hid-keyboard-dongle-nRF/SDK/nRF5_SDK_17.0.2_d674dde/components/libraries/fds/fds.h

704 lines
33 KiB
C

/**
* Copyright (c) 2015 - 2020, Nordic Semiconductor ASA
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form, except as embedded into a Nordic
* Semiconductor ASA integrated circuit in a product or a software update for
* such product, must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. Neither the name of Nordic Semiconductor ASA nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
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*
*/
#ifndef FDS_H__
#define FDS_H__
/**
* @defgroup fds Flash Data Storage
* @ingroup app_common
* @{
*
* @brief Flash Data Storage (FDS).
*
* @details Flash Data Storage is a minimalistic, record-oriented file system for the on-chip
* flash. Files are stored as a collection of records of variable length. FDS supports
* synchronous read operations and asynchronous write operations (write, update,
* and delete). FDS can be used from multiple threads.
*/
#include <stdint.h>
#include <stdbool.h>
#include "sdk_errors.h"
#include "app_util_platform.h"
#ifdef __cplusplus
extern "C" {
#endif
/**@brief Invalid file ID.
*
* This value must not be used as a file ID by the application.
*/
#define FDS_FILE_ID_INVALID (0xFFFF)
/**@brief Record key for deleted records.
*
* This key is used to flag a record as "dirty", which means that it should be removed during
* the next garbage collection. This value must not be used as a record key by the application.
*/
#define FDS_RECORD_KEY_DIRTY (0x0000)
/**@brief FDS return values.
*/
enum
{
FDS_ERR_OPERATION_TIMEOUT = NRF_ERROR_FDS_ERR_BASE, //!< Error. The operation timed out.
FDS_ERR_NOT_INITIALIZED, //!< Error. The module has not been initialized.
FDS_ERR_UNALIGNED_ADDR, //!< Error. The input data is not aligned to a word boundary.
FDS_ERR_INVALID_ARG, //!< Error. The parameter contains invalid data.
FDS_ERR_NULL_ARG, //!< Error. The parameter is NULL.
FDS_ERR_NO_OPEN_RECORDS, //!< Error. The record is not open, so it cannot be closed.
FDS_ERR_NO_SPACE_IN_FLASH, //!< Error. There is no space in flash memory.
FDS_ERR_NO_SPACE_IN_QUEUES, //!< Error. There is no space in the internal queues.
FDS_ERR_RECORD_TOO_LARGE, //!< Error. The record exceeds the maximum allowed size.
FDS_ERR_NOT_FOUND, //!< Error. The record was not found.
FDS_ERR_NO_PAGES, //!< Error. No flash pages are available.
FDS_ERR_USER_LIMIT_REACHED, //!< Error. The maximum number of users has been reached.
FDS_ERR_CRC_CHECK_FAILED, //!< Error. The CRC check failed.
FDS_ERR_BUSY, //!< Error. The underlying flash subsystem was busy.
FDS_ERR_INTERNAL, //!< Error. An internal error occurred.
};
/**@brief The record metadata as stored in flash.
* @warning Do not edit or reorder the fields in this structure.
*/
typedef struct
{
uint16_t record_key; //!< The record key.
uint16_t length_words; //!< The length of the record data (in 4-byte words).
uint16_t file_id; //!< The ID of the file that the record belongs to.
uint16_t crc16; //!< CRC16-CCITT check value.
/* The CRC is calculated over the entire record as stored in flash,
* including the record metadata except the CRC field itself.
*/
uint32_t record_id; //!< The unique record ID (32 bits).
} fds_header_t;
/**@brief The record descriptor structure that is used to manipulate records.
*
* This structure is used by the FDS module. You must provide the descriptor to the module when
* you manipulate existing records. However, you should never modify it or use any of its fields.
*
* @note Never reuse the same descriptor for different records.
*/
typedef struct
{
uint32_t record_id; //!< The unique record ID.
uint32_t const * p_record; //!< The last known location of the record in flash.
uint16_t gc_run_count; //!< Number of times garbage collection has been run.
bool record_is_open; //!< Whether the record is currently open.
} fds_record_desc_t;
/**@brief Structure that can be used to read the contents of a record stored in flash.
*
* This structure does not reflect the physical layout of a record in flash, but it points
* to the locations where the record header (metadata) and the record data are stored.
