cphidgetlist.c

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#include "stdafx.h"
#include "cphidgetlist.h"

/* Adds an element to a list - Duplicates are not allowed.
 * Return:      EPHIDGET_OK on success
 *                      EPHIDGET_DUPLICATE if the element already exists in the list
 */
int CList_addToList(CListHandle *list, void *element, 
        int (*compare_fptr)(void *element1, void *element2))
{
        int result = 0;
        CListHandle trav = 0, newentry = 0;

        TESTPTRS(list, element)

        /* The very first thing we do is make sure none of these already exist in the list */
        result = CList_findInList(*list, element, compare_fptr, NULL);
        switch (result) {
                case EPHIDGET_OK:
                        return EPHIDGET_DUPLICATE;
                case EPHIDGET_NOTFOUND:
                        break;
                default:
                        return result;
        }

        newentry = (CListHandle)malloc(sizeof(CList));
        if (!newentry) return EPHIDGET_NOMEMORY;
        ZEROMEM(newentry, sizeof(CList));

        newentry->next = 0;
        newentry->element = element;

        if (!*list)
                *list = newentry;
        else
        {
                for (trav = *list; trav->next; trav = trav->next);
                trav->next = newentry;
        }
        return EPHIDGET_OK;
}

/* this returns success even if the element is not found in the list
 * this also removes duplicates.
 *
 * but! if we find in the list the exact element, rather then just a match, we need to free it after! 
 * interating, or the compare function will croak!
 */
int CList_removeFromList(CListHandle *list, void *element, 
        int (*compare_fptr)(void *element1, void *element2),
        int freeDevice, void (*free_fptr)(void *element))
{
        CListHandle traverse = 0, last = 0;
        int freeElement = PFALSE;

        TESTPTRS(list, element)

        for (traverse=*list; traverse; traverse = traverse->next) {
                if(compare_fptr(element, traverse->element)) {
                        if(traverse == *list) {
                                *list = traverse->next;
                                if(freeDevice && traverse->element)
                                {
                                        // don't free element in the middle of iterating!
                                        if(traverse->element == element)
                                                freeElement=PTRUE;
                                        else
                                                free_fptr(traverse->element);
                                        traverse->element = 0;
                                }
                                free(traverse); traverse = NULL;
                                traverse=*list;
                                break;
                        }
                        else {
                                last->next=traverse->next;
                                if(freeDevice && traverse->element)
                                {
                                        // don't free element in the middle of iterating!
                                        if(traverse->element == element)
                                                freeElement=PTRUE;
                                        else
                                                free_fptr(traverse->element);
                                        traverse->element = 0;
                                }
                                free(traverse); traverse = NULL;
                                traverse=last;
                        }
                }
                last = traverse;
        }
        
        /* element itself was found in the list, and we want it freed - free it here */
        if(freeElement)
                free_fptr(element);

        return EPHIDGET_OK;
}

/* this takes any list, and frees all of the list element, 
        and can also free the elements that they point to */
int CList_emptyList(CListHandle *list, int freeDevices, void (*free_fptr)(void *element))
{
        CListHandle last = 0, traverse = 0;

        TESTPTR(list)

        last = 0;
        for(traverse = *list; traverse; last = traverse, traverse = traverse->next)
        {
                if(traverse->element && freeDevices)
                {
                        free_fptr(traverse->element);
                        traverse->element = 0;
                }
                if(last)
                {
                        free(last); last = NULL;
                }
        }
        if(last)
        {
                free(last); last = NULL;
        }

        *list = 0;

        return EPHIDGET_OK;
}

/* returns EPHIDGET_OK if the device is in the list */
int CList_findInList(CListHandle list, void *element, 
        int (*compare_fptr)(void *element1, void *element2), void **found_element)
{
        CListHandle trav = 0;

        TESTPTR(element)

        for (trav=list; trav; trav = trav->next) {
                if(compare_fptr(element, trav->element)) {
                        if(found_element) *found_element = trav->element;
                        return EPHIDGET_OK;
                }
        }
        return EPHIDGET_NOTFOUND;
}