -<span style="font-weight: bold"><span style="color: #000000">terminate</span></span>(<span style="color: #009900">StreamID</span>, <span style="color: #009900">Reason</span>, <span style="color: #009900">State</span>) <span style="color: #990000">-></span> <span style="font-weight: bold"><span style="color: #000000">any</span></span>() -<span style="font-weight: bold"><span style="color: #000000">early_error</span></span>(<span style="color: #009900">StreamID</span>, <span style="color: #009900">Reason</span>, <span style="color: #009900">PartialReq</span>, <span style="color: #009900">Resp</span>, <span style="color: #009900">Opts</span>) <span style="color: #990000">-></span> <span style="color: #009900">Resp</span> - -<span style="color: #009900">StreamID</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_stream:streamid</span></span>() -<span style="color: #009900">Req</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:req</span></span>() -<span style="color: #009900">Opts</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy:opts</span></span>() -<span style="color: #009900">Commands</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_stream:commands</span></span>() -<span style="color: #009900">State</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">any</span></span>() -<span style="color: #009900">IsFin</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_stream:fin</span></span>() -<span style="color: #009900">Data</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>() -<span style="color: #009900">Info</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">any</span></span>() -<span style="color: #009900">Reason</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_stream:reason</span></span>() -<span style="color: #009900">PartialReq</span> <span style="color: #990000">-</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:req</span></span>(), <span style="color: #FF6600">except</span> <span style="color: #FF6600">all</span> <span style="color: #FF6600">fields</span> <span style="color: #FF6600">are</span> <span style="color: #FF6600">optional</span> -<span style="color: #009900">Resp</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_stream:resp_command</span></span>()</tt></pre></div></div> -<div class="paragraph"><p>HTTP/1.1 will initialize a stream only when the request-line -and all headers have been received. When errors occur before -that point Cowboy will call the callback <code>early_error/5</code> -with a partial request, the error reason and the response -Cowboy intends to send. All other events go throuh the -stream handler using the normal callbacks.</p></div> -<div class="paragraph"><p>HTTP/2 will initialize the stream when the <code>HEADERS</code> block has -been fully received and decoded. Any protocol error occuring -before that will not result in a response being sent and -will therefore not go through the stream handler. In addition -Cowboy may terminate streams without sending an HTTP response -back.</p></div> -<div class="paragraph"><p>The stream is initialized by calling <code>init/3</code>. All streams -that are initialized will eventually be terminated by calling -<code>terminate/3</code>.</p></div> -<div class="paragraph"><p>When Cowboy receives data for the stream it will call <code>data/4</code>. -The data given is the request body after any transfer decoding -has been applied.</p></div> -<div class="paragraph"><p>When Cowboy receives a message addressed to a stream, or when -Cowboy needs to inform the stream handler that an internal -event has occurred, it will call <code>info/3</code>.</p></div> -</div> -</div> -<div class="sect1"> +<pre><tt><b><font color="#000000">init</font></b>(<font color="#009900">StreamID</font>, <font color="#009900">Req</font>, <font color="#009900">Opts</font>) <font color="#990000">-></font> {<font color="#009900">Commands</font>, <font color="#009900">State</font>} +<b><font color="#000000">data</font></b>(<font color="#009900">StreamID</font>, <font color="#009900">IsFin</font>, <font color="#009900">Data</font>, <font color="#009900">State</font>) <font color="#990000">-></font> {<font color="#009900">Commands</font>, <font color="#009900">State</font>} +<b><font color="#000000">info</font></b>(<font color="#009900">StreamID</font>, <font color="#009900">Info</font>, <font color="#009900">State</font>) <font color="#990000">-></font> {<font color="#009900">Commands</font>, <font color="#009900">State</font>} +<b><font color="#000000">terminate</font></b>(<font color="#009900">StreamID</font>, <font color="#009900">Reason</font>, <font