<liclass="toctree-l2"><aclass="reference internal"href="package_README.html#client-server-and-proxy-programs">Client, Server and Proxy programs</a></li>
<h2>Remarks<aclass="headerlink"href="#remarks"title="Permalink to this headline">¶</a></h2>
<p>Do not call <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a>, <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> from the nghttp2 callback functions
directly or indirectly. It will lead to the crash. You can submit
requests or frames in the callbacks then call <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a>,
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> outside of the
callbacks.</p>
</div>
<divclass="section"id="macros">
<h2>Macros<aclass="headerlink"href="#macros"title="Permalink to this headline">¶</a></h2>
<dlclass="macro">
<dtid="NGHTTP2_VERSION">
<ttclass="descname">NGHTTP2_VERSION</tt><aclass="headerlink"href="#NGHTTP2_VERSION"title="Permalink to this definition">¶</a></dt>
<dd><p>Version number of the nghttp2 library release</p>
<ttclass="descname">NGHTTP2_PROTO_VERSION_ID</tt><aclass="headerlink"href="#NGHTTP2_PROTO_VERSION_ID"title="Permalink to this definition">¶</a></dt>
<dd><p>The protocol version identification of this library supports.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_PROTO_VERSION_ID_LEN">
<ttclass="descname">NGHTTP2_PROTO_VERSION_ID_LEN</tt><aclass="headerlink"href="#NGHTTP2_PROTO_VERSION_ID_LEN"title="Permalink to this definition">¶</a></dt>
<dd><p>The length of <aclass="reference internal"href="#NGHTTP2_PROTO_VERSION_ID"title="NGHTTP2_PROTO_VERSION_ID"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_PROTO_VERSION_ID</span></tt></a>.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_VERSION_AGE">
<ttclass="descname">NGHTTP2_VERSION_AGE</tt><aclass="headerlink"href="#NGHTTP2_VERSION_AGE"title="Permalink to this definition">¶</a></dt>
<dd><p>The age of <aclass="reference internal"href="#nghttp2_info"title="nghttp2_info"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_info</span></tt></a></p>
<ttclass="descname">NGHTTP2_INITIAL_WINDOW_SIZE</tt><aclass="headerlink"href="#NGHTTP2_INITIAL_WINDOW_SIZE"title="Permalink to this definition">¶</a></dt>
<dd><p>The initial window size for stream level flow control.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_INITIAL_CONNECTION_WINDOW_SIZE">
<ttclass="descname">NGHTTP2_INITIAL_CONNECTION_WINDOW_SIZE</tt><aclass="headerlink"href="#NGHTTP2_INITIAL_CONNECTION_WINDOW_SIZE"title="Permalink to this definition">¶</a></dt>
<dd><p>The initial window size for connection level flow control.</p>
<ttclass="descname">NGHTTP2_MAX_HEADER_TABLE_SIZE</tt><aclass="headerlink"href="#NGHTTP2_MAX_HEADER_TABLE_SIZE"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_CLIENT_CONNECTION_HEADER</tt><aclass="headerlink"href="#NGHTTP2_CLIENT_CONNECTION_HEADER"title="Permalink to this definition">¶</a></dt>
<dd><p>The client connection header.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_CLIENT_CONNECTION_HEADER_LEN">
<ttclass="descname">NGHTTP2_CLIENT_CONNECTION_HEADER_LEN</tt><aclass="headerlink"href="#NGHTTP2_CLIENT_CONNECTION_HEADER_LEN"title="Permalink to this definition">¶</a></dt>
<dd><p>The length of <aclass="reference internal"href="#NGHTTP2_CLIENT_CONNECTION_HEADER"title="NGHTTP2_CLIENT_CONNECTION_HEADER"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_CLIENT_CONNECTION_HEADER</span></tt></a>.</p>
<ttclass="descname">NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS</tt><aclass="headerlink"href="#NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS"title="Permalink to this definition">¶</a></dt>
<dd><p>Default maximum concurrent streams.</p>
</dd></dl>
</div>
<divclass="section"id="enums">
<h2>Enums<aclass="headerlink"href="#enums"title="Permalink to this headline">¶</a></h2>
<dlclass="type">
<dtid="nghttp2_error">
<ttclass="descname">nghttp2_error</tt><aclass="headerlink"href="#nghttp2_error"title="Permalink to this definition">¶</a></dt>
<dd><p>Error codes used in this library. The code range is [-999, -500],
inclusive. The following values are defined:</p>
<dlclass="macro">
<dtid="NGHTTP2_ERR_INVALID_ARGUMENT">
<ttclass="descname">NGHTTP2_ERR_INVALID_ARGUMENT</tt><aclass="headerlink"href="#NGHTTP2_ERR_INVALID_ARGUMENT"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_UNSUPPORTED_VERSION</tt><aclass="headerlink"href="#NGHTTP2_ERR_UNSUPPORTED_VERSION"title="Permalink to this definition">¶</a></dt>
Used as a return value from <aclass="reference internal"href="#nghttp2_send_callback"title="nghttp2_send_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_send_callback</span></tt></a> and
<aclass="reference internal"href="#nghttp2_recv_callback"title="nghttp2_recv_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_recv_callback</span></tt></a> to indicate that the operation
would block.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_PROTO">
<ttclass="descname">NGHTTP2_ERR_PROTO</tt><aclass="headerlink"href="#NGHTTP2_ERR_PROTO"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_data_source_read_callback"title="nghttp2_data_source_read_callback"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_data_source_read_callback()</span></tt></a> to indicate that data
transfer is postponed. See
<aclass="reference internal"href="#nghttp2_data_source_read_callback"title="nghttp2_data_source_read_callback"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_data_source_read_callback()</span></tt></a> for details.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE">
<ttclass="descname">NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE</tt><aclass="headerlink"href="#NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE"title="Permalink to this definition">¶</a></dt>
The stream is already closed; or the stream ID is invalid.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_STREAM_CLOSING">
<ttclass="descname">NGHTTP2_ERR_STREAM_CLOSING</tt><aclass="headerlink"href="#NGHTTP2_ERR_STREAM_CLOSING"title="Permalink to this definition">¶</a></dt>
RST_STREAM has been added to the outbound queue. The stream is in
closing state.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_STREAM_SHUT_WR">
<ttclass="descname">NGHTTP2_ERR_STREAM_SHUT_WR</tt><aclass="headerlink"href="#NGHTTP2_ERR_STREAM_SHUT_WR"title="Permalink to this definition">¶</a></dt>
The transmission is not allowed for this stream (e.g., a frame
with END_STREAM flag set has already sent).</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_INVALID_STREAM_ID">
<ttclass="descname">NGHTTP2_ERR_INVALID_STREAM_ID</tt><aclass="headerlink"href="#NGHTTP2_ERR_INVALID_STREAM_ID"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_INVALID_STREAM_STATE</tt><aclass="headerlink"href="#NGHTTP2_ERR_INVALID_STREAM_STATE"title="Permalink to this definition">¶</a></dt>
The state of the stream is not valid (e.g., DATA cannot be sent
to the stream if response HEADERS has not been sent).</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_DEFERRED_DATA_EXIST">
<ttclass="descname">NGHTTP2_ERR_DEFERRED_DATA_EXIST</tt><aclass="headerlink"href="#NGHTTP2_ERR_DEFERRED_DATA_EXIST"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_START_STREAM_NOT_ALLOWED</tt><aclass="headerlink"href="#NGHTTP2_ERR_START_STREAM_NOT_ALLOWED"title="Permalink to this definition">¶</a></dt>
Starting new stream is not allowed. (e.g., GOAWAY has been sent
and/or received.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_GOAWAY_ALREADY_SENT">
<ttclass="descname">NGHTTP2_ERR_GOAWAY_ALREADY_SENT</tt><aclass="headerlink"href="#NGHTTP2_ERR_GOAWAY_ALREADY_SENT"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_INVALID_HEADER_BLOCK</tt><aclass="headerlink"href="#NGHTTP2_ERR_INVALID_HEADER_BLOCK"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE</tt><aclass="headerlink"href="#NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_FRAME_SIZE_ERROR</tt><aclass="headerlink"href="#NGHTTP2_ERR_FRAME_SIZE_ERROR"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_INSUFF_BUFSIZE</tt><aclass="headerlink"href="#NGHTTP2_ERR_INSUFF_BUFSIZE"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_TOO_MANY_INFLIGHT_SETTINGS</tt><aclass="headerlink"href="#NGHTTP2_ERR_TOO_MANY_INFLIGHT_SETTINGS"title="Permalink to this definition">¶</a></dt>
The errors <<aclass="reference internal"href="#NGHTTP2_ERR_FATAL"title="NGHTTP2_ERR_FATAL"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_FATAL</span></tt></a> mean that the library is
under unexpected condition and cannot process any further data
reliably (e.g., out of memory).</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_ERR_NOMEM">
<ttclass="descname">NGHTTP2_ERR_NOMEM</tt><aclass="headerlink"href="#NGHTTP2_ERR_NOMEM"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_ERR_CALLBACK_FAILURE</tt><aclass="headerlink"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_FLAG_END_PUSH_PROMISE</tt><aclass="headerlink"href="#NGHTTP2_FLAG_END_PUSH_PROMISE"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_SETTINGS_HEADER_TABLE_SIZE</tt><aclass="headerlink"href="#NGHTTP2_SETTINGS_HEADER_TABLE_SIZE"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_SETTINGS_ENABLE_PUSH</tt><aclass="headerlink"href="#NGHTTP2_SETTINGS_ENABLE_PUSH"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS</tt><aclass="headerlink"href="#NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE</tt><aclass="headerlink"href="#NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE"title="Permalink to this definition">¶</a></dt>
Maximum ID of <aclass="reference internal"href="#nghttp2_settings_id"title="nghttp2_settings_id"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_settings_id</span></tt></a>.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_error_code">
<ttclass="descname">nghttp2_error_code</tt><aclass="headerlink"href="#nghttp2_error_code"title="Permalink to this definition">¶</a></dt>
<dd><p>The status codes for the RST_STREAM and GOAWAY frames.</p>
<dlclass="macro">
<dtid="NGHTTP2_NO_ERROR">
<ttclass="descname">NGHTTP2_NO_ERROR</tt><aclass="headerlink"href="#NGHTTP2_NO_ERROR"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_FLOW_CONTROL_ERROR</tt><aclass="headerlink"href="#NGHTTP2_FLOW_CONTROL_ERROR"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">NGHTTP2_INADEQUATE_SECURITY</tt><aclass="headerlink"href="#NGHTTP2_INADEQUATE_SECURITY"title="Permalink to this definition">¶</a></dt>
The HEADERS frame is the first response headers, which is
analogous to SYN_REPLY in SPDY.</p>
</dd></dl>
<dlclass="macro">
<dtid="NGHTTP2_HCAT_PUSH_RESPONSE">
<ttclass="descname">NGHTTP2_HCAT_PUSH_RESPONSE</tt><aclass="headerlink"href="#NGHTTP2_HCAT_PUSH_RESPONSE"title="Permalink to this definition">¶</a></dt>
The HEADERS frame which does not apply for the above categories,
which is analogous to HEADERS in SPDY.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_opt">
