278 lines
12 KiB
C++
278 lines
12 KiB
C++
#ifndef NVS_HANDLE_HPP_
|
|
#define NVS_HANDLE_HPP_
|
|
|
|
#include <string>
|
|
#include <memory>
|
|
#include <type_traits>
|
|
|
|
#include "nvs.h"
|
|
|
|
namespace nvs {
|
|
|
|
/**
|
|
* The possible blob types. This is a helper definition for template functions.
|
|
*/
|
|
enum class ItemType : uint8_t {
|
|
U8 = NVS_TYPE_U8,
|
|
I8 = NVS_TYPE_I8,
|
|
U16 = NVS_TYPE_U16,
|
|
I16 = NVS_TYPE_I16,
|
|
U32 = NVS_TYPE_U32,
|
|
I32 = NVS_TYPE_I32,
|
|
U64 = NVS_TYPE_U64,
|
|
I64 = NVS_TYPE_I64,
|
|
SZ = NVS_TYPE_STR,
|
|
BLOB = 0x41,
|
|
BLOB_DATA = NVS_TYPE_BLOB,
|
|
BLOB_IDX = 0x48,
|
|
ANY = NVS_TYPE_ANY
|
|
};
|
|
|
|
|
|
/**
|
|
* @brief A handle allowing nvs-entry related operations on the NVS.
|
|
*
|
|
* @note The scope of this handle may vary depending on the implementation, but normally would be the namespace of
|
|
* a particular partition. Outside that scope, nvs entries can't be accessed/altered.
|
|
*/
|
|
class NVSHandle {
|
|
public:
|
|
virtual ~NVSHandle() { }
|
|
|
|
/**
|
|
* @brief set value for given key
|
|
*
|
|
* Sets value for key. Note that physical storage will not be updated until nvs_commit function is called.
|
|
*
|
|
* @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. Allowed types are the ones declared in ItemType as well as enums.
|
|
* For strings, the maximum length (including null character) is
|
|
* 4000 bytes.
|
|
* Note that enums loose their type information when stored in NVS. Ensure that the correct
|
|
* enum type is used during retrieval with \ref get_item!
|
|
*
|
|
* @return
|
|
* - ESP_OK if value was set successfully
|
|
* - 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
|
|
*/
|
|
template<typename T>
|
|
esp_err_t set_item(const char *key, T value);
|
|
virtual
|
|
esp_err_t set_string(const char *key, const char* value) = 0;
|
|
|
|
/**
|
|
* @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.
|
|
*
|
|
* @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 value The output value. All integral types which are declared in ItemType as well as enums
|
|
* are allowed. Note however that enums lost their type information when stored in NVS.
|
|
* Ensure that the correct enum type is used during retrieval with \ref get_item!
|
|
*
|
|
* @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_NAME if key name doesn't satisfy constraints
|
|
* - ESP_ERR_NVS_INVALID_LENGTH if length is not sufficient to store data
|
|
*/
|
|
template<typename T>
|
|
esp_err_t get_item(const char *key, T &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] key Key name. Maximal length is 15 characters. Shouldn't be empty.
|
|
* @param[in] blob The blob value to set.
|
|
* @param[in] len length of binary value to set, in bytes; Maximum length is
|
|
* 508000 bytes or (97.6% of the partition size - 4000) bytes
|
|
* whichever is lower.
|
|
*
|
|
* @return
|
|
* - ESP_OK if value was set successfully
|
|
* - 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
|
|
*
|
|
* @note compare to \ref nvs_set_blob in nvs.h
|
|
*/
|
|
virtual esp_err_t set_blob(const char *key, const void* blob, size_t len) = 0;
|
|
|
|
/**
|
|
* @brief get value for given key
|
|
*
|
|
* These functions retrieve the data of an entry, given its key. 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.
|
|
*
|
|
* Both functions expect out_value to be a pointer to an already allocated variable
|
|
* of the given type.
|
|
*
|
|
* 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.
|
|
*
|
|
* @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_str/ Pointer to the output value.
|
|
* out_blob
|
|
* @param[inout] length A non-zero pointer to the variable holding the length of out_value.
|
|
* It will be set to the actual length of the value
|
|
* written. For nvs_get_str this includes the 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_NAME if key name doesn't satisfy constraints
|
|
* - ESP_ERR_NVS_INVALID_LENGTH if length is not sufficient to store data
|
|
*/
|
|
virtual esp_err_t get_string(const char *key, char* out_str, size_t len) = 0;
|
|
virtual esp_err_t get_blob(const char *key, void* out_blob, size_t len) = 0;
|
|
|
|
/**
|
|
* @brief Looks up the size of an entry's data.
|
|
*
|
|
* For strings, this size includes the zero terminator.
