trees-binary.sgml

GLib是GTK+和GNOME工程的基础底层核心程序库

<refentry id="glib-Balanced-Binary-Trees">
<refmeta>
<refentrytitle>Balanced Binary Trees</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>GLIB Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>Balanced Binary Trees</refname><refpurpose>a sorted collection of key/value pairs optimized for searching
and traversing in order.</refpurpose>
</refnamediv>

<refsynopsisdiv><title>Synopsis</title>
<synopsis>

#include &lt;glib.h&gt;


struct      <link linkend="GTree">GTree</link>;
<link linkend="GTree">GTree</link>*      <link linkend="g-tree-new">g_tree_new</link>                      (<link linkend="GCompareFunc">GCompareFunc</link> key_compare_func);
<link linkend="GTree">GTree</link>*      <link linkend="g-tree-new-with-data">g_tree_new_with_data</link>            (<link linkend="GCompareDataFunc">GCompareDataFunc</link> key_compare_func,
                                             <link linkend="gpointer">gpointer</link> key_compare_data);
<link linkend="GTree">GTree</link>*      <link linkend="g-tree-new-full">g_tree_new_full</link>                 (<link linkend="GCompareDataFunc">GCompareDataFunc</link> key_compare_func,
                                             <link linkend="gpointer">gpointer</link> key_compare_data,
                                             <link linkend="GDestroyNotify">GDestroyNotify</link> key_destroy_func,
                                             <link linkend="GDestroyNotify">GDestroyNotify</link> value_destroy_func);
void        <link linkend="g-tree-insert">g_tree_insert</link>                   (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gpointer">gpointer</link> key,
                                             <link linkend="gpointer">gpointer</link> value);
void        <link linkend="g-tree-replace">g_tree_replace</link>                  (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gpointer">gpointer</link> key,
                                             <link linkend="gpointer">gpointer</link> value);
<link linkend="gint">gint</link>        <link linkend="g-tree-nnodes">g_tree_nnodes</link>                   (<link linkend="GTree">GTree</link> *tree);
<link linkend="gint">gint</link>        <link linkend="g-tree-height">g_tree_height</link>                   (<link linkend="GTree">GTree</link> *tree);
<link linkend="gpointer">gpointer</link>    <link linkend="g-tree-lookup">g_tree_lookup</link>                   (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gconstpointer">gconstpointer</link> key);
<link linkend="gboolean">gboolean</link>    <link linkend="g-tree-lookup-extended">g_tree_lookup_extended</link>          (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gconstpointer">gconstpointer</link> lookup_key,
                                             <link linkend="gpointer">gpointer</link> *orig_key,
                                             <link linkend="gpointer">gpointer</link> *value);
void        <link linkend="g-tree-foreach">g_tree_foreach</link>                  (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="GTraverseFunc">GTraverseFunc</link> func,
                                             <link linkend="gpointer">gpointer</link> user_data);
void        <link linkend="g-tree-traverse">g_tree_traverse</link>                 (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="GTraverseFunc">GTraverseFunc</link> traverse_func,
                                             <link linkend="GTraverseType">GTraverseType</link> traverse_type,
                                             <link linkend="gpointer">gpointer</link> user_data);
<link linkend="gboolean">gboolean</link>    (<link linkend="GTraverseFunc">*GTraverseFunc</link>)                (<link linkend="gpointer">gpointer</link> key,
                                             <link linkend="gpointer">gpointer</link> value,
                                             <link linkend="gpointer">gpointer</link> data);
enum        <link linkend="GTraverseType">GTraverseType</link>;
<link linkend="gpointer">gpointer</link>    <link linkend="g-tree-search">g_tree_search</link>                   (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="GCompareFunc">GCompareFunc</link> search_func,
                                             <link linkend="gconstpointer">gconstpointer</link> user_data);
void        <link linkend="g-tree-remove">g_tree_remove</link>                   (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gconstpointer">gconstpointer</link> key);
void        <link linkend="g-tree-steal">g_tree_steal</link>                    (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gconstpointer">gconstpointer</link> key);
void        <link linkend="g-tree-destroy">g_tree_destroy</link>                  (<link linkend="GTree">GTree</link> *tree);
</synopsis>
</refsynopsisdiv>





<refsect1>
<title>Description</title>
<para>
The <link linkend="GTree">GTree</link> structure and its associated functions provide a sorted collection
of key/value pairs optimized for searching and traversing in order.
</para>
<para>
To create a new <link linkend="GTree">GTree</link> use <link linkend="g-tree-new">g_tree_new</link>().
</para>
<para>
To insert a key/value pair into a <link linkend="GTree">GTree</link> use <link linkend="g-tree-insert">g_tree_insert</link>().
</para>
<para>
To lookup the value corresponding to a given key, use <link linkend="g-tree-lookup">g_tree_lookup</link>() and
<link linkend="g-tree-lookup-extended">g_tree_lookup_extended</link>().
</para>
<para>
To find out the number of nodes in a <link linkend="GTree">GTree</link>, use <link linkend="g-tree-nnodes">g_tree_nnodes</link>().
To get the height of a <link linkend="GTree">GTree</link>, use <link linkend="g-tree-height">g_tree_height</link>().
</para>
<para>
To traverse a <link linkend="GTree">GTree</link>, calling a function for each node visited in the
traversal, use <link linkend="g-tree-foreach">g_tree_foreach</link>().
</para>
<para>
To remove a key/value pair use <link linkend="g-tree-remove">g_tree_remove</link>().
</para>
<para>
To destroy a <link linkend="GTree">GTree</link>, use <link linkend="g-tree-destroy">g_tree_destroy</link>().
</para>
</refsect1>

