mirror of
https://github.com/google/pebble.git
synced 2025-07-06 23:00:29 -04:00
Import of the watch repository from Pebble
This commit is contained in:
commit
3b92768480
10334 changed files with 2564465 additions and 0 deletions
93
src/libutil/circular_cache.c
Normal file
93
src/libutil/circular_cache.c
Normal file
|
@ -0,0 +1,93 @@
|
|||
/*
|
||||
* Copyright 2024 Google LLC
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
#include "util/circular_cache.h"
|
||||
|
||||
#include "util/assert.h"
|
||||
#include "util/math.h"
|
||||
|
||||
#include <string.h>
|
||||
|
||||
void circular_cache_init(CircularCache* c, uint8_t* buffer, size_t item_size,
|
||||
int total_items, Comparator compare_cb) {
|
||||
UTIL_ASSERT(c);
|
||||
UTIL_ASSERT(buffer);
|
||||
UTIL_ASSERT(item_size);
|
||||
UTIL_ASSERT(compare_cb);
|
||||
|
||||
*c = (CircularCache) {
|
||||
.cache = buffer,
|
||||
.next_erased_item_idx = 0,
|
||||
.item_size = item_size,
|
||||
.total_items = total_items,
|
||||
.compare_cb = compare_cb
|
||||
};
|
||||
}
|
||||
|
||||
void circular_cache_set_item_destructor(CircularCache *c, CircularCacheItemDestructor destructor) {
|
||||
c->item_destructor = destructor;
|
||||
}
|
||||
|
||||
static uint8_t* prv_get_item_at_index(CircularCache* c, int index) {
|
||||
return c->cache + index * c->item_size;
|
||||
}
|
||||
|
||||
bool circular_cache_contains(CircularCache* c, void* theirs) {
|
||||
return (circular_cache_get(c, theirs) != NULL);
|
||||
}
|
||||
|
||||
void *circular_cache_get(CircularCache* c, void* theirs) {
|
||||
for (int i = 0; i < c->total_items; ++i) {
|
||||
uint8_t* ours = prv_get_item_at_index(c, i);
|
||||
if (c->compare_cb(ours, theirs) == 0) {
|
||||
return ours;
|
||||
}
|
||||
}
|
||||
return NULL;
|
||||
}
|
||||
|
||||
void circular_cache_push(CircularCache* c, void* new_item) {
|
||||
uint8_t* old_item = prv_get_item_at_index(c, c->next_erased_item_idx);
|
||||
if (c->item_destructor) {
|
||||
c->item_destructor(old_item);
|
||||
}
|
||||
memcpy(old_item, new_item, c->item_size);
|
||||
++c->next_erased_item_idx;
|
||||
UTIL_ASSERT(c->next_erased_item_idx <= c->total_items);
|
||||
if (c->next_erased_item_idx == c->total_items) {
|
||||
c->next_erased_item_idx = 0;
|
||||
}
|
||||
}
|
||||
|
||||
void circular_cache_fill(CircularCache *c, uint8_t *item) {
|
||||
// If you need item_destructor and fill, add an index pointing to the oldest item for destruction
|
||||
UTIL_ASSERT(c->item_destructor == NULL);
|
||||
for (int i = 0; i < c->total_items; ++i) {
|
||||
memcpy(c->cache + i * c->item_size, item, c->item_size);
|
||||
}
|
||||
}
|
||||
|
||||
void circular_cache_flush(CircularCache *c) {
|
||||
// This assumes that the user of this library can differentiate empty entries in the cache from
|
||||
// valid ones.
|
||||
for (int i = 0; i < c->total_items; i++) {
|
||||
uint8_t* item = prv_get_item_at_index(c, i);
|
||||
if (c->item_destructor) {
|
||||
c->item_destructor(item);
|
||||
}
|
||||
}
|
||||
c->next_erased_item_idx = 0;
|
||||
}
|
Loading…
Add table
Add a link
Reference in a new issue