color="#009900">State</font>) <font color="#990000">-></font> <b><font color="#000000">any</font></b>() +<b><font color="#000000">early_error</font></b>(<font color="#009900">StreamID</font>, <font color="#009900">Reason</font>, <font color="#009900">PartialReq</font>, <font color="#009900">Resp</font>, <font color="#009900">Opts</font>) <font color="#990000">-></font> <font color="#009900">Resp</font> + +<font color="#009900">StreamID</font> <font color="#990000">::</font> <b><font color="#000000">cowboy_stream:streamid</font></b>() +<font color="#009900">Req</font> <font color="#990000">::</font> <b><font color="#000000">cowboy_req:req</font></b>() +<font color="#009900">Opts</font> <font color="#990000">::</font> <b><font color="#000000">cowboy:opts</font></b>() +<font color="#009900">Commands</font> <font color="#990000">::</font> <b><font color="#000000">cowboy_stream:commands</font></b>() +<font color="#009900">State</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>() +<font color="#009900">IsFin</font> <font color="#990000">::</font> <b><font color="#000000">cowboy_stream:fin</font></b>() +<font color="#009900">Data</font> <font color="#990000">::</font> <b><font color="#000080">binary</font></b>() +<font color="#009900">Info</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>() +<font color="#009900">Reason</font> <font color="#990000">::</font> <b><font color="#000000">cowboy_stream:reason</font></b>() +<font color="#009900">PartialReq</font> <font color="#990000">-</font> <b><font color="#000000">cowboy_req:req</font></b>(), <font color="#FF6600">except</font> <font color="#FF6600">all</font> <font color="#FF6600">fields</font> <font color="#FF6600">are</font> <font color="#FF6600">optional</font> +<font color="#009900">Resp</font> <font color="#990000">::</font> <b><font color="#000000">cowboy_stream:resp_command</font></b>()</tt></pre> +</div></div> +<p>HTTP/1.1 will initialize a stream only when the request-line and all headers have been received. When errors occur before that point Cowboy will call the callback <code>early_error/5</code> with a partial request, the error reason and the response Cowboy intends to send. All other events go throuh the stream handler using the normal callbacks.</p> +<p>HTTP/2 will initialize the stream when the <code>HEADERS</code> block has been fully received and decoded. Any protocol error occuring before that will not result in a response being sent and will therefore not go through the stream handler. In addition Cowboy may terminate streams without sending an HTTP response back.</p> +<p>The stream is initialized by calling <code>init/3</code>. All streams that are initialized will eventually be terminated by calling <code>terminate/3</code>.</p> +<p>When Cowboy receives data for the stream it will call <code>data/4</code>. The data given is the request body after any transfer decoding has been applied.</p> +<p>When Cowboy receives a message addressed to a stream, or when Cowboy needs to inform the stream handler that an internal event has occurred, it will call <code>info/3</code>.</p> <h2 id="commands">Commands</h2> -<div class="sectionbody"> -<div class="paragraph"><p>Stream handlers can return a list of commands to be executed -from the <code>init/3</code>, <code>data/4</code> and <code>info/3</code> callbacks. In addition, -the <code>early_error/5</code> callback must return a response command.</p></div> -<div class="paragraph"><p>The following commands are defined:</p></div> -<div class="sect2"> +<p>Stream handlers can return a list of commands to be executed from the <code>init/3</code>, <code>data/4</code> and <code>info/3</code> callbacks. In addition, the <code>early_error/5</code> callback must return a response command.</p> +<!-- @todo We need a 'log' command that would call error_logger.--> +<!-- It's better than doing in the handlers directly because--> +<!-- then we can have other stream handlers manipulate those logs.--> +<!-- @todo We need a command to send a message so that other--> +<!-- stream handlers can manipulate these messages if necessary.--> +<p>The following commands are defined:</p> <h3 id="response_command">response</h3> -<div class="paragraph"><p>Send a response to the client.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Send a response to the client.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">response</span>, <span style="font-weight: bold"><span style="color: #000000">cowboy:http_status</span></span>(), <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>(), - <span style="font-weight: bold"><span style="color: #000000">cowboy_req:resp_body</span></span>()}</tt></pre></div></div> -<div class="paragraph"><p>No more data can be sent after this command.