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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
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<title>VIPS Reference Manual: VipsOperation</title>
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<a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span> 
                  <a href="#VipsOperation.description" class="shortcut">Description</a></span><span id="nav_hierarchy"> <span class="dim">|</span> 
                  <a href="#VipsOperation.object-hierarchy" class="shortcut">Object Hierarchy</a></span><span id="nav_signals"> <span class="dim">|</span> 
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<div class="refentry">
<a name="VipsOperation"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="VipsOperation.top_of_page"></a>VipsOperation</span></h2>
<p>VipsOperation — the VIPS operation base object class</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="VipsOperation.stability-level"></a><h2>Stability Level</h2>
Stable, unless otherwise indicated
</div>
<div class="refsect1">
<a name="VipsOperation.functions"></a><h2>Functions</h2>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="VipsOperation.html#VipsOperationBuildFn" title="VipsOperationBuildFn ()">*VipsOperationBuildFn</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="VipsOperation.html#VipsOperationFlags" title="enum VipsOperationFlags"><span class="returnvalue">VipsOperationFlags</span></a>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-operation-get-flags" title="vips_operation_get_flags ()">vips_operation_get_flags</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-operation-class-print-usage" title="vips_operation_class_print_usage ()">vips_operation_class_print_usage</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-operation-invalidate" title="vips_operation_invalidate ()">vips_operation_invalidate</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-operation-call-valist" title="vips_operation_call_valist ()">vips_operation_call_valist</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="VipsOperation.html" title="VipsOperation"><span class="returnvalue">VipsOperation</span></a> *
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-operation-new" title="vips_operation_new ()">vips_operation_new</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-call" title="vips_call ()">vips_call</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-call-split" title="vips_call_split ()">vips_call_split</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-call-split-option-string" title="vips_call_split_option_string ()">vips_call_split_option_string</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-call-options" title="vips_call_options ()">vips_call_options</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-call-argv" title="vips_call_argv ()">vips_call_argv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-drop-all" title="vips_cache_drop_all ()">vips_cache_drop_all</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-operation-buildp" title="vips_cache_operation_buildp ()">vips_cache_operation_buildp</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="VipsOperation.html" title="VipsOperation"><span class="returnvalue">VipsOperation</span></a> *
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-operation-build" title="vips_cache_operation_build ()">vips_cache_operation_build</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-print" title="vips_cache_print ()">vips_cache_print</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-set-max" title="vips_cache_set_max ()">vips_cache_set_max</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-set-max-mem" title="vips_cache_set_max_mem ()">vips_cache_set_max_mem</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-get-max" title="vips_cache_get_max ()">vips_cache_get_max</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-get-size" title="vips_cache_get_size ()">vips_cache_get_size</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">size_t</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-get-max-mem" title="vips_cache_get_max_mem ()">vips_cache_get_max_mem</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">int</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-get-max-files" title="vips_cache_get_max_files ()">vips_cache_get_max_files</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-set-max-files" title="vips_cache_set_max_files ()">vips_cache_set_max_files</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-set-dump" title="vips_cache_set_dump ()">vips_cache_set_dump</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="VipsOperation.html#vips-cache-set-trace" title="vips_cache_set_trace ()">vips_cache_set_trace</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="VipsOperation.signals"></a><h2>Signals</h2>
<div class="informaltable"><table border="0">
<colgroup>
<col width="150px" class="signals_return">
<col width="300px" class="signals_name">
<col width="200px" class="signals_flags">
</colgroup>
<tbody><tr>
<td class="signal_type"><span class="returnvalue">void</span></td>
<td class="signal_name"><a class="link" href="VipsOperation.html#VipsOperation-invalidate" title="The “invalidate” signal">invalidate</a></td>
