source: downloads/openal-0.0.8/src/al_rctree.c @ 53

/* -*- mode: C; tab-width:8; c-basic-offset:8 -*-
 * vi:set ts=8:
 *
 * al_rctree.h
 *
 * Stuff related to the rctree data structure.
 */
#include "al_debug.h"
#include "al_config.h"
#include "al_rctree.h"
#include "al_siteconfig.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
 * AL_RcTreeNodes are used to help manage AL_rctrees.
 */
typedef struct _AL_RcTreeNode {
        ALuint size;
        ALuint freeslots;
        AL_rctree **data;
} AL_RcTreeNode;

/*
 * rlist is the data structure we use to manage AL_rcTreeNodes.
 */
static AL_RcTreeNode rlist = { 0, 0, NULL };

/*
 * rlist_add_rctree( AL_rctree *node )
 *
 * Adds a reference to node to the rlist.
 */
static void rlist_add_rctree(AL_rctree *node);

/*
 * rlist_delete_rctree( AL_rctree *node )
 *
 * Removes a reference to node from the rlist.
 */
static void rlist_delete_rctree( AL_rctree *node );

/*
 * rlist_realloc( void )
 *
 * Increases the size of rlist.
 */
static void rlist_realloc( void );

/*
 * _alRcTreeAlloc( void )
 *
 * Creates, initializes and returns an AL_rctree.
 */
AL_rctree *_alRcTreeAlloc( void ) {
        AL_rctree *retval;

        retval = malloc( sizeof *retval );
        if(retval == NULL) {
                /* _alDCSetError(AL_NO_MEMORY); */
                return NULL;
        }

        memset(retval, 0, sizeof *retval);

        rlist_add_rctree( retval );

        retval->type      = ALRC_INVALID;

        retval->data.proc = 0;
        retval->data.ccell.car = NULL;
        retval->data.ccell.cdr = NULL;

        return retval;
}

/*
 * _alRcTreeFree( AL_rctree *node )
 *
 * Finalizes and deallocates an AL_rctree node, removing the rlist reference
 * at the same time.
 */
void _alRcTreeFree( AL_rctree *node ) {
        if(node == NULL) {
                return;
        }

        if( node->type == ALRC_CONSCELL ) {
                _alRcTreeFree( node->data.ccell.car );
                _alRcTreeFree( node->data.ccell.cdr );
        }

        /* remove reference from our list */
        rlist_delete_rctree( node );

        free( node );

        return;
}

/*
 * _alRcTreeDestroyAll( void )
 *
 * Deallocates any and all AL_rctree objects creates thus far.
 */
void _alRcTreeDestroyAll( void ) {
        ALuint i;

        for(i = 0; i < rlist.size; i++) {
                if(rlist.data[i] == NULL) {
                        continue;
                }

                free(rlist.data[i]);
        }

        free(rlist.data);

        rlist.data      = NULL;
        rlist.size      = 0;
        rlist.freeslots = 0;

        return;
}

/*
 * rlist_add_rctree( AL_rctree *node )
 *
 * Adds a reference to node to the rlist.
 */
static void rlist_add_rctree( AL_rctree *node ) {
        ALuint i;

        if(rlist.freeslots <= 0) {
                rlist_realloc();
        }

        for(i = 0; i < rlist.size; i++) {
                if(rlist.data[i] == NULL) {
                        rlist.freeslots--;
                        rlist.data[i] = node;

                        return;
                }
        }

        /* weird.  Do something here. */
        assert(0);

        return;
}

/*
 * rlist_add_rctree( AL_rctree *node )
 *
 * Adds a reference to node to the rlist.
 */
static void rlist_delete_rctree( AL_rctree *node ) {
        ALuint i;

        for(i = 0; i < rlist.size; i++) {
                if(rlist.data[i] == node) {
                        rlist.freeslots++;
                        rlist.data[i] = NULL;

                        return;
                }
        }

        /* not found */

        return;
}

/*
 * rlist_realloc( void )
 *
 * Increases the size of rlist.
 */
static void rlist_realloc( void ) {
        ALuint newsize = rlist.size * 2 + 1;
        ALuint i;
        void *temp;

        temp = realloc( rlist.data, newsize * sizeof *rlist.data );
        if(temp == NULL) {
                assert(0);
                return;
        }

        rlist.data = temp;

        for(i = rlist.size; i < newsize; i++) {
                rlist.data[i] = NULL;
        }

        rlist.freeslots += newsize - rlist.size;

        rlist.size = newsize;

        return;
}