// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// 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.
#ifndef ESP_NVS_H
#define ESP_NVS_H
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include "esp_err.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* Opaque pointer type representing non-volatile storage handle
*/
typedef uint32_t nvs_handle;
#define ESP_ERR_NVS_BASE 0x1100 /*!< Starting number of error codes */
#define ESP_ERR_NVS_NOT_INITIALIZED (ESP_ERR_NVS_BASE + 0x01) /*!< The storage driver is not initialized */
#define ESP_ERR_NVS_NOT_FOUND (ESP_ERR_NVS_BASE + 0x02) /*!< Id namespace doesn’t exist yet and mode is NVS_READONLY */
#define ESP_ERR_NVS_TYPE_MISMATCH (ESP_ERR_NVS_BASE + 0x03) /*!< The type of set or get operation doesn't match the type of value stored in NVS */
#define ESP_ERR_NVS_READ_ONLY (ESP_ERR_NVS_BASE + 0x04) /*!< Storage handle was opened as read only */
#define ESP_ERR_NVS_NOT_ENOUGH_SPACE (ESP_ERR_NVS_BASE + 0x05) /*!< There is not enough space in the underlying storage to save the value */
#define ESP_ERR_NVS_INVALID_NAME (ESP_ERR_NVS_BASE + 0x06) /*!< Namespace name doesn’t satisfy constraints */
#define ESP_ERR_NVS_INVALID_HANDLE (ESP_ERR_NVS_BASE + 0x07) /*!< Handle has been closed or is NULL */
#define ESP_ERR_NVS_REMOVE_FAILED (ESP_ERR_NVS_BASE + 0x08) /*!< The value wasn’t updated because flash write operation has failed. The value was written however, and update will be finished after re-initialization of nvs, provided that flash operation doesn’t fail again. */
#define ESP_ERR_NVS_KEY_TOO_LONG (ESP_ERR_NVS_BASE + 0x09) /*!< Key name is too long */
#define ESP_ERR_NVS_PAGE_FULL (ESP_ERR_NVS_BASE + 0x0a) /*!< Internal error; never returned by nvs_ API functions */
#define ESP_ERR_NVS_INVALID_STATE (ESP_ERR_NVS_BASE + 0x0b) /*!< NVS is in an inconsistent state due to a previous error. Call nvs_flash_init and nvs_open again, then retry. */
#define ESP_ERR_NVS_INVALID_LENGTH (ESP_ERR_NVS_BASE + 0x0c) /*!< String or blob length is not sufficient to store data */
#define ESP_ERR_NVS_NO_FREE_PAGES (ESP_ERR_NVS_BASE + 0x0d) /*!< NVS partition doesn't contain any empty pages. This may happen if NVS partition was truncated. Erase the whole partition and call nvs_flash_init again. */
#define ESP_ERR_NVS_VALUE_TOO_LONG (ESP_ERR_NVS_BASE + 0x0e) /*!< String or blob length is longer than supported by the implementation */
#define ESP_ERR_NVS_PART_NOT_FOUND (ESP_ERR_NVS_BASE + 0x0f) /*!< Partition with specified name is not found in the partition table */
#define NVS_DEFAULT_PART_NAME "nvs" /*!< Default partition name of the NVS partition in the partition table */
/**
* @brief Mode of opening the non-volatile storage
*
*/
typedef enum {
NVS_READONLY, /*!< Read only */
NVS_READWRITE /*!< Read and write */
} nvs_open_mode;
/**
* @brief Open non-volatile storage with a given namespace from the default NVS partition
*
* Multiple internal ESP-IDF and third party application modules can store
* their key-value pairs in the NVS module. In order to reduce possible
* conflicts on key names, each module can use its own namespace.
* The default NVS partition is the one that is labelled "nvs" in the partition
* table.
*
* @param[in] name Namespace name. Maximal length is determined by the
* underlying implementation, but is guaranteed to be
* at least 15 characters. Shouldn't be empty.
* @param[in] open_mode NVS_READWRITE or NVS_READONLY. If NVS_READONLY, will
* open a handle for reading only. All write requests will
* be rejected for this handle.
* @param[out] out_handle If successful (return code is zero), handle will be
* returned in this argument.