<td class="signal_flags">Run Last</td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="VipsOperation.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody><tr>
<td class="datatype_keyword">enum</td>
<td class="function_name"><a class="link" href="VipsOperation.html#VipsOperationFlags" title="enum VipsOperationFlags">VipsOperationFlags</a></td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="VipsOperation.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen">    <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject">GObject</a>
    <span class="lineart">╰──</span> <a class="link" href="VipsObject.html" title="VipsObject">VipsObject</a>
        <span class="lineart">╰──</span> VipsOperation
            <span class="lineart">╰──</span> <a class="link" href="VipsForeignSave.html#VipsForeign">VipsForeign</a>
</pre>
</div>
<div class="refsect1">
<a name="VipsOperation.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;vips/vips.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="VipsOperation.description"></a><h2>Description</h2>
<p>The <a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> class and associated types and macros.</p>
<p><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> is the base class for all operations in libvips. It builds
on <a class="link" href="VipsObject.html" title="VipsObject"><span class="type">VipsObject</span></a> to provide the introspection and command-line interface to
libvips. </p>
<p>It also maintains a cache of recent operations. See below. </p>
<p>vips_call(), <a class="link" href="VipsOperation.html#vips-call-split" title="vips_call_split ()"><code class="function">vips_call_split()</code></a> and <a class="link" href="VipsOperation.html#vips-call-split-option-string" title="vips_call_split_option_string ()"><code class="function">vips_call_split_option_string()</code></a> are used
by vips to implement the C API. They can execute any <a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a>,
passing in a set of required and optional arguments. Normally you would not
use these functions directly: every operation has a tiny wrapper function
which provides type-safety for the required arguments. For example,
<a class="link" href="libvips-conversion.html#vips-embed" title="vips_embed ()"><code class="function">vips_embed()</code></a> is defined as:</p>
<div class="informalexample"><pre class="programlisting">
int
vips_embed( VipsImage *in, VipsImage **out, 
  int x, int y, int width, int height, ... )
{
  va_list ap;
  int result;

  va_start( ap, height );
  result = vips_call_split( "embed", ap, in, out, x, y, width, height );
  va_end( ap );

  return( result );
}
</pre></div>
<p></p>
<p>Use <a class="link" href="VipsOperation.html#vips-call-argv" title="vips_call_argv ()"><code class="function">vips_call_argv()</code></a> to run any vips operation from a command-line style
argc/argv array. This is the thing used by the vips main program to
implement the vips command-line interface. </p>
<div class="refsect3">
<a name="id-1.3.6.9.9"></a><h4>
<a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> and reference counting</h4>
<p>After calling a <a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> you are responsible for unreffing any output
objects. For example, consider:</p>
<div class="informalexample"><pre class="programlisting">
VipsImage *im = ...;
VipsImage *t1; 

if (vips_invert (im, &amp;t1, NULL)) 
  error ..
</pre></div>
<p></p>
<p>This will invert <em class="parameter"><code>im</code></em>
 and return it as a new <a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a>, <em class="parameter"><code>t1</code></em>
. As the caller
of <a class="link" href="libvips-arithmetic.html#vips-invert" title="vips_invert ()"><code class="function">vips_invert()</code></a>, you are responsible for <em class="parameter"><code>t1</code></em>
 and must unref it when you no
longer need it. If <a class="link" href="libvips-arithmetic.html#vips-invert" title="vips_invert ()"><code class="function">vips_invert()</code></a> fails, no <em class="parameter"><code>t1</code></em>
 is returned and you don't
need to do anything. </p>
<p>Consider running two operations, one after the other. You could write:</p>
<div class="informalexample"><pre class="programlisting">
VipsImage *im = ...;
VipsImage *t1, *t2;

if (vips_invert (im, &amp;t1, NULL)) {
  g_object_unref (im);
  return -1;
}
g_object_unref (im);

if (vips_flip (t1, &amp;t2, VIPS_DIRECTION_HORIZONTAL, NULL)) {
  g_object_unref (t1);
  return -1;
}
g_object_unref (t1);
</pre></div>
<p></p>
<p>This is correct, but rather long-winded. libvips provides a handy thing to
make a vector of auto-freeing object references. You can write this as:</p>
<div class="informalexample"><pre class="programlisting">
VipsObject *parent = ...;
VipsImage *im = ...;
VipsImage *t = (VipsImage **) vips_object_local_array (parent, 2);

if (vips_invert (im, &amp;t[0], NULL) ||
  vips_flip (t[0], &amp;t[1], VIPS_DIRECTION_HORIZONTAL, NULL))
  return -1;
</pre></div>
<p></p>
<p>where <em class="parameter"><code>parent</code></em>
 is some enclosing object which will be unreffed when this
task is complete. <a class="link" href="VipsObject.html#vips-object-local-array" title="vips_object_local_array ()"><code class="function">vips_object_local_array()</code></a> makes an array of <a class="link" href="VipsObject.html" title="VipsObject"><span class="type">VipsObject</span></a>
