src/list.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "cx/list.h"

#include <string.h>

// <editor-fold desc="Store Pointers Functionality">

static _Thread_local cx_compare_func cx_pl_cmpfunc_impl;

static int cx_pl_cmpfunc(
        void const *l,
        void const *r
) {
    void *const *lptr = l;
    void *const *rptr = r;
    void const *left = lptr == NULL ? NULL : *lptr;
    void const *right = rptr == NULL ? NULL : *rptr;
    return cx_pl_cmpfunc_impl(left, right);
}

static void cx_pl_hack_cmpfunc(struct cx_list_s const *list) {
    // cast away const - this is the hacky thing
    struct cx_list_s *l = (struct cx_list_s *) list;
    cx_pl_cmpfunc_impl = l->cmpfunc;
    l->cmpfunc = cx_pl_cmpfunc;
}

static void cx_pl_unhack_cmpfunc(struct cx_list_s const *list) {
    // cast away const - this is the hacky thing
    struct cx_list_s *l = (struct cx_list_s *) list;
    l->cmpfunc = cx_pl_cmpfunc_impl;
}

static void cx_pl_destructor(struct cx_list_s *list) {
    list->climpl->destructor(list);
}

static int cx_pl_insert_element(
        struct cx_list_s *list,
        size_t index,
        void const *element
) {
    return list->climpl->insert_element(list, index, &element);
}

static size_t cx_pl_insert_array(
        struct cx_list_s *list,
        size_t index,
        void const *array,
        size_t n
) {
    return list->climpl->insert_array(list, index, array, n);
}

static int cx_pl_insert_iter(
        struct cx_mut_iterator_s *iter,
        void const *elem,
        int prepend
) {
    struct cx_list_s *list = iter->src_handle;
    return list->climpl->insert_iter(iter, &elem, prepend);
}

static int cx_pl_remove(
        struct cx_list_s *list,
        size_t index
) {
    return list->climpl->remove(list, index);
}

static void cx_pl_clear(struct cx_list_s *list) {
    list->climpl->clear(list);
}

static int cx_pl_swap(
        struct cx_list_s *list,
        size_t i,
        size_t j
) {
    return list->climpl->swap(list, i, j);
}

static void *cx_pl_at(
        struct cx_list_s const *list,
        size_t index
) {
    void **ptr = list->climpl->at(list, index);
    return ptr == NULL ? NULL : *ptr;
}

static ssize_t cx_pl_find_remove(
        struct cx_list_s *list,
        void const *elem,
        bool remove
) {
    cx_pl_hack_cmpfunc(list);
    ssize_t ret = list->climpl->find_remove(list, &elem, remove);
    cx_pl_unhack_cmpfunc(list);
    return ret;
}

static void cx_pl_sort(struct cx_list_s *list) {
    cx_pl_hack_cmpfunc(list);
    list->climpl->sort(list);
    cx_pl_unhack_cmpfunc(list);
}

static int cx_pl_compare(
        struct cx_list_s const *list,
        struct cx_list_s const *other
) {
    cx_pl_hack_cmpfunc(list);
    int ret = list->climpl->compare(list, other);
    cx_pl_unhack_cmpfunc(list);
    return ret;
}

static void cx_pl_reverse(struct cx_list_s *list) {
    list->climpl->reverse(list);
}

static void *cx_pl_iter_current(void const *it) {
    struct cx_iterator_s const *iter = it;
    void **ptr = iter->base.current_impl(it);
    return ptr == NULL ? NULL : *ptr;
}

static struct cx_iterator_s cx_pl_iterator(
        struct cx_list_s const *list,
        size_t index,
        bool backwards
) {
    struct cx_iterator_s iter = list->climpl->iterator(list, index, backwards);
    iter.base.current_impl = iter.base.current;
    iter.base.current = cx_pl_iter_current;
    return iter;
}

static cx_list_class cx_pointer_list_class = {
        cx_pl_destructor,
        cx_pl_insert_element,
        cx_pl_insert_array,
        cx_pl_insert_iter,
        cx_pl_remove,
        cx_pl_clear,
        cx_pl_swap,
        cx_pl_at,
        cx_pl_find_remove,
        cx_pl_sort,
        cx_pl_compare,
        cx_pl_reverse,
        cx_pl_iterator,
};

void cxListStoreObjects(CxList *list) {
    list->store_pointer = false;
    if (list->climpl != NULL) {
        list->cl = list->climpl;
        list->climpl = NULL;
    }
}

void cxListStorePointers(CxList *list) {
    list->item_size = sizeof(void *);
    list->store_pointer = true;
    list->climpl = list->cl;
    list->cl = &cx_pointer_list_class;
}