*/
typedef struct
{
fds_header_t const * p_header; //!< Location of the record header in flash.
void const * p_data; //!< Location of the record data in flash.
} fds_flash_record_t;
/**@brief A record to be written to flash. */
typedef struct
{
uint16_t file_id; //!< The ID of the file that the record belongs to.
uint16_t key; //!< The record key.
struct
{
void const * p_data;
uint32_t length_words;
} data;
} fds_record_t;
/**@brief A token to a reserved space in flash, created by @ref fds_reserve.
*
* This token can be used to write the record in the reserved space (@ref fds_record_write_reserved)
* or to cancel the reservation (@ref fds_reserve_cancel).
*/
typedef struct
{
uint16_t page; //!< The logical ID of the page where space was reserved.
uint16_t length_words; //!< The amount of space reserved (in 4-byte words).
} fds_reserve_token_t;
/**@brief A token to keep information about the progress of @ref fds_record_find,
* @ref fds_record_find_by_key, and @ref fds_record_find_in_file.
*
* @note Always zero-initialize the token before using it for the first time.
* @note Never reuse the same token to search for different records.
*/
typedef struct
{
uint32_t const * p_addr;
uint16_t page;
} fds_find_token_t;
/**@brief FDS event IDs.
*/
typedef enum
{
FDS_EVT_INIT, //!< Event for @ref fds_init.
FDS_EVT_WRITE, //!< Event for @ref fds_record_write and @ref fds_record_write_reserved.
FDS_EVT_UPDATE, //!< Event for @ref fds_record_update.
FDS_EVT_DEL_RECORD, //!< Event for @ref fds_record_delete.
FDS_EVT_DEL_FILE, //!< Event for @ref fds_file_delete.
FDS_EVT_GC //!< Event for @ref fds_gc.
} fds_evt_id_t;
ANON_UNIONS_ENABLE;
/**@brief An FDS event. */
typedef struct
{
fds_evt_id_t id; //!< The event ID. See @ref fds_evt_id_t.
ret_code_t result; //!< The result of the operation related to this event.
union
{
struct
{
uint32_t record_id;
uint16_t file_id;
uint16_t record_key;
bool is_record_updated;
} write; //!< Information for @ref FDS_EVT_WRITE and @ref FDS_EVT_UPDATE events.
struct
{
uint32_t record_id;
uint16_t file_id;
uint16_t record_key;
} del; //!< Information for @ref FDS_EVT_DEL_RECORD and @ref FDS_EVT_DEL_FILE events.
};
} fds_evt_t;
ANON_UNIONS_DISABLE;
/**@brief File system statistics. */
typedef struct
{
uint16_t pages_available; //!< The number of pages available.
uint16_t open_records; //!< The number of open records.
uint16_t valid_records; //!< The number of valid records.
uint16_t dirty_records; //!< The number of deleted ("dirty") records.
uint16_t words_reserved; //!< The number of words reserved by @ref fds_reserve().
/**@brief The number of words written to flash, including those reserved for future writes. */
uint16_t words_used;
/**@brief The largest number of free contiguous words in the file system.
*
* This number indicates the largest record that can be stored by FDS.
* It takes into account all reservations for future writes.
*/
uint16_t largest_contig;
/**@brief The largest number of words that can be reclaimed by garbage collection.
*
* The actual amount of space freed by garbage collection might be less than this value if
* records are open while garbage collection is run.
*/
uint16_t freeable_words;
/**@brief Filesystem corruption has been detected.
*
* One or more corrupted records were detected. FDS will heal the filesystem automatically
* next time garbage collection is run, but some data may be lost.
*
* @note: This flag is unrelated to CRC failures.
*/
bool corruption;
} fds_stat_t;
/**@brief FDS event handler function prototype.
*
* @param p_evt The event.
*/
typedef void (*fds_cb_t)(fds_evt_t const * p_evt);
/**@brief Function for registering an FDS event handler.
*
* The maximum amount of handlers that can be registered can be configured by changing the value
* of @ref FDS_MAX_USERS in fds_config.h.
*
* @param[in] cb The event handler function.
*
* @retval NRF_SUCCESS If the event handler was registered successfully.
* @retval FDS_ERR_USER_LIMIT_REACHED If the maximum number of registered callbacks is reached.
