root/third_party/libxml/src/list.c

DEFINITIONS

1. xmlLinkDeallocator
2. xmlLinkCompare
3. xmlListLowerSearch
4. xmlListHigherSearch
5. xmlListLinkSearch
6. xmlListLinkReverseSearch
7. xmlListCreate
8. xmlListSearch
9. xmlListReverseSearch
10. xmlListInsert
11. xmlListAppend
12. xmlListDelete
13. xmlListRemoveFirst
14. xmlListRemoveLast
15. xmlListRemoveAll
16. xmlListClear
17. xmlListEmpty
18. xmlListFront
19. xmlListEnd
20. xmlListSize
21. xmlListPopFront
22. xmlListPopBack
23. xmlListPushFront
24. xmlListPushBack
25. xmlLinkGetData
26. xmlListReverse
27. xmlListSort
28. xmlListWalk
29. xmlListReverseWalk
30. xmlListMerge
31. xmlListDup
32. xmlListCopy

/*
 * list.c: lists handling implementation
 *
 * Copyright (C) 2000 Gary Pennington and Daniel Veillard.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE AUTHORS AND
 * CONTRIBUTORS ACCEPT NO RESPONSIBILITY IN ANY CONCEIVABLE MANNER.
 *
 * Author: Gary.Pennington@uk.sun.com
 */

#define IN_LIBXML
#include "libxml.h"

#include <stdlib.h>
#include <string.h>
#include <libxml/xmlmemory.h>
#include <libxml/list.h>
#include <libxml/globals.h>

/*
 * Type definition are kept internal
 */

struct _xmlLink
{
    struct _xmlLink *next;
    struct _xmlLink *prev;
    void *data;
};

struct _xmlList
{
    xmlLinkPtr sentinel;
    void (*linkDeallocator)(xmlLinkPtr );
    int (*linkCompare)(const void *, const void*);
};

/************************************************************************
 *                                    *
 *                Interfaces                *
 *                                    *
 ************************************************************************/

/**
 * xmlLinkDeallocator:
 * @l:  a list
 * @lk:  a link
 *
 * Unlink and deallocate @lk from list @l
 */
static void
xmlLinkDeallocator(xmlListPtr l, xmlLinkPtr lk)
{
    (lk->prev)->next = lk->next;
    (lk->next)->prev = lk->prev;
    if(l->linkDeallocator)
        l->linkDeallocator(lk);
    xmlFree(lk);
}

/**
 * xmlLinkCompare:
 * @data0:  first data
 * @data1:  second data
 *
 * Compares two arbitrary data
 *
 * Returns -1, 0 or 1 depending on whether data1 is greater equal or smaller
 *          than data0
 */
static int
xmlLinkCompare(const void *data0, const void *data1)
{
    if (data0 < data1)
        return (-1);
    else if (data0 == data1)
        return (0);
    return (1);
}

/**
 * xmlListLowerSearch:
 * @l:  a list
 * @data:  a data
 *
 * Search data in the ordered list walking from the beginning
 *
 * Returns the link containing the data or NULL
 */
static xmlLinkPtr 
xmlListLowerSearch(xmlListPtr l, void *data) 
{
    xmlLinkPtr lk;

    if (l == NULL)
        return(NULL);
    for(lk = l->sentinel->next;lk != l->sentinel && l->linkCompare(lk->data, data) <0 ;lk = lk->next);
    return lk;    
}

/**
 * xmlListHigherSearch:
 * @l:  a list
 * @data:  a data
 *
 * Search data in the ordered list walking backward from the end
 *
 * Returns the link containing the data or NULL
 */
static xmlLinkPtr 
xmlListHigherSearch(xmlListPtr l, void *data) 
{
    xmlLinkPtr lk;

    if (l == NULL)
        return(NULL);
    for(lk = l->sentinel->prev;lk != l->sentinel && l->linkCompare(lk->data, data) >0 ;lk = lk->prev);
    return lk;    
}