*
* @return
* - ESP_OK if storage handle was opened successfully
* - ESP_ERR_NVS_NOT_INITIALIZED if the storage driver is not initialized
* - ESP_ERR_NVS_PART_NOT_FOUND if the partition with label "nvs" is not found
* - ESP_ERR_NVS_NOT_FOUND id namespace doesn't exist yet and
* mode is NVS_READONLY
* - ESP_ERR_NVS_INVALID_NAME if namespace name doesn't satisfy constraints
* - other error codes from the underlying storage driver
*/
esp_err_t nvs_open(const char* name, nvs_open_mode open_mode, nvs_handle *out_handle);
/**
* @brief Open non-volatile storage with a given namespace from specified partition
*
* The behaviour is same as nvs_open() API. However this API can operate on a specified NVS
* partition instead of default NVS partition. Note that the specified partition must be registered
* with NVS using nvs_flash_init_partition() API.
*
* @param[in] part_name Label (name) of the partition of interest for object read/write/erase
* @param[in] name Namespace name. Maximal length is determined by the
* underlying implementation, but is guaranteed to be
* at least 15 characters. Shouldn't be empty.
* @param[in] open_mode NVS_READWRITE or NVS_READONLY. If NVS_READONLY, will
* open a handle for reading only. All write requests will
* be rejected for this handle.
* @param[out] out_handle If successful (return code is zero), handle will be
* returned in this argument.
*
* @return
* - ESP_OK if storage handle was opened successfully
* - ESP_ERR_NVS_NOT_INITIALIZED if the storage driver is not initialized
* - ESP_ERR_NVS_PART_NOT_FOUND if the partition with specified name is not found
* - ESP_ERR_NVS_NOT_FOUND id namespace doesn't exist yet and
* mode is NVS_READONLY
* - ESP_ERR_NVS_INVALID_NAME if namespace name doesn't satisfy constraints
* - other error codes from the underlying storage driver
*/
esp_err_t nvs_open_from_partition(const char *part_name, const char* name, nvs_open_mode open_mode, nvs_handle *out_handle);
/**@{*/
/**
* @brief set value for given key
*
* This family of functions set value for the key, given its name. Note that
* actual storage will not be updated until nvs_commit function is called.
*
* @param[in] handle Handle obtained from nvs_open function.
* Handles that were opened read only cannot be used.
* @param[in] key Key name. Maximal length is determined by the underlying
* implementation, but is guaranteed to be at least
* 15 characters. Shouldn't be empty.
* @param[in] value The value to set.
* For strings, the maximum length (including null character) is
* 1984 bytes.
*
* @return
* - ESP_OK if value was set successfully
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - ESP_ERR_NVS_READ_ONLY if storage handle was opened as read only
* - ESP_ERR_NVS_INVALID_NAME if key name doesn't satisfy constraints
* - ESP_ERR_NVS_NOT_ENOUGH_SPACE if there is not enough space in the
* underlying storage to save the value
* - ESP_ERR_NVS_REMOVE_FAILED if the value wasn't updated because flash
* write operation has failed. The value was written however, and
* update will be finished after re-initialization of nvs, provided that
* flash operation doesn't fail again.
* - ESP_ERR_NVS_VALUE_TOO_LONG if the string value is too long
*/
esp_err_t nvs_set_i8 (nvs_handle handle, const char* key, int8_t value);
esp_err_t nvs_set_u8 (nvs_handle handle, const char* key, uint8_t value);
esp_err_t nvs_set_i16 (nvs_handle handle, const char* key, int16_t value);
esp_err_t nvs_set_u16 (nvs_handle handle, const char* key, uint16_t value);
esp_err_t nvs_set_i32 (nvs_handle handle, const char* key, int32_t value);
esp_err_t nvs_set_u32 (nvs_handle handle, const char* key, uint32_t value);
esp_err_t nvs_set_i64 (nvs_handle handle, const char* key, int64_t value);
esp_err_t nvs_set_u64 (nvs_handle handle, const char* key, uint64_t value);
esp_err_t nvs_set_str (nvs_handle handle, const char* key, const char* value);
/**@}*/
/**
* @brief set variable length binary value for given key
*
* This family of functions set value for the key, given its name. Note that
* actual storage will not be updated until nvs_commit function is called.