*/
ret_code_t fds_register(fds_cb_t cb);
/**@brief Function for initializing the module.
*
* This function initializes the module and installs the file system (unless it is installed
* already).
*
* This function is asynchronous. Completion is reported through the @ref FDS_EVT_INIT event.
* Make sure to call @ref fds_register before calling @ref fds_init so that you receive
* @ref FDS_EVT_INIT.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NO_PAGES If there is no space available in flash memory to install the
* file system.
*/
ret_code_t fds_init(void);
/**@brief Function for writing a record to flash.
*
* There are no restrictions on the file ID and the record key, except that the record key must be
* different from @ref FDS_RECORD_KEY_DIRTY and the file ID must be different from
* @ref FDS_FILE_ID_INVALID. In particular, no restrictions are made regarding the uniqueness of
* the file ID or the record key. All records with the same file ID are grouped into one file.
* If no file with the specified ID exists, it is created. There can be multiple records with the
* same record key in a file.
*
* Some modules need exclusive use of certain file IDs and record keys.
* See @ref lib_fds_functionality_keys for details.
*
* Record data can consist of multiple chunks. The data must be aligned to a 4 byte boundary, and
* because it is not buffered internally, it must be kept in memory until the callback for the
* operation has been received. The length of the data must not exceed @ref FDS_VIRTUAL_PAGE_SIZE
* words minus 14 bytes.
*
* This function is asynchronous. Completion is reported through @ref FDS_EVT_WRITE event that is
* sent to the registered event handler function.
*
* @param[out] p_desc The descriptor of the record that was written. Pass NULL if you do not
* need the descriptor.
* @param[in] p_record The record to be written to flash. The record is required to be word
* aligned.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_record is NULL.
* @retval FDS_ERR_INVALID_ARG If the file ID or the record key is invalid.
* @retval FDS_ERR_UNALIGNED_ADDR If the record data is not aligned to a 4 byte boundary.
* @retval FDS_ERR_RECORD_TOO_LARGE If the record data exceeds the maximum length.
* @retval FDS_ERR_NO_SPACE_IN_QUEUES If the operation queue is full or there are more record
* chunks than can be buffered.
* @retval FDS_ERR_NO_SPACE_IN_FLASH If there is not enough free space in flash to store the
* record.
*/
ret_code_t fds_record_write(fds_record_desc_t * p_desc,
fds_record_t const * p_record);
/**@brief Function for reserving space in flash.
*
* This function can be used to reserve space in flash memory. To write a record into the reserved
* space, use @ref fds_record_write_reserved. Alternatively, use @ref fds_reserve_cancel to cancel
* a reservation.
*
* Note that this function does not write any data to flash.
*
* @param[out] p_token A token that can be used to write a record in the reserved space or
* cancel the reservation.
* @param[in] length_words The length of the record data (in 4-byte words).
*
* @retval NRF_SUCCESS If the flash space was reserved successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_token is NULL instead of a valid token address.
* @retval FDS_ERR_RECORD_TOO_LARGE If the record length exceeds the maximum length.
* @retval FDS_ERR_NO_SPACE_IN_FLASH If there is not enough free space in flash to store the
* record.
*/
ret_code_t fds_reserve(fds_reserve_token_t * p_token, uint16_t length_words);
/**@brief Function for canceling an @ref fds_reserve operation.
*
* @param[in] p_token The token that identifies the reservation, produced by @ref fds_reserve.
*
* @retval NRF_SUCCESS If the reservation was canceled.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_token is NULL instead of a valid token address.
* @retval FDS_ERR_INVALID_ARG If @p p_token contains invalid data.
*/
ret_code_t fds_reserve_cancel(fds_reserve_token_t * p_token);
/**@brief Function for writing a record to a space in flash that was reserved using
* @ref fds_reserve.
*
* There are no restrictions on the file ID and the record key, except that the record key must be
* different from @ref FDS_RECORD_KEY_DIRTY and the file ID must be different from
* @ref FDS_FILE_ID_INVALID. In particular, no restrictions are made regarding the uniqueness of
* the file ID or the record key. All records with the same file ID are grouped into one file.
* If no file with the specified ID exists, it is created. There can be multiple records with the
* same record key in a file.
