unleashed-firmware/lib/toolbox/stream/stream_cache.h
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

94 lines
2.6 KiB
C

#pragma once
#include "stream.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef struct StreamCache StreamCache;
/**
* Allocate stream cache.
* @return StreamCache* pointer to a StreamCache instance
*/
StreamCache* stream_cache_alloc();
/**
* Free stream cache.
* @param cache Pointer to a StreamCache instance
*/
void stream_cache_free(StreamCache* cache);
/**
* Drop the cache contents and set it to initial state.
* @param cache Pointer to a StreamCache instance
*/
void stream_cache_drop(StreamCache* cache);
/**
* Determine if the internal cursor is at end the end of cached data.
* @param cache Pointer to a StreamCache instance
* @return True if cursor is at end, otherwise false.
*/
bool stream_cache_at_end(StreamCache* cache);
/**
* Get the current size of cached data.
* @param cache Pointer to a StreamCache instance
* @return Size of cached data.
*/
size_t stream_cache_size(StreamCache* cache);
/**
* Get the internal cursor position.
* @param cache Pointer to a StreamCache instance
* @return Cursor position inside the cache.
*/
size_t stream_cache_pos(StreamCache* cache);
/**
* Load the cache with new data from a stream.
* @param cache Pointer to a StreamCache instance
* @param stream Pointer to a Stream instance
* @return Size of newly cached data.
*/
size_t stream_cache_fill(StreamCache* cache, Stream* stream);
/**
* Write as much cached data as possible to a stream.
* @param cache Pointer to a StreamCache instance
* @param stream Pointer to a Stream instance
* @return True on success, False on failure.
*/
bool stream_cache_flush(StreamCache* cache, Stream* stream);
/**
* Read cached data and advance the internal cursor.
* @param cache Pointer to a StreamCache instance.
* @param data Pointer to a data buffer. Must be initialized.
* @param size Maximum size in bytes to read from the cache.
* @return Actual size that was read.
*/
size_t stream_cache_read(StreamCache* cache, uint8_t* data, size_t size);
/**
* Write to cached data and advance the internal cursor.
* @param cache Pointer to a StreamCache instance.
* @param data Pointer to a data buffer.
* @param size Maximum size in bytes to write to the cache.
* @return Actual size that was written.
*/
size_t stream_cache_write(StreamCache* cache, const uint8_t* data, size_t size);
/**
* Move the internal cursor relatively to its current position.
* @param cache Pointer to a StreamCache instance.
* @param offset Cursor offset.
* @return Actual cursor offset. Equal to offset parameter on hit.
*/
int32_t stream_cache_seek(StreamCache* cache, int32_t offset);
#ifdef __cplusplus
}
#endif