(or <a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a>, in this case) where when <em class="parameter"><code>parent</code></em>
 is freed, all non-NULL
<a class="link" href="VipsObject.html" title="VipsObject"><span class="type">VipsObject</span></a> in the array are also unreffed.</p>
</div>
<div class="refsect3">
<a name="id-1.3.6.9.10"></a><h4>The <a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> cache</h4>
<p>Because all <a class="link" href="VipsObject.html" title="VipsObject"><span class="type">VipsObject</span></a> are immutable, they can be cached. The cache is
very simple to use: instead of calling <a class="link" href="VipsObject.html#vips-object-build" title="vips_object_build ()"><code class="function">vips_object_build()</code></a>, instead call 
<a class="link" href="VipsOperation.html#vips-cache-operation-build" title="vips_cache_operation_build ()"><code class="function">vips_cache_operation_build()</code></a>. This function calculates a hash from the
operations's input arguments and looks it up in table of all recent
operations. If there's a hit, the new operation is unreffed, the old
operation reffed, and the old operation returned in place of the new one.</p>
<p>The cache size is controlled with <a class="link" href="VipsOperation.html#vips-cache-set-max" title="vips_cache_set_max ()"><code class="function">vips_cache_set_max()</code></a> and friends.</p>
</div>
</div>
<div class="refsect1">
<a name="VipsOperation.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="VipsOperationBuildFn"></a><h3>VipsOperationBuildFn ()</h3>
<pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
<span class="c_punctuation">(</span>*VipsOperationBuildFn<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="VipsObject.html" title="VipsObject"><span class="type">VipsObject</span></a> *Param1</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-operation-get-flags"></a><h3>vips_operation_get_flags ()</h3>
<pre class="programlisting"><a class="link" href="VipsOperation.html#VipsOperationFlags" title="enum VipsOperationFlags"><span class="returnvalue">VipsOperationFlags</span></a>
vips_operation_get_flags (<em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *operation</code></em>);</pre>
<p>Returns the set of flags for this operation.</p>
<div class="refsect3">
<a name="id-1.3.6.10.3.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>operation</p></td>
<td class="parameter_description"><p>operation to fetch flags from</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.6.10.3.6"></a><h4>Returns</h4>
<p> 0 on success, or -1 on error.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-operation-class-print-usage"></a><h3>vips_operation_class_print_usage ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_operation_class_print_usage (<em class="parameter"><code><span class="type">VipsOperationClass</span> *operation_class</code></em>);</pre>
<p>Print a usage message for the operation to stdout.</p>
<div class="refsect3">
<a name="id-1.3.6.10.4.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>operation_class</p></td>
<td class="parameter_description"><p>class to print usage for</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-operation-invalidate"></a><h3>vips_operation_invalidate ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_operation_invalidate (<em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *operation</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-operation-call-valist"></a><h3>vips_operation_call_valist ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_operation_call_valist (<em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *operation</code></em>,
                            <em class="parameter"><code><span class="type">va_list</span> ap</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-operation-new"></a><h3>vips_operation_new ()</h3>
<pre class="programlisting"><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="returnvalue">VipsOperation</span></a> *
vips_operation_new (<em class="parameter"><code>const <span class="type">char</span> *name</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-call"></a><h3>vips_call ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_call (<em class="parameter"><code>const <span class="type">char</span> *operation_name</code></em>,
           <em class="parameter"><code>...</code></em>);</pre>
<p>vips_call() calls the named operation, passing in required arguments, and
then setting any optional ones from the remainder of the arguments as a set
of name/value pairs. </p>
<p>For example, <a class="link" href="libvips-conversion.html#vips-embed" title="vips_embed ()"><code class="function">vips_embed()</code></a> takes six required arguments, <em class="parameter"><code>in</code></em>
, <em class="parameter"><code>out</code></em>
, <em class="parameter"><code>x</code></em>
, <em class="parameter"><code>y</code></em>
, 
<em class="parameter"><code>width</code></em>
, <em class="parameter"><code>height</code></em>
; and has two optional arguments, <em class="parameter"><code>extend</code></em>
 and <em class="parameter"><code>background</code></em>
.