*
* Record data can consist of multiple chunks. The data must be aligned to a 4 byte boundary, and
* because it is not buffered internally, it must be kept in memory until the callback for the
* operation has been received. The length of the data must not exceed @ref FDS_VIRTUAL_PAGE_SIZE
* words minus 14 bytes.
*
* This function is asynchronous. Completion is reported through an event that is sent to the
* registered event handler function.
*
* @note
* This function behaves similarly to @ref fds_record_write, with the exception that it never
* fails with the error @ref FDS_ERR_NO_SPACE_IN_FLASH.
*
* @param[out] p_desc The descriptor of the record that was written. Pass NULL if you do not
* need the descriptor.
* @param[in] p_record The record to be written to flash. The record is required
* to be word aligned.
* @param[in] p_token The token that identifies the space reserved in flash.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_token is NULL instead of a valid token address.
* @retval FDS_ERR_INVALID_ARG If the file ID or the record key is invalid.
* @retval FDS_ERR_UNALIGNED_ADDR If the record data is not aligned to a 4 byte boundary.
* @retval FDS_ERR_RECORD_TOO_LARGE If the record data exceeds the maximum length.
* @retval FDS_ERR_NO_SPACE_IN_QUEUES If the operation queue is full or there are more record
* chunks than can be buffered.
*/
ret_code_t fds_record_write_reserved(fds_record_desc_t * p_desc,
fds_record_t const * p_record,
fds_reserve_token_t const * p_token);
/**@brief Function for deleting a record.
*
* Deleted records cannot be located using @ref fds_record_find, @ref fds_record_find_by_key, or
* @ref fds_record_find_in_file. Additionally, they can no longer be opened using
* @ref fds_record_open.
*
* Note that deleting a record does not free the space it occupies in flash memory.
* To reclaim flash space used by deleted records, call @ref fds_gc to run garbage collection.
*
* This function is asynchronous. Completion is reported through the @ref FDS_EVT_DEL_RECORD event
* that is sent to the registered event handler function.
*
* @param[in] p_desc The descriptor of the record that should be deleted.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If the specified record descriptor @p p_desc is NULL.
* @retval FDS_ERR_NO_SPACE_IN_QUEUES If the operation queue is full.
*/
ret_code_t fds_record_delete(fds_record_desc_t * p_desc);
/**@brief Function for deleting all records in a file.
*
* This function deletes a file, including all its records. Deleted records cannot be located
* using @ref fds_record_find, @ref fds_record_find_by_key, or @ref fds_record_find_in_file.
* Additionally, they can no longer be opened using @ref fds_record_open.
*
* Note that deleting records does not free the space they occupy in flash memory.
* To reclaim flash space used by deleted records, call @ref fds_gc to run garbage collection.
*
* This function is asynchronous. Completion is reported through the @ref FDS_EVT_DEL_FILE event
* that is sent to the registered event handler function.
*
* @param[in] file_id The ID of the file to be deleted.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_INVALID_ARG If the specified @p file_id is invalid.
* @retval FDS_ERR_NO_SPACE_IN_QUEUES If the operation queue is full.
*/
ret_code_t fds_file_delete(uint16_t file_id);
/**@brief Function for updating a record.
*
* Updating a record first writes a new record (@p p_record) to flash and then deletes the
* old record (identified by @p p_desc).
*
* There are no restrictions on the file ID and the record key, except that the record key must be
* different from @ref FDS_RECORD_KEY_DIRTY and the file ID must be different from
* @ref FDS_FILE_ID_INVALID. In particular, no restrictions are made regarding the uniqueness of
* the file ID or the record key. All records with the same file ID are grouped into one file.
* If no file with the specified ID exists, it is created. There can be multiple records with the
* same record key in a file.
*
* Record data can consist of multiple chunks. The data must be aligned to a 4 byte boundary, and
* because it is not buffered internally, it must be kept in memory until the callback for the
* operation has been received. The length of the data must not exceed @ref FDS_VIRTUAL_PAGE_SIZE
* words minus 14 bytes.
*
* This function is asynchronous. Completion is reported through the @ref FDS_EVT_UPDATE event
* that is sent to the registered event handler function.
*
* @param[in, out] p_desc The descriptor of the record to update. When the function
* returns with NRF_SUCCESS, this parameter contains the
* descriptor of the newly written record.
