/* mbed Microcontroller Library
* Copyright (c) 2017 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*/
/** \addtogroup storage */
/** @{*/
#ifndef MBED_LFSFILESYSTEM_H
#define MBED_LFSFILESYSTEM_H
#include "filesystem/FileSystem.h"
#include "blockdevice/BlockDevice.h"
#include "rtos/Mutex.h"
#include "littlefs/lfs.h"
namespace mbed {
/**
* LittleFileSystem, a little file system
*
* Synchronization level: Thread safe
*/
class LittleFileSystem : public mbed::FileSystem {
public:
/** Lifetime of the LittleFileSystem
*
* @param name Name of the file system in the tree.
* @param bd Block device to mount. Mounted immediately if not NULL.
* @param read_size
* Minimum size of a block read. This determines the size of read buffers.
* This may be larger than the physical read size to improve performance
* by caching more of the block device.
* @param prog_size
* Minimum size of a block program. This determines the size of program
* buffers. This may be larger than the physical program size to improve
* performance by caching more of the block device.
* @param block_size
* Size of an erasable block. This does not impact ram consumption and
* may be larger than the physical erase size. However, this should be
* kept small as each file currently takes up an entire block.
* @param lookahead
* Number of blocks to lookahead during block allocation. A larger
* lookahead reduces the number of passes required to allocate a block.
* The lookahead buffer requires only 1 bit per block so it can be quite
* large with little ram impact. Should be a multiple of 32.
*/
LittleFileSystem(const char *name = NULL, mbed::BlockDevice *bd = NULL,
lfs_size_t read_size = MBED_LFS_READ_SIZE,
lfs_size_t prog_size = MBED_LFS_PROG_SIZE,
lfs_size_t block_size = MBED_LFS_BLOCK_SIZE,
lfs_size_t lookahead = MBED_LFS_LOOKAHEAD);
virtual ~LittleFileSystem();
/** Format a block device with the LittleFileSystem.
*
* The block device to format should be mounted when this function is called.
*
* @param bd This is the block device that will be formatted.
* @param read_size
* Minimum size of a block read. This determines the size of read buffers.
* This may be larger than the physical read size to improve performance
* by caching more of the block device.
* @param prog_size
* Minimum size of a block program. This determines the size of program
* buffers. This may be larger than the physical program size to improve
* performance by caching more of the block device.
* @param block_size
* Size of an erasable block. This does not impact ram consumption and
* may be larger than the physical erase size. However, this should be
* kept small as each file currently takes up an entire block.
* @param lookahead
* Number of blocks to lookahead during block allocation. A larger
* lookahead reduces the number of passes required to allocate a block.
* The lookahead buffer requires only 1 bit per block so it can be quite
* large with little ram impact. Should be a multiple of 32.
*/
static int format(mbed::BlockDevice *bd,
lfs_size_t read_size = MBED_LFS_READ_SIZE,
lfs_size_t prog_size = MBED_LFS_PROG_SIZE,
lfs_size_t block_size = MBED_LFS_BLOCK_SIZE,
lfs_size_t lookahead = MBED_LFS_LOOKAHEAD);
/** Mount a file system to a block device.
*
* @param bd Block device to mount to.
* @return 0 on success, negative error code on failure.
*/
virtual int mount(mbed::BlockDevice *bd);
/** Unmount a file system from the underlying block device.
*
* @return 0 on success, negative error code on failure
*/
virtual int unmount();
/** Reformat a file system. Results in an empty and mounted file system.
*
* @param bd
* Block device to reformat and mount. If NULL, the mounted
* Block device is used.
* Note: If mount fails, bd must be provided.
* Default: NULL
*
* @return 0 on success, negative error code on failure
*/
virtual int reformat(mbed::BlockDevice *bd);
/** Remove a file from the file system.
*
* @param path The name of the file to remove.
* @return 0 on success, negative error code on failure
*/
virtual int remove(const char *path);
/** Rename a file in the file system.
*
* @param path The name of the file to rename.
* @param newpath The name to rename it to.
* @return 0 on success, negative error code on failure
*/
virtual int rename(const char *path, const char *newpath);
/** Store information about the file in a stat structure
*
* @param path The name of the file to find information about.
* @param st The stat buffer to write to.
* @return 0 on success, negative error code on failure
*/
virtual int stat(const char *path, struct stat *st);
/** Create a directory in the file system.
*
* @param path The name of the directory to create.
* @param mode The permissions with which to create the directory.
* @return 0 on success, negative error code on failure
*/
virtual int mkdir(const char *path, mode_t mode);
/** Store information about the mounted file system in a statvfs structure.
