From 2e8f578aafe9c9131542b777643dc88929da6cac Mon Sep 17 00:00:00 2001 From: "radek.tandler" Date: Thu, 6 Aug 2026 11:48:14 +0200 Subject: [PATCH] docs(nvs_flash): correct public API docs for error code -align nvs.h / nvs_handle.hpp Doxygen with the implementation: fix return codes -guard nvs_open against a NULL out_handle --- components/nvs_flash/include/nvs.h | 68 +++++++++------ components/nvs_flash/include/nvs_handle.hpp | 92 +++++++++++++++++---- components/nvs_flash/src/nvs_api.cpp | 4 + 3 files changed, 123 insertions(+), 41 deletions(-) diff --git a/components/nvs_flash/include/nvs.h b/components/nvs_flash/include/nvs.h index 38f67e38e6b..dfb98f29525 100644 --- a/components/nvs_flash/include/nvs.h +++ b/components/nvs_flash/include/nvs.h @@ -152,9 +152,9 @@ typedef struct nvs_opaque_iterator_t *nvs_iterator_t; * NVS partition (only if NVS assertion checks are disabled) * - 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 + * - ESP_ERR_NVS_NOT_FOUND if namespace doesn't exist yet and * mode is NVS_READONLY - * - ESP_ERR_NVS_INVALID_NAME if namespace name doesn't satisfy constraints + * - ESP_ERR_NVS_KEY_TOO_LONG if the namespace name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - ESP_ERR_NO_MEM in case memory could not be allocated for the internal structures * - ESP_ERR_NVS_NOT_ENOUGH_SPACE if there is no space for a new entry or there are too many different * namespaces (maximum allowed different namespaces: 254) @@ -173,9 +173,12 @@ esp_err_t nvs_open(const char* namespace_name, nvs_open_mode_t open_mode, nvs_ha * * @param[in] part_name Label (name) of the partition of interest for object read/write/erase * @param[in] namespace_name Namespace name. Maximum length is (NVS_KEY_NAME_MAX_SIZE-1) 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[in] open_mode NVS_READONLY opens a read only handle + * NVS_READWRITE opens a read/write handle. erase and set operations are allowed. + * previous data is marked as deleted only and new data is written to a new location. + * NVS_READWRITE_PURGE opens a read/write handle. Update and erase operations are allowed. + * previous data is purged from flash memory to ensure that it cannot be recovered. + * New data is written to a new location. * @param[out] out_handle If successful (return code is zero), handle will be * returned in this argument. * @@ -185,9 +188,9 @@ esp_err_t nvs_open(const char* namespace_name, nvs_open_mode_t open_mode, nvs_ha * NVS partition (only if NVS assertion checks are disabled) * - 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 + * - ESP_ERR_NVS_NOT_FOUND if namespace doesn't exist yet and * mode is NVS_READONLY - * - ESP_ERR_NVS_INVALID_NAME if namespace name doesn't satisfy constraints + * - ESP_ERR_NVS_KEY_TOO_LONG if the namespace name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - ESP_ERR_NO_MEM in case memory could not be allocated for the internal structures * - ESP_ERR_NVS_NOT_ENOUGH_SPACE if there is no space for a new entry or there are too many different * namespaces (maximum allowed different namespaces: 254) @@ -218,7 +221,7 @@ esp_err_t nvs_open_from_partition(const char *part_name, const char* namespace_n * NVS partition (only if NVS assertion checks are disabled) * - 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_KEY_TOO_LONG if the key name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - 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 @@ -280,13 +283,17 @@ esp_err_t nvs_set_u64 (nvs_handle_t handle, const char* key, uint64_t value); /** * @brief set string for given key * - * Sets string value for the key. Function requires whole space for new data to be available - * as contiguous entries in same nvs page. Operation consumes 1 overhead entry and 1 entry per - * each 32 characters of new string including zero character to be set. In case of value update - * for existing key, entries occupied by the previous value and overhead entry are returned to - * the pool of available entries. + * Sets string value for the key. The whole string (including the null terminator) must fit as a + * contiguous run of entries on a single NVS page. The operation consumes 1 overhead (metadata) + * entry plus \c ceil((strlen(value) + 1) / 32) data entries. + * + * On update, the new value is written first and the previous value is