* @param[in] p_record The updated record to be written to flash. The record is required
* to be word aligned.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_INVALID_ARG If the file ID or the record key is invalid.
* @retval FDS_ERR_UNALIGNED_ADDR If the record data is not aligned to a 4 byte boundary.
* @retval FDS_ERR_RECORD_TOO_LARGE If the record data exceeds the maximum length.
* @retval FDS_ERR_NO_SPACE_IN_QUEUES If the operation queue is full or there are more record
* chunks than can be buffered.
* @retval FDS_ERR_NO_SPACE_IN_FLASH If there is not enough free space in flash to store the
* updated record.
*/
ret_code_t fds_record_update(fds_record_desc_t * p_desc,
fds_record_t const * p_record);
/**@brief Function for iterating through all records in flash.
*
* To search for the next record, call the function again and supply the same @ref fds_find_token_t
* structure to resume searching from the last record that was found.
*
* Note that the order with which records are iterated is not defined.
*
* @param[out] p_desc The descriptor of the record that was found.
* @param[out] p_token A token containing information about the progress of the operation.
*
* @retval NRF_SUCCESS If a record was found.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_desc or @p p_token is NULL.
* @retval FDS_ERR_NOT_FOUND If no matching record was found.
*/
ret_code_t fds_record_iterate(fds_record_desc_t * p_desc,
fds_find_token_t * p_token);
/**@brief Function for searching for records with a given record key in a file.
*
* This function finds the first record in a file that has the given record key. To search for the
* next record with the same key in the file, call the function again and supply the same
* @ref fds_find_token_t structure to resume searching from the last record that was found.
*
* @param[in] file_id The file ID.
* @param[in] record_key The record key.
* @param[out] p_desc The descriptor of the record that was found.
* @param[out] p_token A token containing information about the progress of the operation.
*
* @retval NRF_SUCCESS If a record was found.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_desc or @p p_token is NULL.
* @retval FDS_ERR_NOT_FOUND If no matching record was found.
*/
ret_code_t fds_record_find(uint16_t file_id,
uint16_t record_key,
fds_record_desc_t * p_desc,
fds_find_token_t * p_token);
/**@brief Function for searching for records with a given record key.
*
* This function finds the first record with a given record key, independent of the file it
* belongs to. To search for the next record with the same key, call the function again and supply
* the same @ref fds_find_token_t structure to resume searching from the last record that was found.
*
* @param[in] record_key The record key.
* @param[out] p_desc The descriptor of the record that was found.
* @param[out] p_token A token containing information about the progress of the operation.
*
* @retval NRF_SUCCESS If a record was found.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_desc or @p p_token is NULL.
* @retval FDS_ERR_NOT_FOUND If no record with the given key was found.
*/
ret_code_t fds_record_find_by_key(uint16_t record_key,
fds_record_desc_t * p_desc,
fds_find_token_t * p_token);
/**@brief Function for searching for any record in a file.
*
* This function finds the first record in a file, independent of its record key.
* To search for the next record in the same file, call the function again and supply the same
* @ref fds_find_token_t structure to resume searching from the last record that was found.
*
* @param[in] file_id The file ID.
* @param[out] p_desc The descriptor of the record that was found.
* @param[out] p_token A token containing information about the progress of the operation.
*
* @retval NRF_SUCCESS If a record was found.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_desc or @p p_token is NULL.
* @retval FDS_ERR_NOT_FOUND If no matching record was found.
*/
ret_code_t fds_record_find_in_file(uint16_t file_id,
fds_record_desc_t * p_desc,
fds_find_token_t * p_token);
/**@brief Function for opening a record for reading.
*
* This function opens a record that is stored in flash, so that it can be read. The function
* initializes an @ref fds_flash_record_t structure, which can be used to access the record data as
* well as its associated metadata. The pointers provided in the @ref fds_flash_record_t structure
* are pointers to flash memory.
*
* Opening a record with @ref fds_record_open prevents garbage collection to run on the virtual
* flash page in which record is stored, so that the contents of the memory pointed by fields in
* @ref fds_flash_record_t are guaranteed to remain unmodified as long as the record is kept open.
