| /* |
| * nghttp2 - HTTP/2 C Library |
| * |
| * Copyright (c) 2012 Tatsuhiro Tsujikawa |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining |
| * a copy of this software and associated documentation files (the |
| * "Software"), to deal in the Software without restriction, including |
| * without limitation the rights to use, copy, modify, merge, publish, |
| * distribute, sublicense, and/or sell copies of the Software, and to |
| * permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE |
| * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION |
| * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
| * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| #include "nghttp2_pq.h" |
| |
| #include <stdio.h> |
| #include <assert.h> |
| |
| #include "nghttp2_helper.h" |
| |
| int nghttp2_pq_init(nghttp2_pq *pq, nghttp2_less less, nghttp2_mem *mem) { |
| pq->mem = mem; |
| pq->capacity = 0; |
| pq->q = NULL; |
| pq->length = 0; |
| pq->less = less; |
| return 0; |
| } |
| |
| void nghttp2_pq_free(nghttp2_pq *pq) { |
| nghttp2_mem_free(pq->mem, pq->q); |
| pq->q = NULL; |
| } |
| |
| static void swap(nghttp2_pq *pq, size_t i, size_t j) { |
| nghttp2_pq_entry *a = pq->q[i]; |
| nghttp2_pq_entry *b = pq->q[j]; |
| |
| pq->q[i] = b; |
| b->index = i; |
| pq->q[j] = a; |
| a->index = j; |
| } |
| |
| static void bubble_up(nghttp2_pq *pq, size_t index) { |
| size_t parent; |
| while (index != 0) { |
| parent = (index - 1) / 2; |
| if (!pq->less(pq->q[index], pq->q[parent])) { |
| return; |
| } |
| swap(pq, parent, index); |
| index = parent; |
| } |
| } |
| |
| int nghttp2_pq_push(nghttp2_pq *pq, nghttp2_pq_entry *item) { |
| if (pq->capacity <= pq->length) { |
| void *nq; |
| size_t ncapacity; |
| |
| ncapacity = nghttp2_max(4, (pq->capacity * 2)); |
| |
| nq = nghttp2_mem_realloc(pq->mem, pq->q, |
| ncapacity * sizeof(nghttp2_pq_entry *)); |
| if (nq == NULL) { |
| return NGHTTP2_ERR_NOMEM; |
| } |
| pq->capacity = ncapacity; |
| pq->q = nq; |
| } |
| pq->q[pq->length] = item; |
| item->index = pq->length; |
| ++pq->length; |
| bubble_up(pq, pq->length - 1); |
| return 0; |
| } |
| |
| nghttp2_pq_entry *nghttp2_pq_top(nghttp2_pq *pq) { |
| if (pq->length == 0) { |
| return NULL; |
| } else { |
| return pq->q[0]; |
| } |
| } |
| |
| static void bubble_down(nghttp2_pq *pq, size_t index) { |
| size_t i, j, minindex; |
| for (;;) { |
| j = index * 2 + 1; |
| minindex = index; |
| for (i = 0; i < 2; ++i, ++j) { |
| if (j >= pq->length) { |
| break; |
| } |
| if (pq->less(pq->q[j], pq->q[minindex])) { |
| minindex = j; |
| } |
| } |
| if (minindex == index) { |
| return; |
| } |
| swap(pq, index, minindex); |
| index = minindex; |
| } |
| } |
| |
| void nghttp2_pq_pop(nghttp2_pq *pq) { |
| if (pq->length > 0) { |
| pq->q[0] = pq->q[pq->length - 1]; |
| pq->q[0]->index = 0; |
| --pq->length; |
| bubble_down(pq, 0); |
| } |
| } |
| |
| void nghttp2_pq_remove(nghttp2_pq *pq, nghttp2_pq_entry *item) { |
| assert(pq->q[item->index] == item); |
| |
| if (item->index == 0) { |
| nghttp2_pq_pop(pq); |
| return; |
| } |
| |
| if (item->index == pq->length - 1) { |
| --pq->length; |
| return; |
| } |
| |
| pq->q[item->index] = pq->q[pq->length - 1]; |
| pq->q[item->index]->index = item->index; |
| --pq->length; |
| |
| if (pq->less(item, pq->q[item->index])) { |
| bubble_down(pq, item->index); |
| } else { |
| bubble_up(pq, item->index); |
| } |
| } |
| |
| int nghttp2_pq_empty(nghttp2_pq *pq) { return pq->length == 0; } |
| |
| size_t nghttp2_pq_size(nghttp2_pq *pq) { return pq->length; } |
| |
| void nghttp2_pq_update(nghttp2_pq *pq, nghttp2_pq_item_cb fun, void *arg) { |
| size_t i; |
| int rv = 0; |
| if (pq->length == 0) { |
| return; |
| } |
| for (i = 0; i < pq->length; ++i) { |
| rv |= (*fun)(pq->q[i], arg); |
| } |
| if (rv) { |
| for (i = pq->length; i > 0; --i) { |
| bubble_down(pq, i - 1); |
| } |
| } |
| } |
| |
| int nghttp2_pq_each(nghttp2_pq *pq, nghttp2_pq_item_cb fun, void *arg) { |
| size_t i; |
| |
| if (pq->length == 0) { |
| return 0; |
| } |
| for (i = 0; i < pq->length; ++i) { |
| if ((*fun)(pq->q[i], arg)) { |
| return 1; |
| } |
| } |
| return 0; |
| } |