/**
 * xmlListSearch:
 * @l:  a list
 * @data:  a data
 *
 * Search data in the list
 *
 * Returns the link containing the data or NULL
 */
static xmlLinkPtr 
xmlListLinkSearch(xmlListPtr l, void *data) 
{
    xmlLinkPtr lk;
    if (l == NULL)
        return(NULL);
    lk = xmlListLowerSearch(l, data);
    if (lk == l->sentinel)
        return NULL;
    else {
        if (l->linkCompare(lk->data, data) ==0)
            return lk;
        return NULL;
    }
}

/**
 * xmlListLinkReverseSearch:
 * @l:  a list
 * @data:  a data
 *
 * Search data in the list processing backward
 *
 * Returns the link containing the data or NULL
 */
static xmlLinkPtr 
xmlListLinkReverseSearch(xmlListPtr l, void *data) 
{
    xmlLinkPtr lk;
    if (l == NULL)
        return(NULL);
    lk = xmlListHigherSearch(l, data);
    if (lk == l->sentinel)
        return NULL;
    else {
        if (l->linkCompare(lk->data, data) ==0)
            return lk;
        return NULL;
    }
}

/**
 * xmlListCreate:
 * @deallocator:  an optional deallocator function
 * @compare:  an optional comparison function
 *
 * Create a new list
 *
 * Returns the new list or NULL in case of error
 */
xmlListPtr
xmlListCreate(xmlListDeallocator deallocator, xmlListDataCompare compare)
{
    xmlListPtr l;
    if (NULL == (l = (xmlListPtr )xmlMalloc( sizeof(xmlList)))) {
        xmlGenericError(xmlGenericErrorContext, 
                        "Cannot initialize memory for list");
        return (NULL);
    }
    /* Initialize the list to NULL */
    memset(l, 0, sizeof(xmlList));
    
    /* Add the sentinel */
    if (NULL ==(l->sentinel = (xmlLinkPtr )xmlMalloc(sizeof(xmlLink)))) {
        xmlGenericError(xmlGenericErrorContext, 
                        "Cannot initialize memory for sentinel");
        xmlFree(l);
        return (NULL);
    }
    l->sentinel->next = l->sentinel;
    l->sentinel->prev = l->sentinel;
    l->sentinel->data = NULL;
    
    /* If there is a link deallocator, use it */
    if (deallocator != NULL)
        l->linkDeallocator = deallocator;
    /* If there is a link comparator, use it */
    if (compare != NULL)
        l->linkCompare = compare;
    else /* Use our own */
        l->linkCompare = xmlLinkCompare;
    return l;
}
    
/**
 * xmlListSearch:
 * @l:  a list
 * @data:  a search value
 *
 * Search the list for an existing value of @data
 *
 * Returns the value associated to @data or NULL in case of error
 */
void *
xmlListSearch(xmlListPtr l, void *data) 
{
    xmlLinkPtr lk;
    if (l == NULL)
        return(NULL);
    lk = xmlListLinkSearch(l, data);
    if (lk)
        return (lk->data);
    return NULL;
}

/**
 * xmlListReverseSearch:
 * @l:  a list
 * @data:  a search value
 *
 * Search the list in reverse order for an existing value of @data
 *
 * Returns the value associated to @data or NULL in case of error
 */
void *
xmlListReverseSearch(xmlListPtr l, void *data) 
{
    xmlLinkPtr lk;
    if (l == NULL)
        return(NULL);
    lk = xmlListLinkReverseSearch(l, data);
    if (lk)
        return (lk->data);
    return NULL;
}

/**
 * xmlListInsert:
 * @l:  a list
 * @data:  the data
 *
 * Insert data in the ordered list at the beginning for this value
 *
 * Returns 0 in case of success, 1 in case of failure
 */
int
xmlListInsert(xmlListPtr l, void *data) 
{
    xmlLinkPtr lkPlace, lkNew;

    if (l == NULL)
        return(1);
    lkPlace = xmlListLowerSearch(l, data);
    /* Add the new link */
    lkNew = (xmlLinkPtr) xmlMalloc(sizeof(xmlLink));
    if (lkNew == NULL) {
        xmlGenericError(xmlGenericErrorContext, 
                        "Cannot initialize memory for new link");
        return (1);
    }
    lkNew->data = data;
    lkPlace = lkPlace->prev;
    lkNew->next = lkPlace->next;
    (lkPlace->next)->prev = lkNew;
    lkPlace->next = lkNew;
    lkNew->prev = lkPlace;
    return 0;
}

