| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * 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. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * 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 |
| * OWNER 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 "src/core/ext/transport/chttp2/transport/stream_map.h" |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/useful.h> |
| |
| void grpc_chttp2_stream_map_init(grpc_chttp2_stream_map *map, |
| size_t initial_capacity) { |
| GPR_ASSERT(initial_capacity > 1); |
| map->keys = gpr_malloc(sizeof(uint32_t) * initial_capacity); |
| map->values = gpr_malloc(sizeof(void *) * initial_capacity); |
| map->count = 0; |
| map->free = 0; |
| map->capacity = initial_capacity; |
| } |
| |
| void grpc_chttp2_stream_map_destroy(grpc_chttp2_stream_map *map) { |
| gpr_free(map->keys); |
| gpr_free(map->values); |
| } |
| |
| static size_t compact(uint32_t *keys, void **values, size_t count) { |
| size_t i, out; |
| |
| for (i = 0, out = 0; i < count; i++) { |
| if (values[i]) { |
| keys[out] = keys[i]; |
| values[out] = values[i]; |
| out++; |
| } |
| } |
| |
| return out; |
| } |
| |
| void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map *map, uint32_t key, |
| void *value) { |
| size_t count = map->count; |
| size_t capacity = map->capacity; |
| uint32_t *keys = map->keys; |
| void **values = map->values; |
| |
| GPR_ASSERT(count == 0 || keys[count - 1] < key); |
| GPR_ASSERT(value); |
| GPR_ASSERT(grpc_chttp2_stream_map_find(map, key) == NULL); |
| |
| if (count == capacity) { |
| if (map->free > capacity / 4) { |
| count = compact(keys, values, count); |
| map->free = 0; |
| } else { |
| /* resize when less than 25% of the table is free, because compaction |
| won't help much */ |
| map->capacity = capacity = 3 * capacity / 2; |
| map->keys = keys = gpr_realloc(keys, capacity * sizeof(uint32_t)); |
| map->values = values = gpr_realloc(values, capacity * sizeof(void *)); |
| } |
| } |
| |
| keys[count] = key; |
| values[count] = value; |
| map->count = count + 1; |
| } |
| |
| static void **find(grpc_chttp2_stream_map *map, uint32_t key) { |
| size_t min_idx = 0; |
| size_t max_idx = map->count; |
| size_t mid_idx; |
| uint32_t *keys = map->keys; |
| void **values = map->values; |
| uint32_t mid_key; |
| |
| if (max_idx == 0) return NULL; |
| |
| while (min_idx < max_idx) { |
| /* find the midpoint, avoiding overflow */ |
| mid_idx = min_idx + ((max_idx - min_idx) / 2); |
| mid_key = keys[mid_idx]; |
| |
| if (mid_key < key) { |
| min_idx = mid_idx + 1; |
| } else if (mid_key > key) { |
| max_idx = mid_idx; |
| } else /* mid_key == key */ |
| { |
| return &values[mid_idx]; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| void *grpc_chttp2_stream_map_delete(grpc_chttp2_stream_map *map, uint32_t key) { |
| void **pvalue = find(map, key); |
| void *out = NULL; |
| if (pvalue != NULL) { |
| out = *pvalue; |
| *pvalue = NULL; |
| map->free += (out != NULL); |
| /* recognize complete emptyness and ensure we can skip |
| * defragmentation later */ |
| if (map->free == map->count) { |
| map->free = map->count = 0; |
| } |
| GPR_ASSERT(grpc_chttp2_stream_map_find(map, key) == NULL); |
| } |
| return out; |
| } |
| |
| void *grpc_chttp2_stream_map_find(grpc_chttp2_stream_map *map, uint32_t key) { |
| void **pvalue = find(map, key); |
| return pvalue != NULL ? *pvalue : NULL; |
| } |
| |
| size_t grpc_chttp2_stream_map_size(grpc_chttp2_stream_map *map) { |
| return map->count - map->free; |
| } |
| |
| void *grpc_chttp2_stream_map_rand(grpc_chttp2_stream_map *map) { |
| if (map->count == map->free) { |
| return NULL; |
| } |
| if (map->free != 0) { |
| map->count = compact(map->keys, map->values, map->count); |
| map->free = 0; |
| } |
| return map->values[((size_t)rand()) % map->count]; |
| } |
| |
| void grpc_chttp2_stream_map_for_each(grpc_chttp2_stream_map *map, |
| void (*f)(void *user_data, uint32_t key, |
| void *value), |
| void *user_data) { |
| size_t i; |
| |
| for (i = 0; i < map->count; i++) { |
| if (map->values[i]) { |
| f(user_data, map->keys[i], map->values[i]); |
| } |
| } |
| } |