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<li class="toctree-l1 current"><a class="current reference internal" href="#">Tutorial: HPACK API</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#deflating-encoding-headers">Deflating (encoding) headers</a></li>
<li class="toctree-l2"><a class="reference internal" href="#inflating-decoding-headers">Inflating (decoding) headers</a></li>
<li class="toctree-l2"><a class="reference internal" href="#deflate-c">deflate.c</a></li>
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<div class="section" id="tutorial-hpack-api">
<h1>Tutorial: HPACK API<a class="headerlink" href="#tutorial-hpack-api" title="Permalink to this headline">¶</a></h1>
<p>In this tutorial, we describe basic use of nghttp2’s HPACK API. We
briefly describe the APIs for deflating and inflating header fields.
The full example of using these APIs, <a class="reference internal" href="#deflate-c">deflate.c</a>, is attached at the
end of this page. It also resides in the examples directory in the
archive or repository.</p>
<div class="section" id="deflating-encoding-headers">
<h2>Deflating (encoding) headers<a class="headerlink" href="#deflating-encoding-headers" title="Permalink to this headline">¶</a></h2>
<p>First we need to initialize a <a class="reference internal" href="types.html#c.nghttp2_hd_deflater" title="nghttp2_hd_deflater"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_hd_deflater</span></code></a> object using
the <a class="reference internal" href="nghttp2_hd_deflate_new.html#c.nghttp2_hd_deflate_new" title="nghttp2_hd_deflate_new"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_new()</span></code></a> function:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="kt">int</span> <span class="nf">nghttp2_hd_deflate_new</span><span class="p">(</span><span class="n">nghttp2_hd_deflater</span> <span class="o">**</span><span class="n">deflater_ptr</span><span class="p">,</span>
<span class="kt">size_t</span> <span class="n">deflate_hd_table_bufsize_max</span><span class="p">);</span>
</pre></div>
</div>
<p>This function allocates a <a class="reference internal" href="types.html#c.nghttp2_hd_deflater" title="nghttp2_hd_deflater"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_hd_deflater</span></code></a> object,
initializes it, and assigns its pointer to <code class="docutils literal notranslate"><span class="pre">*deflater_ptr</span></code>. The
<em>deflate_hd_table_bufsize_max</em> is the upper bound of header table size
the deflater will use. This will limit the memory usage by the
deflater object for the dynamic header table. If in doubt, just
specify 4096 here, which is the default upper bound of dynamic header
table buffer size.</p>
<p>To encode header fields, use the <a class="reference internal" href="nghttp2_hd_deflate_hd.html#c.nghttp2_hd_deflate_hd" title="nghttp2_hd_deflate_hd"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_hd()</span></code></a> function:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="kt">ssize_t</span> <span class="nf">nghttp2_hd_deflate_hd</span><span class="p">(</span><span class="n">nghttp2_hd_deflater</span> <span class="o">*</span><span class="n">deflater</span><span class="p">,</span>
<span class="kt">uint8_t</span> <span class="o">*</span><span class="n">buf</span><span class="p">,</span> <span class="kt">size_t</span> <span class="n">buflen</span><span class="p">,</span>
<span class="k">const</span> <span class="n">nghttp2_nv</span> <span class="o">*</span><span class="n">nva</span><span class="p">,</span> <span class="kt">size_t</span> <span class="n">nvlen</span><span class="p">);</span>
</pre></div>
</div>
<p>The <em>deflater</em> is the deflater object initialized by
<a class="reference internal" href="nghttp2_hd_deflate_new.html#c.nghttp2_hd_deflate_new" title="nghttp2_hd_deflate_new"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_new()</span></code></a> described above. The encoded byte string is
written to the buffer <em>buf</em>, which has length <em>buflen</em>. The <em>nva</em> is
a pointer to an array of headers fields, each of type
<a class="reference internal" href="types.html#c.nghttp2_nv" title="nghttp2_nv"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_nv</span></code></a>. <em>nvlen</em> is the number of header fields which
<em>nva</em> contains.</p>
<p>It is important to initialize and assign all members of