<ttclass="descname">nghttp2_opt</tt><aclass="headerlink"href="#nghttp2_opt"title="Permalink to this definition">¶</a></dt>
<dd><p>Configuration options for <aclass="reference internal"href="#nghttp2_session"title="nghttp2_session"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_session</span></tt></a>.</p>
<ttclass="descname">NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE</tt><aclass="headerlink"href="#NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE"title="Permalink to this definition">¶</a></dt>
stream automatically. If this option is set to nonzero, the
library won’t send WINDOW_UPDATE for a stream and the application
is responsible for sending WINDOW_UPDATE using
<aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>. By default, this option is set to
<ttclass="descname">NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE</tt><aclass="headerlink"href="#NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"title="Permalink to this definition">¶</a></dt>
connection automatically. If this option is set to nonzero, the
library won’t send WINDOW_UPDATE for a connection and the
application is responsible for sending WINDOW_UPDATE with stream
ID 0 using <aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>. By default, this
<ttclass="descname">NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS</tt><aclass="headerlink"href="#NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">nghttp2_info</tt><aclass="headerlink"href="#nghttp2_info"title="Permalink to this definition">¶</a></dt>
<dd><p>This struct is what <aclass="reference internal"href="#nghttp2_version"title="nghttp2_version"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_version()</span></tt></a> returns. It holds
information about the particular nghttp2 version.</p>
<dlclass="member">
<dtid="nghttp2_info.age">
int <ttclass="descname">age</tt><aclass="headerlink"href="#nghttp2_info.age"title="Permalink to this definition">¶</a></dt>
<dd><p>Age of this struct. This instance of nghttp2 sets it to
<aclass="reference internal"href="#NGHTTP2_VERSION_AGE"title="NGHTTP2_VERSION_AGE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_VERSION_AGE</span></tt></a> but a future version may bump it and
add more struct fields at the bottom</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_info.version_num">
int <ttclass="descname">version_num</tt><aclass="headerlink"href="#nghttp2_info.version_num"title="Permalink to this definition">¶</a></dt>
<dd><p>the <aclass="reference internal"href="#NGHTTP2_VERSION_NUM"title="NGHTTP2_VERSION_NUM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_VERSION_NUM</span></tt></a> number (since age ==1)</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_info.version_str">
const char *<ttclass="descname">version_str</tt><aclass="headerlink"href="#nghttp2_info.version_str"title="Permalink to this definition">¶</a></dt>
<dd><p>points to the <aclass="reference internal"href="#NGHTTP2_VERSION"title="NGHTTP2_VERSION"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_VERSION</span></tt></a> string (since age ==1)</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_info.proto_str">
const char *<ttclass="descname">proto_str</tt><aclass="headerlink"href="#nghttp2_info.proto_str"title="Permalink to this definition">¶</a></dt>
<dd><p>points to the <aclass="reference internal"href="#NGHTTP2_PROTO_VERSION_ID"title="NGHTTP2_PROTO_VERSION_ID"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_PROTO_VERSION_ID</span></tt></a> string this
uint8_t <ttclass="descname">type</tt><aclass="headerlink"href="#nghttp2_frame_hd.type"title="Permalink to this definition">¶</a></dt>
<dd><p>The type of this frame. See <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_frame()</span></tt></a>.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame_hd.flags">
uint8_t <ttclass="descname">flags</tt><aclass="headerlink"href="#nghttp2_frame_hd.flags"title="Permalink to this definition">¶</a></dt>
<dd><p>The flags.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_data_source">
<ttclass="descname">nghttp2_data_source</tt><aclass="headerlink"href="#nghttp2_data_source"title="Permalink to this definition">¶</a></dt>
<dd><p>This union represents the some kind of data source passed to
<aclass="reference internal"href="#nghttp2_data_source_read_callback"title="nghttp2_data_source_read_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_data_source_read_callback</span></tt></a>.</p>
<dlclass="member">
<dtid="nghttp2_data_source.fd">
int <ttclass="descname">fd</tt><aclass="headerlink"href="#nghttp2_data_source.fd"title="Permalink to this definition">¶</a></dt>
<dd><p>The integer field, suitable for a file descriptor.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_data_source.ptr">
void *<ttclass="descname">ptr</tt><aclass="headerlink"href="#nghttp2_data_source.ptr"title="Permalink to this definition">¶</a></dt>
<dd><p>The pointer to an arbitrary object.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_data_source_read_callback">
typedef ssize_t <ttclass="descname">(*nghttp2_data_source_read_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em>, uint8_t<em> *buf</em>, size_t<em> length</em>, int<em> *eof</em>, <aclass="reference internal"href="#nghttp2_data_source"title="nghttp2_data_source">nghttp2_data_source</a><em> *source</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_data_source_read_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the library wants to read data from
the <em>source</em>. The read data is sent in the stream <em>stream_id</em>. The
implementation of this function must read at most <em>length</em> bytes of
data from <em>source</em> (or possibly other places) and store them in
<em>buf</em> and return number of data stored in <em>buf</em>. If EOF is reached,
set <em>*eof</em> to 1. If the application wants to postpone DATA frames,
(e.g., asynchronous I/O, or reading data blocks for long time), it
is achieved by returning <aclass="reference internal"href="#NGHTTP2_ERR_DEFERRED"title="NGHTTP2_ERR_DEFERRED"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_DEFERRED</span></tt></a> without
reading any data in this invocation. The library removes DATA
frame from the outgoing queue temporarily. To move back deferred
DATA frame to outgoing queue, call <aclass="reference internal"href="#nghttp2_session_resume_data"title="nghttp2_session_resume_data"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_resume_data()</span></tt></a>.
In case of error, there are 2 choices. Returning
<aclass="reference internal"href="#NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"title="NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE</span></tt></a> will close the stream
by issuing RST_STREAM with <aclass="reference internal"href="#NGHTTP2_INTERNAL_ERROR"title="NGHTTP2_INTERNAL_ERROR"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_INTERNAL_ERROR</span></tt></a>.
Returning <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a> will signal the
entire session failure.</p>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_data_provider">
<ttclass="descname">nghttp2_data_provider</tt><aclass="headerlink"href="#nghttp2_data_provider"title="Permalink to this definition">¶</a></dt>
<dd><p>This struct represents the data source and the way to read a chunk
of data from it.</p>
<dlclass="member">
<dtid="nghttp2_data_provider.source">
<aclass="reference internal"href="#nghttp2_data_source"title="nghttp2_data_source">nghttp2_data_source</a><ttclass="descname">source</tt><aclass="headerlink"href="#nghttp2_data_provider.source"title="Permalink to this definition">¶</a></dt>
<dd><p>The data source.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_data_provider.read_callback">
<aclass="reference internal"href="#nghttp2_data_source_read_callback"title="nghttp2_data_source_read_callback">nghttp2_data_source_read_callback</a><ttclass="descname">read_callback</tt><aclass="headerlink"href="#nghttp2_data_provider.read_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>The callback function to read a chunk of data from the <em>source</em>.</p>
<ttclass="descname">nghttp2_headers</tt><aclass="headerlink"href="#nghttp2_headers"title="Permalink to this definition">¶</a></dt>
<dd><p>The HEADERS frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_headers.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_headers.hd"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a> *<ttclass="descname">nva</tt><aclass="headerlink"href="#nghttp2_headers.nva"title="Permalink to this definition">¶</a></dt>
<dd><p>The name/value pairs.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_headers.nvlen">
size_t <ttclass="descname">nvlen</tt><aclass="headerlink"href="#nghttp2_headers.nvlen"title="Permalink to this definition">¶</a></dt>
<dd><p>The number of name/value pairs in <em>nva</em>.</p>
<aclass="reference internal"href="#nghttp2_headers_category"title="nghttp2_headers_category">nghttp2_headers_category</a><ttclass="descname">cat</tt><aclass="headerlink"href="#nghttp2_headers.cat"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">nghttp2_priority</tt><aclass="headerlink"href="#nghttp2_priority"title="Permalink to this definition">¶</a></dt>
<dd><p>The PRIORITY frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_priority.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_priority.hd"title="Permalink to this definition">¶</a></dt>
<dd><p>The frame header.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_priority.pri">
int32_t <ttclass="descname">pri</tt><aclass="headerlink"href="#nghttp2_priority.pri"title="Permalink to this definition">¶</a></dt>
<dd><p>The priority.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_rst_stream">
<ttclass="descname">nghttp2_rst_stream</tt><aclass="headerlink"href="#nghttp2_rst_stream"title="Permalink to this definition">¶</a></dt>
<dd><p>The RST_STREAM frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_rst_stream.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_rst_stream.hd"title="Permalink to this definition">¶</a></dt>
<dd><p>The frame header.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_rst_stream.error_code">
<aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><ttclass="descname">error_code</tt><aclass="headerlink"href="#nghttp2_rst_stream.error_code"title="Permalink to this definition">¶</a></dt>
<dd><p>The error code. See <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_error_code</span></tt></a>.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_settings_entry">
<ttclass="descname">nghttp2_settings_entry</tt><aclass="headerlink"href="#nghttp2_settings_entry"title="Permalink to this definition">¶</a></dt>
<dd><p>The SETTINGS ID/Value pair. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_settings_entry.settings_id">