</p></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#FF6600">response</font>, <b><font color="#000000">cowboy:http_status</font></b>(), <b><font color="#000000">cowboy:http_headers</font></b>(), + <b><font color="#000000">cowboy_req:resp_body</font></b>()}</tt></pre> +</div></div> +<p>No more data can be sent after this command.</p> <h3 id="headers_command">headers</h3> -<div class="paragraph"><p>Initiate a response to the client.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Initiate a response to the client.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">headers</span>, <span style="font-weight: bold"><span style="color: #000000">cowboy:http_status</span></span>(), <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>()}</tt></pre></div></div> -<div class="paragraph"><p>This initiates a response to the client. The stream -will end when a data command with the <code>fin</code> flag is -returned.</p></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#FF6600">headers</font>, <b><font color="#000000">cowboy:http_status</font></b>(), <b><font color="#000000">cowboy:http_headers</font></b>()}</tt></pre> +</div></div> +<p>This initiates a response to the client. The stream will end when a data command with the <code>fin</code> flag is returned.</p> <h3 id="data_command">data</h3> -<div class="paragraph"><p>Send data to the client.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Send data to the client.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">data</span>, <span style="font-weight: bold"><span style="color: #000000">fin</span></span>(), <span style="font-weight: bold"><span style="color: #000000">iodata</span></span>()}</tt></pre></div></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#FF6600">data</font>, <b><font color="#000000">fin</font></b>(), <b><font color="#000000">iodata</font></b>()}</tt></pre> +</div></div> <h3 id="push_command">push</h3> -<div class="paragraph"><p>Push a resource to the client.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Push a resource to the client.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">push</span>, <span style="color: #009900">Method</span>, <span style="color: #009900">Scheme</span>, <span style="color: #009900">Host</span>, <span style="font-weight: bold"><span style="color: #000000">inet:port_number</span></span>(), - <span style="color: #009900">Path</span>, <span style="color: #009900">Qs</span>, <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>()} +<pre><tt>{<font color="#FF6600">push</font>, <font color="#009900">Method</font>, <font color="#009900">Scheme</font>, <font color="#009900">Host</font>, <b><font color="#000000">inet:port_number</font></b>(), + <font color="#009900">Path</font>, <font color="#009900">Qs</font>, <b><font color="#000000">cowboy:http_headers</font></b>()} -<span style="color: #009900">Method</span> <span style="color: #990000">=</span> <span style="color: #009900">Scheme</span> <span style="color: #990000">=</span> <span style="color: #009900">Host</span> <span style="color: #990000">=</span> <span style="color: #009900">Path</span> <span style="color: #990000">=</span> <span style="color: #009900">Qs</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>()</tt></pre></div></div> -<div class="paragraph"><p>The command will be ignored if the protocol does not provide -any server push mechanism.</p></div> -</div> -<div class="sect2"> +<font color="#009900">Method</font> <font color="#990000">=</font> <font color="#009900">Scheme</font> <font color="#990000">=</font> <font color="#009900">Host</font> <font color="#990000">=</font> <font color="#009900">Path</font> <font color="#990000">=</font> <font color="#009900">Qs</font> <font color="#990000">=</font> <b><font color="#000080">binary</font></b>()</tt></pre> +</div></div> +<p>The command will be ignored if the protocol does not provide any server push mechanism.</p> <h3 id="_flow">flow</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">flow</span>, <span style="font-weight: bold"><span style="color: #000000">pos_integer</span></span>()}</tt></pre></div></div> -<div class="paragraph"><p>Request more data to be read from the request body. The -exact behavior depends on the protocol.</p></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#FF6600">flow</font>, <b><font color="#000000">pos_integer</font></b>()}</tt></pre> +</div></div> +<p>Request more data to be read from the request body. The exact behavior depends on the protocol.