|
|
*/
|
|
virtual esp_err_t get_item_size(ItemType datatype, const char *key, size_t &size) = 0;
|
|
|
|
/**
|
|
* @brief Erases an entry.
|
|
*/
|
|
virtual esp_err_t erase_item(const char* key) = 0;
|
|
|
|
/**
|
|
* Erases all entries in the scope of this handle. The scope may vary, depending on the implementation.
|
|
*
|
|
* @not If you want to erase the whole nvs flash (partition), refer to \ref
|
|
*/
|
|
virtual esp_err_t erase_all() = 0;
|
|
|
|
/**
|
|
* Commits all changes done through this handle so far.
|
|
*/
|
|
virtual esp_err_t commit() = 0;
|
|
|
|
/**
|
|
* @brief Calculate all entries in the scope of the handle.
|
|
*
|
|
* @param[out] used_entries Returns amount of used entries from a namespace on success.
|
|
*
|
|
*
|
|
* @return
|
|
* - ESP_OK if the changes have been written successfully.
|
|
* Return param used_entries will be filled valid value.
|
|
* - ESP_ERR_NVS_NOT_INITIALIZED if the storage driver is not initialized.
|
|
* Return param used_entries will be filled 0.
|
|
* - ESP_ERR_INVALID_ARG if nvs_stats equal to NULL.
|
|
* - Other error codes from the underlying storage driver.
|
|
* Return param used_entries will be filled 0.
|
|
*/
|
|
virtual esp_err_t get_used_entry_count(size_t& usedEntries) = 0;
|
|
|
|
protected:
|
|
virtual esp_err_t set_typed_item(ItemType datatype, const char *key, const void* data, size_t dataSize) = 0;
|
|
|
|
virtual esp_err_t get_typed_item(ItemType datatype, const char *key, void* data, size_t dataSize) = 0;
|
|
};
|
|
|
|
/**
|
|
* @brief Opens non-volatile storage and returns a handle object.
|
|
*
|
|
* The handle is automatically closed on desctruction. The scope of the handle is the namespace ns_name
|
|
* in a particular partition partition_name.
|
|
* The parameters partition_name, ns_name and open_mode have the same meaning and restrictions as the parameters
|
|
* part_name, name and open_mode in \ref nvs_open_from_partition, respectively.
|
|
*
|
|
* @param err an optional pointer to an esp_err_t result of the open operation, having the same meaning as the return
|
|
* value in \ref nvs_open_from_partition:
|
|
* - 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
|
|
*
|
|
* @return shared pointer of an nvs handle on success, an empty shared pointer otherwise
|
|
*/
|
|
std::unique_ptr<NVSHandle> open_nvs_handle_from_partition(const char *partition_name,
|
|
const char *ns_name,
|
|
nvs_open_mode_t open_mode,
|
|
esp_err_t *err = nullptr);
|
|
|
|
/**
|
|
* @brief This function does the same as \ref open_nvs_handle_from_partition but uses the default nvs partition
|
|
* instead of a partition_name parameter.
|
|
*/
|
|
std::unique_ptr<NVSHandle> open_nvs_handle(const char *ns_name,
|
|
nvs_open_mode_t open_mode,
|
|
esp_err_t *err = nullptr);
|
|
|
|
// Helper functions for template usage
|
|
/**
|
|
* Help to translate all integral types into ItemType.
|
|
*/
|
|
template<typename T, typename std::enable_if<std::is_integral<T>::value, void*>::type = nullptr>
|
|
constexpr ItemType itemTypeOf()
|
|
{
|
|
return static_cast<ItemType>(((std::is_signed<T>::value)?0x10:0x00) | sizeof(T));
|
|
}
|
|
|
|
/**
|
|
* Help to translate all enum types into integral ItemType.
|
|
*/
|
|
template<typename T, typename std::enable_if<std::is_enum<T>::value, int>::type = 0>
|
|
constexpr ItemType itemTypeOf()
|
|
{
|
|
return static_cast<ItemType>(((std::is_signed<T>::value)?0x10:0x00) | sizeof(T));
|
|
}
|
|
|
|
template<typename T>
|
|
constexpr ItemType itemTypeOf(const T&)
|
|
{
|
|
return itemTypeOf<T>();
|
|
}
|
|
|
|
// Template Implementations
|
|
template<typename T>
|
|
esp_err_t NVSHandle::set_item(const char *key, T value) {
|
|
return set_typed_item(itemTypeOf(value), key, &value, sizeof(value));
|
|
}
|
|
|
|
template<typename T>
|
|
esp_err_t NVSHandle::get_item(const char *key, T &value) {
|
|
return get_typed_item(itemTypeOf(value), key, &value, sizeof(value));
|
|
}
|
|
|
|
} // nvs
|
|
|
|
#endif // NVS_HANDLE_HPP_
|
|
|