*
* When you are done reading a record, call @ref fds_record_close to close it. Garbage collection
* can then reclaim space on the virtual page where the record is stored. Note that you must
* provide the same descriptor for @ref fds_record_close as you did for this function.
*
* @param[in] p_desc The descriptor of the record to open.
* @param[out] p_flash_record The record, as stored in flash.
*
* @retval NRF_SUCCESS If the record was opened successfully.
* @retval FDS_ERR_NULL_ARG If @p p_desc or @p p_flash_record is NULL.
* @retval FDS_ERR_NOT_FOUND If the record was not found. It might have been deleted, or
* it might not have been written yet.
* @retval FDS_ERR_CRC_CHECK_FAILED If the CRC check for the record failed.
*/
ret_code_t fds_record_open(fds_record_desc_t * p_desc,
fds_flash_record_t * p_flash_record);
/**@brief Function for closing a record.
*
* Closing a record allows garbage collection to run on the virtual page in which the record is
* stored (if no other records remain open on that page). The descriptor passed as an argument
* must be the same as the one used to open the record using @ref fds_record_open.
*
* Note that closing a record does not invalidate its descriptor. You can still supply the
* descriptor to all functions that accept a record descriptor as a parameter.
*
* @param[in] p_desc The descriptor of the record to close.
*
* @retval NRF_SUCCESS If the record was closed successfully.
* @retval FDS_ERR_NULL_ARG If @p p_desc is NULL.
* @retval FDS_ERR_NO_OPEN_RECORDS If the record is not open.
* @retval FDS_ERR_NOT_FOUND If the record could not be found.
*/
ret_code_t fds_record_close(fds_record_desc_t * p_desc);
/**@brief Function for running garbage collection.
*
* Garbage collection reclaims the flash space that is occupied by records that have been deleted,
* or that failed to be completely written due to, for example, a power loss.
*
* This function is asynchronous. Completion is reported through the @ref FDS_EVT_GC event that
* is sent to the registered event handler function.
*
* @retval NRF_SUCCESS If the operation was queued successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NO_SPACE_IN_QUEUES If the operation queue is full.
*/
ret_code_t fds_gc(void);
/**@brief Function for obtaining a descriptor from a record ID.
*
* This function can be used to reconstruct a descriptor from a record ID, like the one that is
* passed to the callback function.
*
* @note
* This function does not check whether a record with the given record ID exists.
* If a non-existing record ID is supplied, the resulting descriptor is invalid and will cause
* other functions to fail when it is supplied as parameter.
*
* @param[out] p_desc The descriptor of the record with the given record ID.
* @param[in] record_id The record ID for which a descriptor should be returned.
*
* @retval NRF_SUCCESS If a descriptor was returned.
* @retval FDS_ERR_NULL_ARG If @p p_desc is NULL.
*/
ret_code_t fds_descriptor_from_rec_id(fds_record_desc_t * p_desc,
uint32_t record_id);
/**@brief Function for obtaining a record ID from a record descriptor.
*
* This function can be used to extract a record ID from a descriptor. For example, you could use
* it in the callback function to compare the record ID of an event to the record IDs of the
* records for which you have a descriptor.
*
* @warning
* This function does not check whether the record descriptor is valid. If the descriptor is not
* initialized or has been tampered with, the resulting record ID might be invalid.
*
* @param[in] p_desc The descriptor from which the record ID should be extracted.
* @param[out] p_record_id The record ID that is contained in the given descriptor.
*
* @retval NRF_SUCCESS If a record ID was returned.
* @retval FDS_ERR_NULL_ARG If @p p_desc or @p p_record_id is NULL.
*/
ret_code_t fds_record_id_from_desc(fds_record_desc_t const * p_desc,
uint32_t * p_record_id);
/**@brief Function for retrieving file system statistics.
*
* This function retrieves file system statistics, such as the number of open records, the space
* that can be reclaimed by garbage collection, and others.
*
* @param[out] p_stat File system statistics.
*
* @retval NRF_SUCCESS If the statistics were returned successfully.
* @retval FDS_ERR_NOT_INITIALIZED If the module is not initialized.
* @retval FDS_ERR_NULL_ARG If @p p_stat is NULL.
*/
ret_code_t fds_stat(fds_stat_t * p_stat);
/** @} */
#ifdef __cplusplus
}
#endif
#endif // FDS_H__