/*
* Part of esp-open-rtos
* Copyright (C) 2016 Alex Stewart
* BSD Licensed as described in the file LICENSE
*/
#ifndef _SYSPARAM_H_
#define _SYSPARAM_H_
#include <esp/types.h>
#ifndef DEFAULT_SYSPARAM_SECTORS
#define DEFAULT_SYSPARAM_SECTORS 4
#endif
/** @file sysparam.h
*
* Read/write "system parameters" to persistent flash.
*
* System parameters are stored as key/value pairs. Keys are string values
* between 1 and 65535 characters long. Values can be any data up to 65535
* bytes in length (but are most commonly also text strings). Up to 126 key/
* value pairs can be stored at a time.
*
* Keys and values are stored in flash using a progressive list structure
* which allows space-efficient storage and minimizes flash erase cycles,
* improving write speed and increasing the lifespan of the flash memory.
*/
/** Status codes returned by all sysparam functions
*
* Error codes (`SYSPARAM_ERR_*`) all have values less than zero, and can be
* returned by any function. Values greater than zero are non-error status
* codes which may be returned by some functions to indicate various results.
*/
typedef enum {
SYSPARAM_OK = 0, ///< Success
SYSPARAM_NOTFOUND = 1, ///< Entry not found matching criteria
SYSPARAM_PARSEFAILED = 2, ///< Unable to parse retrieved value
SYSPARAM_ERR_NOINIT = -1, ///< sysparam_init() must be called first
SYSPARAM_ERR_BADVALUE = -2, ///< One or more arguments were invalid
SYSPARAM_ERR_FULL = -3, ///< No space left in sysparam area (or too many keys in use)
SYSPARAM_ERR_IO = -4, ///< I/O error reading/writing flash
SYSPARAM_ERR_CORRUPT = -5, ///< Sysparam region has bad/corrupted data
SYSPARAM_ERR_NOMEM = -6, ///< Unable to allocate memory
} sysparam_status_t;
/** Structure used by sysparam_iter_next() to keep track of its current state
* and return its results. This should be initialized by calling
* sysparam_iter_start() and cleaned up afterward by calling
* sysparam_iter_end().
*/
typedef struct {
char *key;
uint8_t *value;
size_t key_len;
size_t value_len;
bool binary;
size_t bufsize;
struct sysparam_context *ctx;
} sysparam_iter_t;
/** Initialize sysparam and set up the current area of flash to use.
*
* This must be called (and return successfully) before any other sysparam
* routines (except sysparam_create_area()) are called.
*
* This should normally be taken care of automatically on boot by the OS
* startup routines. It may be necessary to call it specially, however, if
* the normal initialization failed, or after calling sysparam_create_area()
* to reformat the current area.
*
* This routine will start at `base_addr` and scan all sectors up to
* `top_addr` looking for a valid sysparam area. If `top_addr` is zero (or
* equal to `base_addr`, then only the sector at `base_addr` will be checked.
*
* @param[in] base_addr The flash address to start looking for the start of
* the (already present) sysparam area
* @param[in] top_addr The flash address to stop looking for the sysparam
* area
*
* @retval ::SYSPARAM_OK Initialization successful.
* @retval ::SYSPARAM_NOTFOUND The specified address does not appear to
* contain a sysparam area. It may be
* necessary to call sysparam_create_area() to
* create one first.
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_init(uint32_t base_addr, uint32_t top_addr);
/** Create a new sysparam area in flash at the specified address.
*
* By default, this routine will scan the specified area to make sure it
* appears to be empty (i.e. all 0xFF bytes) before setting it up as a new
* sysparam area. If there appears to be other data already present, it will
* not overwrite it. Setting `force` to `true` will cause it to clobber any
* existing data instead.
*
* @param[in] base_addr The flash address at which it should start
* (must be a multiple of the sector size)
* @param[in] num_sectors The number of flash sectors to use for the sysparam
* area. This should be an even number >= 2. Note
* that the actual amount of useable parameter space
* will be roughly half this amount.
* @param[in] force Proceed even if the space does not appear to be empty
*
* @retval ::SYSPARAM_OK Area (re)created successfully.