*
* @param[in] handle Handle obtained from nvs_open function.
* Handles that were opened read only cannot be used.
* @param[in] key Key name. Maximal length is 15 characters. Shouldn't be empty.
* @param[in] value The value to set.
* @param[in] length length of binary value to set, in bytes; Maximum length is
* 1984 bytes.
*
* @return
* - ESP_OK if value was set successfully
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - ESP_ERR_NVS_READ_ONLY if storage handle was opened as read only
* - ESP_ERR_NVS_INVALID_NAME if key name doesn't satisfy constraints
* - ESP_ERR_NVS_NOT_ENOUGH_SPACE if there is not enough space in the
* underlying storage to save the value
* - ESP_ERR_NVS_REMOVE_FAILED if the value wasn't updated because flash
* write operation has failed. The value was written however, and
* update will be finished after re-initialization of nvs, provided that
* flash operation doesn't fail again.
* - ESP_ERR_NVS_VALUE_TOO_LONG if the value is too long
*/
esp_err_t nvs_set_blob(nvs_handle handle, const char* key, const void* value, size_t length);
/**@{*/
/**
* @brief get value for given key
*
* These functions retrieve value for the key, given its name. If key does not
* exist, or the requested variable type doesn't match the type which was used
* when setting a value, an error is returned.
*
* In case of any error, out_value is not modified.
*
* All functions expect out_value to be a pointer to an already allocated variable
* of the given type.
*
* \code{c}
* // Example of using nvs_get_i32:
* int32_t max_buffer_size = 4096; // default value
* esp_err_t err = nvs_get_i32(my_handle, "max_buffer_size", &max_buffer_size);
* assert(err == ESP_OK || err == ESP_ERR_NVS_NOT_FOUND);
* // if ESP_ERR_NVS_NOT_FOUND was returned, max_buffer_size will still
* // have its default value.
*
* \endcode
*
* @param[in] handle Handle obtained from nvs_open function.
* @param[in] key Key name. Maximal length is determined by the underlying
* implementation, but is guaranteed to be at least
* 15 characters. Shouldn't be empty.
* @param out_value Pointer to the output value.
* May be NULL for nvs_get_str and nvs_get_blob, in this
* case required length will be returned in length argument.
*
* @return
* - ESP_OK if the value was retrieved successfully
* - ESP_ERR_NVS_NOT_FOUND if the requested key doesn't exist
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - ESP_ERR_NVS_INVALID_NAME if key name doesn't satisfy constraints
* - ESP_ERR_NVS_INVALID_LENGTH if length is not sufficient to store data
*/
esp_err_t nvs_get_i8 (nvs_handle handle, const char* key, int8_t* out_value);
esp_err_t nvs_get_u8 (nvs_handle handle, const char* key, uint8_t* out_value);
esp_err_t nvs_get_i16 (nvs_handle handle, const char* key, int16_t* out_value);
esp_err_t nvs_get_u16 (nvs_handle handle, const char* key, uint16_t* out_value);
esp_err_t nvs_get_i32 (nvs_handle handle, const char* key, int32_t* out_value);
esp_err_t nvs_get_u32 (nvs_handle handle, const char* key, uint32_t* out_value);
esp_err_t nvs_get_i64 (nvs_handle handle, const char* key, int64_t* out_value);
esp_err_t nvs_get_u64 (nvs_handle handle, const char* key, uint64_t* out_value);
/**@}*/
/**
* @brief get value for given key
*
* These functions retrieve value for the key, given its name. If key does not
* exist, or the requested variable type doesn't match the type which was used
* when setting a value, an error is returned.
*
* In case of any error, out_value is not modified.
*
* All functions expect out_value to be a pointer to an already allocated variable
* of the given type.
*
* nvs_get_str and nvs_get_blob functions support WinAPI-style length queries.
* To get the size necessary to store the value, call nvs_get_str or nvs_get_blob
* with zero out_value and non-zero pointer to length. Variable pointed to
* by length argument will be set to the required length. For nvs_get_str,
* this length includes the zero terminator. When calling nvs_get_str and
* nvs_get_blob with non-zero out_value, length has to be non-zero and has to
* point to the length available in out_value.