</p> <h3 id="_spawn">spawn</h3> -<div class="paragraph"><p>Inform Cowboy that a process was spawned and should be -supervised.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Inform Cowboy that a process was spawned and should be supervised.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="font-weight: bold"><span style="color: #000080">spawn</span></span>, <span style="font-weight: bold"><span style="color: #000080">pid</span></span>(), <span style="font-weight: bold"><span style="color: #000000">timeout</span></span>()}</tt></pre></div></div> -</div> -<div class="sect2"> +<pre><tt>{<b><font color="#000080">spawn</font></b>, <b><font color="#000080">pid</font></b>(), <b><font color="#000000">timeout</font></b>()}</tt></pre> +</div></div> <h3 id="_error_response">error_response</h3> -<div class="paragraph"><p>Send an error response if no response was sent previously.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Send an error response if no response was sent previously.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">error_response</span>, <span style="font-weight: bold"><span style="color: #000000">cowboy:http_status</span></span>(), <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>(), <span style="font-weight: bold"><span style="color: #000000">iodata</span></span>()}</tt></pre></div></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#FF6600">error_response</font>, <b><font color="#000000">cowboy:http_status</font></b>(), <b><font color="#000000">cowboy:http_headers</font></b>(), <b><font color="#000000">iodata</font></b>()}</tt></pre> +</div></div> <h3 id="switch_protocol_command">switch_protocol</h3> -<div class="paragraph"><p>Switch to a different protocol.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Switch to a different protocol.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">switch_protocol</span>, <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>(), <span style="font-weight: bold"><span style="color: #000000">module</span></span>(), <span style="font-weight: bold"><span style="color: #000000">state</span></span>()}</tt></pre></div></div> -<div class="paragraph"><p>Contains the headers that will be sent in the 101 response, -along with the module implementing the protocol we are -switching to and its initial state.</p></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#FF6600">switch_protocol</font>, <b><font color="#000000">cowboy:http_headers</font></b>(), <b><font color="#000000">module</font></b>(), <b><font color="#000000">state</font></b>()}</tt></pre> +</div></div> +<p>Contains the headers that will be sent in the 101 response, along with the module implementing the protocol we are switching to and its initial state.</p> <h3 id="_stop">stop</h3> -<div class="paragraph"><p>Stop the stream.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Stop the stream.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="color: #FF6600">stop</span></tt></pre></div></div> -<div class="paragraph"><p>While no more data can be sent after the <code>fin</code> flag was set, -the stream is still tracked by Cowboy until it is stopped by -the handler.</p></div> -<div class="paragraph"><p>The behavior when stopping a stream for which no response -has been sent will vary depending on the protocol. The stream -will end successfully as far as the client is concerned.</p></div> -<div class="paragraph"><p>To indicate that an error occurred, either use <code>error_response</code> -before stopping, or use <code>internal_error</code>.</p></div> -</div> -<div class="sect2"> +<pre><tt><font color="#FF6600">stop</font></tt></pre> +</div></div> +<p>While no more data can be sent after the <code>fin</code> flag was set, the stream is still tracked by Cowboy until it is stopped by the handler.</p> +<p>The behavior when stopping a stream for which no response has been sent will vary depending on the protocol. The stream will end successfully as far as the client is concerned.</p> +<p>To indicate that an error occurred, either use <code>error_response</code> before stopping, or use <code>internal_error</code>.</p> <h3 id="_internal_error">internal_error</h3> -<div class="paragraph"><p>Stop the stream with an error.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<p>Stop the stream with an error.