int32_t <ttclass="descname">settings_id</tt><aclass="headerlink"href="#nghttp2_settings_entry.settings_id"title="Permalink to this definition">¶</a></dt>
<dd><p>The SETTINGS ID. See <aclass="reference internal"href="#nghttp2_settings_id"title="nghttp2_settings_id"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_settings_id</span></tt></a>.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_settings_entry.value">
uint32_t <ttclass="descname">value</tt><aclass="headerlink"href="#nghttp2_settings_entry.value"title="Permalink to this definition">¶</a></dt>
<dd><p>The value of this entry.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_settings">
<ttclass="descname">nghttp2_settings</tt><aclass="headerlink"href="#nghttp2_settings"title="Permalink to this definition">¶</a></dt>
<dd><p>The SETTINGS frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_settings.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_settings.hd"title="Permalink to this definition">¶</a></dt>
<dd><p>The frame header.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_settings.niv">
size_t <ttclass="descname">niv</tt><aclass="headerlink"href="#nghttp2_settings.niv"title="Permalink to this definition">¶</a></dt>
<dd><p>The number of SETTINGS ID/Value pairs in <em>iv</em>.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_settings.iv">
<aclass="reference internal"href="#nghttp2_settings_entry"title="nghttp2_settings_entry">nghttp2_settings_entry</a> *<ttclass="descname">iv</tt><aclass="headerlink"href="#nghttp2_settings.iv"title="Permalink to this definition">¶</a></dt>
<dd><p>The pointer to the array of SETTINGS ID/Value pair.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_push_promise">
<ttclass="descname">nghttp2_push_promise</tt><aclass="headerlink"href="#nghttp2_push_promise"title="Permalink to this definition">¶</a></dt>
<dd><p>The PUSH_PROMISE frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_push_promise.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_push_promise.hd"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a> *<ttclass="descname">nva</tt><aclass="headerlink"href="#nghttp2_push_promise.nva"title="Permalink to this definition">¶</a></dt>
<dd><p>The name/value pairs.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_push_promise.nvlen">
size_t <ttclass="descname">nvlen</tt><aclass="headerlink"href="#nghttp2_push_promise.nvlen"title="Permalink to this definition">¶</a></dt>
<dd><p>The number of name/value pairs in <em>nva</em>.</p>
int32_t <ttclass="descname">promised_stream_id</tt><aclass="headerlink"href="#nghttp2_push_promise.promised_stream_id"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">nghttp2_ping</tt><aclass="headerlink"href="#nghttp2_ping"title="Permalink to this definition">¶</a></dt>
<dd><p>The PING frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_ping.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_ping.hd"title="Permalink to this definition">¶</a></dt>
<ttclass="descname">nghttp2_goaway</tt><aclass="headerlink"href="#nghttp2_goaway"title="Permalink to this definition">¶</a></dt>
<dd><p>The GOAWAY frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_goaway.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_goaway.hd"title="Permalink to this definition">¶</a></dt>
<dd><p>The frame header.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_goaway.last_stream_id">
int32_t <ttclass="descname">last_stream_id</tt><aclass="headerlink"href="#nghttp2_goaway.last_stream_id"title="Permalink to this definition">¶</a></dt>
<dd><p>The last stream stream ID.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_goaway.error_code">
<aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><ttclass="descname">error_code</tt><aclass="headerlink"href="#nghttp2_goaway.error_code"title="Permalink to this definition">¶</a></dt>
<dd><p>The error code. See <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_error_code</span></tt></a>.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_goaway.opaque_data">
uint8_t *<ttclass="descname">opaque_data</tt><aclass="headerlink"href="#nghttp2_goaway.opaque_data"title="Permalink to this definition">¶</a></dt>
<dd><p>The additional debug data</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_goaway.opaque_data_len">
size_t <ttclass="descname">opaque_data_len</tt><aclass="headerlink"href="#nghttp2_goaway.opaque_data_len"title="Permalink to this definition">¶</a></dt>
<dd><p>The length of <em>opaque_data</em> member.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_window_update">
<ttclass="descname">nghttp2_window_update</tt><aclass="headerlink"href="#nghttp2_window_update"title="Permalink to this definition">¶</a></dt>
<dd><p>The WINDOW_UPDATE frame. It has the following members:</p>
<dlclass="member">
<dtid="nghttp2_window_update.hd">
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_window_update.hd"title="Permalink to this definition">¶</a></dt>
int32_t <ttclass="descname">window_size_increment</tt><aclass="headerlink"href="#nghttp2_window_update.window_size_increment"title="Permalink to this definition">¶</a></dt>
<dd><p>The window size increment.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_frame">
<ttclass="descname">nghttp2_frame</tt><aclass="headerlink"href="#nghttp2_frame"title="Permalink to this definition">¶</a></dt>
<dd><p>This union includes all frames to pass them to various function
<aclass="reference internal"href="#nghttp2_frame_hd"title="nghttp2_frame_hd">nghttp2_frame_hd</a><ttclass="descname">hd</tt><aclass="headerlink"href="#nghttp2_frame.hd"title="Permalink to this definition">¶</a></dt>
<dd><p>The frame header, which is convenient to inspect frame header.</p>
<aclass="reference internal"href="#nghttp2_data"title="nghttp2_data">nghttp2_data</a><ttclass="descname">data</tt><aclass="headerlink"href="#nghttp2_frame.data"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_headers"title="nghttp2_headers">nghttp2_headers</a><ttclass="descname">headers</tt><aclass="headerlink"href="#nghttp2_frame.headers"title="Permalink to this definition">¶</a></dt>
<dd><p>The HEADERS frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.priority">
<aclass="reference internal"href="#nghttp2_priority"title="nghttp2_priority">nghttp2_priority</a><ttclass="descname">priority</tt><aclass="headerlink"href="#nghttp2_frame.priority"title="Permalink to this definition">¶</a></dt>
<dd><p>The PRIORITY frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.rst_stream">
<aclass="reference internal"href="#nghttp2_rst_stream"title="nghttp2_rst_stream">nghttp2_rst_stream</a><ttclass="descname">rst_stream</tt><aclass="headerlink"href="#nghttp2_frame.rst_stream"title="Permalink to this definition">¶</a></dt>
<dd><p>The RST_STREAM frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.settings">
<aclass="reference internal"href="#nghttp2_settings"title="nghttp2_settings">nghttp2_settings</a><ttclass="descname">settings</tt><aclass="headerlink"href="#nghttp2_frame.settings"title="Permalink to this definition">¶</a></dt>
<dd><p>The SETTINGS frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.push_promise">
<aclass="reference internal"href="#nghttp2_push_promise"title="nghttp2_push_promise">nghttp2_push_promise</a><ttclass="descname">push_promise</tt><aclass="headerlink"href="#nghttp2_frame.push_promise"title="Permalink to this definition">¶</a></dt>
<dd><p>The PUSH_PROMISE frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.ping">
<aclass="reference internal"href="#nghttp2_ping"title="nghttp2_ping">nghttp2_ping</a><ttclass="descname">ping</tt><aclass="headerlink"href="#nghttp2_frame.ping"title="Permalink to this definition">¶</a></dt>
<dd><p>The PING frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.goaway">
<aclass="reference internal"href="#nghttp2_goaway"title="nghttp2_goaway">nghttp2_goaway</a><ttclass="descname">goaway</tt><aclass="headerlink"href="#nghttp2_frame.goaway"title="Permalink to this definition">¶</a></dt>
<dd><p>The GOAWAY frame.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_frame.window_update">
<aclass="reference internal"href="#nghttp2_window_update"title="nghttp2_window_update">nghttp2_window_update</a><ttclass="descname">window_update</tt><aclass="headerlink"href="#nghttp2_frame.window_update"title="Permalink to this definition">¶</a></dt>
<dd><p>The WINDOW_UPDATE frame.</p>
</dd></dl>
</dd></dl>
<dlclass="type">
<dtid="nghttp2_send_callback">
typedef ssize_t <ttclass="descname">(*nghttp2_send_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const uint8_t<em> *data</em>, size_t<em> length</em>, int<em> flags</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_send_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when <em>session</em> wants to send data to the
remote peer. The implementation of this function must send at most
<em>length</em> bytes of data stored in <em>data</em>. The <em>flags</em> is currently
not used and always 0. It must return the number of bytes sent if
it succeeds. If it cannot send any single byte without blocking,
it must return <aclass="reference internal"href="#NGHTTP2_ERR_WOULDBLOCK"title="NGHTTP2_ERR_WOULDBLOCK"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_WOULDBLOCK</span></tt></a>. For other errors, it
must return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>. The <em>user_data</em>
pointer is the third argument passed in to the call to
<aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
typedef ssize_t <ttclass="descname">(*nghttp2_recv_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> *buf</em>, size_t<em> length</em>, int<em> flags</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when <em>session</em> wants to receive data from
the remote peer. The implementation of this function must read at
most <em>length</em> bytes of data and store it in <em>buf</em>. The <em>flags</em> is
currently not used and always 0. It must return the number of bytes
written in <em>buf</em> if it succeeds. If it cannot read any single byte
without blocking, it must return <aclass="reference internal"href="#NGHTTP2_ERR_WOULDBLOCK"title="NGHTTP2_ERR_WOULDBLOCK"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_WOULDBLOCK</span></tt></a>. If
it gets EOF before it reads any single byte, it must return
<aclass="reference internal"href="#NGHTTP2_ERR_EOF"title="NGHTTP2_ERR_EOF"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_EOF</span></tt></a>. For other errors, it must return
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>. Returning 0 is treated as
<aclass="reference internal"href="#NGHTTP2_ERR_WOULDBLOCK"title="NGHTTP2_ERR_WOULDBLOCK"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_WOULDBLOCK</span></tt></a>. The <em>user_data</em> pointer is the
third argument passed in to the call to
<aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_frame_recv_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_frame_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked by <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> when a aframe
is received. The <em>user_data</em> pointer is the third argument passed
in to the call to <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or
<p>If frame is HEADERS or PUSH_PROMISE, the <ttclass="docutils literal"><spanclass="pre">nva</span></tt> and <ttclass="docutils literal"><spanclass="pre">nvlen</span></tt>
member of their data structure are always <ttclass="docutils literal"><spanclass="pre">NULL</span></tt> and 0
respectively. The header name/value pairs are emitted via
<aclass="reference internal"href="#nghttp2_on_header_callback"title="nghttp2_on_header_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_header_callback</span></tt></a>.</p>
<p>For HEADERS, PUSH_PROMISE and DATA frames, this callback may be
called after stream is closed (see
<aclass="reference internal"href="#nghttp2_on_stream_close_callback"title="nghttp2_on_stream_close_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_stream_close_callback</span></tt></a>). The application should
check that stream is still alive using its own stream management or
<aclass="reference internal"href="#nghttp2_session_get_stream_user_data"title="nghttp2_session_get_stream_user_data"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_get_stream_user_data()</span></tt></a>.</p>
<p>Only HEADERS and DATA frame can signal the end of incoming data. If
<ttclass="docutils literal"><spanclass="pre">frame->hd.flags</span><spanclass="pre">&</span><spanclass="pre">NGHTTP2_FLAG_END_STREAM</span></tt> is nonzero, the
<em>frame</em> is the last frame from the remote peer in this stream.</p>
succeeds. If nonzero value is returned, it is treated as fatal
error and <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a>
functions immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_invalid_frame_recv_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><em> error_code</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_invalid_frame_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked by <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> when an
invalid non-DATA frame is received. The <em>error_code</em> is one of the
<aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code"><ttclass="xref c c-macro docutils literal"><spanclass="pre">nghttp2_error_code</span></tt></a> and indicates the error. When this
callback function is invoked, the library automatically submits
either RST_STREAM or GOAWAY frame. The <em>user_data</em> pointer is the
third argument passed in to the call to
<aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>If frame is HEADERS or PUSH_PROMISE, the <ttclass="docutils literal"><spanclass="pre">nva</span></tt> and <ttclass="docutils literal"><spanclass="pre">nvlen</span></tt>
member of their data structure are always <ttclass="docutils literal"><spanclass="pre">NULL</span></tt> and 0
<p>The implementation of this function must return 0 if it
succeeds. If nonzero is returned, it is treated as fatal error and
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_data_chunk_recv_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, const uint8_t<em> *data</em>, size_t<em> len</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_data_chunk_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when a chunk of data in DATA frame is
received. The <em>stream_id</em> is the stream ID this DATA frame belongs
to. The <em>flags</em> is the flags of DATA frame which this data chunk is
contained. <ttclass="docutils literal"><spanclass="pre">(flags</span><spanclass="pre">&</span><spanclass="pre">NGHTTP2_FLAG_END_STREAM)</span><spanclass="pre">!=</span><spanclass="pre">0</span></tt> does not
necessarily mean this chunk of data is the last one in the
stream. You should use <aclass="reference internal"href="#nghttp2_on_frame_recv_callback"title="nghttp2_on_frame_recv_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_frame_recv_callback</span></tt></a> to
know all data frames are received. The <em>user_data</em> pointer is the
third argument passed in to the call to
<aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>If the application uses <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a>, it can return
<aclass="reference internal"href="#NGHTTP2_ERR_PAUSE"title="NGHTTP2_ERR_PAUSE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_PAUSE</span></tt></a> to make <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a>
return without processing further input bytes. The memory by
pointed by the <em>data</em> is retained until
<aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> is
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> functions
typedef int <ttclass="descname">(*nghttp2_before_frame_send_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_before_frame_send_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked before the non-DATA frame <em>frame</em> is
sent. This may be useful, for example, to know the stream ID of
HEADERS and PUSH_PROMISE frame (see also
<aclass="reference internal"href="#nghttp2_session_get_stream_user_data"title="nghttp2_session_get_stream_user_data"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_get_stream_user_data()</span></tt></a>), which is not assigned
when it was queued. The <em>user_data</em> pointer is the third argument
passed in to the call to <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>The implementation of this function must return 0 if it
succeeds. If nonzero is returned, it is treated as fatal error and
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_frame_send_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_frame_send_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked after the frame <em>frame</em> is sent. The
<em>user_data</em> pointer is the third argument passed in to the call to
<aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>The implementation of this function must return 0 if it
succeeds. If nonzero is returned, it is treated as fatal error and
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_frame_not_send_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, int<em> lib_error_code</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_frame_not_send_callback"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_error"title="nghttp2_error"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_error</span></tt></a>. The <em>user_data</em> pointer is the third
argument passed in to the call to <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>The implementation of this function must return 0 if it
succeeds. If nonzero is returned, it is treated as fatal error and
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_stream_close_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em>, <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><em> error_code</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_stream_close_callback"title="Permalink to this definition">¶</a></dt>
closed. The reason of closure is indicated by the <em>error_code</em>. The
stream_user_data, which was specified in <aclass="reference internal"href="#nghttp2_submit_request"title="nghttp2_submit_request"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_request()</span></tt></a>
or <aclass="reference internal"href="#nghttp2_submit_headers"title="nghttp2_submit_headers"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_headers()</span></tt></a>, is still available in this
function. The <em>user_data</em> pointer is the third argument passed in
to the call to <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>The implementation of this function must return 0 if it
succeeds. If nonzero is returned, it is treated as fatal error and
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_unknown_frame_recv_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const uint8_t<em> *head</em>, size_t<em> headlen</em>, const uint8_t<em> *payload</em>, size_t<em> payloadlen</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_unknown_frame_recv_callback"title="Permalink to this definition">¶</a></dt>
length of the <em>payload</em>. This is the data after the length
field. The <em>user_data</em> pointer is the third argument passed in to
the call to <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
<p>The implementation of this function must return 0 if it
succeeds. If nonzero is returned, it is treated as fatal error and
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_begin_headers_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_begin_headers_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the reception of header block in
HEADERS or PUSH_PROMISE is started. Each header name/value pair
will be emitted by <aclass="reference internal"href="#nghttp2_on_header_callback"title="nghttp2_on_header_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_header_callback</span></tt></a>.</p>
<p>The <ttclass="docutils literal"><spanclass="pre">frame->hd.flags</span></tt> may not have
<aclass="reference internal"href="#NGHTTP2_FLAG_END_HEADERS"title="NGHTTP2_FLAG_END_HEADERS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_END_HEADERS</span></tt></a> flag set, which indicates that one
or more CONTINUATION frames are involved. But the application does
not need to care about that because the header name/value pairs are
emitted transparently regardless of CONTINUATION frames.</p>
<p>The implementation of this function must return 0 if it succeeds or
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>. If nonzero value other than
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a> is returned, it is treated as
if <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a> is returned. If
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a> is returned,
<aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> function will immediately return
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef int <ttclass="descname">(*nghttp2_on_header_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, const uint8_t<em> *name</em>, size_t<em> namelen</em>, const uint8_t<em> *value</em>, size_t<em> valuelen</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_on_header_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when a header name/value pair is received
for the <em>frame</em>. When this callback is invoked, <ttclass="docutils literal"><spanclass="pre">frame->hd.type</span></tt>
is either <aclass="reference internal"href="#NGHTTP2_HEADERS"title="NGHTTP2_HEADERS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_HEADERS</span></tt></a> or <aclass="reference internal"href="#NGHTTP2_PUSH_PROMISE"title="NGHTTP2_PUSH_PROMISE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_PUSH_PROMISE</span></tt></a>.