* It is suggested that nvs_get/set_str is used for zero-terminated C strings, and
* nvs_get/set_blob used for arbitrary data structures.
*
* \code{c}
* // Example (without error checking) of using nvs_get_str to get a string into dynamic array:
* size_t required_size;
* nvs_get_str(my_handle, "server_name", NULL, &required_size);
* char* server_name = malloc(required_size);
* nvs_get_str(my_handle, "server_name", server_name, &required_size);
*
* // Example (without error checking) of using nvs_get_blob to get a binary data
* into a static array:
* uint8_t mac_addr[6];
* size_t size = sizeof(mac_addr);
* nvs_get_blob(my_handle, "dst_mac_addr", mac_addr, &size);
* \endcode
*
* @param[in] handle Handle obtained from nvs_open function.
* @param[in] key Key name. Maximal length is determined by the underlying
* implementation, but is guaranteed to be at least
* 15 characters. Shouldn't be empty.
* @param out_value Pointer to the output value.
* May be NULL for nvs_get_str and nvs_get_blob, in this
* case required length will be returned in length argument.
* @param[inout] length A non-zero pointer to the variable holding the length of out_value.
* In case out_value a zero, will be set to the length
* required to hold the value. In case out_value is not
* zero, will be set to the actual length of the value
* written. For nvs_get_str this includes zero terminator.
*
* @return
* - ESP_OK if the value was retrieved successfully
* - ESP_ERR_NVS_NOT_FOUND if the requested key doesn't exist
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - ESP_ERR_NVS_INVALID_NAME if key name doesn't satisfy constraints
* - ESP_ERR_NVS_INVALID_LENGTH if length is not sufficient to store data
*/
/**@{*/
esp_err_t nvs_get_str (nvs_handle handle, const char* key, char* out_value, size_t* length);
esp_err_t nvs_get_blob(nvs_handle handle, const char* key, void* out_value, size_t* length);
/**@}*/
/**
* @brief Erase key-value pair with given key name.
*
* Note that actual storage may not be updated until nvs_commit function is called.
*
* @param[in] handle Storage handle obtained with nvs_open.
* Handles that were opened read only cannot be used.
*
* @param[in] key Key name. Maximal length is determined by the underlying
* implementation, but is guaranteed to be at least
* 15 characters. Shouldn't be empty.
*
* @return
* - ESP_OK if erase operation was successful
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - ESP_ERR_NVS_READ_ONLY if handle was opened as read only
* - ESP_ERR_NVS_NOT_FOUND if the requested key doesn't exist
* - other error codes from the underlying storage driver
*/
esp_err_t nvs_erase_key(nvs_handle handle, const char* key);
/**
* @brief Erase all key-value pairs in a namespace
*
* Note that actual storage may not be updated until nvs_commit function is called.
*
* @param[in] handle Storage handle obtained with nvs_open.
* Handles that were opened read only cannot be used.
*
* @return
* - ESP_OK if erase operation was successful
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - ESP_ERR_NVS_READ_ONLY if handle was opened as read only
* - other error codes from the underlying storage driver
*/
esp_err_t nvs_erase_all(nvs_handle handle);
/**
* @brief Write any pending changes to non-volatile storage
*
* After setting any values, nvs_commit() must be called to ensure changes are written
* to non-volatile storage. Individual implementations may write to storage at other times,
* but this is not guaranteed.
*
* @param[in] handle Storage handle obtained with nvs_open.
* Handles that were opened read only cannot be used.
*
* @return
* - ESP_OK if the changes have been written successfully
* - ESP_ERR_NVS_INVALID_HANDLE if handle has been closed or is NULL
* - other error codes from the underlying storage driver
*/
esp_err_t nvs_commit(nvs_handle handle);
/**
* @brief Close the storage handle and free any allocated resources
*
* This function should be called for each handle opened with nvs_open once
* the handle is not in use any more. Closing the handle may not automatically
* write the changes to nonvolatile storage. This has to be done explicitly using
* nvs_commit function.
* Once this function is called on a handle, the handle should no longer be used.
*
* @param[in] handle Storage handle to close
*/
void nvs_close(nvs_handle handle);
#ifdef __cplusplus
} // extern "C"
#endif
#endif //ESP_NVS_H