/**
 * xmlListAppend:
 * @l:  a list
 * @data:  the data
 *
 * Insert data in the ordered list at the end for this value
 *
 * Returns 0 in case of success, 1 in case of failure
 */
int xmlListAppend(xmlListPtr l, void *data) 
{
    xmlLinkPtr lkPlace, lkNew;

    if (l == NULL)
        return(1);
    lkPlace = xmlListHigherSearch(l, data);
    /* Add the new link */
    lkNew = (xmlLinkPtr) xmlMalloc(sizeof(xmlLink));
    if (lkNew == NULL) {
        xmlGenericError(xmlGenericErrorContext, 
                        "Cannot initialize memory for new link");
        return (1);
    }
    lkNew->data = data;
    lkNew->next = lkPlace->next;
    (lkPlace->next)->prev = lkNew;
    lkPlace->next = lkNew;
    lkNew->prev = lkPlace;
    return 0;
}

/**
 * xmlListDelete:
 * @l:  a list
 *
 * Deletes the list and its associated data
 */
void xmlListDelete(xmlListPtr l)
{
    if (l == NULL)
        return;

    xmlListClear(l);
    xmlFree(l->sentinel);
    xmlFree(l);
}

/**
 * xmlListRemoveFirst:
 * @l:  a list
 * @data:  list data
 *
 * Remove the first instance associated to data in the list
 *
 * Returns 1 if a deallocation occured, or 0 if not found
 */
int
xmlListRemoveFirst(xmlListPtr l, void *data)
{
    xmlLinkPtr lk;
    
    if (l == NULL)
        return(0);
    /*Find the first instance of this data */
    lk = xmlListLinkSearch(l, data);
    if (lk != NULL) {
        xmlLinkDeallocator(l, lk);
        return 1;
    }
    return 0;
}

/**
 * xmlListRemoveLast:
 * @l:  a list
 * @data:  list data
 *
 * Remove the last instance associated to data in the list
 *
 * Returns 1 if a deallocation occured, or 0 if not found
 */
int
xmlListRemoveLast(xmlListPtr l, void *data)
{
    xmlLinkPtr lk;
    
    if (l == NULL)
        return(0);
    /*Find the last instance of this data */
    lk = xmlListLinkReverseSearch(l, data);
    if (lk != NULL) {
        xmlLinkDeallocator(l, lk);
        return 1;
    }
    return 0;
}

/**
 * xmlListRemoveAll:
 * @l:  a list
 * @data:  list data
 *
 * Remove the all instance associated to data in the list
 *
 * Returns the number of deallocation, or 0 if not found
 */
int
xmlListRemoveAll(xmlListPtr l, void *data)
{
    int count=0;
    
    if (l == NULL)
        return(0);

    while(xmlListRemoveFirst(l, data))
        count++;
    return count;
}

/**
 * xmlListClear:
 * @l:  a list
 *
 * Remove the all data in the list
 */
void
xmlListClear(xmlListPtr l)
{
    xmlLinkPtr  lk;
    
    if (l == NULL)
        return;
    lk = l->sentinel->next;
    while(lk != l->sentinel) {
        xmlLinkPtr next = lk->next;

        xmlLinkDeallocator(l, lk);
        lk = next;
    }
}

/**
 * xmlListEmpty:
 * @l:  a list
 *
 * Is the list empty ?
 *
 * Returns 1 if the list is empty, 0 if not empty and -1 in case of error
 */
int
xmlListEmpty(xmlListPtr l)
{
    if (l == NULL)
        return(-1);
    return (l->sentinel->next == l->sentinel);
}