You can run it with <a class="link" href="VipsOperation.html#vips-call" title="vips_call ()"><code class="function">vips_call()</code></a> like this: </p>
<div class="informalexample"><pre class="programlisting">
VipsImage *in = ...
VipsImage *out;

if( vips_call( "embed", in, &amp;out, 10, 10, 100, 100,
	"extend", VIPS_EXTEND_COPY,
	NULL ) )
	... error
</pre></div>
<p></p>
<p>Normally of course you'd just use the <a class="link" href="libvips-conversion.html#vips-embed" title="vips_embed ()"><code class="function">vips_embed()</code></a> wrapper function and get
type-safety for the required arguments. </p>
<p>See also: <a class="link" href="VipsOperation.html#vips-call-split" title="vips_call_split ()"><code class="function">vips_call_split()</code></a>, <a class="link" href="VipsOperation.html#vips-call-options" title="vips_call_options ()"><code class="function">vips_call_options()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.8.10"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>...</p></td>
<td class="parameter_description"><p>required args, then a <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>-terminated list of argument/value pairs</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.6.10.8.11"></a><h4>Returns</h4>
<p> 0 on success, -1 on error</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-call-split"></a><h3>vips_call_split ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_call_split (<em class="parameter"><code>const <span class="type">char</span> *operation_name</code></em>,
                 <em class="parameter"><code><span class="type">va_list</span> optional</code></em>,
                 <em class="parameter"><code>...</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-call-split-option-string"></a><h3>vips_call_split_option_string ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_call_split_option_string (<em class="parameter"><code>const <span class="type">char</span> *operation_name</code></em>,
                               <em class="parameter"><code>const <span class="type">char</span> *option_string</code></em>,
                               <em class="parameter"><code><span class="type">va_list</span> optional</code></em>,
                               <em class="parameter"><code>...</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-call-options"></a><h3>vips_call_options ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_call_options (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Commandline-option-parser.html#GOptionGroup"><span class="type">GOptionGroup</span></a> *group</code></em>,
                   <em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *operation</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-call-argv"></a><h3>vips_call_argv ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_call_argv (<em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *operation</code></em>,
                <em class="parameter"><code><span class="type">int</span> argc</code></em>,
                <em class="parameter"><code><span class="type">char</span> **argv</code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-drop-all"></a><h3>vips_cache_drop_all ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_drop_all (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Drop the whole operation cache, handy for leak tracking.</p>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-operation-buildp"></a><h3>vips_cache_operation_buildp ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_cache_operation_buildp (<em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> **operation</code></em>);</pre>
<p>Look up <em class="parameter"><code>operation</code></em>
 in the cache. If we get a hit, unref <em class="parameter"><code>operation</code></em>
, ref the
old one and return that through the argument pointer. </p>
<p>If we miss, build and add <em class="parameter"><code>operation</code></em>
.</p>
<div class="refsect3">
<a name="id-1.3.6.10.14.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>operation</p></td>
<td class="parameter_description"><p>pointer to operation to lookup</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.6.10.14.7"></a><h4>Returns</h4>
<p> 0 on success, or -1 on error.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-operation-build"></a><h3>vips_cache_operation_build ()</h3>
<pre class="programlisting"><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="returnvalue">VipsOperation</span></a> *
vips_cache_operation_build (<em class="parameter"><code><a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *operation</code></em>);</pre>
<p>A binding-friendly version of <a class="link" href="VipsOperation.html#vips-cache-operation-buildp" title="vips_cache_operation_buildp ()"><code class="function">vips_cache_operation_buildp()</code></a>.</p>
<p>After calling this, <em class="parameter"><code>operation</code></em>
 has the same ref count as when it went in,
and the result must be freed with <a class="link" href="VipsObject.html#vips-object-unref-outputs" title="vips_object_unref_outputs ()"><code class="function">vips_object_unref_outputs()</code></a> and