erased afterwards, so free + * space for the new value is required regardless of the size of the old one. Entries occupied by + * the previous value become available only for subsequent operations (and only after page reclaim). + * * Note that storage of long string values can fail due to fragmentation of nvs pages even if * \c available_entries returned by \c nvs_get_stats suggests enough overall space available. + * See the NVS documentation section "Space Consumption" for details. * Note that the underlying storage will not be updated until \c nvs_commit is called. * * @@ -300,9 +307,11 @@ esp_err_t nvs_set_u64 (nvs_handle_t handle, const char* key, uint64_t value); * * @return * - ESP_OK if value was set successfully + * - ESP_FAIL if there is an internal error; most likely due to corrupted + * NVS partition (only if NVS assertion checks are disabled) * - 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_KEY_TOO_LONG if the key name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - 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 @@ -317,10 +326,19 @@ esp_err_t nvs_set_str (nvs_handle_t handle, const char* key, const char* value); /** * @brief set variable length binary value for given key * - * Sets variable length binary value for the key. Function uses 2 overhead and 1 entry - * per each 32 bytes of new data from the pool of available entries. See \c nvs_get_stats . - * In case of value update for existing key, space occupied by the existing value and 2 overhead entries - * are returned to the pool of available entries. + * Sets variable length binary value for the key. A blob is stored as one \c BLOB_INDEX entry plus + * one or more data chunks (each chunk is a \c BLOB_DATA header entry followed by its payload + * entries, on a separate page). Storing a blob therefore needs + * \c 1 + k + ceil(length / 32) entries, where \c k is the number of chunks/pages used. The + * overhead is exactly 2 entries only when the blob fits in a single chunk; fragmentation + * increases \c k. See \c nvs_get_stats and the NVS documentation section "Space Consumption". + * + * On update, the new value is written first and the previous value is erased afterwards, so free + * space for the new value is required regardless of the size of the old one. Entries occupied by + * the previous value become available only for subsequent operations (and only after page reclaim). + * + * Note that storage of large blobs can fail due to fragmentation of nvs pages even if + * \c available_entries returned by \c nvs_get_stats suggests enough overall space available. * Note that the underlying storage will not be updated until \c nvs_commit is called. * * @param[in] handle Handle obtained from nvs_open function. @@ -337,7 +355,7 @@ esp_err_t nvs_set_str (nvs_handle_t handle, const char* key, const char* value); * NVS partition (only if NVS assertion checks are disabled) * - 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_KEY_TOO_LONG if the key name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - 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 @@ -384,6 +402,7 @@ esp_err_t nvs_set_blob(nvs_handle_t handle, const char* key, const void* value, * - 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_NVS_TYPE_MISMATCH if the type of the stored value doesn't match the requested type */ esp_err_t nvs_get_i8 (nvs_handle_t handle, const char* key, int8_t* out_value); @@ -491,7 +510,7 @@ esp_err_t nvs_get_u64 (nvs_handle_t handle, const char* key, uint64_t* out_value * NVS partition (only if NVS assertion checks are disabled) * - 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_TYPE_MISMATCH if the type of the stored value doesn't match the requested type * - ESP_ERR_NVS_INVALID_LENGTH if \c length is not sufficient to store data */ esp_err_t nvs_get_str (nvs_handle_t handle, const char* key, char* out_value, size_t* length); @@ -645,12 +664,11 @@ typedef struct { * @return * - ESP_OK if the changes have been written successfully. * Return param nvs_stats will be filled. - * - ESP_ERR_NVS_PART_NOT_FOUND if the partition with label "name" is not found. - * Return param nvs_stats will be filled 0. - * - ESP_ERR_NVS_NOT_INITIALIZED if the storage driver is not initialized. - * Return param nvs_stats will be filled 0. + * - ESP_ERR_NVS_NOT_INITIALIZED if