/** * Copyright (c) 2015 - 2019, 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 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #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 #include #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_SUCCESS = NRF_SUCCESS, //!< The operation completed successfully. FDS_ERR_OPERATION_TIMEOUT, //!< 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 FDS_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 an event. Make sure to call * @ref fds_register before calling @ref fds_init so that you receive the completion event. * * @retval FDS_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 an 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 FDS_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 FDS_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 FDS_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 FDS_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 an event that is sent to the * registered event handler function. * * @param[in] p_desc The descriptor of the record that should be deleted. * * @retval FDS_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 an event that is sent to the * registered event handler function. * * @param[in] file_id The ID of the file to be deleted. * * @retval FDS_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 an 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 FDS_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 FDS_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 FDS_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 FDS_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 FDS_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 FDS_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 FDS_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 FDS_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 an event that is sent to the * registered event handler function. * * @retval FDS_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 FDS_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 FDS_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 FDS_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__