NVS save/load string value

CMakeLists.txt

@@ -5,4 +5,4 @@
 cmake_minimum_required(VERSION 3.5)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
-project(blackmagick)
+project(blackmagic)

components/mlib/CMakeLists.txt

@@ -1,3 +1,3 @@
-idf_component_register(SRCS "m_string.c"
+idf_component_register(SRCS "m-string.c"
                     PRIV_INCLUDE_DIRS "mlib"
                     INCLUDE_DIRS ".")

components/mlib/m-string.c

@@ -1,5 +1,5 @@
 #include "mlib\m-string.h"
-#include "m_string.h"
+#include "m-string.h"
 
 struct mstring_t {
     string_t str;
@@ -27,6 +27,15 @@ void mstring_set(mstring_t* mstr, const char* text) {
     string_set_str(mstr->str, text);
 }
 
+void mstring_reset(mstring_t* mstr) {
+    string_reset(mstr->str);
+}
+
+void mstring_cat(mstring_t* mstr, const char* text) 
+{
+    string_cat_str(mstr->str, text);
+}
+
 int mstring_printf(mstring_t* mstr, const char format[], ...) {
     va_list args;
     va_start(args, format);

components/mlib/m-string.h

@@ -1,5 +1,5 @@
 /**
- * @file m_string.h
+ * @file m-string.h
  * 
  * M*Lib string wrapper, to prevent inline code pollution
  * 
@@ -34,6 +34,20 @@ void mstring_free(mstring_t* mstr);
  */
 void mstring_set(mstring_t* mstr, const char* text);
 
+/**
+ * Reset string value
+ * @param mstr 
+ * @param text 
+ */
+void mstring_reset(mstring_t* mstr);
+
+/**
+ * Concatenate value
+ * @param mstr 
+ * @param text 
+ */
+void mstring_cat(mstring_t* mstr, const char* text);
+
 /**
  * Printf string value
  * @param mstr 

main/nvs.c

@@ -1,11 +1,63 @@
 #include <nvs_flash.h>
 #include <esp_log.h>
+#include "nvs.h"
+
+#define TAG "nvs"
+#define NVS_STORE "nvs_storage"
 
 void nvs_init(void) {
+    ESP_LOGI(TAG, "init");
     esp_err_t ret = nvs_flash_init();
     if(ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+        ESP_LOGI(TAG, "erasing");
         ESP_ERROR_CHECK(nvs_flash_erase());
         ret = nvs_flash_init();
     }
     ESP_ERROR_CHECK(ret);
+    ESP_LOGI(TAG, "done");
 }
+
+esp_err_t nvs_save_string(const char* key, const mstring_t* value) {
+    nvs_handle_t nvs_handle;
+    esp_err_t err;
+
+    err = nvs_open(NVS_STORE, NVS_READWRITE, &nvs_handle);
+    if(err != ESP_OK) return err;
+
+    err = nvs_set_str(nvs_handle, key, mstring_get_cstr(value));
+    if(err != ESP_OK) return err;
+
+    err = nvs_commit(nvs_handle);
+    if(err != ESP_OK) return err;
+
+    nvs_close(nvs_handle);
+    return ESP_OK;
+}
+
+esp_err_t nvs_load_string(const char* key, mstring_t* value) {
+    nvs_handle_t nvs_handle;
+    esp_err_t err;
+    char* buffer = NULL;
+
+    do {
+        err = nvs_open(NVS_STORE, NVS_READWRITE, &nvs_handle);
+        if(err != ESP_OK) return err;
+
+        size_t required_size = 0;
+        err = nvs_get_str(nvs_handle, key, NULL, &required_size);
+        if(err != ESP_OK) return err;
+
+        buffer = malloc(required_size + sizeof(uint32_t));
+        err = nvs_get_str(nvs_handle, key, buffer, &required_size);
+        if(err != ESP_OK) return err;
+
+        mstring_set(value, buffer);
+
+        nvs_close(nvs_handle);
+        err = ESP_OK;
+    } while(0);
+
+    if(buffer != NULL) free(buffer);
+
+    return err;
+}

main/nvs.h

@@ -1,3 +1,7 @@
 #pragma once
+#include <m-string.h>
+#include <esp_err.h>
 
-void nvs_init(void);
+void nvs_init(void);
+esp_err_t nvs_save_string(const char* key, const mstring_t* value);
+esp_err_t nvs_load_string(const char* key, mstring_t* value);