[FL-2655, FL-2650] Buffered file streams (#1424)

* Initial buffered file stream implementation
* Fix logical errors
* Fix more logical errors
* Minimally working implementation
* Adapt infrared unit tests for buffered streams
* Increase read buffer size from 512 to 1K
* Correct naming and formatting
* More code improvements
* Allow passing access and open modes for buffered streams
* Implement tests for buffered streams
* Better file and method names
* Add comments and correct formatting
* Use buffered streams in Infrared
* Fix compilation error
This commit is contained in:
Georgii Surkov
2022-07-22 19:00:25 +03:00
committed by GitHub
parent ec57dd310a
commit 16e598b2c0
10 changed files with 501 additions and 11 deletions

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#include "buffered_file_stream.h"
#include "stream_i.h"
#include "file_stream.h"
#include "stream_cache.h"
typedef struct {
Stream stream_base;
Stream* file_stream;
StreamCache* cache;
} BufferedFileStream;
static void buffered_file_stream_free(BufferedFileStream* stream);
static bool buffered_file_stream_eof(BufferedFileStream* stream);
static void buffered_file_stream_clean(BufferedFileStream* stream);
static bool
buffered_file_stream_seek(BufferedFileStream* stream, int32_t offset, StreamOffset offset_type);
static size_t buffered_file_stream_tell(BufferedFileStream* stream);
static size_t buffered_file_stream_size(BufferedFileStream* stream);
static size_t
buffered_file_stream_write(BufferedFileStream* stream, const uint8_t* data, size_t size);
static size_t buffered_file_stream_read(BufferedFileStream* stream, uint8_t* data, size_t size);
static bool buffered_file_stream_delete_and_insert(
BufferedFileStream* stream,
size_t delete_size,
StreamWriteCB write_callback,
const void* ctx);
const StreamVTable buffered_file_stream_vtable = {
.free = (StreamFreeFn)buffered_file_stream_free,
.eof = (StreamEOFFn)buffered_file_stream_eof,
.clean = (StreamCleanFn)buffered_file_stream_clean,
.seek = (StreamSeekFn)buffered_file_stream_seek,
.tell = (StreamTellFn)buffered_file_stream_tell,
.size = (StreamSizeFn)buffered_file_stream_size,
.write = (StreamWriteFn)buffered_file_stream_write,
.read = (StreamReadFn)buffered_file_stream_read,
.delete_and_insert = (StreamDeleteAndInsertFn)buffered_file_stream_delete_and_insert,
};
Stream* buffered_file_stream_alloc(Storage* storage) {
BufferedFileStream* stream = malloc(sizeof(BufferedFileStream));
stream->file_stream = file_stream_alloc(storage);
stream->cache = stream_cache_alloc();
stream->stream_base.vtable = &buffered_file_stream_vtable;
return (Stream*)stream;
}
bool buffered_file_stream_open(
Stream* _stream,
const char* path,
FS_AccessMode access_mode,
FS_OpenMode open_mode) {
furi_assert(_stream);
BufferedFileStream* stream = (BufferedFileStream*)_stream;
stream_cache_drop(stream->cache);
furi_check(stream->stream_base.vtable == &buffered_file_stream_vtable);
return file_stream_open(stream->file_stream, path, access_mode, open_mode);
}
bool buffered_file_stream_close(Stream* _stream) {
furi_assert(_stream);
BufferedFileStream* stream = (BufferedFileStream*)_stream;
furi_check(stream->stream_base.vtable == &buffered_file_stream_vtable);
return file_stream_close(stream->file_stream);
}
FS_Error buffered_file_stream_get_error(Stream* _stream) {
furi_assert(_stream);
BufferedFileStream* stream = (BufferedFileStream*)_stream;
furi_check(stream->stream_base.vtable == &buffered_file_stream_vtable);
return file_stream_get_error(stream->file_stream);
}
static void buffered_file_stream_free(BufferedFileStream* stream) {
furi_assert(stream);
stream_free(stream->file_stream);
stream_cache_free(stream->cache);
free(stream);
}
static bool buffered_file_stream_eof(BufferedFileStream* stream) {
return stream_cache_at_end(stream->cache) && stream_eof(stream->file_stream);
}
static void buffered_file_stream_clean(BufferedFileStream* stream) {
stream_cache_drop(stream->cache);
stream_clean(stream->file_stream);
}
static bool buffered_file_stream_seek(
BufferedFileStream* stream,
int32_t offset,
StreamOffset offset_type) {
bool success = false;
int32_t new_offset = offset;
if(offset_type == StreamOffsetFromCurrent) {
new_offset -= stream_cache_seek(stream->cache, offset);
if(new_offset < 0) {
new_offset -= (int32_t)stream_cache_size(stream->cache);
}
}
if((new_offset != 0) || (offset_type != StreamOffsetFromCurrent)) {
stream_cache_drop(stream->cache);
success = stream_seek(stream->file_stream, new_offset, offset_type);
} else {
success = true;
}
return success;
}
static size_t buffered_file_stream_tell(BufferedFileStream* stream) {
return stream_tell(stream->file_stream) + stream_cache_pos(stream->cache) -
stream_cache_size(stream->cache);
}
static size_t buffered_file_stream_size(BufferedFileStream* stream) {
return stream_cache_size(stream->cache) + stream_size(stream->file_stream);
}
static size_t
buffered_file_stream_write(BufferedFileStream* stream, const uint8_t* data, size_t size) {
stream_cache_drop(stream->cache);
return stream_write(stream->file_stream, data, size);
}
static size_t buffered_file_stream_read(BufferedFileStream* stream, uint8_t* data, size_t size) {
size_t need_to_read = size;
while(need_to_read) {
need_to_read -=
stream_cache_read(stream->cache, data + (size - need_to_read), need_to_read);
if(need_to_read) {
if(!stream_cache_fill(stream->cache, stream->file_stream)) {
break;
}
}
}
return size - need_to_read;
}
static bool buffered_file_stream_delete_and_insert(
BufferedFileStream* stream,
size_t delete_size,
StreamWriteCB write_callback,
const void* ctx) {
stream_cache_drop(stream->cache);
return stream_delete_and_insert(stream->file_stream, delete_size, write_callback, ctx);
}

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#pragma once
#include <stdlib.h>
#include <storage/storage.h>
#include "stream.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* Allocate a file stream with buffered read operations
* @return Stream*
*/
Stream* buffered_file_stream_alloc(Storage* storage);
/**
* Opens an existing file or creates a new one.
* @param stream pointer to file stream object.
* @param path path to file
* @param access_mode access mode from FS_AccessMode
* @param open_mode open mode from FS_OpenMode
* @return success flag. You need to close the file even if the open operation failed.
*/
bool buffered_file_stream_open(
Stream* stream,
const char* path,
FS_AccessMode access_mode,
FS_OpenMode open_mode);
/**
* Closes the file.
* @param stream
* @return true
* @return false
*/
bool buffered_file_stream_close(Stream* stream);
/**
* Retrieves the error id from the file object
* @param stream pointer to stream object.
* @return FS_Error error id
*/
FS_Error buffered_file_stream_get_error(Stream* stream);
#ifdef __cplusplus
}
#endif

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#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;
}
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;
}
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 = -MIN(cache->position, (size_t)abs(offset));
}
cache->position += actual_offset;
return actual_offset;
}

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#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);
/**
* 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);
/**
* 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