After all header name/value pairs are processed with this callback,
<aclass="reference internal"href="#nghttp2_on_frame_recv_callback"title="nghttp2_on_frame_recv_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_frame_recv_callback</span></tt></a> will be invoked. If there
is an error in decompression,
<aclass="reference internal"href="#nghttp2_on_frame_recv_callback"title="nghttp2_on_frame_recv_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_frame_recv_callback</span></tt></a> for the <em>frame</em> will not be
<p>Please note that nghttp2 library does not perform any validity
check against the <em>name</em> and the <em>value</em>. For example, the
<em>namelen</em> could be 0, and/or the <em>value</em> contains <ttclass="docutils literal"><spanclass="pre">0x0a</span></tt> or
<ttclass="docutils literal"><spanclass="pre">0x0d</span></tt>. The application must check them if it matters. The
helper function <aclass="reference internal"href="#nghttp2_check_header_name"title="nghttp2_check_header_name"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_check_header_name()</span></tt></a> and
<aclass="reference internal"href="#nghttp2_check_header_value"title="nghttp2_check_header_value"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_check_header_value()</span></tt></a> provide simple validation against
HTTP2 header field construction rule.</p>
<p>One more thing to note is that the <em>value</em> may contain <ttclass="docutils literal"><spanclass="pre">NULL</span></tt>
(<ttclass="docutils literal"><spanclass="pre">0x00</span></tt>) characters. It is used to concatenate header values
which share the same header field name. The application should
split these values if it wants to get individual value. This
concatenation is used in order to keep the ordering of headers.</p>
<p>If the application uses <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a>, it can return
<aclass="reference internal"href="#NGHTTP2_ERR_PAUSE"title="NGHTTP2_ERR_PAUSE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_PAUSE</span></tt></a> to make <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a>
return without processing further input bytes. The memory pointed
by <em>frame</em>, <em>name</em> and <em>value</em> parameters are retained until
<aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> or <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> is
called. The application must retain the input bytes which was used
to produce these parameters, because it may refer to the memory
<p>Returning <aclass="reference internal"href="#NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"title="NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE</span></tt></a> will close
the stream by issuing RST_STREAM with
<aclass="reference internal"href="#NGHTTP2_INTERNAL_ERROR"title="NGHTTP2_INTERNAL_ERROR"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_INTERNAL_ERROR</span></tt></a>. In this case,
<aclass="reference internal"href="#nghttp2_on_frame_recv_callback"title="nghttp2_on_frame_recv_callback"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_on_frame_recv_callback</span></tt></a> will not be invoked.</p>
succeeds. It may return <aclass="reference internal"href="#NGHTTP2_ERR_PAUSE"title="NGHTTP2_ERR_PAUSE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_PAUSE</span></tt></a> or
<aclass="reference internal"href="#NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"title="NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE</span></tt></a>. For other critical
failures, it must return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>. If
the other nonzero value is returned, it is treated as
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>. If
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a> is returned,
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_mem_recv"title="nghttp2_session_mem_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_mem_recv()</span></tt></a> functions
immediately return <aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
typedef ssize_t <ttclass="descname">(*nghttp2_select_padding_callback)</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const <aclass="reference internal"href="#nghttp2_frame"title="nghttp2_frame">nghttp2_frame</a><em> *frame</em>, size_t<em> max_payloadlen</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_select_padding_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the library asks application how
much padding is required for the transmission of the <em>frame</em>. The
application must choose the total length of payload including
padded bytes in range [frame->hd.length, max_payloadlen],
inclusive. Choosing number not in this range will be treated as
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>. Returning
<ttclass="docutils literal"><spanclass="pre">frame->hd.length</span></tt> means no padding is added. Returning
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a> will make
<aclass="reference internal"href="#nghttp2_session_send"title="nghttp2_session_send"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_send()</span></tt></a> function immediately return
<aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a>.</p>
<ttclass="descname">nghttp2_session_callbacks</tt><aclass="headerlink"href="#nghttp2_session_callbacks"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback functions.</p>
<dlclass="member">
<dtid="nghttp2_session_callbacks.send_callback">
<aclass="reference internal"href="#nghttp2_send_callback"title="nghttp2_send_callback">nghttp2_send_callback</a><ttclass="descname">send_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.send_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the <em>session</em> wants to send data
to the remote peer.</p>
</dd></dl>
<dlclass="member">
<dtid="nghttp2_session_callbacks.recv_callback">
<aclass="reference internal"href="#nghttp2_recv_callback"title="nghttp2_recv_callback">nghttp2_recv_callback</a><ttclass="descname">recv_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the <em>session</em> wants to receive
<aclass="reference internal"href="#nghttp2_on_frame_recv_callback"title="nghttp2_on_frame_recv_callback">nghttp2_on_frame_recv_callback</a><ttclass="descname">on_frame_recv_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_frame_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked by <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> when a
<aclass="reference internal"href="#nghttp2_on_invalid_frame_recv_callback"title="nghttp2_on_invalid_frame_recv_callback">nghttp2_on_invalid_frame_recv_callback</a><ttclass="descname">on_invalid_frame_recv_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_invalid_frame_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked by <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> when an
<aclass="reference internal"href="#nghttp2_on_data_chunk_recv_callback"title="nghttp2_on_data_chunk_recv_callback">nghttp2_on_data_chunk_recv_callback</a><ttclass="descname">on_data_chunk_recv_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_data_chunk_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when a chunk of data in DATA frame is
<aclass="reference internal"href="#nghttp2_before_frame_send_callback"title="nghttp2_before_frame_send_callback">nghttp2_before_frame_send_callback</a><ttclass="descname">before_frame_send_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.before_frame_send_callback"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_on_frame_send_callback"title="nghttp2_on_frame_send_callback">nghttp2_on_frame_send_callback</a><ttclass="descname">on_frame_send_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_frame_send_callback"title="Permalink to this definition">¶</a></dt>
<aclass="reference internal"href="#nghttp2_on_frame_not_send_callback"title="nghttp2_on_frame_not_send_callback">nghttp2_on_frame_not_send_callback</a><ttclass="descname">on_frame_not_send_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_frame_not_send_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>The callback function invoked when a non-DATA frame is not sent
<aclass="reference internal"href="#nghttp2_on_stream_close_callback"title="nghttp2_on_stream_close_callback">nghttp2_on_stream_close_callback</a><ttclass="descname">on_stream_close_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_stream_close_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the stream is closed.</p>
<aclass="reference internal"href="#nghttp2_on_unknown_frame_recv_callback"title="nghttp2_on_unknown_frame_recv_callback">nghttp2_on_unknown_frame_recv_callback</a><ttclass="descname">on_unknown_frame_recv_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_unknown_frame_recv_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the received frame type is
<aclass="reference internal"href="#nghttp2_on_begin_headers_callback"title="nghttp2_on_begin_headers_callback">nghttp2_on_begin_headers_callback</a><ttclass="descname">on_begin_headers_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_begin_headers_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the reception of header block in
<aclass="reference internal"href="#nghttp2_on_header_callback"title="nghttp2_on_header_callback">nghttp2_on_header_callback</a><ttclass="descname">on_header_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.on_header_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when a header name/value pair is
<aclass="reference internal"href="#nghttp2_select_padding_callback"title="nghttp2_select_padding_callback">nghttp2_select_padding_callback</a><ttclass="descname">select_padding_callback</tt><aclass="headerlink"href="#nghttp2_session_callbacks.select_padding_callback"title="Permalink to this definition">¶</a></dt>
<dd><p>Callback function invoked when the library asks application how
much padding is required for the transmission of the given frame.</p>
uint32_t <ttclass="descname">peer_max_concurrent_streams</tt><aclass="headerlink"href="#nghttp2_opt_set.peer_max_concurrent_streams"title="Permalink to this definition">¶</a></dt>
<dd><p><aclass="reference internal"href="#NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"title="NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS</span></tt></a></p>
uint8_t <ttclass="descname">no_auto_stream_window_update</tt><aclass="headerlink"href="#nghttp2_opt_set.no_auto_stream_window_update"title="Permalink to this definition">¶</a></dt>
<dd><p><aclass="reference internal"href="#NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE"title="NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE</span></tt></a></p>
uint8_t <ttclass="descname">no_auto_connection_window_update</tt><aclass="headerlink"href="#nghttp2_opt_set.no_auto_connection_window_update"title="Permalink to this definition">¶</a></dt>
<dd><p><aclass="reference internal"href="#NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"title="NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE</span></tt></a></p>
<ttclass="descname">nghttp2_gzip</tt><aclass="headerlink"href="#nghttp2_gzip"title="Permalink to this definition">¶</a></dt>
<dd><p>The gzip stream to inflate data. The details of this structure are
intentionally hidden from the public API.</p>
</dd></dl>
</div>
<divclass="section"id="functions">
<h2>Functions<aclass="headerlink"href="#functions"title="Permalink to this headline">¶</a></h2>
<dlclass="function">
<dtid="nghttp2_session_client_new">
int <ttclass="descname">nghttp2_session_client_new</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> **session_ptr</em>, const <aclass="reference internal"href="#nghttp2_session_callbacks"title="nghttp2_session_callbacks">nghttp2_session_callbacks</a><em> *callbacks</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_session_client_new"title="Permalink to this definition">¶</a></dt>
<dd><p>Initializes <em>*session_ptr</em> for client use. The all members of
<em>callbacks</em> are copied to <em>*session_ptr</em>. Therefore <em>*session_ptr</em>
does not store <em>callbacks</em>. <em>user_data</em> is an arbitrary user
supplied data, which will be passed to the callback functions.</p>
<p>The <aclass="reference internal"href="#nghttp2_session_callbacks.send_callback"title="nghttp2_session_callbacks.send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.send_callback</span></tt></a> must be
specified. If the application code uses <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a>,
the <aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> must be
specified. The other members of <em>callbacks</em> can be <ttclass="docutils literal"><spanclass="pre">NULL</span></tt>.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_session_server_new">
int <ttclass="descname">nghttp2_session_server_new</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> **session_ptr</em>, const <aclass="reference internal"href="#nghttp2_session_callbacks"title="nghttp2_session_callbacks">nghttp2_session_callbacks</a><em> *callbacks</em>, void<em> *user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_session_server_new"title="Permalink to this definition">¶</a></dt>
<dd><p>Initializes <em>*session_ptr</em> for server use. The all members of
<em>callbacks</em> are copied to <em>*session_ptr</em>. Therefore <em>*session_ptr</em>
does not store <em>callbacks</em>. <em>user_data</em> is an arbitrary user
supplied data, which will be passed to the callback functions.</p>
<p>The <aclass="reference internal"href="#nghttp2_session_callbacks.send_callback"title="nghttp2_session_callbacks.send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.send_callback</span></tt></a> must be
specified. If the application code uses <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a>,
the <aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> must be
specified. The other members of <em>callbacks</em> can be <ttclass="docutils literal"><spanclass="pre">NULL</span></tt>.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
int <ttclass="descname">nghttp2_session_client_new2</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> **session_ptr</em>, const <aclass="reference internal"href="#nghttp2_session_callbacks"title="nghttp2_session_callbacks">nghttp2_session_callbacks</a><em> *callbacks</em>, void<em> *user_data</em>, uint32_t<em> opt_set_mask</em>, const <aclass="reference internal"href="#nghttp2_opt_set"title="nghttp2_opt_set">nghttp2_opt_set</a><em> *opt_set</em><big>)</big><aclass="headerlink"href="#nghttp2_session_client_new2"title="Permalink to this definition">¶</a></dt>
<dd><p>Like <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a>, but with additional options
specified in the <em>opt_set</em>. The caller must set bitwise-OR of
<aclass="reference internal"href="#nghttp2_opt"title="nghttp2_opt"><ttclass="xref c c-macro docutils literal"><spanclass="pre">nghttp2_opt</span></tt></a> for given options. For example, if it
specifies <aclass="reference internal"href="#NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"title="NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE</span></tt></a> and
<aclass="reference internal"href="#NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"title="NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS</span></tt></a> in the <em>opt_set</em>,
<p>If the <em>opt_set_mask</em> is 0, the <em>opt_set</em> could be <ttclass="docutils literal"><spanclass="pre">NULL</span></tt> safely
and the call is equivalent to <aclass="reference internal"href="#nghttp2_session_client_new"title="nghttp2_session_client_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_client_new()</span></tt></a>.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
int <ttclass="descname">nghttp2_session_server_new2</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> **session_ptr</em>, const <aclass="reference internal"href="#nghttp2_session_callbacks"title="nghttp2_session_callbacks">nghttp2_session_callbacks</a><em> *callbacks</em>, void<em> *user_data</em>, uint32_t<em> opt_set_mask</em>, const <aclass="reference internal"href="#nghttp2_opt_set"title="nghttp2_opt_set">nghttp2_opt_set</a><em> *opt_set</em><big>)</big><aclass="headerlink"href="#nghttp2_session_server_new2"title="Permalink to this definition">¶</a></dt>
<dd><p>Like <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>, but with additional options
specified in the <em>opt_set</em>. The caller must set bitwise-OR of
<aclass="reference internal"href="#nghttp2_opt"title="nghttp2_opt"><ttclass="xref c c-macro docutils literal"><spanclass="pre">nghttp2_opt</span></tt></a> for given options. For example, if it
specifies <aclass="reference internal"href="#NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"title="NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE</span></tt></a> and
<aclass="reference internal"href="#NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"title="NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_PEER_MAX_CONCURRENT_STREAMS</span></tt></a> in the <em>opt_set</em>,
<p>If the <em>opt_set_mask</em> is 0, the <em>opt_set</em> could be <ttclass="docutils literal"><spanclass="pre">NULL</span></tt> safely
and the call is equivalent to <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>.</p>
void <ttclass="descname">nghttp2_session_del</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_del"title="Permalink to this definition">¶</a></dt>
<dd><p>Frees any resources allocated for <em>session</em>. If <em>session</em> is
<ttclass="docutils literal"><spanclass="pre">NULL</span></tt>, this function does nothing.</p>
int <ttclass="descname">nghttp2_session_send</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_send"title="Permalink to this definition">¶</a></dt>
<dd><p>Sends pending frames to the remote peer.</p>
<p>This function retrieves the highest prioritized frame from the
outbound queue and sends it to the remote peer. It does this as
many as possible until the user callback
<aclass="reference internal"href="#nghttp2_session_callbacks.send_callback"title="nghttp2_session_callbacks.send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.send_callback</span></tt></a> returns
<aclass="reference internal"href="#NGHTTP2_ERR_WOULDBLOCK"title="NGHTTP2_ERR_WOULDBLOCK"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_WOULDBLOCK</span></tt></a> or the outbound queue becomes empty.