<refsect1>
<title>Details</title>
<refsect2>
<title><anchor id="GTree">struct GTree</title>
<programlisting>struct GTree;</programlisting>
<para>
The <structname>GTree</structname> struct is an opaque data structure representing a
<link linkend="glib-Balanced-Binary-Trees">Balanced Binary Tree</link>.
It should be accessed only by using the following functions.
</para></refsect2>
<refsect2>
<title><anchor id="g-tree-new">g_tree_new ()</title>
<programlisting><link linkend="GTree">GTree</link>*      g_tree_new                      (<link linkend="GCompareFunc">GCompareFunc</link> key_compare_func);</programlisting>
<para>
Creates a new <link linkend="GTree">GTree</link>.</para>
<para>

</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>key_compare_func</parameter>&nbsp;:</entry>
<entry> the function used to order the nodes in the <link linkend="GTree">GTree</link>.
  It should return values similar to the standard 
  <function><link linkend="strcmp">strcmp</link>()</function> function -
  0 if the two arguments are equal, a negative value if the first argument 
  comes before the second, or a positive value if the first argument comes 
  after the second.
</entry></row>
<row><entry align="right"><emphasis>Returns</emphasis> :</entry><entry> a new <link linkend="GTree">GTree</link>.
</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="g-tree-new-with-data">g_tree_new_with_data ()</title>
<programlisting><link linkend="GTree">GTree</link>*      g_tree_new_with_data            (<link linkend="GCompareDataFunc">GCompareDataFunc</link> key_compare_func,
                                             <link linkend="gpointer">gpointer</link> key_compare_data);</programlisting>
<para>
Creates a new <link linkend="GTree">GTree</link> with a comparison function that accepts user data.
See <link linkend="g-tree-new">g_tree_new</link>() for more details.</para>
<para>

</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>key_compare_func</parameter>&nbsp;:</entry>
<entry> <function><link linkend="qsort">qsort</link>()</function>-style comparison function.
</entry></row>
<row><entry align="right"><parameter>key_compare_data</parameter>&nbsp;:</entry>
<entry> data to pass to comparison function.
</entry></row>
<row><entry align="right"><emphasis>Returns</emphasis> :</entry><entry> a new <link linkend="GTree">GTree</link>.
</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="g-tree-new-full">g_tree_new_full ()</title>
<programlisting><link linkend="GTree">GTree</link>*      g_tree_new_full                 (<link linkend="GCompareDataFunc">GCompareDataFunc</link> key_compare_func,
                                             <link linkend="gpointer">gpointer</link> key_compare_data,
                                             <link linkend="GDestroyNotify">GDestroyNotify</link> key_destroy_func,
                                             <link linkend="GDestroyNotify">GDestroyNotify</link> value_destroy_func);</programlisting>
<para>
Creates a new <link linkend="GTree">GTree</link> like <link linkend="g-tree-new">g_tree_new</link>() and allows to specify functions 
to free the memory allocated for the key and value that get called when 
removing the entry from the <link linkend="GTree">GTree</link>.</para>
<para>

</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>key_compare_func</parameter>&nbsp;:</entry>
<entry> <function><link linkend="qsort">qsort</link>()</function>-style comparison function.
</entry></row>
<row><entry align="right"><parameter>key_compare_data</parameter>&nbsp;:</entry>
<entry> data to pass to comparison function.
</entry></row>
<row><entry align="right"><parameter>key_destroy_func</parameter>&nbsp;:</entry>
<entry> a function to free the memory allocated for the key 
  used when removing the entry from the <link linkend="GTree">GTree</link> or <literal>NULL</literal> if you don't
  want to supply such a function.
</entry></row>
<row><entry align="right"><parameter>value_destroy_func</parameter>&nbsp;:</entry>
<entry> a function to free the memory allocated for the 
  value used when removing the entry from the <link linkend="GTree">GTree</link> or <literal>NULL</literal> if you 
  don't want to supply such a function.
</entry></row>
<row><entry align="right"><emphasis>Returns</emphasis> :</entry><entry> a new <link linkend="GTree">GTree</link>.
</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="g-tree-insert">g_tree_insert ()</title>
<programlisting>void        g_tree_insert                   (<link linkend="GTree">GTree</link> *tree,
                                             <link linkend="gpointer">gpointer</link> key,
                                             <link linkend="gpointer">gpointer</link> value);</programlisting>
<para>
Inserts a key/value pair into a <link linkend="GTree">GTree</link>. If the given key already exists 
in the <link linkend="GTree">GTree</link> its corresponding value is set to the new value. If you 
supplied a value_destroy_func when creating the <link linkend="GTree">GTree</link>, the old value is 
freed using that function. If you supplied a <parameter>key_destroy_func</parameter> when 
creating the <link linkend="GTree">GTree</link>, the passed key is freed using that function.
</para>
<para>
The tree is automatically 'balanced' as new key/value pairs are added,