flipperzero-firmware/lib/toolbox/stream/stream_cache.c
Georgii Surkov 135fbd294b
[FL-2693] RW buffered streams (#1523)
* Add write methods for stream cache
* Fix logical error
* Implement write cache for buffered file streams
* Minor code refactoring
* Less ugly code
* Better read() implementation
* Intermediate implementation
* Fix logical error
* Code cleanup
* Update FFF comments
* Fix logical error
* Github: rsync with delete

Co-authored-by: あく <alleteam@gmail.com>
2022-08-04 01:43:14 +09:00

93 lines
2.6 KiB
C

#include "stream_cache.h"
#define STREAM_CACHE_MAX_SIZE 1024U
struct StreamCache {
uint8_t data[STREAM_CACHE_MAX_SIZE];
size_t data_size;
size_t position;
};
StreamCache* stream_cache_alloc() {
StreamCache* cache = malloc(sizeof(StreamCache));
cache->data_size = 0;
cache->position = 0;
return cache;
}
void stream_cache_free(StreamCache* cache) {
furi_assert(cache);
cache->data_size = 0;
cache->position = 0;
free(cache);
}
void stream_cache_drop(StreamCache* cache) {
cache->data_size = 0;
cache->position = 0;
}
bool stream_cache_at_end(StreamCache* cache) {
furi_assert(cache->data_size >= cache->position);
return cache->data_size == cache->position;
}
size_t stream_cache_size(StreamCache* cache) {
return cache->data_size;
}
size_t stream_cache_pos(StreamCache* cache) {
return cache->position;
}
size_t stream_cache_fill(StreamCache* cache, Stream* stream) {
const size_t size_read = stream_read(stream, cache->data, STREAM_CACHE_MAX_SIZE);
cache->data_size = size_read;
cache->position = 0;
return size_read;
}
bool stream_cache_flush(StreamCache* cache, Stream* stream) {
const size_t size_written = stream_write(stream, cache->data, cache->data_size);
const bool success = (size_written == cache->data_size);
cache->data_size = 0;
cache->position = 0;
return success;
}
size_t stream_cache_read(StreamCache* cache, uint8_t* data, size_t size) {
furi_assert(cache->data_size >= cache->position);
const size_t size_read = MIN(size, cache->data_size - cache->position);
if(size_read > 0) {
memcpy(data, cache->data + cache->position, size_read);
cache->position += size_read;
}
return size_read;
}
size_t stream_cache_write(StreamCache* cache, const uint8_t* data, size_t size) {
furi_assert(cache->data_size >= cache->position);
const size_t size_written = MIN(size, STREAM_CACHE_MAX_SIZE - cache->position);
if(size_written > 0) {
memcpy(cache->data + cache->position, data, size_written);
cache->position += size_written;
if(cache->position > cache->data_size) {
cache->data_size = cache->position;
}
}
return size_written;
}
int32_t stream_cache_seek(StreamCache* cache, int32_t offset) {
furi_assert(cache->data_size >= cache->position);
int32_t actual_offset = 0;
if(offset > 0) {
actual_offset = MIN(cache->data_size - cache->position, (size_t)offset);
} else if(offset < 0) {
actual_offset = MAX(-((int32_t)cache->position), offset);
}
cache->position += actual_offset;
return actual_offset;
}