the storage driver is not initialized, or if the + * partition with label \c part_name is not found / not initialized. + * Return param nvs_stats will be filled with 0. * - ESP_ERR_INVALID_ARG if nvs_stats is equal to NULL. - * - ESP_ERR_INVALID_STATE if there is page with the status of INVALID. + * - ESP_ERR_NVS_INVALID_STATE if there is a page with the status of INVALID. * Return param nvs_stats will be filled not with correct values because * not all pages will be counted. Counting will be interrupted at the first INVALID page. */ diff --git a/components/nvs_flash/include/nvs_handle.hpp b/components/nvs_flash/include/nvs_handle.hpp index b1515116d63..0d5e8355c58 100644 --- a/components/nvs_flash/include/nvs_handle.hpp +++ b/components/nvs_flash/include/nvs_handle.hpp @@ -73,15 +73,19 @@ public: * * @return * - ESP_OK if value was set successfully + * - ESP_ERR_NVS_INVALID_HANDLE if the 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_KEY_TOO_LONG if the key name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - 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_NVS_VALUE_TOO_LONG if the value is too long + * - ESP_FAIL if there is an internal error; most likely due to corrupted + * NVS partition (only if NVS assertion checks are disabled) + * - other error codes from the underlying storage driver */ template esp_err_t set_item(const char *key, T value); @@ -104,9 +108,12 @@ public: * * @return * - ESP_OK if the value was retrieved successfully + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL * - 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 + * - ESP_ERR_NVS_TYPE_MISMATCH if the type of the stored value doesn't match the requested type + * - ESP_FAIL if there is an internal error; most likely due to corrupted + * NVS partition (only if NVS assertion checks are disabled) + * - other error codes from the underlying storage driver */ template esp_err_t get_item(const char *key, T &value); @@ -125,8 +132,9 @@ public: * * @return * - ESP_OK if value was set successfully + * - ESP_ERR_NVS_INVALID_HANDLE if the 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_KEY_TOO_LONG if the key name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - 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 @@ -134,6 +142,9 @@ public: * 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_FAIL if there is an internal error; most likely due to corrupted + * NVS partition (only if NVS assertion checks are disabled) + * - other error codes from the underlying storage driver * * @note compare to \ref nvs_set_blob in nvs.h */ @@ -162,9 +173,13 @@ public: * * @return * - ESP_OK if the value was retrieved successfully + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL * - 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_TYPE_MISMATCH if the type of the stored value doesn't match the requested type * - ESP_ERR_NVS_INVALID_LENGTH if length is not sufficient to store data + * - ESP_FAIL if there is an internal error; most likely due to corrupted + * NVS partition (only if NVS assertion checks are disabled) + * - other error codes from the underlying storage driver */ 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; @@ -178,8 +193,10 @@ public: * For strings, this size includes the zero terminator. * * @return - ESP_OK if the item with specified type and key exists. Its size will be returned via \c size. - * - ESP_ERR_NVS_NOT_FOUND if an item with the requested key and type doesn't exist or any other - * error occurs. + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL + * - ESP_ERR_NVS_NOT_FOUND if an item with the requested key and type doesn't exist + * - ESP_ERR_NVS_TYPE_MISMATCH if an item with the requested key exists but has a different type + * - other error codes from the underlying storage driver */ virtual esp_err_t get_item_size(ItemType datatype, const char *key, size_t &size) = 0; @@ -200,18 +217,46 @@ public: /** * @brief Erases an entry. + * + * @param[in] key Key name. Maximum length is (NVS_KEY_NAME_MAX_SIZE-1) characters. Shouldn't be empty. + * + * @return + * - ESP_OK if erase operation was successful + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL + * - ESP_ERR_NVS_READ_ONLY if storage handle was opened as read only + * - ESP_ERR_NVS_NOT_FOUND if the requested key doesn't exist + * - ESP_FAIL