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #FF6600">internal_error</span>, <span style="color: #009900">Reason</span>, <span style="color: #009900">HumanReadable</span>} - -<span style="color: #009900">Reason</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">any</span></span>() -<span style="color: #009900">HumanReadable</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000080">atom</span></span>()</tt></pre></div></div> -<div class="paragraph"><p>This command should be used when the stream cannot continue -because of an internal error. An <code>error_response</code> command -may be sent before that to advertise to the client why the -stream is dropped.</p></div> -</div> -</div> -</div> -<div class="sect1"> +<pre><tt>{<font color="#FF6600">internal_error</font>, <font color="#009900">Reason</font>, <font color="#009900">HumanReadable</font>} + +<font color="#009900">Reason</font> <font color="#990000">=</font> <b><font color="#000000">any</font></b>() +<font color="#009900">HumanReadable</font> <font color="#990000">=</font> <b><font color="#000080">atom</font></b>()</tt></pre> +</div></div> +<p>This command should be used when the stream cannot continue because of an internal error. An <code>error_response</code> command may be sent before that to advertise to the client why the stream is dropped.</p> <h2 id="_predefined_events">Predefined events</h2> -<div class="sectionbody"> -<div class="paragraph"><p>Cowboy will forward all messages sent to the stream to -the <code>info/3</code> callback. To send a message to a stream, -send a message to the connection process with the form -<code>{{Pid, StreamID}, Msg}</code>. The connection process will -then forward <code>Msg</code> to the stream handlers.</p></div> -<div class="paragraph"><p>Cowboy will also forward the exit signals for the -processes that the stream spawned.</p></div> -<div class="sect2"> +<p>Cowboy will forward all messages sent to the stream to the <code>info/3</code> callback. To send a message to a stream, send a message to the connection process with the form <code>{{Pid, StreamID}, Msg}</code>. The connection process will then forward <code>Msg</code> to the stream handlers.</p> +<p>Cowboy will also forward the exit signals for the processes that the stream spawned.</p> <h3 id="_exit">EXIT</h3> -<div class="paragraph"><p>A process spawned by this stream has exited.</p></div> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<!-- info(_StreamID, {'EXIT', Pid, normal}, State=#state{pid=Pid}) ->--> +<!-- info(_StreamID, {'EXIT', Pid, {_Reason, [_, {cow_http_hd, _, _, _}|_]}}, State=#state{pid=Pid}) ->--> +<!-- info(StreamID, Exit = {'EXIT', Pid, {Reason, Stacktrace}}, State=#state{ref=Ref, pid=Pid}) ->--> +<p>A process spawned by this stream has exited.</p> +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt>{<span style="color: #000080">'EXIT'</span>, <span style="font-weight: bold"><span style="color: #000080">pid</span></span>(), <span style="font-weight: bold"><span style="color: #000000">any</span></span>()}</tt></pre></div></div> -<div class="paragraph"><p>This is the raw exit message without any modification.</p></div> -</div> -<div class="sect2"> +<pre><tt>{<font color="#000080">'EXIT'</font>, <b><font color="#000080">pid</font></b>(), <b><font color="#000000">any</font></b>()}</tt></pre> +</div></div> +<p>This is the raw exit message without any modification.</p> +<!-- === read_body--> +<!-- --> +<!-- //info(_StreamID, {read_body, Ref, Length, _},--> +<!-- //info(StreamID, {read_body, Ref, Length, Period}, State) ->--> +<!-- --> +<!-- TODO yeah I am not actually sure this one should be public just yet--> +<!-- TODO if it is, then we probably shouldn't send a message directly,--> +<!-- TODO but rather return a command that will end up sending the message--> +<!-- --> +<!-- TODO The problem being that no stream handler has access to that--> +<!-- TODO message if we send it directly. So we should have a command--> +<!-- TODO send_message or something that can be seen from all handlers.--> +<!-- --> +<!-- TODO The thing is that stream handlers can have 0 to N processes--> +<!-- TODO so we have to make it easy to say which process should--> +<!-- TODO receive the message, and perhaps *identify* which process--> +<!-- TODO gets it?--> <h3 id="_response">response</h3> -<div class="paragraph"><p>Same as the <a href="../response_command">response command</a>.</p></div> -<div class="paragraph"><p>Usually sent when the request process replies to the client. -May also be sent by Cowboy internally.</p></div> -</div> -<div class="sect2"> +<p>Same as the <a href="../response_command">response command</a>.</p> +<p>Usually sent when the request process replies to the client. May also be sent by Cowboy internally.</p> <h3 id="_headers">headers</h3> -<div class="paragraph"><p>Same as the <a href="../headers_command">headers command</a>.