<a class="reference internal" href="types.html#c.nghttp2_nv" title="nghttp2_nv"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_nv</span></code></a>. For security sensitive header fields (such as
cookies), set the <a class="reference internal" href="enums.html#c.NGHTTP2_NV_FLAG_NO_INDEX" title="NGHTTP2_NV_FLAG_NO_INDEX"><code class="xref c c-macro docutils literal notranslate"><span class="pre">NGHTTP2_NV_FLAG_NO_INDEX</span></code></a> flag in
<a class="reference internal" href="types.html#c.nghttp2_nv.flags" title="nghttp2_nv.flags"><code class="xref c c-member docutils literal notranslate"><span class="pre">nghttp2_nv.flags</span></code></a>. Setting this flag prevents recovery of
sensitive header fields by compression based attacks: This is achieved
by not inserting the header field into the dynamic header table.</p>
<p><a class="reference internal" href="nghttp2_hd_deflate_hd.html#c.nghttp2_hd_deflate_hd" title="nghttp2_hd_deflate_hd"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_hd()</span></code></a> processes all headers given in <em>nva</em>. The
<em>nva</em> must include all request or response header fields to be sent in
one HEADERS (or optionally following (multiple) CONTINUATION
frame(s)). The <em>buf</em> must have enough space to store the encoded
result, otherwise the function will fail. To estimate the upper bound
of the encoded result length, use <a class="reference internal" href="nghttp2_hd_deflate_bound.html#c.nghttp2_hd_deflate_bound" title="nghttp2_hd_deflate_bound"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_bound()</span></code></a>:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="kt">size_t</span> <span class="nf">nghttp2_hd_deflate_bound</span><span class="p">(</span><span class="n">nghttp2_hd_deflater</span> <span class="o">*</span><span class="n">deflater</span><span class="p">,</span>
<span class="k">const</span> <span class="n">nghttp2_nv</span> <span class="o">*</span><span class="n">nva</span><span class="p">,</span> <span class="kt">size_t</span> <span class="n">nvlen</span><span class="p">);</span>
</pre></div>
</div>
<p>Pass this function the same parameters (<em>deflater</em>, <em>nva</em>, and
<em>nvlen</em>) which will be passed to <a class="reference internal" href="nghttp2_hd_deflate_hd.html#c.nghttp2_hd_deflate_hd" title="nghttp2_hd_deflate_hd"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_hd()</span></code></a>.</p>
<p>Subsequent calls to <a class="reference internal" href="nghttp2_hd_deflate_hd.html#c.nghttp2_hd_deflate_hd" title="nghttp2_hd_deflate_hd"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_hd()</span></code></a> will use the current
encoder state and perform differential encoding, which yields HPAC’s
fundamental compression gain.</p>
<p>If <a class="reference internal" href="nghttp2_hd_deflate_hd.html#c.nghttp2_hd_deflate_hd" title="nghttp2_hd_deflate_hd"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_hd()</span></code></a> fails, the failure is fatal and any
further calls with the same deflater object will fail. Thus it’s very
important to use <a class="reference internal" href="nghttp2_hd_deflate_bound.html#c.nghttp2_hd_deflate_bound" title="nghttp2_hd_deflate_bound"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_bound()</span></code></a> to determine the
required size of the output buffer.</p>
<p>To delete a <a class="reference internal" href="types.html#c.nghttp2_hd_deflater" title="nghttp2_hd_deflater"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_hd_deflater</span></code></a> object, use the
<a class="reference internal" href="nghttp2_hd_deflate_del.html#c.nghttp2_hd_deflate_del" title="nghttp2_hd_deflate_del"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_deflate_del()</span></code></a> function.</p>
</div>
<div class="section" id="inflating-decoding-headers">
<h2>Inflating (decoding) headers<a class="headerlink" href="#inflating-decoding-headers" title="Permalink to this headline">¶</a></h2>
<p>A <a class="reference internal" href="types.html#c.nghttp2_hd_inflater" title="nghttp2_hd_inflater"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_hd_inflater</span></code></a> object is used to inflate compressed
header data. To initialize the object, use
<a class="reference internal" href="nghttp2_hd_inflate_new.html#c.nghttp2_hd_inflate_new" title="nghttp2_hd_inflate_new"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_inflate_new()</span></code></a>:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="kt">int</span> <span class="nf">nghttp2_hd_inflate_new</span><span class="p">(</span><span class="n">nghttp2_hd_inflater</span> <span class="o">**</span><span class="n">inflater_ptr</span><span class="p">);</span>