<a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#g-object-unref"><code class="function">g_object_unref()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.15.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>operation</p></td>
<td class="parameter_description"><p>operation to lookup</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.3.6.10.15.7"></a><h4>Returns</h4>
<p> The built operation. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-print"></a><h3>vips_cache_print ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_print (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Print the whole operation cache to stdout. Handy for debugging.</p>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-set-max"></a><h3>vips_cache_set_max ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_set_max (<em class="parameter"><code><span class="type">int</span> max</code></em>);</pre>
<p>Set the maximum number of operations we keep in cache.</p>
<div class="refsect3">
<a name="id-1.3.6.10.17.5"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>max</p></td>
<td class="parameter_description"><p>maximum number of operation to cache</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-set-max-mem"></a><h3>vips_cache_set_max_mem ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_set_max_mem (<em class="parameter"><code><span class="type">size_t</span> max_mem</code></em>);</pre>
<p>Set the maximum amount of tracked memory we allow before we start dropping
cached operations. See <a class="link" href="libvips-memory.html#vips-tracked-get-mem" title="vips_tracked_get_mem ()"><code class="function">vips_tracked_get_mem()</code></a>.</p>
<p>See also: <a class="link" href="libvips-memory.html#vips-tracked-get-mem" title="vips_tracked_get_mem ()"><code class="function">vips_tracked_get_mem()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.18.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>max_mem</p></td>
<td class="parameter_description"><p>maximum amount of tracked memory we use </p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-get-max"></a><h3>vips_cache_get_max ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_cache_get_max (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Get the maximum number of operations we keep in cache.</p>
<div class="refsect3">
<a name="id-1.3.6.10.19.5"></a><h4>Returns</h4>
<p> the maximum number of operations we keep in cache</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-get-size"></a><h3>vips_cache_get_size ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_cache_get_size (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Get the current number of operations in cache.</p>
<div class="refsect3">
<a name="id-1.3.6.10.20.5"></a><h4>Returns</h4>
<p> get the current number of operations in cache.</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-get-max-mem"></a><h3>vips_cache_get_max_mem ()</h3>
<pre class="programlisting"><span class="returnvalue">size_t</span>
vips_cache_get_max_mem (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Get the maximum amount of tracked memory we allow before we start dropping
cached operations. See <a class="link" href="libvips-memory.html#vips-tracked-get-mem" title="vips_tracked_get_mem ()"><code class="function">vips_tracked_get_mem()</code></a>.</p>
<p>See also: <a class="link" href="libvips-memory.html#vips-tracked-get-mem" title="vips_tracked_get_mem ()"><code class="function">vips_tracked_get_mem()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.21.6"></a><h4>Returns</h4>
<p> the maximum amount of tracked memory we allow</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-get-max-files"></a><h3>vips_cache_get_max_files ()</h3>
<pre class="programlisting"><span class="returnvalue">int</span>
vips_cache_get_max_files (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>Get the maximum number of tracked files we allow before we start dropping
cached operations. See <a class="link" href="libvips-memory.html#vips-tracked-get-files" title="vips_tracked_get_files ()"><code class="function">vips_tracked_get_files()</code></a>.</p>
<p>See also: <a class="link" href="libvips-memory.html#vips-tracked-get-files" title="vips_tracked_get_files ()"><code class="function">vips_tracked_get_files()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.22.6"></a><h4>Returns</h4>
<p> the maximum number of tracked files we allow</p>
<p></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-set-max-files"></a><h3>vips_cache_set_max_files ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_set_max_files (<em class="parameter"><code><span class="type">int</span> max_files</code></em>);</pre>
<p>Set the maximum number of tracked files we allow before we start dropping
cached operations. See <a class="link" href="libvips-memory.html#vips-tracked-get-files" title="vips_tracked_get_files ()"><code class="function">vips_tracked_get_files()</code></a>.</p>