</p></div> -<div class="paragraph"><p>Sent when the request process starts replying to the client.</p></div> -</div> -<div class="sect2"> +<p>Same as the <a href="../headers_command">headers command</a>.</p> +<p>Sent when the request process starts replying to the client.</p> <h3 id="_data">data</h3> -<div class="paragraph"><p>Same as the <a href="../data_command">data command</a>.</p></div> -<div class="paragraph"><p>Sent when the request process streams data to the client.</p></div> -</div> -<div class="sect2"> +<p>Same as the <a href="../data_command">data command</a>.</p> +<p>Sent when the request process streams data to the client.</p> <h3 id="_push">push</h3> -<div class="paragraph"><p>Same as the <a href="../push_command">push command</a>.</p></div> -<div class="paragraph"><p>Sent when the request process pushes a resource to the client.</p></div> -</div> -<div class="sect2"> +<p>Same as the <a href="../push_command">push command</a>.</p> +<p>Sent when the request process pushes a resource to the client.</p> <h3 id="_switch_protocol">switch_protocol</h3> -<div class="paragraph"><p>Same as the <a href="../switch_protocol_command">switch_protocol command</a>.</p></div> -<div class="paragraph"><p>Sent when switching to the HTTP/2 or Websocket protocol.</p></div> -</div> -</div> -</div> -<div class="sect1"> +<p>Same as the <a href="../switch_protocol_command">switch_protocol command</a>.</p> +<!-- @todo Not done for HTTP/2 yet.--> +<p>Sent when switching to the HTTP/2 or Websocket protocol.</p> <h2 id="_exports">Exports</h2> -<div class="sectionbody"> -<div class="paragraph"><p>The following function should be called by modules implementing -stream handlers to execute the next stream handler in the list:</p></div> -<div class="ulist"><ul> -<li> -<p> -<a href="../cowboy_stream.init">cowboy_stream:init(3)</a> - Initialize a stream -</p> +<p>The following function should be called by modules implementing stream handlers to execute the next stream handler in the list:</p> +<ul><li><a href="../cowboy_stream.init">cowboy_stream:init(3)</a> - Initialize a stream </li> -<li> -<p> -<a href="../cowboy_stream.data">cowboy_stream:data(3)</a> - Handle data for a stream -</p> +<li><a href="../cowboy_stream.data">cowboy_stream:data(3)</a> - Handle data for a stream </li> -<li> -<p> -<a href="../cowboy_stream.info">cowboy_stream:info(3)</a> - Handle a message for a stream -</p> +<li><a href="../cowboy_stream.info">cowboy_stream:info(3)</a> - Handle a message for a stream </li> -<li> -<p> -<a href="../cowboy_stream.terminate">cowboy_stream:terminate(3)</a> - Terminate a stream -</p> +<li><a href="../cowboy_stream.terminate">cowboy_stream:terminate(3)</a> - Terminate a stream </li> -<li> -<p> -<a href="../cowboy_stream.early_error">cowboy_stream:early_error(3)</a> - Handle an early error for a stream -</p> +<li><a href="../cowboy_stream.early_error">cowboy_stream:early_error(3)</a> - Handle an early error for a stream </li> -</ul></div> -</div> -</div> -<div class="sect1"> +</ul> <h2 id="_types">Types</h2> -<div class="sectionbody"> -<div class="sect2"> <h3 id="_commands">commands()</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">commands</span></span>() <span style="color: #990000">::</span> [<span style="color: #009900">Command</span>]</tt></pre></div></div> -<div class="paragraph"><p>See the <a href="../commands">list of commands</a> for details.</p></div> -</div> -<div class="sect2"> +<pre><tt><b><font color="#000000">commands</font></b>() <font color="#990000">::</font> [<font color="#009900">Command</font>]</tt></pre> +</div></div> +<p>See the <a href="../commands">list of commands</a> for details.</p> <h3 id="_fin">fin()</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">fin</span></span>() <span style="color: #990000">::</span> <span style="color: #FF6600">fin</span> | <span style="color: #FF6600">nofin</span></tt></pre></div></div> -<div class="paragraph"><p>Used in commands and events to indicate that this is -the end of the stream.</p></div> -</div> -<div class="sect2"> +<pre><tt><b><font color="#000000">fin</font></b>() <font color="#990000">::</font> <font color="#FF6600">fin</font> | <font color="#FF6600">nofin</font></tt></pre> +</div></div> +<p>Used in commands and events to indicate that this is the end of the stream.