source: vbox/trunk/src/VBox/GuestHost/OpenGL/util/list.c@ 15539

#include "cr_list.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct CRListIterator {
        void *element;
        CRListIterator *prev;
        CRListIterator *next;
};

struct CRList {
        CRListIterator *head;
        CRListIterator *tail;
        unsigned size;
};

CRList *crAllocList( void )
{
        CRList *l = malloc( sizeof( CRList ) );
        assert( l );

        l->head = malloc( sizeof( CRListIterator ) );
        assert( l->head );

        l->tail = malloc( sizeof( CRListIterator ) );
        assert( l->tail );

        l->head->prev = NULL;
        l->head->next = l->tail;

        l->tail->prev = l->head;
        l->tail->next = NULL;

        l->size = 0;

        return l;
}

void crFreeList( CRList *l )
{
        CRListIterator *t1;

        assert( l != NULL );
        t1 = l->head;
        while ( t1 != NULL )
        {
                CRListIterator *t2 = t1;
                t1 = t1->next;
                t2->prev = NULL;
                t2->next = NULL;
                t2->element = NULL;
                free( t2 );
        }
        l->size = 0;
        free( l );
}

unsigned crListSize( const CRList *l )
{
        return l->size;
}

int crListIsEmpty( const CRList *l )
{
        assert( l != NULL );
        return l->size == 0;
}

void crListInsert( CRList *l, CRListIterator *iter, void *elem )
{
        CRListIterator *p;

        assert( l != NULL );
        assert( iter != NULL );
        assert( iter != l->head );

        p = malloc( sizeof( CRListIterator ) );
        assert( p != NULL );
        p->prev = iter->prev;
        p->next = iter;
        p->prev->next = p;
        iter->prev = p;

        p->element = elem;
        l->size++;
}

void crListErase( CRList *l, CRListIterator *iter )
{
        assert( l != NULL );
        assert( iter != NULL );
        assert( iter != l->head );
        assert( iter != l->tail );
        assert( l->size > 0 );

        iter->next->prev = iter->prev;
        iter->prev->next = iter->next;

        iter->prev = NULL;
        iter->next = NULL;
        iter->element = NULL;
        free( iter );

        l->size--;
}

void crListClear( CRList *l )
{
        assert( l != NULL );
        while ( !crListIsEmpty( l ) )
        {
                crListPopFront( l );
        }
}

void crListPushBack( CRList *l, void *elem )
{
        assert( l != NULL );
        crListInsert( l, l->tail, elem );
}

void crListPushFront( CRList *l, void *elem )
{
        assert( l != NULL );
        crListInsert( l, l->head->next, elem );
}

void crListPopBack( CRList *l )
{
        assert( l != NULL );
        assert( l->size > 0 );
        crListErase( l, l->tail->prev );
}

void crListPopFront( CRList *l )
{
        assert( l != NULL );
        assert( l->size > 0 );
        crListErase( l, l->head->next );
}

void *crListFront( CRList *l )
{
        assert( l != NULL );
        assert( l->size > 0 );
        assert( l->head != NULL );
        assert( l->head->next != NULL );
        return l->head->next->element;
}

void *crListBack( CRList *l )
{
        assert( l != NULL );
        assert( l->size > 0 );
        assert( l->tail != NULL );
        assert( l->tail->prev != NULL );
        return l->tail->prev->element;
}

CRListIterator *crListBegin( CRList *l )
{
        assert( l != NULL );
        assert( l->head != NULL );
        assert( l->head->next != NULL );
        return l->head->next;
}

CRListIterator *crListEnd( CRList *l )
{
        assert( l != NULL );
        assert( l->tail != NULL );
        return l->tail;
}

CRListIterator *crListNext( CRListIterator *iter )
{
        assert( iter != NULL );
        assert( iter->next != NULL );
        return iter->next;
}

CRListIterator *crListPrev( CRListIterator *iter )
{
        assert( iter != NULL );
        assert( iter->prev != NULL );
        return iter->prev;
}

void *crListElement( CRListIterator *iter )
{
        assert( iter != NULL );
        return iter->element;
}

CRListIterator *crListFind( CRList *l, void *element, CRListCompareFunc compare )
{
        CRListIterator *iter;

        assert( l != NULL );
        assert( compare );

        for ( iter = crListBegin( l ); iter != crListEnd( l ); iter = crListNext( iter ) )
        {
                if ( compare( element, iter->element ) == 0 )
                {
                        return iter;
                }
        }
        return NULL;
}

void crListApply( CRList *l, CRListApplyFunc apply, void *arg )
{
        CRListIterator *iter;

        assert( l != NULL );
        for ( iter = crListBegin( l ); iter != crListEnd( l ); iter = crListNext( iter ) )
        {
                apply( iter->element, arg );
        }
}

#if CR_TESTING_LIST

static void printElement( void *elem, void *arg )
{
        char *s = elem;
        FILE *fp = arg;

        assert( s != NULL );
        assert( fp != NULL );
        fprintf( fp, "%s ", s );
}

static void printList( CRList *l )
{
        assert( l != NULL );
        crListApply( l, printElement, stderr );
        fprintf( stderr, "\n" );
}

static int elementCompare( void *a, void *b )
{
        return strcmp( a, b );
}

int main( void )
{
        char *names[] = { "a", "b", "c", "d", "e", "f" };
        CRList *l;
        CRListIterator *iter;
        int i, n;

        n = sizeof( names ) / sizeof( names[0] );
        fprintf( stderr, "n=%d\n", n );

        l = crAllocList(  );
        for ( i = 0; i < n; ++i )
        {
                crListPushBack( l, names[i] );
        }
        printList( l );

        crListPushFront( l, "x" );
        printList( l );

        crListPushBack( l, "y" );
        printList( l );

        crListPopFront( l );
        printList( l );

        crListPopBack( l );
        printList( l );

        iter = crListFind( l, "c", elementCompare );
        assert( iter != NULL );
        crListInsert( l, iter, "z" );
        printList( l );

        iter = crListFind( l, "d", elementCompare );
        assert( iter != NULL );
        crListErase( l, iter );
        printList( l );

        crListClear( l );
        printList( l );
        fprintf( stderr, "size: %d\n", crListSize( l ) );
        fprintf( stderr, "is empty: %d\n", crListIsEmpty( l ) );

        crListPushBack( l, "w" );
        crListPushBack( l, "t" );
        crListPushBack( l, "c" );
        printList( l );

        fprintf( stderr, "front: %s\n", ( char * ) crListFront( l ) );
        fprintf( stderr, "back: %s\n", ( char * ) crListBack( l ) );
        fprintf( stderr, "size: %d\n", crListSize( l ) );
        fprintf( stderr, "is empty: %d\n", crListIsEmpty( l ) );

        crFreeList( l );
        return 0;
}

#endif // CR_TESTING_LIST