<p>See also: <a class="link" href="libvips-memory.html#vips-tracked-get-files" title="vips_tracked_get_files ()"><code class="function">vips_tracked_get_files()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.23.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>max_files</p></td>
<td class="parameter_description"><p>max open files we allow</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-set-dump"></a><h3>vips_cache_set_dump ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_set_dump (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> dump</code></em>);</pre>
<p>Handy for debugging. Print the operation cache to stdout just before exit.</p>
<p>See also: <a class="link" href="VipsOperation.html#vips-cache-set-trace" title="vips_cache_set_trace ()"><code class="function">vips_cache_set_trace()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.24.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>dump</p></td>
<td class="parameter_description"><p>if <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>, dump the operation cache on exit</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="vips-cache-set-trace"></a><h3>vips_cache_set_trace ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
vips_cache_set_trace (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> trace</code></em>);</pre>
<p>Handy for debugging. Print operation cache actions to stdout as we run.</p>
<p>See also: <a class="link" href="VipsOperation.html#vips-cache-set-dump" title="vips_cache_set_dump ()"><code class="function">vips_cache_set_dump()</code></a>.</p>
<div class="refsect3">
<a name="id-1.3.6.10.25.6"></a><h4>Parameters</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>trace</p></td>
<td class="parameter_description"><p>if <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>, trace the operation cache </p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="VipsOperation.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="VipsOperationFlags"></a><h3>enum VipsOperationFlags</h3>
<div class="warning"><p><code class="literal">VipsOperationFlags</code> is deprecated and should not be used in newly-written code.</p></div>
<p>Flags we associate with an operation.</p>
<p><em class="parameter"><code>VIPS_OPERATION_SEQUENTIAL</code></em>
 means that the operation works like <a class="link" href="libvips-convolution.html#vips-conv" title="vips_conv ()"><code class="function">vips_conv()</code></a>:
it can happily process images top-to-bottom with only small non-local
references.</p>
<p><em class="parameter"><code>VIPS_OPERATION_SEQUENTIAL_UNBUFFERED</code></em>
 means that the operation works like 
<a class="link" href="libvips-conversion.html#vips-copy" title="vips_copy ()"><code class="function">vips_copy()</code></a>: it can happily process images top-to-bottom and makes no 
non-local references. </p>
<p><em class="parameter"><code>VIPS_OPERATION_NOCACHE</code></em>
 means that the operation must not be cached by
vips. </p>
<p><em class="parameter"><code>VIPS_OPERATION_DEPRECATED</code></em>
 means this is an old operation kept in vips for
compatibility only and should be hidden from users.</p>
<div class="refsect3">
<a name="id-1.3.6.11.2.9"></a><h4>Members</h4>
<div class="informaltable"><table width="100%" border="0">
<colgroup>
<col width="300px" class="enum_members_name">
<col class="enum_members_description">
<col width="200px" class="enum_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="enum_member_name"><p><a name="VIPS-OPERATION-NONE:CAPS"></a>VIPS_OPERATION_NONE</p></td>
<td class="enum_member_description">
<p>no flags</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="VIPS-OPERATION-SEQUENTIAL:CAPS"></a>VIPS_OPERATION_SEQUENTIAL</p></td>
<td class="enum_member_description">
<p>can work sequentially</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="VIPS-OPERATION-SEQUENTIAL-UNBUFFERED:CAPS"></a>VIPS_OPERATION_SEQUENTIAL_UNBUFFERED</p></td>
<td> </td>
<td> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="VIPS-OPERATION-NOCACHE:CAPS"></a>VIPS_OPERATION_NOCACHE</p></td>
<td class="enum_member_description">
<p>must not be cached</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
<tr>
<td class="enum_member_name"><p><a name="VIPS-OPERATION-DEPRECATED:CAPS"></a>VIPS_OPERATION_DEPRECATED</p></td>
<td class="enum_member_description">
<p>a compatibility thing</p>
</td>
<td class="enum_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="VipsOperation.signal-details"></a><h2>Signal Details</h2>
<div class="refsect2">
<a name="VipsOperation-invalidate"></a><h3>The <code class="literal">“invalidate”</code> signal</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
user_function (<a class="link" href="VipsOperation.html" title="VipsOperation"><span class="type">VipsOperation</span></a> *vipsoperation,
               <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a>       user_data)</pre>
<p>Flags: Run Last</p>
</div>
</div>
<div class="refsect1">
<a name="VipsOperation.see-also"></a><h2>See Also</h2>
object
</div>
</div>
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