</pre></div>
</div>
<p>To inflate header data, use <a class="reference internal" href="nghttp2_hd_inflate_hd2.html#c.nghttp2_hd_inflate_hd2" title="nghttp2_hd_inflate_hd2"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_inflate_hd2()</span></code></a>:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="kt">ssize_t</span> <span class="nf">nghttp2_hd_inflate_hd2</span><span class="p">(</span><span class="n">nghttp2_hd_inflater</span> <span class="o">*</span><span class="n">inflater</span><span class="p">,</span>
<span class="n">nghttp2_nv</span> <span class="o">*</span><span class="n">nv_out</span><span class="p">,</span> <span class="kt">int</span> <span class="o">*</span><span class="n">inflate_flags</span><span class="p">,</span>
<span class="k">const</span> <span class="kt">uint8_t</span> <span class="o">*</span><span class="n">in</span><span class="p">,</span> <span class="kt">size_t</span> <span class="n">inlen</span><span class="p">,</span>
<span class="kt">int</span> <span class="n">in_final</span><span class="p">);</span>
</pre></div>
</div>
<p><a class="reference internal" href="nghttp2_hd_inflate_hd2.html#c.nghttp2_hd_inflate_hd2" title="nghttp2_hd_inflate_hd2"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_inflate_hd2()</span></code></a> reads a stream of bytes and outputs a
single header field at a time. Multiple calls are normally required to
read a full stream of bytes and output all of the header fields.</p>
<p>The <em>inflater</em> is the inflater object initialized above. The <em>nv_out</em>
is a pointer to a <a class="reference internal" href="types.html#c.nghttp2_nv" title="nghttp2_nv"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_nv</span></code></a> into which one header field may
be stored. The <em>in</em> is a pointer to input data, and <em>inlen</em> is its
length. The caller is not required to specify the whole deflated
header data via <em>in</em> at once: Instead it can call this function
multiple times as additional data bytes become available. If
<em>in_final</em> is nonzero, it tells the function that the passed data is
the final sequence of deflated header data.</p>
<p>The <em>inflate_flags</em> is an output parameter; on success the function
sets it to a bitset of flags. It will be described later.</p>
<p>This function returns when each header field is inflated. When this
happens, the function sets the <a class="reference internal" href="enums.html#c.NGHTTP2_HD_INFLATE_EMIT" title="NGHTTP2_HD_INFLATE_EMIT"><code class="xref c c-macro docutils literal notranslate"><span class="pre">NGHTTP2_HD_INFLATE_EMIT</span></code></a> flag
in <em>inflate_flags</em>, and a header field is stored in <em>nv_out</em>. The
return value indicates the number of bytes read from <em>in</em> processed so
far, which may be less than <em>inlen</em>. The caller should call the
function repeatedly until all bytes are processed. Processed bytes
should be removed from <em>in</em>, and <em>inlen</em> should be adjusted
appropriately.</p>
<p>If <em>in_final</em> is nonzero and all given data was processed, the
function sets the <a class="reference internal" href="enums.html#c.NGHTTP2_HD_INFLATE_FINAL" title="NGHTTP2_HD_INFLATE_FINAL"><code class="xref c c-macro docutils literal notranslate"><span class="pre">NGHTTP2_HD_INFLATE_FINAL</span></code></a> flag in
<em>inflate_flags</em>. When you see this flag set, call the
<a class="reference internal" href="nghttp2_hd_inflate_end_headers.html#c.nghttp2_hd_inflate_end_headers" title="nghttp2_hd_inflate_end_headers"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_inflate_end_headers()</span></code></a> function.</p>
<p>If <em>in_final</em> is zero and the <a class="reference internal" href="enums.html#c.NGHTTP2_HD_INFLATE_EMIT" title="NGHTTP2_HD_INFLATE_EMIT"><code class="xref c c-macro docutils literal notranslate"><span class="pre">NGHTTP2_HD_INFLATE_EMIT</span></code></a> flag is
not set, it indicates that all given data was processed. The caller
is required to pass additional data.</p>
<p>Example usage of <a class="reference internal" href="nghttp2_hd_inflate_hd2.html#c.nghttp2_hd_inflate_hd2" title="nghttp2_hd_inflate_hd2"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_inflate_hd2()</span></code></a> is shown in the