This function calls several callback functions which are passed
when initializing the <em>session</em>. Here is the simple time chart
which tells when each callback is invoked:</p>
<olclass="arabic simple">
<li>Get the next frame to send from outbound queue.</li>
<li>Prepare transmission of the frame.</li>
<li>If the control frame cannot be sent because some preconditions
are not met (e.g., request HEADERS cannot be sent after
<aclass="reference internal"href="#nghttp2_session_callbacks.on_frame_not_send_callback"title="nghttp2_session_callbacks.on_frame_not_send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_frame_not_send_callback</span></tt></a> is
<li><aclass="reference internal"href="#nghttp2_session_callbacks.before_frame_send_callback"title="nghttp2_session_callbacks.before_frame_send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.before_frame_send_callback</span></tt></a> is
<li><aclass="reference internal"href="#nghttp2_session_callbacks.send_callback"title="nghttp2_session_callbacks.send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.send_callback</span></tt></a> is invoked one
<li><aclass="reference internal"href="#nghttp2_session_callbacks.on_frame_send_callback"title="nghttp2_session_callbacks.on_frame_send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_frame_send_callback</span></tt></a> is
<li>If the transmission of the frame triggers closure of the stream,
the stream is closed and
<aclass="reference internal"href="#nghttp2_session_callbacks.on_stream_close_callback"title="nghttp2_session_callbacks.on_stream_close_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_stream_close_callback</span></tt></a> is
invoked.</li>
</ol>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
<dt><aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a></dt>
<dd>The callback function failed.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_session_recv">
int <ttclass="descname">nghttp2_session_recv</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_recv"title="Permalink to this definition">¶</a></dt>
<dd><p>Receives frames from the remote peer.</p>
<p>This function receives as many frames as possible until the user
callback <aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> returns
<aclass="reference internal"href="#NGHTTP2_ERR_WOULDBLOCK"title="NGHTTP2_ERR_WOULDBLOCK"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_WOULDBLOCK</span></tt></a>. This function calls several
callback functions which are passed when initializing the
<em>session</em>. Here is the simple time chart which tells when each
callback is invoked:</p>
<olclass="arabic simple">
<li><aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> is invoked one
<li><aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> is invoked
<aclass="reference internal"href="#nghttp2_session_callbacks.on_frame_recv_callback"title="nghttp2_session_callbacks.on_frame_recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_frame_recv_callback</span></tt></a> is
<li>If the frame is the control frame:<olclass="arabic">
<li><aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> is invoked
<aclass="reference internal"href="#nghttp2_session_callbacks.on_header_callback"title="nghttp2_session_callbacks.on_header_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_header_callback</span></tt></a> is
invoked for each header name/value pair. After all name/value
<aclass="reference internal"href="#nghttp2_session_callbacks.on_frame_recv_callback"title="nghttp2_session_callbacks.on_frame_recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_frame_recv_callback</span></tt></a> is
invoked. For other frames,
<aclass="reference internal"href="#nghttp2_session_callbacks.on_frame_recv_callback"title="nghttp2_session_callbacks.on_frame_recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_frame_recv_callback</span></tt></a> is
invoked.
If the reception of the frame triggers the closure of the
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_EOF"title="NGHTTP2_ERR_EOF"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_EOF</span></tt></a></dt>
<dd>The remote peer did shutdown on the connection.</dd>
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
<dt><aclass="reference internal"href="#NGHTTP2_ERR_CALLBACK_FAILURE"title="NGHTTP2_ERR_CALLBACK_FAILURE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_CALLBACK_FAILURE</span></tt></a></dt>
<dd>The callback function failed.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_session_mem_recv">
ssize_t <ttclass="descname">nghttp2_session_mem_recv</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const uint8_t<em> *in</em>, size_t<em> inlen</em><big>)</big><aclass="headerlink"href="#nghttp2_session_mem_recv"title="Permalink to this definition">¶</a></dt>
<dd><p>Processes data <em>in</em> as an input from the remote endpoint. The
<em>inlen</em> indicates the number of bytes in the <em>in</em>.</p>
<p>This function behaves like <aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a> except that it
does not use <aclass="reference internal"href="#nghttp2_session_callbacks.recv_callback"title="nghttp2_session_callbacks.recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.recv_callback</span></tt></a> to
receive data; the <em>in</em> is the only data for the invocation of this
function. If all bytes are processed, this function returns. The
other callbacks are called in the same way as they are in
<aclass="reference internal"href="#nghttp2_session_recv"title="nghttp2_session_recv"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_recv()</span></tt></a>.</p>
<p>In the current implementation, this function always tries to
processes all input data unless either an error occurs or
<aclass="reference internal"href="#NGHTTP2_ERR_PAUSE"title="NGHTTP2_ERR_PAUSE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_PAUSE</span></tt></a> is returned from
<aclass="reference internal"href="#nghttp2_session_callbacks.on_header_callback"title="nghttp2_session_callbacks.on_header_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_header_callback</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_callbacks.on_data_chunk_recv_callback"title="nghttp2_session_callbacks.on_data_chunk_recv_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.on_data_chunk_recv_callback</span></tt></a>.
If <aclass="reference internal"href="#NGHTTP2_ERR_PAUSE"title="NGHTTP2_ERR_PAUSE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_PAUSE</span></tt></a> is used, the return value includes the
number of bytes which was used to produce the data or frame for the
int <ttclass="descname">nghttp2_session_resume_data</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em><big>)</big><aclass="headerlink"href="#nghttp2_session_resume_data"title="Permalink to this definition">¶</a></dt>
<dd><p>Puts back previously deferred DATA frame in the stream <em>stream_id</em>
to the outbound queue.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_INVALID_ARGUMENT"title="NGHTTP2_ERR_INVALID_ARGUMENT"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_INVALID_ARGUMENT</span></tt></a></dt>
<dd>The stream does not exist or no deferred data exist.</dd>
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_session_want_read">
int <ttclass="descname">nghttp2_session_want_read</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_want_read"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns nonzero value if <em>session</em> wants to receive data from the
remote peer.</p>
<p>If both <aclass="reference internal"href="#nghttp2_session_want_read"title="nghttp2_session_want_read"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_read()</span></tt></a> and
<aclass="reference internal"href="#nghttp2_session_want_write"title="nghttp2_session_want_write"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_write()</span></tt></a> return 0, the application should
drop the connection.</p>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_session_want_write">
int <ttclass="descname">nghttp2_session_want_write</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_want_write"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns nonzero value if <em>session</em> wants to send data to the remote
peer.</p>
<p>If both <aclass="reference internal"href="#nghttp2_session_want_read"title="nghttp2_session_want_read"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_read()</span></tt></a> and
<aclass="reference internal"href="#nghttp2_session_want_write"title="nghttp2_session_want_write"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_write()</span></tt></a> return 0, the application should
drop the connection.</p>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_session_get_stream_user_data">
void* <ttclass="descname">nghttp2_session_get_stream_user_data</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em><big>)</big><aclass="headerlink"href="#nghttp2_session_get_stream_user_data"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns stream_user_data for the stream <em>stream_id</em>. The
stream_user_data is provided by <aclass="reference internal"href="#nghttp2_submit_request"title="nghttp2_submit_request"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_request()</span></tt></a>,
<aclass="reference internal"href="#nghttp2_submit_headers"title="nghttp2_submit_headers"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_headers()</span></tt></a> or
<aclass="reference internal"href="#nghttp2_session_set_stream_user_data"title="nghttp2_session_set_stream_user_data"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_set_stream_user_data()</span></tt></a>. Unless it is set using
<aclass="reference internal"href="#nghttp2_session_set_stream_user_data"title="nghttp2_session_set_stream_user_data"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_set_stream_user_data()</span></tt></a>, if the stream is
initiated by the remote endpoint, stream_user_data is always
<ttclass="docutils literal"><spanclass="pre">NULL</span></tt>. If the stream does not exist, this function returns
int <ttclass="descname">nghttp2_session_set_stream_user_data</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em>, void<em> *stream_user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_session_set_stream_user_data"title="Permalink to this definition">¶</a></dt>
<dd><p>Sets the <em>stream_user_data</em> to the stream denoted by the
<em>stream_id</em>. If a stream user data is already set to the stream, it
is replaced with the <em>stream_user_data</em>. It is valid to specify
<ttclass="docutils literal"><spanclass="pre">NULL</span></tt> in the <em>stream_user_data</em>, which nullifies the associated
size_t <ttclass="descname">nghttp2_session_get_outbound_queue_size</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_get_outbound_queue_size"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the number of frames in the outbound queue. This does not
int32_t <ttclass="descname">nghttp2_session_get_stream_effective_recv_data_length</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em><big>)</big><aclass="headerlink"href="#nghttp2_session_get_stream_effective_recv_data_length"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the number of DATA payload in bytes received without
WINDOW_UPDATE transmission for the stream <em>stream_id</em>. The local
