amxc_llist_it.c

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#include <stdlib.h>
 
#include <amxc/amxc_llist.h>
#include <amxc/amxc_macros.h>
 
static bool amxc_llist_it_are_adjacent(amxc_llist_it_t* const it1,
                                       amxc_llist_it_t* const it2) {
    return (it1->next == it2);
}
 
static void amxc_llist_it_update(amxc_llist_it_t* const it) {
    if(it->prev == NULL) {
        if(it->llist != NULL) {
            it->llist->head = it;
        }
    } else {
        it->prev->next = it;
    }
 
    if(it->next == NULL) {
        if(it->llist != NULL) {
            it->llist->tail = it;
        }
    } else {
        it->next->prev = it;
    }
}
 
int amxc_llist_it_init(amxc_llist_it_t* const it) {
    int retval = -1;
    when_null(it, exit);
 
    it->next = NULL;
    it->prev = NULL;
    it->llist = NULL;
 
    retval = 0;
 
exit:
    return retval;
}
 
void amxc_llist_it_clean(amxc_llist_it_t* const it, amxc_llist_it_delete_t func) {
    amxc_llist_it_take(it);
    if((it != NULL) && (func != NULL)) {
        func(it);
    }
}
 
void amxc_llist_it_take(amxc_llist_it_t* const it) {
    when_null(it, exit);
    when_null(it->llist, exit);
 
    if(it->prev != NULL) {
        it->prev->next = it->next;
    } else {
        it->llist->head = it->next;
    }
    if(it->next != NULL) {
        it->next->prev = it->prev;
    } else {
        it->llist->tail = it->prev;
    }
 
    it->next = NULL;
    it->prev = NULL;
    it->llist = NULL;
exit:
    return;
}
 
int amxc_llist_it_insert_before(amxc_llist_it_t* const reference,
                                amxc_llist_it_t* const it) {
    int retval = -1;
    when_null(reference, exit);
    when_null(it, exit);
    when_null(reference->llist, exit);
 
    amxc_llist_it_take(it);
 
    it->next = reference;
    it->prev = reference->prev;
    it->llist = reference->llist;
    reference->prev = it;
 
    if(it->prev != NULL) {
        it->prev->next = it;
    } else {
        it->llist->head = it;
    }
 
    retval = 0;
exit:
    return retval;
}
 
int amxc_llist_it_insert_after(amxc_llist_it_t* const reference,
                               amxc_llist_it_t* const it) {
    int retval = -1;
    when_null(reference, exit);
    when_null(it, exit);
    when_null(reference->llist, exit);
 
    amxc_llist_it_take(it);
 
    it->next = reference->next;
    it->prev = reference;
    it->llist = reference->llist;
    reference->next = it;
 
    if(it->next != NULL) {
        it->next->prev = it;
    } else {
        it->llist->tail = it;
    }
 
    retval = 0;
exit:
    return retval;
}
 
unsigned int amxc_llist_it_index_of(const amxc_llist_it_t* const it) {
    size_t index = 0;
    const amxc_llist_it_t* pos = NULL;
    if((it == NULL) || (it->llist == NULL)) {
        index = AMXC_LLIST_RANGE;
        goto exit;
    }
 
    pos = it;
    while(pos->prev) {
        index++;
        pos = pos->prev;
    }
 
exit:
    return index;
}
 
int amxc_llist_it_swap(amxc_llist_it_t* it1,
                       amxc_llist_it_t* it2) {
    int retval = -1;
    amxc_llist_it_t* swapperVector[4] = { NULL, NULL, NULL, NULL };
 
    when_null(it1, exit);
    when_null(it2, exit);
 
    if(it1 == it2) {
        retval = 0;
        goto exit;
    }
 
    if(it1->llist != it2->llist) {
        amxc_llist_t* temp = it1->llist;
        it1->llist = it2->llist;
        it2->llist = temp;
    }
 
    if(it2->next == it1) {
        amxc_llist_it_t* temp = it1;
        it1 = it2;
        it2 = temp;
    }
 
    swapperVector[0] = it1->prev;
    swapperVector[1] = it2->prev;
    swapperVector[2] = it1->next;
    swapperVector[3] = it2->next;
 
    if(amxc_llist_it_are_adjacent(it1, it2)) {
        it1->prev = swapperVector[2];
        it2->prev = swapperVector[0];
        it1->next = swapperVector[3];
        it2->next = swapperVector[1];
    } else {
        it1->prev = swapperVector[1];
        it2->prev = swapperVector[0];
        it1->next = swapperVector[3];
        it2->next = swapperVector[2];
    }
 
    amxc_llist_it_update(it1);
    amxc_llist_it_update(it2);
 
    retval = 0;
 
exit:
    return retval;
}