<code class="xref c c-func docutils literal notranslate"><span class="pre">inflate_header_block()</span></code> function in <a class="reference internal" href="#deflate-c">deflate.c</a>.</p>
<p>Finally, to delete a <a class="reference internal" href="types.html#c.nghttp2_hd_inflater" title="nghttp2_hd_inflater"><code class="xref c c-type docutils literal notranslate"><span class="pre">nghttp2_hd_inflater</span></code></a> object, use
<a class="reference internal" href="nghttp2_hd_inflate_del.html#c.nghttp2_hd_inflate_del" title="nghttp2_hd_inflate_del"><code class="xref c c-func docutils literal notranslate"><span class="pre">nghttp2_hd_inflate_del()</span></code></a>.</p>
</div>
<div class="section" id="deflate-c">
<h2>deflate.c<a class="headerlink" href="#deflate-c" title="Permalink to this headline">¶</a></h2>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="cm">/*</span>
<span class="cm"> * nghttp2 - HTTP/2 C Library</span>
<span class="cm"> *</span>
<span class="cm"> * Copyright (c) 2014 Tatsuhiro Tsujikawa</span>
<span class="cm"> *</span>
<span class="cm"> * Permission is hereby granted, free of charge, to any person obtaining</span>
<span class="cm"> * a copy of this software and associated documentation files (the</span>
<span class="cm"> * "Software"), to deal in the Software without restriction, including</span>
<span class="cm"> * without limitation the rights to use, copy, modify, merge, publish,</span>
<span class="cm"> * distribute, sublicense, and/or sell copies of the Software, and to</span>
<span class="cm"> * permit persons to whom the Software is furnished to do so, subject to</span>
<span class="cm"> * the following conditions:</span>
<span class="cm"> *</span>
<span class="cm"> * The above copyright notice and this permission notice shall be</span>
<span class="cm"> * included in all copies or substantial portions of the Software.</span>
<span class="cm"> *</span>
<span class="cm"> * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,</span>
<span class="cm"> * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF</span>
<span class="cm"> * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND</span>
<span class="cm"> * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE</span>
<span class="cm"> * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION</span>
<span class="cm"> * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION</span>
<span class="cm"> * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.</span>
<span class="cm"> */</span>
<span class="cp">#ifdef HAVE_CONFIG_H</span>
<span class="cp"># include <config.h></span>
<span class="cp">#endif </span><span class="cm">/* !HAVE_CONFIG_H */</span><span class="cp"></span>
<span class="cp">#include</span> <span class="cpf"><stdio.h></span><span class="cp"></span>
<span class="cp">#include</span> <span class="cpf"><string.h></span><span class="cp"></span>
<span class="cp">#include</span> <span class="cpf"><nghttp2/nghttp2.h></span><span class="cp"></span>
<span class="cp">#define MAKE_NV(K, V) \</span>
<span class="cp"> { \</span>
<span class="cp"> (uint8_t *)K, (uint8_t *)V, sizeof(K) - 1, sizeof(V) - 1, \</span>
<span class="cp"> NGHTTP2_NV_FLAG_NONE \</span>
<span class="cp"> }</span>
<span class="k">static</span> <span class="kt">void</span> <span class="nf">deflate</span><span class="p">(</span><span class="n">nghttp2_hd_deflater</span> <span class="o">*</span><span class="n">deflater</span><span class="p">,</span>
<span class="n">nghttp2_hd_inflater</span> <span class="o">*</span><span class="n">inflater</span><span class="p">,</span> <span class="k">const</span> <span class="n">nghttp2_nv</span> <span class="o">*</span><span class="k">const</span> <span class="n">nva</span><span class="p">,</span>
<span class="kt">size_t</span> <span class="n">nvlen</span><span class="p">);</span>
<span class="k">static</span> <span class="kt">int</span> <span class="nf">inflate_header_block</span><span class="p">(</span><span class="n">nghttp2_hd_inflater</span> <span class="o">*</span><span class="n">inflater</span><span class="p">,</span> <span class="kt">uint8_t</span> <span class="o">*</span><span class="n">in</span><span class="p">,</span>
<span class="kt">size_t</span> <span class="n">inlen</span><span class="p">,</span> <span class="kt">int</span> <span class="n">final</span><span class="p">);</span>
<span class="kt">int</span> <span class="nf">main</span><span class="p">()</span> <span class="p">{</span>
