diff options
Diffstat (limited to 'src/core/transport/chttp2/stream_map.c')
| -rw-r--r-- | src/core/transport/chttp2/stream_map.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/core/transport/chttp2/stream_map.c b/src/core/transport/chttp2/stream_map.c new file mode 100644 index 0000000000..9ac3a4750d --- /dev/null +++ b/src/core/transport/chttp2/stream_map.c @@ -0,0 +1,154 @@ +/* + * + * Copyright 2014, 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/transport/chttp2/stream_map.h" +#include <grpc/support/alloc.h> +#include <grpc/support/log.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(gpr_uint32) * 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(gpr_uint32 *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, gpr_uint32 key, + void *value) { + size_t count = map->count; + size_t capacity = map->capacity; + gpr_uint32 *keys = map->keys; + void **values = map->values; + + GPR_ASSERT(count == 0 || keys[count - 1] < key); + GPR_ASSERT(value); + + 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(gpr_uint32)); + 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, gpr_uint32 key) { + size_t min_idx = 0; + size_t max_idx = map->count; + size_t mid_idx; + gpr_uint32 *keys = map->keys; + void **values = map->values; + gpr_uint32 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, + gpr_uint32 key) { + void **pvalue = find(map, key); + void *out = NULL; + if (pvalue != NULL) { + out = *pvalue; + *pvalue = NULL; + map->free += (out != NULL); + } + return out; +} + +void *grpc_chttp2_stream_map_find(grpc_chttp2_stream_map *map, gpr_uint32 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_for_each(grpc_chttp2_stream_map *map, + void (*f)(void *user_data, gpr_uint32 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]); + } + } +} |