* @retval ::SYSPARAM_NOTFOUND `force` was not specified, and the area at
* `base_addr` appears to have other data. No
* action taken.
* @retval ::SYSPARAM_ERR_BADVALUE The `num_sectors` value was not even (or
* was zero)
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*
* Note: This routine can create a sysparam area in another location than the
* one currently being used, but does not change which area is currently used
* (you will need to call sysparam_init() again if you want to do that). If
* you reformat the area currently being used, you will also need to call
* sysparam_init() again afterward before you will be able to continue using
* it.
*/
sysparam_status_t sysparam_create_area(uint32_t base_addr, uint16_t num_sectors, bool force);
/** Get the start address and size of the currently active sysparam area
*
* Fills in `base_addr` and `num_sectors` with the location and size of the
* currently active sysparam area. The returned values correspond to the
* arguments passed to the sysparam_create_area() call when the area was
* originally created.
*
* @param[out] base_addr The flash address at which the sysparam area starts
* @param[out] num_sectors The number of flash sectors used by the sysparam
* area
*
* @retval ::SYSPARAM_OK Completed successfully
* @retval ::SYSPARAM_ERR_NOINIT No current sysparam area is active
*/
sysparam_status_t sysparam_get_info(uint32_t *base_addr, uint32_t *num_sectors);
/** Compact the sysparam area.
*
* This also flattens the log.
*
* @retval ::SYSPARAM_OK Completed successfully
* @retval ::SYSPARAM_ERR_NOINIT No current sysparam area is active
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_compact();
/** Get the value associated with a key
*
* This is the core "get value" function. It will retrieve the value for the
* specified key in a freshly malloc()'d buffer and return it. Raw values can
* contain any data (including zero bytes), so the `actual_length` parameter
* should be used to determine the length of the data in the buffer.
*
* It is up to the caller to free() the returned buffer when done using it.
*
* Note: If the status result is anything other than ::SYSPARAM_OK, the value
* in `destptr` is not changed. This means it is possible to set a default
* value before calling this function which will be left as-is if a sysparam
* value could not be successfully read.
*
* @param[in] key Key name (zero-terminated string)
* @param[out] destptr Pointer to a location to hold the address of the
* returned data buffer
* @param[out] actual_length Pointer to a location to hold the length of the
* returned data buffer (may be NULL)
* @param[out] is_binary Pointer to a bool to hold whether the returned
* value is "binary" or not (may be NULL)
*
* @retval ::SYSPARAM_OK Value successfully retrieved.
* @retval ::SYSPARAM_NOTFOUND Key/value not found. No buffer returned.
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_get_data(const char *key, uint8_t **destptr, size_t *actual_length, bool *is_binary);
/** Get the value associated with a key (static value buffer)
*
* This performs the same function as sysparam_get_data() but without
* allocating memory for the result value. It can thus be used before the heap
* has been configured or in other cases where using the heap would be a
* problem (i.e. in an OOM handler, etc). It requires that the caller pass in
* a suitably sized buffer for the value to be read (if the supplied buffer is
* not large enough, the returned value will be truncated and the full required
* length will be returned in `actual_length`).
*
* @param[in] key Key name (zero-terminated string)
* @param[in] dest Pointer to a buffer to hold the returned value.
* @param[in] dest_size Length of the supplied buffer in bytes.
* @param[out] actual_length Pointer to a location to hold the actual length
* of the data which was associated with the key
* (may be NULL).
* @param[out] is_binary Pointer to a bool to hold whether the returned
* value is "binary" or not (may be NULL)
*
* @retval ::SYSPARAM_OK Value successfully retrieved
* @retval ::SYSPARAM_NOTFOUND Key/value not found
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_NOMEM The supplied buffer is too small
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_get_data_static(const char *key, uint8_t *dest, size_t dest_size, size_t *actual_length, bool *is_binary);
/** Get the string value associated with a key
*
* This routine can be used if you know that the value in a key will (or at
* least should) be a string. It will return a zero-terminated char buffer
* containing the value retrieved.
*
* It is up to the caller to free() the returned buffer when done using it.