/**
 * xmlListFront:
 * @l:  a list
 *
 * Get the first element in the list
 *
 * Returns the first element in the list, or NULL
 */
xmlLinkPtr 
xmlListFront(xmlListPtr l)
{
    if (l == NULL)
        return(NULL);
    return (l->sentinel->next);
}
    
/**
 * xmlListEnd:
 * @l:  a list
 *
 * Get the last element in the list
 *
 * Returns the last element in the list, or NULL
 */
xmlLinkPtr 
xmlListEnd(xmlListPtr l)
{
    if (l == NULL)
        return(NULL);
    return (l->sentinel->prev);
}
    
/**
 * xmlListSize:
 * @l:  a list
 *
 * Get the number of elements in the list
 *
 * Returns the number of elements in the list or -1 in case of error
 */
int
xmlListSize(xmlListPtr l)
{
    xmlLinkPtr lk;
    int count=0;

    if (l == NULL)
        return(-1);
    /* TODO: keep a counter in xmlList instead */
    for(lk = l->sentinel->next; lk != l->sentinel; lk = lk->next, count++);
    return count;
}

/**
 * xmlListPopFront:
 * @l:  a list
 *
 * Removes the first element in the list
 */
void
xmlListPopFront(xmlListPtr l)
{
    if(!xmlListEmpty(l))
        xmlLinkDeallocator(l, l->sentinel->next);
}

/**
 * xmlListPopBack:
 * @l:  a list
 *
 * Removes the last element in the list
 */
void
xmlListPopBack(xmlListPtr l)
{
    if(!xmlListEmpty(l))
        xmlLinkDeallocator(l, l->sentinel->prev);
}

/**
 * xmlListPushFront:
 * @l:  a list
 * @data:  new data
 *
 * add the new data at the beginning of the list
 *
 * Returns 1 if successful, 0 otherwise
 */
int
xmlListPushFront(xmlListPtr l, void *data) 
{
    xmlLinkPtr lkPlace, lkNew;

    if (l == NULL)
        return(0);
    lkPlace = l->sentinel;
    /* Add the new link */
    lkNew = (xmlLinkPtr) xmlMalloc(sizeof(xmlLink));
    if (lkNew == NULL) {
        xmlGenericError(xmlGenericErrorContext, 
                        "Cannot initialize memory for new link");
        return (0);
    }
    lkNew->data = data;
    lkNew->next = lkPlace->next;
    (lkPlace->next)->prev = lkNew;
    lkPlace->next = lkNew;
    lkNew->prev = lkPlace;
    return 1;
}

/**
 * xmlListPushBack:
 * @l:  a list
 * @data:  new data
 *
 * add the new data at the end of the list
 *
 * Returns 1 if successful, 0 otherwise
 */
int
xmlListPushBack(xmlListPtr l, void *data) 
{
    xmlLinkPtr lkPlace, lkNew;

    if (l == NULL)
        return(0);
    lkPlace = l->sentinel->prev;
    /* Add the new link */
    if (NULL ==(lkNew = (xmlLinkPtr )xmlMalloc(sizeof(xmlLink)))) {
        xmlGenericError(xmlGenericErrorContext, 
                        "Cannot initialize memory for new link");
        return (0);
    }
    lkNew->data = data;
    lkNew->next = lkPlace->next;
    (lkPlace->next)->prev = lkNew;
    lkPlace->next = lkNew;
    lkNew->prev = lkPlace;
    return 1;
}

/**
 * xmlLinkGetData:
 * @lk:  a link
 *
 * See Returns.
 *
 * Returns a pointer to the data referenced from this link
 */
void *
xmlLinkGetData(xmlLinkPtr lk)
{
    if (lk == NULL)
        return(NULL);
    return lk->data;
}