// </editor-fold>

// <editor-fold desc="empty list implementation">

static void cx_emptyl_noop(__attribute__((__unused__)) CxList *list) {
    // this is a noop, but MUST be implemented
}

static void *cx_emptyl_at(
        __attribute__((__unused__)) struct cx_list_s const *list,
        __attribute__((__unused__)) size_t index
) {
    return NULL;
}

static ssize_t cx_emptyl_find_remove(
        __attribute__((__unused__)) struct cx_list_s *list,
        __attribute__((__unused__)) void const *elem,
        __attribute__((__unused__)) bool remove
) {
    return -1;
}

static int cx_emptyl_compare(
        __attribute__((__unused__)) struct cx_list_s const *list,
        struct cx_list_s const *other
) {
    if (other->size == 0) return 0;
    return -1;
}

static bool cx_emptyl_iter_valid(__attribute__((__unused__)) void const *iter) {
    return false;
}

static CxIterator cx_emptyl_iterator(
        struct cx_list_s const *list,
        size_t index,
        __attribute__((__unused__)) bool backwards
) {
    CxIterator iter = {0};
    iter.src_handle = list;
    iter.index = index;
    iter.base.valid = cx_emptyl_iter_valid;
    return iter;
}

static cx_list_class cx_empty_list_class = {
        cx_emptyl_noop,
        NULL,
        NULL,
        NULL,
        NULL,
        cx_emptyl_noop,
        NULL,
        cx_emptyl_at,
        cx_emptyl_find_remove,
        cx_emptyl_noop,
        cx_emptyl_compare,
        cx_emptyl_noop,
        cx_emptyl_iterator,
};

CxList cx_empty_list = {
        NULL,
        NULL,
        0,
        0,
        NULL,
        NULL,
        NULL,
        false,
        &cx_empty_list_class,
        NULL
};

CxList *const cxEmptyList = &cx_empty_list;

// </editor-fold>

void cxListDestroy(CxList *list) {
    list->cl->destructor(list);
}

int cxListCompare(
        CxList const *list,
        CxList const *other
) {
    if (
        // if one is storing pointers but the other is not
        (list->store_pointer ^ other->store_pointer) ||

        // if one class is wrapped but the other is not
        ((list->climpl == NULL) ^ (other->climpl == NULL)) ||

        // if the resolved compare functions are not the same
        ((list->climpl != NULL ? list->climpl->compare : list->cl->compare) !=
         (other->climpl != NULL ? other->climpl->compare : other->cl->compare))
    ) {
        // lists are definitely different - cannot use internal compare function
        if (list->size == other->size) {
            CxIterator left = list->cl->iterator(list, 0, false);
            CxIterator right = other->cl->iterator(other, 0, false);
            for (size_t i = 0; i < list->size; i++) {
                void *leftValue = cxIteratorCurrent(left);
                void *rightValue = cxIteratorCurrent(right);
                int d = list->cmpfunc(leftValue, rightValue);
                if (d != 0) {
                    return d;
                }
                cxIteratorNext(left);
                cxIteratorNext(right);
            }
            return 0;
        } else {
            return list->size < other->size ? -1 : 1;
        }
    } else {
        // lists are compatible
        return list->cl->compare(list, other);
    }
}

CxMutIterator cxListMutIteratorAt(
        CxList *list,
        size_t index
) {
    CxIterator it = list->cl->iterator(list, index, false);
    it.base.mutating = true;

    // we know the iterators share the same memory layout
    CxMutIterator iter;
    memcpy(&iter, &it, sizeof(CxMutIterator));
    return iter;
}

CxMutIterator cxListMutBackwardsIteratorAt(
        CxList *list,
        size_t index
) {
    CxIterator it = list->cl->iterator(list, index, true);
    it.base.mutating = true;

    // we know the iterators share the same memory layout
    CxMutIterator iter;
    memcpy(&iter, &it, sizeof(CxMutIterator));
    return iter;
}