if there is an internal error; most likely due to corrupted + * NVS partition (only if NVS assertion checks are disabled) + * - other error codes from the underlying storage driver */ 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 + * The scope may vary, depending on the implementation (typically the opened namespace). + * + * @note If you want to erase the whole NVS flash partition, use nvs_flash_erase() / + * nvs_flash_erase_partition() instead. + * + * @return + * - ESP_OK if erase operation was successful + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL + * - ESP_ERR_NVS_READ_ONLY if storage handle was opened as read only + * - other error codes from the underlying storage driver */ virtual esp_err_t erase_all() = 0; /** - * Purges all erased entries in the scope of this handle. The scope may vary, depending on the implementation. + * @brief Purges all erased entries in the scope of this handle. + * + * The scope may vary, depending on the implementation. + * + * @return + * - ESP_OK if purge operation was successful + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL + * - ESP_ERR_NVS_READ_ONLY if storage handle was opened as read only + * - other error codes from the underlying storage driver */ virtual esp_err_t purge_all() = 0; @@ -219,6 +264,10 @@ public: * Commits all changes done through this handle so far. * Currently, NVS writes to storage right after the set and get functions, * but this is not guaranteed. + * + * @return + * - ESP_OK if commit was successful + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL */ virtual esp_err_t commit() = 0; @@ -229,13 +278,14 @@ public: * * * @return - * - ESP_OK if the changes have been written successfully. - * Return param used_entries will be filled valid value. + * - ESP_OK if the used entry count has been calculated successfully. + * Return param usedEntries will be filled with a valid value. + * - ESP_ERR_NVS_INVALID_HANDLE if the handle has been closed or is NULL. + * Return param usedEntries will be filled with 0. * - 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. + * Return param usedEntries will be filled with 0. * - Other error codes from the underlying storage driver. - * Return param used_entries will be filled 0. + * Return param usedEntries will be filled with 0. */ virtual esp_err_t get_used_entry_count(size_t& usedEntries) = 0; @@ -260,8 +310,11 @@ protected: * - 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 + * - ESP_ERR_NVS_KEY_TOO_LONG if the namespace name is longer than (NVS_KEY_NAME_MAX_SIZE-1) characters * - ESP_ERR_NOT_ALLOWED if the NVS partition is read-only and mode is NVS_READWRITE + * - ESP_ERR_NVS_NOT_ENOUGH_SPACE if there is no space for a new entry or there are too many + * different namespaces (maximum allowed different namespaces: 254) + * - ESP_ERR_NO_MEM if memory could not be allocated for the internal structures * - other error codes from the underlying storage driver * * @return unique pointer of an nvs handle on success, an empty unique pointer otherwise @@ -274,6 +327,13 @@ std::unique_ptr open_nvs_handle_from_partition(const char *partition_ /** * @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. + * + * @param[in] ns_name Namespace name. Maximum length is (NVS_KEY_NAME_MAX_SIZE-1) characters. + * @param[in] open_mode NVS_READONLY, NVS_READWRITE, or NVS_READWRITE_PURGE. + * @param[out] err Optional pointer to an esp_err_t result of the open operation. See + * open_nvs_handle_from_partition() for the list of possible error codes. + * + * @return unique pointer of an nvs handle on success, an empty unique pointer otherwise */ std::unique_ptr open_nvs_handle(const char *ns_name, nvs_open_mode_t open_mode, diff --git a/components/nvs_flash/src/nvs_api.cpp b/components/nvs_flash/src/nvs_api.cpp index 6407faae252..f32bc0686cf 100644 --- a/components/nvs_flash/src/nvs_api.cpp +++ b/components/nvs_flash/src/nvs_api.cpp @@ -293,6 +293,10 @@ static esp_err_t nvs_find_ns_handle(nvs_handle_t c_handle, NVSHandleSimple** han extern "C" esp_err_t nvs_open_from_partition(const char *part_name, const char* namespace_name, nvs_open_mode_t open_mode, nvs_handle_t *out_handle) { + if (out_handle == nullptr) { + return ESP_ERR_INVALID_ARG; + } + esp_err_t lock_result = Lock::init(); if (lock_result != ESP_OK) { return lock_result;