/**
 * xmlListReverse:
 * @l:  a list
 *
 * Reverse the order of the elements in the list
 */
void
xmlListReverse(xmlListPtr l)
{
    xmlLinkPtr lk;
    xmlLinkPtr lkPrev;

    if (l == NULL)
        return;
    lkPrev = l->sentinel;
    for (lk = l->sentinel->next; lk != l->sentinel; lk = lk->next) {
        lkPrev->next = lkPrev->prev;
        lkPrev->prev = lk;
        lkPrev = lk;
    }
    /* Fix up the last node */
    lkPrev->next = lkPrev->prev;
    lkPrev->prev = lk;
}

/**
 * xmlListSort:
 * @l:  a list
 *
 * Sort all the elements in the list
 */
void
xmlListSort(xmlListPtr l)
{
    xmlListPtr lTemp;
    
    if (l == NULL)
        return;
    if(xmlListEmpty(l))
        return;

    /* I think that the real answer is to implement quicksort, the
     * alternative is to implement some list copying procedure which
     * would be based on a list copy followed by a clear followed by
     * an insert. This is slow...
     */

    if (NULL ==(lTemp = xmlListDup(l)))
        return;
    xmlListClear(l);
    xmlListMerge(l, lTemp);
    xmlListDelete(lTemp);
    return;
}

/**
 * xmlListWalk:
 * @l:  a list
 * @walker:  a processing function
 * @user:  a user parameter passed to the walker function
 *
 * Walk all the element of the first from first to last and
 * apply the walker function to it
 */
void
xmlListWalk(xmlListPtr l, xmlListWalker walker, const void *user) {
    xmlLinkPtr lk;

    if ((l == NULL) || (walker == NULL))
        return;
    for(lk = l->sentinel->next; lk != l->sentinel; lk = lk->next) {
        if((walker(lk->data, user)) == 0)
                break;
    }
}

/**
 * xmlListReverseWalk:
 * @l:  a list
 * @walker:  a processing function
 * @user:  a user parameter passed to the walker function
 *
 * Walk all the element of the list in reverse order and
 * apply the walker function to it
 */
void
xmlListReverseWalk(xmlListPtr l, xmlListWalker walker, const void *user) {
    xmlLinkPtr lk;

    if ((l == NULL) || (walker == NULL))
        return;
    for(lk = l->sentinel->prev; lk != l->sentinel; lk = lk->prev) {
        if((walker(lk->data, user)) == 0)
                break;
    }
}

/**
 * xmlListMerge:
 * @l1:  the original list
 * @l2:  the new list
 *
 * include all the elements of the second list in the first one and
 * clear the second list
 */
void
xmlListMerge(xmlListPtr l1, xmlListPtr l2)
{
    xmlListCopy(l1, l2);
    xmlListClear(l2);
}

/**
 * xmlListDup:
 * @old:  the list
 *
 * Duplicate the list
 * 
 * Returns a new copy of the list or NULL in case of error
 */
xmlListPtr 
xmlListDup(const xmlListPtr old)
{
    xmlListPtr cur;

    if (old == NULL)
        return(NULL);
    /* Hmmm, how to best deal with allocation issues when copying
     * lists. If there is a de-allocator, should responsibility lie with
     * the new list or the old list. Surely not both. I'll arbitrarily
     * set it to be the old list for the time being whilst I work out
     * the answer
     */
    if (NULL ==(cur = xmlListCreate(NULL, old->linkCompare)))
        return (NULL);
    if (0 != xmlListCopy(cur, old))
        return NULL;
    return cur;
}

/**
 * xmlListCopy:
 * @cur:  the new list
 * @old:  the old list
 *
 * Move all the element from the old list in the new list
 * 
 * Returns 0 in case of success 1 in case of error
 */
int
xmlListCopy(xmlListPtr cur, const xmlListPtr old)
{
    /* Walk the old tree and insert the data into the new one */
    xmlLinkPtr lk;

    if ((old == NULL) || (cur == NULL))
        return(1);
    for(lk = old->sentinel->next; lk != old->sentinel; lk = lk->next) {
        if (0 !=xmlListInsert(cur, lk->data)) {
            xmlListDelete(cur);
            return (1);
        }
    }
    return (0);    
}
/* xmlListUnique() */
/* xmlListSwap */
#define bottom_list
#include "elfgcchack.h"