</p> <h3 id="_partial_req">partial_req()</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">req</span></span>() <span style="color: #990000">::</span> #{ - <span style="color: #0000FF">method</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="font-style: italic"><span style="color: #9A1900">%% case sensitive</span></span> - <span style="color: #0000FF">version</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000000">cowboy:http_version</span></span>() | <span style="font-weight: bold"><span style="color: #000080">atom</span></span>(), - <span style="color: #0000FF">scheme</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="font-style: italic"><span style="color: #9A1900">%% lowercase; case insensitive</span></span> - <span style="color: #0000FF">host</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="font-style: italic"><span style="color: #9A1900">%% lowercase; case insensitive</span></span> - <span style="color: #0000FF">port</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000000">inet:port_number</span></span>(), - <span style="color: #0000FF">path</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="font-style: italic"><span style="color: #9A1900">%% case sensitive</span></span> - <span style="color: #0000FF">qs</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="font-style: italic"><span style="color: #9A1900">%% case sensitive</span></span> - <span style="color: #0000FF">headers</span> <span style="color: #990000">=></span> <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>(), - <span style="color: #0000FF">peer</span> <span style="color: #990000">=></span> {<span style="font-weight: bold"><span style="color: #000000">inet:ip_address</span></span>(), <span style="font-weight: bold"><span style="color: #000000">inet:port_number</span></span>()} -}</tt></pre></div></div> -<div class="paragraph"><p>Partial request information received when an early error is -detected.</p></div> -</div> -<div class="sect2"> +<pre><tt><b><font color="#000000">req</font></b>() <font color="#990000">::</font> #{ + <font color="#0000FF">method</font> <font color="#990000">=></font> <b><font color="#000080">binary</font></b>(), <i><font color="#9A1900">%% case sensitive</font></i> + <font color="#0000FF">version</font> <font color="#990000">=></font> <b><font color="#000000">cowboy:http_version</font></b>() | <b><font color="#000080">atom</font></b>(), + <font color="#0000FF">scheme</font> <font color="#990000">=></font> <b><font color="#000080">binary</font></b>(), <i><font color="#9A1900">%% lowercase; case insensitive</font></i> + <font color="#0000FF">host</font> <font color="#990000">=></font> <b><font color="#000080">binary</font></b>(), <i><font color="#9A1900">%% lowercase; case insensitive</font></i> + <font color="#0000FF">port</font> <font color="#990000">=></font> <b><font color="#000000">inet:port_number</font></b>(), + <font color="#0000FF">path</font> <font color="#990000">=></font> <b><font color="#000080">binary</font></b>(), <i><font color="#9A1900">%% case sensitive</font></i> + <font color="#0000FF">qs</font> <font color="#990000">=></font> <b><font color="#000080">binary</font></b>(), <i><font color="#9A1900">%% case sensitive</font></i> + <font color="#0000FF">headers</font> <font color="#990000">=></font> <b><font color="#000000">cowboy:http_headers</font></b>(), + <font color="#0000FF">peer</font> <font color="#990000">=></font> {<b><font color="#000000">inet:ip_address</font></b>(), <b><font color="#000000">inet:port_number</font></b>()} +}</tt></pre> +</div></div> +<p>Partial request information received when an early error is detected.</p> <h3 id="_reason">reason()</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">reason</span></span>() <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000080">normal</span></span> - | {<span style="color: #FF6600">internal_error</span>, <span style="color: #FF6600">timeout</span> | {<span style="color: #FF6600">error</span> | <span style="font-weight: bold"><span style="color: #000080">exit</span></span> | <span style="font-weight: bold"><span style="color: #000080">throw</span></span>, <span style="font-weight: bold"><span style="color: #000000">any</span></span>()}, <span style="color: #009900">HumanReadable</span>} - | {<span style="color: #FF6600">socket_error</span>, <span style="color: #FF6600">closed</span> | <span style="font-weight: bold"><span style="color: #000080">atom</span></span>(), <span style="color: #009900">HumanReadable</span>} - | {<span style="color: #FF6600">stream_error</span>, <span style="color: #009900">Error</span>, <span style="color: #009900">HumanReadable</span>} - | {<span style="color: #FF6600">connection_error</span>, <span style="color: #009900">Error</span>, <span style="color: #009900">HumanReadable</span>} - | {<span style="color: #FF6600">stop</span>, <span style="font-weight: bold"><span style="color: #000000">cow_http2:frame</span></span>(), <span style="color: #009900">HumanReadable</span>} - -<span style="color: #009900">Error</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000080">atom</span></span>() -<span style="color: #009900">HumanReadable</span> <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000080">atom</span></span>()</tt></pre></div></div> -<div class="paragraph"><p>Reason for the stream termination.