variables: use a binary search tree instead of a table

This makes insertion/deletion faster, and saves a lot of code

src/libvlc.h

@@ -162,10 +162,9 @@ typedef struct vlc_object_internals_t
     char           *psz_name; /* given name */
 
     /* Object variables */
-    variable_t    **pp_vars;
+    void           *var_root;
     vlc_mutex_t     var_lock;
     vlc_cond_t      var_wait;
-    int             i_vars;
 
     /* Thread properties, if any */
     vlc_thread_t    thread_id;

src/misc/objects.c

@@ -54,6 +54,7 @@
 # include <errno.h> /* ENOSYS */
 #endif
 
+#include <search.h>
 #include <limits.h>
 #include <assert.h>
 
@@ -131,7 +132,7 @@ void *__vlc_custom_create( vlc_object_t *p_this, size_t i_size,
         p_new->i_flags = p_this->i_flags
             & (OBJECT_FLAGS_NODBG|OBJECT_FLAGS_QUIET|OBJECT_FLAGS_NOINTERACT);
 
-    p_priv->pp_vars = NULL;
+    p_priv->var_root = NULL;
 
     if( p_this == NULL )
     {
@@ -281,12 +282,8 @@ static void vlc_object_destroy( vlc_object_t *p_this )
     /* Any thread must have been cleaned up at this point. */
     assert( !p_priv->b_thread );
 
-    /* Destroy the associated variables, starting from the end so that
-     * no memmove calls have to be done. */
-    while( p_priv->i_vars )
-    {
-        var_Destroy( p_this, p_priv->pp_vars[p_priv->i_vars - 1]->psz_name );
-    }
+    /* Destroy the associated variables. */
+    var_DestroyAll( p_this );
 
     vlc_cond_destroy( &p_priv->var_wait );
     vlc_mutex_destroy( &p_priv->var_lock );
@@ -766,56 +763,13 @@ vlc_list_t *__vlc_list_children( vlc_object_t *obj )
     return l;
 }
 
-/*****************************************************************************
- * DumpCommand: print the current vlc structure
- *****************************************************************************
- * This function prints either an ASCII tree showing the connections between
- * vlc objects, and additional information such as their refcount, thread ID,
- * etc. (command "tree"), or the same data as a simple list (command "list").
- *****************************************************************************/
-static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd,
-                        vlc_value_t oldval, vlc_value_t newval, void *p_data )
+static void DumpVariable (const void *data, const VISIT which, const int depth)
 {
-    (void)oldval; (void)p_data;
-    vlc_object_t *p_object = NULL;
-
-    if( *newval.psz_string )
-    {
-        /* try using the object's name to find it */
-        p_object = vlc_object_find_name( p_this, newval.psz_string,
-                                         FIND_ANYWHERE );
-        if( !p_object )
-        {
-            return VLC_ENOOBJ;
-        }
-    }
-
-    libvlc_lock (p_this->p_libvlc);
-    if( *psz_cmd == 't' )
-    {
-        char psz_foo[2 * MAX_DUMPSTRUCTURE_DEPTH + 1];
-
-        if( !p_object )
-            p_object = VLC_OBJECT(p_this->p_libvlc);
-
-        psz_foo[0] = '|';
-        DumpStructure( p_object, 0, psz_foo );
-    }
-    else if( *psz_cmd == 'v' )
-    {
-        int i;
-
-        if( !p_object )
-            p_object = p_this->p_libvlc ? VLC_OBJECT(p_this->p_libvlc) : p_this;
-
-        PrintObject( p_object, "" );
+    if (which != postorder && which != leaf)
+        return;
+    (void) depth;
 
-        vlc_mutex_lock( &vlc_internals( p_object )->var_lock );
-        if( !vlc_internals( p_object )->i_vars )
-            printf( " `-o No variables\n" );
-        for( i = 0; i < vlc_internals( p_object )->i_vars; i++ )
-        {
-            const variable_t *p_var = vlc_internals( p_object )->pp_vars[i];
+    const variable_t *p_var = *(const variable_t **)data;
     const char *psz_type = "unknown";
 
     switch( p_var->i_type & VLC_VAR_TYPE )
@@ -840,9 +794,7 @@ static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd,
         MYCASE( LIST, "list" );
 #undef MYCASE
     }
-            printf( " %c-o \"%s\" (%s",
-                    i + 1 == vlc_internals( p_object )->i_vars ? '`' : '|',
-                    p_var->psz_name, psz_type );
+    printf( " *-o \"%s\" (%s", p_var->psz_name, psz_type );
     if( p_var->psz_text )
         printf( ", %s", p_var->psz_text );
     printf( ")" );
@@ -880,7 +832,54 @@ static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd,
             break;
     }
     printf( "\n" );
+}
+
+/*****************************************************************************
+ * DumpCommand: print the current vlc structure
+ *****************************************************************************
+ * This function prints either an ASCII tree showing the connections between
+ * vlc objects, and additional information such as their refcount, thread ID,
+ * etc. (command "tree"), or the same data as a simple list (command "list").
+ *****************************************************************************/
+static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd,
+                        vlc_value_t oldval, vlc_value_t newval, void *p_data )
+{
+    (void)oldval; (void)p_data;
+    vlc_object_t *p_object = NULL;
+
+    if( *newval.psz_string )
+    {
+        /* try using the object's name to find it */
+        p_object = vlc_object_find_name( p_this, newval.psz_string,
+                                         FIND_ANYWHERE );
+        if( !p_object )
+        {
+            return VLC_ENOOBJ;
+        }
     }
+
+    libvlc_lock (p_this->p_libvlc);
+    if( *psz_cmd == 't' )
+    {
+        char psz_foo[2 * MAX_DUMPSTRUCTURE_DEPTH + 1];
+
+        if( !p_object )
+            p_object = VLC_OBJECT(p_this->p_libvlc);
+
+        psz_foo[0] = '|';
+        DumpStructure( p_object, 0, psz_foo );
+    }
+    else if( *psz_cmd == 'v' )
+    {
+        if( !p_object )
+            p_object = p_this->p_libvlc ? VLC_OBJECT(p_this->p_libvlc) : p_this;
+
+        PrintObject( p_object, "" );
+        vlc_mutex_lock( &vlc_internals( p_object )->var_lock );
+        if( vlc_internals( p_object )->var_root == NULL )
+            printf( " `-o No variables\n" );
+        else
+            twalk( vlc_internals( p_object )->var_root, DumpVariable );
         vlc_mutex_unlock( &vlc_internals( p_object )->var_lock );
     }
     libvlc_unlock (p_this->p_libvlc);

src/misc/variables.h

@@ -43,20 +43,18 @@ typedef struct variable_ops_t
  */
 struct variable_t
 {
+    char *       psz_name; /**< The variable unique name (must be first) */
+
     /** The variable's exported value */
     vlc_value_t  val;
 
-    char *       psz_name; /**< The variable unique name */
-    uint32_t     i_hash;   /**< (almost) unique hashed value */
-    int          i_type;   /**< The type of the variable */
-
     /** The variable display name, mainly for use by the interfaces */
     char *       psz_text;
 
     const variable_ops_t *ops;
 
-    /** Creation count: we only destroy the variable if it reaches 0 */
-    int          i_usage;
+    int          i_type;   /**< The type of the variable */
+    unsigned     i_usage;  /**< Reference count */
 
     /** If the variable has min/max/step values */
     vlc_value_t  min, max, step;
@@ -77,4 +75,7 @@ struct variable_t
     /** Array of registered callbacks */
     callback_entry_t * p_entries;
 };
+
+extern void var_DestroyAll( vlc_object_t * );
+
 #endif