<span class="kt">int</span> <span class="n">rv</span><span class="p">;</span>
<span class="n">nghttp2_hd_deflater</span> <span class="o">*</span><span class="n">deflater</span><span class="p">;</span>
<span class="n">nghttp2_hd_inflater</span> <span class="o">*</span><span class="n">inflater</span><span class="p">;</span>
<span class="cm">/* Define 1st header set. This is looks like a HTTP request. */</span>
<span class="n">nghttp2_nv</span> <span class="n">nva1</span><span class="p">[]</span> <span class="o">=</span> <span class="p">{</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">":scheme"</span><span class="p">,</span> <span class="s">"https"</span><span class="p">),</span> <span class="n">MAKE_NV</span><span class="p">(</span><span class="s">":authority"</span><span class="p">,</span> <span class="s">"example.org"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">":path"</span><span class="p">,</span> <span class="s">"/"</span><span class="p">),</span> <span class="n">MAKE_NV</span><span class="p">(</span><span class="s">"user-agent"</span><span class="p">,</span> <span class="s">"libnghttp2"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">"accept-encoding"</span><span class="p">,</span> <span class="s">"gzip, deflate"</span><span class="p">)};</span>
<span class="cm">/* Define 2nd header set */</span>
<span class="n">nghttp2_nv</span> <span class="n">nva2</span><span class="p">[]</span> <span class="o">=</span> <span class="p">{</span><span class="n">MAKE_NV</span><span class="p">(</span><span class="s">":scheme"</span><span class="p">,</span> <span class="s">"https"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">":authority"</span><span class="p">,</span> <span class="s">"example.org"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">":path"</span><span class="p">,</span> <span class="s">"/stylesheet/style.css"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">"user-agent"</span><span class="p">,</span> <span class="s">"libnghttp2"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">"accept-encoding"</span><span class="p">,</span> <span class="s">"gzip, deflate"</span><span class="p">),</span>
<span class="n">MAKE_NV</span><span class="p">(</span><span class="s">"referer"</span><span class="p">,</span> <span class="s">"https://example.org"</span><span class="p">)};</span>
<span class="n">rv</span> <span class="o">=</span> <span class="n">nghttp2_hd_deflate_new</span><span class="p">(</span><span class="o">&</span><span class="n">deflater</span><span class="p">,</span> <span class="mi">4096</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="n">rv</span> <span class="o">!=</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">fprintf</span><span class="p">(</span><span class="n">stderr</span><span class="p">,</span> <span class="s">"nghttp2_hd_deflate_init failed with error: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="n">nghttp2_strerror</span><span class="p">(</span><span class="n">rv</span><span class="p">));</span>
<span class="n">exit</span><span class="p">(</span><span class="n">EXIT_FAILURE</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">rv</span> <span class="o">=</span> <span class="n">nghttp2_hd_inflate_new</span><span class="p">(</span><span class="o">&</span><span class="n">inflater</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="n">rv</span> <span class="o">!=</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">fprintf</span><span class="p">(</span><span class="n">stderr</span><span class="p">,</span> <span class="s">"nghttp2_hd_inflate_init failed with error: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="n">nghttp2_strerror</span><span class="p">(</span><span class="n">rv</span><span class="p">));</span>
<span class="n">exit</span><span class="p">(</span><span class="n">EXIT_FAILURE</span><span class="p">);</span>
<span class="p">}</span>
<span class="cm">/* Encode and decode 1st header set */</span>
<span class="n">deflate</span><span class="p">(</span><span class="n">deflater</span><span class="p">,</span> <span class="n">inflater</span><span class="p">,</span> <span class="n">nva1</span><span class="p">,</span> <span class="k">sizeof</span><span class="p">(</span><span class="n">nva1</span><span class="p">)</span> <span class="o">/</span> <span class="k">sizeof</span><span class="p">(</span><span class="n">nva1</span><span class="p">[</span><span class="mi">0</span><span class="p">]));</span>