*
* Note: If the status result is anything other than ::SYSPARAM_OK, the value
* in `destptr` is not changed. This means it is possible to set a default
* value before calling this function which will be left as-is if a sysparam
* value could not be successfully read.
*
* @param[in] key Key name (zero-terminated string)
* @param[out] destptr Pointer to a location to hold the address of the
* returned data buffer
*
* @retval ::SYSPARAM_OK Value successfully retrieved.
* @retval ::SYSPARAM_NOTFOUND Key/value not found.
* @retval ::SYSPARAM_PARSEFAILED The retrieved value was a binary value
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_get_string(const char *key, char **destptr);
/** Get the int32_t value associated with a key
*
* This routine can be used if you know that the value in a key will (or at
* least should) be an int32_t value. This is done without allocating any
* memory.
*
* Note: If the status result is anything other than ::SYSPARAM_OK, the value
* in `result` is not changed. This means it is possible to set a default
* value before calling this function which will be left as-is if a sysparam
* value could not be successfully read.
*
* @param[in] key Key name (zero-terminated string)
* @param[out] result Pointer to a location to hold returned integer value
*
* @retval ::SYSPARAM_OK Value successfully retrieved.
* @retval ::SYSPARAM_NOTFOUND Key/value not found.
* @retval ::SYSPARAM_PARSEFAILED The retrieved value could not be parsed as
* an integer.
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_get_int32(const char *key, int32_t *result);
/** Get the int8_t value associated with a key
*
* This routine can be used if you know that the value in a key will (or at
* least should) be a uint8_t binary value. This is done without allocating any
* memory.
*
* Note: If the status result is anything other than ::SYSPARAM_OK, the value
* in `result` is not changed. This means it is possible to set a default
* value before calling this function which will be left as-is if a sysparam
* value could not be successfully read.
*
* @param[in] key Key name (zero-terminated string)
* @param[out] result Pointer to a location to hold returned boolean value
*
* @retval ::SYSPARAM_OK Value successfully retrieved.
* @retval ::SYSPARAM_NOTFOUND Key/value not found.
* @retval ::SYSPARAM_PARSEFAILED The retrieved value could not be parsed as a
* boolean setting.
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_get_int8(const char *key, int8_t *result);
/** Get the boolean value associated with a key
*
* This routine can be used if you know that the value in a key will (or at
* least should) be a boolean setting. It will read the specified value as a
* text string and attempt to parse it as a boolean value.
*
* It will recognize the following (case-insensitive) strings:
* * True: "yes", "y", "true", "t", "1"
* * False: "no", "n", "false", "f", "0"
*
* Note: If the status result is anything other than ::SYSPARAM_OK, the value
* in `result` is not changed. This means it is possible to set a default
* value before calling this function which will be left as-is if a sysparam
* value could not be successfully read.
*
* @param[in] key Key name (zero-terminated string)
* @param[out] result Pointer to a location to hold returned boolean value
*
* @retval ::SYSPARAM_OK Value successfully retrieved.
* @retval ::SYSPARAM_NOTFOUND Key/value not found.
* @retval ::SYSPARAM_PARSEFAILED The retrieved value could not be parsed as a
* boolean setting.
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_get_bool(const char *key, bool *result);
/** Set the value associated with a key
*
* The supplied value can be any data, up to 255 bytes in length. If `value`
* is NULL or `value_len` is 0, this is treated as a request to delete any
* current entry matching `key`. This is done without allocating any memory.
*
* If `binary` is true, the data will be considered binary (unprintable) data,
* and this will be annotated in the saved entry. This does not affect the
* saving or loading process in any way, but may be used by some applications
* to (for example) print binary data differently than text entries when
* printing parameter values.
*
* @param[in] key Key name (zero-terminated string)
* @param[in] value Pointer to a buffer containing the value data
* @param[in] value_len Length of the data in the buffer
* @param[in] binary Whether the data should be considered "binary"
* (unprintable) data
*
* @retval ::SYSPARAM_OK Value successfully set.