*
* @param path The name of the file to find information about.
* @param buf The stat buffer to write to.
* @return 0 on success, negative error code on failure
*/
virtual int statvfs(const char *path, struct statvfs *buf);
protected:
#if !(DOXYGEN_ONLY)
/** Open a file on the file system.
*
* @param file Destination of the newly created handle to the referenced file.
* @param path The name of the file to open.
* @param flags The flags that trigger opening of the file. These flags are O_RDONLY, O_WRONLY, and O_RDWR,
* with an O_CREAT, O_TRUNC, or O_APPEND bitwise OR operator.
* @return 0 on success, negative error code on failure.
*/
virtual int file_open(mbed::fs_file_t *file, const char *path, int flags);
/** Close a file
*
* @param file File handle.
* return 0 on success, negative error code on failure
*/
virtual int file_close(mbed::fs_file_t file);
/** Read the contents of a file into a buffer
*
* @param file File handle.
* @param buffer The buffer to read in to.
* @param size The number of bytes to read.
* @return The number of bytes read, 0 at end of file, negative error on failure
*/
virtual ssize_t file_read(mbed::fs_file_t file, void *buffer, size_t size);
/** Write the contents of a buffer to a file
*
* @param file File handle.
* @param buffer The buffer to write from.
* @param size The number of bytes to write.
* @return The number of bytes written, negative error on failure
*/
virtual ssize_t file_write(mbed::fs_file_t file, const void *buffer, size_t size);
/** Flush any buffers associated with the file
*
* @param file File handle.
* @return 0 on success, negative error code on failure
*/
virtual int file_sync(mbed::fs_file_t file);
/** Move the file position to a given offset from a given location
*
* @param file File handle.
* @param offset The offset from whence to move to.
* @param whence The start of where to seek.
* SEEK_SET to start from beginning of file,
* SEEK_CUR to start from current position in file,
* SEEK_END to start from end of file.
* @return The new offset of the file
*/
virtual off_t file_seek(mbed::fs_file_t file, off_t offset, int whence);
/** Get the file position of the file
*
* @param file File handle.
* @return The current offset in the file
*/
virtual off_t file_tell(mbed::fs_file_t file);
/** Get the size of the file
*
* @param file File handle.
* @return Size of the file in bytes
*/
virtual off_t file_size(mbed::fs_file_t file);
/** Truncate or extend a file.
*
* The file's length is set to the specified value. The seek pointer is
* not changed. If the file is extended, the extended area appears as if
* it were zero-filled.
*
* @param file File handle.
* @param length The requested new length for the file
*
* @return Zero on success, negative error code on failure
*/
virtual int file_truncate(mbed::fs_file_t file, off_t length);
/** Open a directory on the file system.
*
* @param dir Destination for the handle to the directory.
* @param path Name of the directory to open.
* @return 0 on success, negative error code on failure
*/
virtual int dir_open(mbed::fs_dir_t *dir, const char *path);
/** Close a directory
*
* @param dir Dir handle.
* return 0 on success, negative error code on failure
*/
virtual int dir_close(mbed::fs_dir_t dir);
/** Read the next directory entry
*
* @param dir Dir handle.
* @param ent The directory entry to fill out.
* @return 1 on reading a filename, 0 at end of directory, negative error on failure
*/
virtual ssize_t dir_read(mbed::fs_dir_t dir, struct dirent *ent);
/** Set the current position of the directory
*
* @param dir Dir handle.
* @param offset Offset of the location to seek to,
* must be a value returned from dir_tell
*/
virtual void dir_seek(mbed::fs_dir_t dir, off_t offset);
/** Get the current position of the directory
*
* @param dir Dir handle.
* @return Position of the directory that can be passed to dir_rewind
*/
virtual off_t dir_tell(mbed::fs_dir_t dir);
/** Rewind the current position to the beginning of the directory
*
* @param dir Dir handle
*/
virtual void dir_rewind(mbed::fs_dir_t dir);
#endif //!(DOXYGEN_ONLY)
private:
lfs_t _lfs; // The actual file system
struct lfs_config _config;
mbed::BlockDevice *_bd; // The block device
// default parameters
const lfs_size_t _read_size;
const lfs_size_t _prog_size;
const lfs_size_t _block_size;
const lfs_size_t _lookahead;
// thread-safe locking
rtos::Mutex _mutex;
};
} // namespace mbed
// Added "using" for backwards compatibility
#ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
using mbed::LittleFileSystem;
#endif
#endif
/** @}*/