<span class="cm">/* Encode and decode 2nd header set, using differential encoding</span>
<span class="cm"> using state after encoding 1st header set. */</span>
<span class="n">deflate</span><span class="p">(</span><span class="n">deflater</span><span class="p">,</span> <span class="n">inflater</span><span class="p">,</span> <span class="n">nva2</span><span class="p">,</span> <span class="k">sizeof</span><span class="p">(</span><span class="n">nva2</span><span class="p">)</span> <span class="o">/</span> <span class="k">sizeof</span><span class="p">(</span><span class="n">nva2</span><span class="p">[</span><span class="mi">0</span><span class="p">]));</span>
<span class="n">nghttp2_hd_inflate_del</span><span class="p">(</span><span class="n">inflater</span><span class="p">);</span>
<span class="n">nghttp2_hd_deflate_del</span><span class="p">(</span><span class="n">deflater</span><span class="p">);</span>
<span class="k">return</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">static</span> <span class="kt">void</span> <span class="nf">deflate</span><span class="p">(</span><span class="n">nghttp2_hd_deflater</span> <span class="o">*</span><span class="n">deflater</span><span class="p">,</span>
<span class="n">nghttp2_hd_inflater</span> <span class="o">*</span><span class="n">inflater</span><span class="p">,</span> <span class="k">const</span> <span class="n">nghttp2_nv</span> <span class="o">*</span><span class="k">const</span> <span class="n">nva</span><span class="p">,</span>
<span class="kt">size_t</span> <span class="n">nvlen</span><span class="p">)</span> <span class="p">{</span>
<span class="kt">ssize_t</span> <span class="n">rv</span><span class="p">;</span>
<span class="kt">uint8_t</span> <span class="o">*</span><span class="n">buf</span><span class="p">;</span>
<span class="kt">size_t</span> <span class="n">buflen</span><span class="p">;</span>
<span class="kt">size_t</span> <span class="n">outlen</span><span class="p">;</span>
<span class="kt">size_t</span> <span class="n">i</span><span class="p">;</span>
<span class="kt">size_t</span> <span class="n">sum</span><span class="p">;</span>
<span class="n">sum</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(</span><span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="n">i</span> <span class="o"><</span> <span class="n">nvlen</span><span class="p">;</span> <span class="o">++</span><span class="n">i</span><span class="p">)</span> <span class="p">{</span>
<span class="n">sum</span> <span class="o">+=</span> <span class="n">nva</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">namelen</span> <span class="o">+</span> <span class="n">nva</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">valuelen</span><span class="p">;</span>
<span class="p">}</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"Input (%zu byte(s)):</span><span class="se">\n\n</span><span class="s">"</span><span class="p">,</span> <span class="n">sum</span><span class="p">);</span>
<span class="k">for</span> <span class="p">(</span><span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="n">i</span> <span class="o"><</span> <span class="n">nvlen</span><span class="p">;</span> <span class="o">++</span><span class="n">i</span><span class="p">)</span> <span class="p">{</span>
<span class="n">fwrite</span><span class="p">(</span><span class="n">nva</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">name</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">nva</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">namelen</span><span class="p">,</span> <span class="n">stdout</span><span class="p">);</span>
<span class="n">printf</span><span class="p">(</span><span class="s">": "</span><span class="p">);</span>
<span class="n">fwrite</span><span class="p">(</span><span class="n">nva</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">value</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">nva</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">valuelen</span><span class="p">,</span> <span class="n">stdout</span><span class="p">);</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"</span><span class="se">\n</span><span class="s">"</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">buflen</span> <span class="o">=</span> <span class="n">nghttp2_hd_deflate_bound</span><span class="p">(</span><span class="n">deflater</span><span class="p">,</span> <span class="n">nva</span><span class="p">,</span> <span class="n">nvlen</span><span class="p">);</span>