* @retval ::SYSPARAM_ERR_NOINIT sysparam_init() must be called first
* @retval ::SYSPARAM_ERR_BADVALUE Either an empty key was provided or
* value_len is too large
* @retval ::SYSPARAM_ERR_FULL No space left in sysparam area
* (or too many keys in use)
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_set_data(const char *key, const uint8_t *value, size_t value_len, bool binary);
/** Set a key's value from a string
*
* Performs the same function as sysparam_set_data(), but accepts a
* zero-terminated string value instead.
*
* @param[in] key Key name (zero-terminated string)
* @param[in] value Value to set (zero-terminated string)
*
* @retval ::SYSPARAM_OK Value successfully set.
* @retval ::SYSPARAM_ERR_BADVALUE Either an empty key was provided or the
* length of `value` is too large
* @retval ::SYSPARAM_ERR_FULL No space left in sysparam area
* (or too many keys in use)
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_set_string(const char *key, const char *value);
/** Set a key's value as a number
*
* Write an int32_t binary value to the specified key. This does the inverse of
* the sysparam_get_int32() function. This is done without allocating any
* memory.
*
* @param[in] key Key name (zero-terminated string)
* @param[in] value Value to set
*
* @retval ::SYSPARAM_OK Value successfully set.
* @retval ::SYSPARAM_ERR_BADVALUE An empty key was provided.
* @retval ::SYSPARAM_ERR_FULL No space left in sysparam area
* (or too many keys in use)
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_set_int32(const char *key, int32_t value);
/** Set a key's value as a number
*
* Write an int8_t binary value to the specified key. This does the inverse of
* the sysparam_get_int8() function. This is done without allocating any
* memory.
*
* @param[in] key Key name (zero-terminated string)
* @param[in] value Value to set
*
* @retval ::SYSPARAM_OK Value successfully set.
* @retval ::SYSPARAM_ERR_BADVALUE An empty key was provided.
* @retval ::SYSPARAM_ERR_FULL No space left in sysparam area
* (or too many keys in use)
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_set_int8(const char *key, int8_t value);
/** Set a key's value as a boolean (yes/no) string
*
* Converts a bool value to a corresponding text string and writes it to the
* specified key. This does the inverse of the sysparam_get_bool()
* function.
*
* @param[in] key Key name (zero-terminated string)
* @param[in] value Value to set
*
* @retval ::SYSPARAM_OK Value successfully set.
* @retval ::SYSPARAM_ERR_BADVALUE An empty key was provided.
* @retval ::SYSPARAM_ERR_FULL No space left in sysparam area
* (or too many keys in use)
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_set_bool(const char *key, bool value);
/** Begin iterating through all key/value pairs
*
* This function initializes a sysparam_iter_t structure to prepare it for
* iterating through the list of key/value pairs using sysparam_iter_next().
* This does not fetch any items (the first successive call to
* sysparam_iter_next() will return the first key/value in the list).
*
* NOTE: When done, you must call sysparam_iter_end() to free the resources
* associated with `iter`, or you will leak memory.
*
* @param[in] iter A pointer to a sysparam_iter_t structure to initialize
*
* @retval ::SYSPARAM_OK Initialization successful
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
*/
sysparam_status_t sysparam_iter_start(sysparam_iter_t *iter);
/** Fetch the next key/value pair
*
* This will retrieve the next key and value from the sysparam area, placing
* them in `iter->key`, and `iter->value` (and updating `iter->key_len` and
* `iter->value_len`).
*
* NOTE: `iter->key` and `iter->value` are static buffers local to the `iter`
* structure, and will be overwritten with the next call to
* sysparam_iter_next() using the same `iter`. They should *not* be free()d
* after use.
*
* @param[in] iter The iterator structure to update
*
* @retval ::SYSPARAM_OK Next key/value retrieved
* @retval ::SYSPARAM_ERR_NOMEM Unable to allocate memory
* @retval ::SYSPARAM_ERR_CORRUPT Sysparam region has bad/corrupted data
* @retval ::SYSPARAM_ERR_IO I/O error reading/writing flash
*/
sysparam_status_t sysparam_iter_next(sysparam_iter_t *iter);
/** Finish iterating through keys/values
*
* Cleans up and releases resources allocated by sysparam_iter_start() /
* sysparam_iter_next().
*/
void sysparam_iter_end(sysparam_iter_t *iter);
#endif /* _SYSPARAM_H_ */