53bf5c497f
- Add LICENSES directory - Download additional licenses used - Add .reuse directory - Add doc about SPDX/reuse Co-authored-by: Florian Märkl <info@florianmaerkl.de>
89 lines
1.5 KiB
C
89 lines
1.5 KiB
C
// SPDX-FileCopyrightText: 2007-2015 ret2libc <sirmy15@gmail.com>
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// SPDX-License-Identifier: LGPL-3.0-only
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#include <rz_util.h>
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RZ_API RQueue *rz_queue_new(int n) {
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if (n <= 0) {
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return NULL;
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}
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RQueue *q = RZ_NEW0(RQueue);
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if (!q) {
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return NULL;
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}
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q->elems = RZ_NEWS0(void *, n);
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if (!q->elems) {
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free(q);
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return NULL;
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}
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q->front = 0;
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q->rear = -1;
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q->size = 0;
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q->capacity = n;
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return q;
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}
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RZ_API void rz_queue_free(RQueue *q) {
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free(q->elems);
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free(q);
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}
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static int is_full(RQueue *q) {
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return q->size == q->capacity;
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}
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static int increase_capacity(RQueue *q) {
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unsigned int new_capacity = q->capacity * 2;
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void **newelems;
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int i, tmp_front;
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newelems = RZ_NEWS0(void *, new_capacity);
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if (!newelems) {
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return false;
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}
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i = -1;
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tmp_front = q->front;
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while (i + 1 < q->size) {
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i++;
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newelems[i] = q->elems[tmp_front];
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tmp_front = (tmp_front + 1) % q->capacity;
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}
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free(q->elems);
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q->elems = newelems;
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q->front = 0;
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q->rear = i;
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q->capacity = new_capacity;
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return true;
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}
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RZ_API int rz_queue_enqueue(RQueue *q, void *el) {
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if (is_full(q)) {
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int res = increase_capacity(q);
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if (!res) {
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return false;
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}
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}
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q->rear = (q->rear + 1) % q->capacity;
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q->elems[q->rear] = el;
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q->size++;
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return true;
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}
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RZ_API void *rz_queue_dequeue(RQueue *q) {
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void *res;
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if (rz_queue_is_empty(q)) {
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return NULL;
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}
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res = q->elems[q->front];
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q->front = (q->front + 1) % q->capacity;
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q->size--;
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return res;
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}
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RZ_API int rz_queue_is_empty(RQueue *q) {
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return q->size == 0;
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}
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