<span class="n">buf</span> <span class="o">=</span> <span class="n">malloc</span><span class="p">(</span><span class="n">buflen</span><span class="p">);</span>
<span class="n">rv</span> <span class="o">=</span> <span class="n">nghttp2_hd_deflate_hd</span><span class="p">(</span><span class="n">deflater</span><span class="p">,</span> <span class="n">buf</span><span class="p">,</span> <span class="n">buflen</span><span class="p">,</span> <span class="n">nva</span><span class="p">,</span> <span class="n">nvlen</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="n">rv</span> <span class="o"><</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">fprintf</span><span class="p">(</span><span class="n">stderr</span><span class="p">,</span> <span class="s">"nghttp2_hd_deflate_hd() failed with error: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span>
<span class="n">nghttp2_strerror</span><span class="p">((</span><span class="kt">int</span><span class="p">)</span><span class="n">rv</span><span class="p">));</span>
<span class="n">free</span><span class="p">(</span><span class="n">buf</span><span class="p">);</span>
<span class="n">exit</span><span class="p">(</span><span class="n">EXIT_FAILURE</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">outlen</span> <span class="o">=</span> <span class="p">(</span><span class="kt">size_t</span><span class="p">)</span><span class="n">rv</span><span class="p">;</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"</span><span class="se">\n</span><span class="s">Deflate (%zu byte(s), ratio %.02f):</span><span class="se">\n\n</span><span class="s">"</span><span class="p">,</span> <span class="n">outlen</span><span class="p">,</span>
<span class="n">sum</span> <span class="o">==</span> <span class="mi">0</span> <span class="o">?</span> <span class="mi">0</span> <span class="o">:</span> <span class="p">(</span><span class="kt">double</span><span class="p">)</span><span class="n">outlen</span> <span class="o">/</span> <span class="p">(</span><span class="kt">double</span><span class="p">)</span><span class="n">sum</span><span class="p">);</span>
<span class="k">for</span> <span class="p">(</span><span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="n">i</span> <span class="o"><</span> <span class="n">outlen</span><span class="p">;</span> <span class="o">++</span><span class="n">i</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">((</span><span class="n">i</span> <span class="o">&</span> <span class="mh">0x0fu</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"%08zX: "</span><span class="p">,</span> <span class="n">i</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"%02X "</span><span class="p">,</span> <span class="n">buf</span><span class="p">[</span><span class="n">i</span><span class="p">]);</span>
<span class="k">if</span> <span class="p">(((</span><span class="n">i</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span> <span class="o">&</span> <span class="mh">0x0fu</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"</span><span class="se">\n</span><span class="s">"</span><span class="p">);</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"</span><span class="se">\n\n</span><span class="s">Inflate:</span><span class="se">\n\n</span><span class="s">"</span><span class="p">);</span>
<span class="cm">/* We pass 1 to final parameter, because buf contains whole deflated</span>
<span class="cm"> header data. */</span>
<span class="n">rv</span> <span class="o">=</span> <span class="n">inflate_header_block</span><span class="p">(</span><span class="n">inflater</span><span class="p">,</span> <span class="n">buf</span><span class="p">,</span> <span class="n">outlen</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="n">rv</span> <span class="o">!=</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">free</span><span class="p">(</span><span class="n">buf</span><span class="p">);</span>
<span class="n">exit</span><span class="p">(</span><span class="n">EXIT_FAILURE</span><span class="p">);</span>
<span class="p">}</span>
<span class="n">printf</span><span class="p">(</span><span class="s">"</span><span class="se">\n</span><span class="s">-----------------------------------------------------------"</span>
<span class="s">"--------------------</span><span class="se">\n</span><span class="s">"</span><span class="p">);</span>
