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/*
*
* Copyright 2015-2016, 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);
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;
}
void grpc_chttp2_stream_map_move_into(grpc_chttp2_stream_map *src,
grpc_chttp2_stream_map *dst) {
/* if src is empty we dont need to do anything */
if (src->count == src->free) {
return;
}
/* if dst is empty we simply need to swap */
if (dst->count == dst->free) {
GPR_SWAP(grpc_chttp2_stream_map, *src, *dst);
return;
}
/* the first element of src must be greater than the last of dst...
* however the maps may need compacting for this property to hold */
if (src->keys[0] <= dst->keys[dst->count - 1]) {
src->count = compact(src->keys, src->values, src->count);
src->free = 0;
dst->count = compact(dst->keys, dst->values, dst->count);
dst->free = 0;
}
GPR_ASSERT(src->keys[0] > dst->keys[dst->count - 1]);
/* if dst doesn't have capacity, resize */
if (dst->count + src->count > dst->capacity) {
dst->capacity = GPR_MAX(dst->capacity * 3 / 2, dst->count + src->count);
dst->keys = gpr_realloc(dst->keys, dst->capacity * sizeof(uint32_t));
dst->values = gpr_realloc(dst->values, dst->capacity * sizeof(void *));
}
memcpy(dst->keys + dst->count, src->keys, src->count * sizeof(uint32_t));
memcpy(dst->values + dst->count, src->values, src->count * sizeof(void *));
dst->count += src->count;
dst->free += src->free;
src->count = 0;
src->free = 0;
}
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;
}
}
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_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]);
}
}
}
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