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287N/A <div class="section" id="upgrading-from-1-x">
287N/A<h1>Upgrading from 1.x<a class="headerlink" href="#upgrading-from-1-x" title="Permalink to this headline">¶</a></h1>
287N/A<p>This chapter lists the backwards incompatible changes introduced in
287N/AJansson 2.0, and the steps that are needed for upgrading your code.</p>
287N/A<p><strong>The incompatibilities are not dramatic.</strong> The biggest change is that
493N/Aall decoding functions now require and extra parameter. Most programs
287N/Acan be modified to work with 2.0 by adding a <tt class="docutils literal"><span class="pre">0</span></tt> as the second
287N/Aparameter to all calls of <a class="reference internal" href="apiref.html#c.json_loads" title="json_loads"><tt class="xref c c-func docutils literal"><span class="pre">json_loads()</span></tt></a>, <a class="reference internal" href="apiref.html#c.json_loadf" title="json_loadf"><tt class="xref c c-func docutils literal"><span class="pre">json_loadf()</span></tt></a>
493N/Aand <a class="reference internal" href="apiref.html#c.json_load_file" title="json_load_file"><tt class="xref c c-func docutils literal"><span class="pre">json_load_file()</span></tt></a>.</p>
287N/A<div class="section" id="compatibility">
287N/A<h2>Compatibility<a class="headerlink" href="#compatibility" title="Permalink to this headline">¶</a></h2>
287N/A<p>Jansson 2.0 is backwards incompatible with the Jansson 1.x releases.
287N/AIt is ABI incompatible, i.e. all programs dynamically linking to the
287N/AJansson library need to be recompiled. It&#8217;s also API incompatible,
i.e. the source code of programs using Jansson 1.x may need
modifications to make them compile against Jansson 2.0.</p>
<p>All the 2.x releases are guaranteed to be backwards compatible for
both ABI and API, so no recompilation or source changes are needed
when upgrading from 2.x to 2.y.</p>
</div>
<div class="section" id="list-of-incompatible-changes">
<h2>List of Incompatible Changes<a class="headerlink" href="#list-of-incompatible-changes" title="Permalink to this headline">¶</a></h2>
<dl class="docutils">
<dt><strong>Decoding flags</strong></dt>
<dd><p class="first">For future needs, a <tt class="docutils literal"><span class="pre">flags</span></tt> parameter was added as the second
parameter to all decoding functions, i.e. <a class="reference internal" href="apiref.html#c.json_loads" title="json_loads"><tt class="xref c c-func docutils literal"><span class="pre">json_loads()</span></tt></a>,
<a class="reference internal" href="apiref.html#c.json_loadf" title="json_loadf"><tt class="xref c c-func docutils literal"><span class="pre">json_loadf()</span></tt></a> and <a class="reference internal" href="apiref.html#c.json_load_file" title="json_load_file"><tt class="xref c c-func docutils literal"><span class="pre">json_load_file()</span></tt></a>. All calls to
these functions need to be changed by adding a <tt class="docutils literal"><span class="pre">0</span></tt> as the second
argument. For example:</p>
<div class="last highlight-c"><div class="highlight"><pre><span class="cm">/* old code */</span>
<span class="n">json_loads</span><span class="p">(</span><span class="n">input</span><span class="p">,</span> <span class="o">&amp;</span><span class="n">error</span><span class="p">);</span>
<span class="cm">/* new code */</span>
<span class="n">json_loads</span><span class="p">(</span><span class="n">input</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="o">&amp;</span><span class="n">error</span><span class="p">);</span>
</pre></div>
</div>
</dd>
<dt><strong>Underlying type of JSON integers</strong></dt>
<dd><p class="first">The underlying C type of JSON integers has been changed from
<tt class="xref c c-type docutils literal"><span class="pre">int</span></tt> to the widest available signed integer type, i.e.
<tt class="xref c c-type docutils literal"><span class="pre">long</span> <span class="pre">long</span></tt> or <tt class="xref c c-type docutils literal"><span class="pre">long</span></tt>, depending on whether
<tt class="xref c c-type docutils literal"><span class="pre">long</span> <span class="pre">long</span></tt> is supported on your system or not. This makes
the whole 64-bit integer range available on most modern systems.</p>
<p class="last"><tt class="docutils literal"><span class="pre">jansson.h</span></tt> has a typedef <a class="reference internal" href="apiref.html#c.json_int_t" title="json_int_t"><tt class="xref c c-type docutils literal"><span class="pre">json_int_t</span></tt></a> to the underlying
integer type. <tt class="xref c c-type docutils literal"><span class="pre">int</span></tt> should still be used in most cases when
dealing with smallish JSON integers, as the compiler handles
implicit type coercion. Only when the full 64-bit range is needed,
<a class="reference internal" href="apiref.html#c.json_int_t" title="json_int_t"><tt class="xref c c-type docutils literal"><span class="pre">json_int_t</span></tt></a> should be explicitly used.</p>
</dd>
<dt><strong>Maximum encoder indentation depth</strong></dt>
<dd>The maximum argument of the <tt class="docutils literal"><span class="pre">JSON_INDENT()</span></tt> macro has been
changed from 255 to 31, to free up bits from the <tt class="docutils literal"><span class="pre">flags</span></tt>
parameter of <a class="reference internal" href="apiref.html#c.json_dumps" title="json_dumps"><tt class="xref c c-func docutils literal"><span class="pre">json_dumps()</span></tt></a>, <a class="reference internal" href="apiref.html#c.json_dumpf" title="json_dumpf"><tt class="xref c c-func docutils literal"><span class="pre">json_dumpf()</span></tt></a> and
<a class="reference internal" href="apiref.html#c.json_dump_file" title="json_dump_file"><tt class="xref c c-func docutils literal"><span class="pre">json_dump_file()</span></tt></a>. If your code uses a bigger indentation
than 31, it needs to be changed.</dd>
<dt><strong>Unsigned integers in API functions</strong></dt>
<dd>Version 2.0 unifies unsigned integer usage in the API. All uses of
<tt class="xref c c-type docutils literal"><span class="pre">unsigned</span> <span class="pre">int</span></tt> and <tt class="xref c c-type docutils literal"><span class="pre">unsigned</span> <span class="pre">long</span></tt> have been replaced
with <tt class="xref c c-type docutils literal"><span class="pre">size_t</span></tt>. This includes flags, container sizes, etc.
This should not require source code changes, as both
<tt class="xref c c-type docutils literal"><span class="pre">unsigned</span> <span class="pre">int</span></tt> and <tt class="xref c c-type docutils literal"><span class="pre">unsigned</span> <span class="pre">long</span></tt> are usually
compatible with <tt class="xref c c-type docutils literal"><span class="pre">size_t</span></tt>.</dd>
</dl>
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<h3><a href="index.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Upgrading from 1.x</a><ul>
<li><a class="reference internal" href="#compatibility">Compatibility</a></li>
<li><a class="reference internal" href="#list-of-incompatible-changes">List of Incompatible Changes</a></li>
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