<span class="n">free</span><span class="p">(</span><span class="n">buf</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">int</span> <span class="nf">inflate_header_block</span><span class="p">(</span><span class="n">nghttp2_hd_inflater</span> <span class="o">*</span><span class="n">inflater</span><span class="p">,</span> <span class="kt">uint8_t</span> <span class="o">*</span><span class="n">in</span><span class="p">,</span>
<span class="kt">size_t</span> <span class="n">inlen</span><span class="p">,</span> <span class="kt">int</span> <span class="n">final</span><span class="p">)</span> <span class="p">{</span>
<span class="kt">ssize_t</span> <span class="n">rv</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(;;)</span> <span class="p">{</span>
<span class="n">nghttp2_nv</span> <span class="n">nv</span><span class="p">;</span>
<span class="kt">int</span> <span class="n">inflate_flags</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="kt">size_t</span> <span class="n">proclen</span><span class="p">;</span>
<span class="n">rv</span> <span class="o">=</span> <span class="n">nghttp2_hd_inflate_hd</span><span class="p">(</span><span class="n">inflater</span><span class="p">,</span> <span class="o">&</span><span class="n">nv</span><span class="p">,</span> <span class="o">&</span><span class="n">inflate_flags</span><span class="p">,</span> <span class="n">in</span><span class="p">,</span> <span class="n">inlen</span><span class="p">,</span> <span class="n">final</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="n">rv</span> <span class="o"><</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="n">fprintf</span><span class="p">(</span><span class="n">stderr</span><span class="p">,</span> <span class="s">"inflate failed with error code %zd"</span><span class="p">,</span> <span class="n">rv</span><span class="p">);</span>
<span class="k">return</span> <span class="o">-</span><span class="mi">1</span><span class="p">;</span>
<span class="p">}</span>
<span class="n">proclen</span> <span class="o">=</span> <span class="p">(</span><span class="kt">size_t</span><span class="p">)</span><span class="n">rv</span><span class="p">;</span>
<span class="n">in</span> <span class="o">+=</span> <span class="n">proclen</span><span class="p">;</span>
<span class="n">inlen</span> <span class="o">-=</span> <span class="n">proclen</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="n">inflate_flags</span> <span class="o">&</span> <span class="n">NGHTTP2_HD_INFLATE_EMIT</span><span class="p">)</span> <span class="p">{</span>
<span class="n">fwrite</span><span class="p">(</span><span class="n">nv</span><span class="p">.</span><span class="n">name</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">nv</span><span class="p">.</span><span class="n">namelen</span><span class="p">,</span> <span class="n">stderr</span><span class="p">);</span>
<span class="n">fprintf</span><span class="p">(</span><span class="n">stderr</span><span class="p">,</span> <span class="s">": "</span><span class="p">);</span>
<span class="n">fwrite</span><span class="p">(</span><span class="n">nv</span><span class="p">.</span><span class="n">value</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">nv</span><span class="p">.</span><span class="n">valuelen</span><span class="p">,</span> <span class="n">stderr</span><span class="p">);</span>
<span class="n">fprintf</span><span class="p">(</span><span class="n">stderr</span><span class="p">,</span> <span class="s">"</span><span class="se">\n</span><span class="s">"</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="n">inflate_flags</span> <span class="o">&</span> <span class="n">NGHTTP2_HD_INFLATE_FINAL</span><span class="p">)</span> <span class="p">{</span>
<span class="n">nghttp2_hd_inflate_end_headers</span><span class="p">(</span><span class="n">inflater</span><span class="p">);</span>
<span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">((</span><span class="n">inflate_flags</span> <span class="o">&</span> <span class="n">NGHTTP2_HD_INFLATE_EMIT</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span> <span class="o">&&</span> <span class="n">inlen</span> <span class="o">==</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">return</span> <span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
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distrib
>
Mageia
>
7
>
armv7hl
>
media
>
core-updates
>
by-pkgid
>
fe6ab4e9347b40dcc38a806b692b7c64
>
files
>
229