(receive) window size can be adjusted by
<aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>. This function takes into account
that and returns effective data length. In particular, if the
local window size is reduced by submitting negative
window_size_increment with <aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>, this
function returns the number of bytes less than actually received.</p>
int32_t <ttclass="descname">nghttp2_session_get_stream_effective_local_window_size</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em><big>)</big><aclass="headerlink"href="#nghttp2_session_get_stream_effective_local_window_size"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the local (receive) window size for the stream
<em>stream_id</em>. The local window size can be adjusted by
<aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>. This function takes into account
int32_t <ttclass="descname">nghttp2_session_get_effective_recv_data_length</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_get_effective_recv_data_length"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the number of DATA payload in bytes received without
WINDOW_UPDATE transmission for a connection. The local (receive)
window size can be adjusted by
<aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>. This function takes into account
that and returns effective data length. In particular, if the local
window size is reduced by submitting negative window_size_increment
with <aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>, this function returns the
int32_t <ttclass="descname">nghttp2_session_get_effective_local_window_size</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em><big>)</big><aclass="headerlink"href="#nghttp2_session_get_effective_local_window_size"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the local (receive) window size for a connection. The local
window size can be adjusted by
<aclass="reference internal"href="#nghttp2_submit_window_update"title="nghttp2_submit_window_update"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_window_update()</span></tt></a>. This function takes into account
int <ttclass="descname">nghttp2_session_terminate_session</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><em> error_code</em><big>)</big><aclass="headerlink"href="#nghttp2_session_terminate_session"title="Permalink to this definition">¶</a></dt>
<dd><p>Signals the session so that the connection should be terminated.</p>
<p>GOAWAY frame with the given <em>error_code</em> will be submitted if it
has not been transmitted. After the transmission, both
<aclass="reference internal"href="#nghttp2_session_want_read"title="nghttp2_session_want_read"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_read()</span></tt></a> and <aclass="reference internal"href="#nghttp2_session_want_write"title="nghttp2_session_want_write"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_write()</span></tt></a>
return 0. If GOAWAY frame has already transmitted at the time when
this function is invoked, <aclass="reference internal"href="#nghttp2_session_want_read"title="nghttp2_session_want_read"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_read()</span></tt></a> and
<aclass="reference internal"href="#nghttp2_session_want_write"title="nghttp2_session_want_write"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_want_write()</span></tt></a> returns 0 immediately after this
<p>This function should be called when the connection should be
terminated after sending GOAWAY. If the remaining streams should be
processed after GOAWAY, use <aclass="reference internal"href="#nghttp2_submit_goaway"title="nghttp2_submit_goaway"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_goaway()</span></tt></a> instead.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
int <ttclass="descname">nghttp2_session_upgrade</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, const uint8_t<em> *settings_payload</em>, size_t<em> settings_payloadlen</em>, void<em> *stream_user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_session_upgrade"title="Permalink to this definition">¶</a></dt>
<dd><p>Performs post-process of HTTP Upgrade request. This function can be
called from both client and server, but the behavior is very
different in each other.</p>
<p>If called from client side, the <em>settings_payload</em> must be the
<aclass="reference internal"href="#nghttp2_submit_settings"title="nghttp2_submit_settings"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_settings()</span></tt></a>. This means that the client application
<aclass="reference internal"href="#NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS"title="NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS</span></tt></a> and
<aclass="reference internal"href="#NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE"title="NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE</span></tt></a>.</dd>
ssize_t <ttclass="descname">nghttp2_pack_settings_payload</tt><big>(</big>uint8_t<em> *buf</em>, size_t<em> buflen</em>, const <aclass="reference internal"href="#nghttp2_settings_entry"title="nghttp2_settings_entry">nghttp2_settings_entry</a><em> *iv</em>, size_t<em> niv</em><big>)</big><aclass="headerlink"href="#nghttp2_pack_settings_payload"title="Permalink to this definition">¶</a></dt>
<dd><p>Serializes the SETTINGS values <em>iv</em> in the <em>buf</em>. The size of the
<em>buf</em> is specified by <em>buflen</em>. The number of entries in the <em>iv</em>
array is given by <em>niv</em>. The required space in <em>buf</em> for the <em>niv</em>
entries is <ttclass="docutils literal"><spanclass="pre">8*niv</span></tt> bytes and if the given buffer is too small, an
error is returned. This function is used mainly for creating a
SETTINGS payload to be sent with the <ttclass="docutils literal"><spanclass="pre">HTTP2-Settings</span></tt> header
field in an HTTP Upgrade request. The data written in <em>buf</em> is NOT
const char* <ttclass="descname">nghttp2_strerror</tt><big>(</big>int<em> lib_error_code</em><big>)</big><aclass="headerlink"href="#nghttp2_strerror"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns string describing the <em>lib_error_code</em>. The
<em>lib_error_code</em> must be one of the <aclass="reference internal"href="#nghttp2_error"title="nghttp2_error"><ttclass="xref c c-macro docutils literal"><spanclass="pre">nghttp2_error</span></tt></a>.</p>
int <ttclass="descname">nghttp2_submit_request</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> pri</em>, const <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a><em> *nva</em>, size_t<em> nvlen</em>, const <aclass="reference internal"href="#nghttp2_data_provider"title="nghttp2_data_provider">nghttp2_data_provider</a><em> *data_prd</em>, void<em> *stream_user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_request"title="Permalink to this definition">¶</a></dt>
value and <aclass="reference internal"href="#NGHTTP2_PRI_LOWEST"title="NGHTTP2_PRI_LOWEST"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_PRI_LOWEST</span></tt></a> is the lowest value.</p>
<p>The <em>nva</em> is an array of name/value pair <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_nv</span></tt></a> with
<p>If <em>data_prd</em> is not <ttclass="docutils literal"><spanclass="pre">NULL</span></tt>, it provides data which will be sent
in subsequent DATA frames. In this case, a method that allows
request message bodies
(<aclass="reference external"href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9">http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9</a>) must
be specified with <ttclass="docutils literal"><spanclass="pre">:method</span></tt> key in <em>nva</em> (e.g. <ttclass="docutils literal"><spanclass="pre">POST</span></tt>). This
<aclass="reference internal"href="#nghttp2_session_callbacks.before_frame_send_callback"title="nghttp2_session_callbacks.before_frame_send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.before_frame_send_callback</span></tt></a>. This
callback is called just before the frame is sent. For HEADERS
frame, the argument frame has the stream ID assigned. Also since
the stream is already opened,
<aclass="reference internal"href="#nghttp2_session_get_stream_user_data"title="nghttp2_session_get_stream_user_data"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_get_stream_user_data()</span></tt></a> can be used to get
<em>stream_user_data</em> to identify which HEADERS we are processing.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_INVALID_ARGUMENT"title="NGHTTP2_ERR_INVALID_ARGUMENT"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_INVALID_ARGUMENT</span></tt></a></dt>
int <ttclass="descname">nghttp2_submit_response</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, int32_t<em> stream_id</em>, const <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a><em> *nva</em>, size_t<em> nvlen</em>, const <aclass="reference internal"href="#nghttp2_data_provider"title="nghttp2_data_provider">nghttp2_data_provider</a><em> *data_prd</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_response"title="Permalink to this definition">¶</a></dt>
<p>The <em>nva</em> is an array of name/value pair <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_nv</span></tt></a> with
response. When pushing a resource using this function, the
<em>session</em> must be configured using <aclass="reference internal"href="#nghttp2_session_server_new"title="nghttp2_session_server_new"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_session_server_new()</span></tt></a>
or its variants and the target stream denoted by the <em>stream_id</em>
must be reserved using <aclass="reference internal"href="#nghttp2_submit_push_promise"title="nghttp2_submit_push_promise"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_push_promise()</span></tt></a>.</p>
int <ttclass="descname">nghttp2_submit_headers</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, int32_t<em> pri</em>, const <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a><em> *nva</em>, size_t<em> nvlen</em>, void<em> *stream_user_data</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_headers"title="Permalink to this definition">¶</a></dt>
<li><aclass="reference internal"href="#NGHTTP2_FLAG_PRIORITY"title="NGHTTP2_FLAG_PRIORITY"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_PRIORITY</span></tt></a></li>
</ul>
<p>If <em>flags</em> includes <aclass="reference internal"href="#NGHTTP2_FLAG_END_STREAM"title="NGHTTP2_FLAG_END_STREAM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_END_STREAM</span></tt></a>, this frame has
END_STREAM flag set. The library does not support header
continuation and the HEADERS frame always has
<aclass="reference internal"href="#NGHTTP2_FLAG_END_HEADERS"title="NGHTTP2_FLAG_END_HEADERS"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_END_HEADERS</span></tt></a> flag set regardless of the <em>flags</em>
<p>The <em>nva</em> is an array of name/value pair <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_nv</span></tt></a> with
<aclass="reference internal"href="#nghttp2_submit_request"title="nghttp2_submit_request"><ttclass="xref c c-func docutils literal"><spanclass="pre">nghttp2_submit_request()</span></tt></a> is useful.</p>