</p></div> -</div> -<div class="sect2"> +<pre><tt><b><font color="#000000">reason</font></b>() <font color="#990000">::</font> <b><font color="#000080">normal</font></b> + | {<font color="#FF6600">internal_error</font>, <font color="#FF6600">timeout</font> | {<font color="#FF6600">error</font> | <b><font color="#000080">exit</font></b> | <b><font color="#000080">throw</font></b>, <b><font color="#000000">any</font></b>()}, <font color="#009900">HumanReadable</font>} + | {<font color="#FF6600">socket_error</font>, <font color="#FF6600">closed</font> | <b><font color="#000080">atom</font></b>(), <font color="#009900">HumanReadable</font>} + | {<font color="#FF6600">stream_error</font>, <font color="#009900">Error</font>, <font color="#009900">HumanReadable</font>} + | {<font color="#FF6600">connection_error</font>, <font color="#009900">Error</font>, <font color="#009900">HumanReadable</font>} + | {<font color="#FF6600">stop</font>, <b><font color="#000000">cow_http2:frame</font></b>(), <font color="#009900">HumanReadable</font>} + +<font color="#009900">Error</font> <font color="#990000">=</font> <b><font color="#000080">atom</font></b>() +<font color="#009900">HumanReadable</font> <font color="#990000">=</font> <b><font color="#000080">atom</font></b>()</tt></pre> +</div></div> +<p>Reason for the stream termination.</p> <h3 id="_resp_command">resp_command()</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">resp_command</span></span>() <span style="color: #990000">::</span> {<span style="color: #FF6600">response</span>, <span style="font-weight: bold"><span style="color: #000000">cowboy:http_status</span></span>(), - <span style="font-weight: bold"><span style="color: #000000">cowboy:http_headers</span></span>(), <span style="font-weight: bold"><span style="color: #000000">cowboy_req:resp_body</span></span>()}</tt></pre></div></div> -<div class="paragraph"><p>See the <a href="../response_command">response command</a> for details.</p></div> -</div> -<div class="sect2"> +<pre><tt><b><font color="#000000">resp_command</font></b>() <font color="#990000">::</font> {<font color="#FF6600">response</font>, <b><font color="#000000">cowboy:http_status</font></b>(), + <b><font color="#000000">cowboy:http_headers</font></b>(), <b><font color="#000000">cowboy_req:resp_body</font></b>()}</tt></pre> +</div></div> +<p>See the <a href="../response_command">response command</a> for details.</p> <h3 id="_streamid">streamid()</h3> -<div class="listingblock"> -<div class="content"><!-- Generator: GNU source-highlight +<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.8 by Lorenzo Bettini http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite --> -<pre><tt><span style="font-weight: bold"><span style="color: #000000">streamid</span></span>() <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">any</span></span>()</tt></pre></div></div> -<div class="paragraph"><p>The identifier for this stream.</p></div> -<div class="paragraph"><p>The identifier is unique over the connection process. -It is possible to form a unique identifier node-wide and -cluster-wide by wrapping it in a <code>{self(), StreamID}</code> -tuple.</p></div> -</div> -</div> -</div> -<div class="sect1"> +<pre><tt><b><font color="#000000">streamid</font></b>() <font color="#990000">::</font> <b><font color="#000000">any</font></b>()</tt></pre> +</div></div> +<p>The identifier for this stream.</p> +<p>The identifier is unique over the connection process. It is possible to form a unique identifier node-wide and cluster-wide by wrapping it in a <code>{self(), StreamID}</code> tuple.</p> <h2 id="_changelog">Changelog</h2> -<div class="sectionbody"> -<div class="ulist"><ul> -<li> -<p> -<strong>2.0</strong>: Module introduced. -</p> +<ul><li><strong>2.0</strong>: Module introduced. </li> -</ul></div> -</div> -</div> -<div class="sect1"> +</ul> <h2 id="_see_also">See also</h2> -<div class="sectionbody"> -<div class="paragraph"><p><a href="..">cowboy(7)</a>, -<a href="../cowboy_http">cowboy_http(3)</a>, -<a href="../cowboy_http2">cowboy_http2(3)</a></p></div> -</div> -</div> +<p><a href="..">cowboy(7)</a>, <a href="../cowboy_http">cowboy_http(3)</a>, <a href="../cowboy_http2">cowboy_http2(3)</a></p> + |