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_submit_data">
int <ttclass="descname">nghttp2_submit_data</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, const <aclass="reference internal"href="#nghttp2_data_provider"title="nghttp2_data_provider">nghttp2_data_provider</a><em> *data_prd</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_data"title="Permalink to this definition">¶</a></dt>
<dd><p>Submits one or more DATA frames to the stream <em>stream_id</em>. The
data to be sent are provided by <em>data_prd</em>. If <em>flags</em> contains
<aclass="reference internal"href="#NGHTTP2_FLAG_END_STREAM"title="NGHTTP2_FLAG_END_STREAM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_END_STREAM</span></tt></a>, the last DATA frame has END_STREAM
flag set.</p>
<p>This function does not take ownership of the <em>data_prd</em>. The
function copies the members of the <em>data_prd</em>.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
int <ttclass="descname">nghttp2_submit_priority</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, int32_t<em> pri</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_priority"title="Permalink to this definition">¶</a></dt>
int <ttclass="descname">nghttp2_submit_rst_stream</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><em> error_code</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_rst_stream"title="Permalink to this definition">¶</a></dt>
int <ttclass="descname">nghttp2_submit_settings</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, const <aclass="reference internal"href="#nghttp2_settings_entry"title="nghttp2_settings_entry">nghttp2_settings_entry</a><em> *iv</em>, size_t<em> niv</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_settings"title="Permalink to this definition">¶</a></dt>
<dd><p>Stores local settings and submits SETTINGS frame. The <em>iv</em> is the
pointer to the array of <aclass="reference internal"href="#nghttp2_settings_entry"title="nghttp2_settings_entry"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_settings_entry</span></tt></a>. The <em>niv</em>
indicates the number of <aclass="reference internal"href="#nghttp2_settings_entry"title="nghttp2_settings_entry"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_settings_entry</span></tt></a>.</p>
<p>SETTINGS with <aclass="reference internal"href="#NGHTTP2_FLAG_ACK"title="NGHTTP2_FLAG_ACK"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_ACK</span></tt></a> is automatically submitted
by the library and application could not send it at its will.</p>
int <ttclass="descname">nghttp2_submit_push_promise</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, const <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a><em> *nva</em>, size_t<em> nvlen</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_push_promise"title="Permalink to this definition">¶</a></dt>
<dd><p>Submits PUSH_PROMISE frame. The <em>flags</em> is currently ignored and
the resulting PUSH_PROMISE frame always has
<aclass="reference internal"href="#NGHTTP2_FLAG_END_PUSH_PROMISE"title="NGHTTP2_FLAG_END_PUSH_PROMISE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_FLAG_END_PUSH_PROMISE</span></tt></a> flag set due to the lack of
<p>The <em>nva</em> is an array of name/value pair <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_nv</span></tt></a> with
<aclass="reference internal"href="#nghttp2_session_callbacks.before_frame_send_callback"title="nghttp2_session_callbacks.before_frame_send_callback"><ttclass="xref c c-member docutils literal"><spanclass="pre">nghttp2_session_callbacks.before_frame_send_callback</span></tt></a>. This
int <ttclass="descname">nghttp2_submit_ping</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, uint8_t<em> *opaque_data</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_ping"title="Permalink to this definition">¶</a></dt>
int <ttclass="descname">nghttp2_submit_goaway</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, <aclass="reference internal"href="#nghttp2_error_code"title="nghttp2_error_code">nghttp2_error_code</a><em> error_code</em>, uint8_t<em> *opaque_data</em>, size_t<em> opaque_data_len</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_goaway"title="Permalink to this definition">¶</a></dt>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_submit_window_update">
int <ttclass="descname">nghttp2_submit_window_update</tt><big>(</big><aclass="reference internal"href="#nghttp2_session"title="nghttp2_session">nghttp2_session</a><em> *session</em>, uint8_t<em> flags</em>, int32_t<em> stream_id</em>, int32_t<em> window_size_increment</em><big>)</big><aclass="headerlink"href="#nghttp2_submit_window_update"title="Permalink to this definition">¶</a></dt>
<p>If the <em>window_size_increment</em> is positive, the WINDOW_UPDATE with
that value as window_size_increment is queued. If the
<em>window_size_increment</em> is larger than the received bytes from the
remote endpoint, the local window size is increased by that
difference.</p>
<p>If the <em>window_size_increment</em> is negative, the local window size
is decreased by -<em>window_size_increment</em>. If
<aclass="reference internal"href="#NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE"title="NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE</span></tt></a> (or
<aclass="reference internal"href="#NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"title="NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE</span></tt></a> if <em>stream_id</em>
is 0) is not set and the library decided that the WINDOW_UPDATE
should be submitted, then WINDOW_UPDATE is queued with the current
int <ttclass="descname">nghttp2_nv_compare_name</tt><big>(</big>const <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a><em> *lhs</em>, const <aclass="reference internal"href="#nghttp2_nv"title="nghttp2_nv">nghttp2_nv</a><em> *rhs</em><big>)</big><aclass="headerlink"href="#nghttp2_nv_compare_name"title="Permalink to this definition">¶</a></dt>
<dd><p>Compares lhs->name with lhs->namelen bytes and rhs->name with
rhs->namelen bytes. Returns negative integer if lhs->name is found
to be less than rhs->name; or returns positive integer if lhs->name
is found to be greater than rhs->name; or returns 0 otherwise.</p>
int <ttclass="descname">nghttp2_select_next_protocol</tt><big>(</big>unsigned char<em> **out</em>, unsigned char<em> *outlen</em>, const unsigned char<em> *in</em>, unsigned int<em> inlen</em><big>)</big><aclass="headerlink"href="#nghttp2_select_next_protocol"title="Permalink to this definition">¶</a></dt>
<ttclass="docutils literal"><spanclass="pre">http/1.1</span></tt> and returns 0. The following step is not taken.</li>
<li>This function selects nothing and returns -1. (So called
non-overlap case). In this case, <em>out</em> and <em>outlen</em> are left
untouched.</li>
</ol>
<p>Selecting <ttclass="docutils literal"><spanclass="pre">HTTP-draft-04/2.0</span></tt> means that <ttclass="docutils literal"><spanclass="pre">HTTP-draft-04/2.0</span></tt> is
written into <em>*out</em> and its length (which is 17) is
<p>See <aclass="reference external"href="http://technotes.googlecode.com/git/nextprotoneg.html">http://technotes.googlecode.com/git/nextprotoneg.html</a> for more
int <ttclass="descname">nghttp2_gzip_inflate_new</tt><big>(</big><aclass="reference internal"href="#nghttp2_gzip"title="nghttp2_gzip">nghttp2_gzip</a><em> **inflater_ptr</em><big>)</big><aclass="headerlink"href="#nghttp2_gzip_inflate_new"title="Permalink to this definition">¶</a></dt>
<dd><p>A helper function to set up a per request gzip stream to inflate data.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_GZIP"title="NGHTTP2_ERR_GZIP"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_GZIP</span></tt></a></dt>
<dd>The initialization of gzip stream failed.</dd>
<dt><aclass="reference internal"href="#NGHTTP2_ERR_NOMEM"title="NGHTTP2_ERR_NOMEM"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_NOMEM</span></tt></a></dt>
<dd>Out of memory.</dd>
</dl>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_gzip_inflate_del">
void <ttclass="descname">nghttp2_gzip_inflate_del</tt><big>(</big><aclass="reference internal"href="#nghttp2_gzip"title="nghttp2_gzip">nghttp2_gzip</a><em> *inflater</em><big>)</big><aclass="headerlink"href="#nghttp2_gzip_inflate_del"title="Permalink to this definition">¶</a></dt>
<dd><p>Frees the inflate stream. The <em>inflater</em> may be <ttclass="docutils literal"><spanclass="pre">NULL</span></tt>.</p>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_gzip_inflate">
int <ttclass="descname">nghttp2_gzip_inflate</tt><big>(</big><aclass="reference internal"href="#nghttp2_gzip"title="nghttp2_gzip">nghttp2_gzip</a><em> *inflater</em>, uint8_t<em> *out</em>, size_t<em> *outlen_ptr</em>, const uint8_t<em> *in</em>, size_t<em> *inlen_ptr</em><big>)</big><aclass="headerlink"href="#nghttp2_gzip_inflate"title="Permalink to this definition">¶</a></dt>
<dd><p>Inflates data in <em>in</em> with the length <em>*inlen_ptr</em> and stores the
inflated data to <em>out</em> which has allocated size at least
<em>*outlen_ptr</em>. On return, <em>*outlen_ptr</em> is updated to represent
the number of data written in <em>out</em>. Similarly, <em>*inlen_ptr</em> is
updated to represent the number of input bytes processed.</p>
<p>This function returns 0 if it succeeds, or one of the following
negative error codes:</p>
<dlclass="docutils">
<dt><aclass="reference internal"href="#NGHTTP2_ERR_GZIP"title="NGHTTP2_ERR_GZIP"><ttclass="xref c c-macro docutils literal"><spanclass="pre">NGHTTP2_ERR_GZIP</span></tt></a></dt>
<aclass="reference internal"href="#nghttp2_info"title="nghttp2_info">nghttp2_info</a> *<ttclass="descname">nghttp2_version</tt><big>(</big>int<em> least_version</em><big>)</big><aclass="headerlink"href="#nghttp2_version"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns a pointer to a nghttp2_info struct with version information about
the run-time library in use. The <em>least_version</em> argument can be set to a
24 bit numerical value for the least accepted version number and if the
condition is not met, this function will return a NULL. Pass in 0 to skip
int <ttclass="descname">nghttp2_is_fatal</tt><big>(</big>int<em> lib_error</em><big>)</big><aclass="headerlink"href="#nghttp2_is_fatal"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns nonzero if the <aclass="reference internal"href="#nghttp2_error"title="nghttp2_error"><ttclass="xref c c-type docutils literal"><spanclass="pre">nghttp2_error</span></tt></a> library error code
int <ttclass="descname">nghttp2_check_header_name</tt><big>(</big>const uint8_t<em> *name</em>, size_t<em> len</em><big>)</big><aclass="headerlink"href="#nghttp2_check_header_name"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns nonzero if HTTP header field name <em>name</em> of length <em>len</em> is
<p>Because this is a header field name in HTTP2, the upper cased alphabet
is treated as error.</p>
</dd></dl>
<dlclass="function">
<dtid="nghttp2_check_header_value">
int <ttclass="descname">nghttp2_check_header_value</tt><big>(</big>const uint8_t<em> *value</em>, size_t<em> len</em><big>)</big><aclass="headerlink"href="#nghttp2_check_header_value"title="Permalink to this definition">¶</a></dt>
<dd><p>Returns nonzero if HTTP header field value <em>value</em> of length <em>len</em>
