Added parameter to Preferences::begin to select non-default NVS partition (#4718)

libraries/Preferences/src/Preferences.cpp

@@ -14,6 +14,7 @@
 #include "Preferences.h"
 
 #include "nvs.h"
+#include "nvs_flash.h"
 
 const char * nvs_errors[] = { "OTHER", "NOT_INITIALIZED", "NOT_FOUND", "TYPE_MISMATCH", "READ_ONLY", "NOT_ENOUGH_SPACE", "INVALID_NAME", "INVALID_HANDLE", "REMOVE_FAILED", "KEY_TOO_LONG", "PAGE_FULL", "INVALID_STATE", "INVALID_LENGTH"};
 #define nvs_error(e) (((e)>ESP_ERR_NVS_BASE)?nvs_errors[(e)&~(ESP_ERR_NVS_BASE)]:nvs_errors[0])
@@ -28,12 +29,22 @@ Preferences::~Preferences(){
     end();
 }
 
-bool Preferences::begin(const char * name, bool readOnly){
+bool Preferences::begin(const char * name, bool readOnly, const char* partition_label){
     if(_started){
         return false;
     }
     _readOnly = readOnly;
-    esp_err_t err = nvs_open(name, readOnly?NVS_READONLY:NVS_READWRITE, &_handle);
+    esp_err_t err = ESP_OK;
+    if (partition_label != NULL) {
+        err = nvs_flash_init_partition(partition_label);
+        if (err) {
+            log_e("nvs_flash_init_partition failed: %s", nvs_error(err));
+            return false;
+        }
+        err = nvs_open_from_partition(partition_label, name, readOnly ? NVS_READONLY : NVS_READWRITE, &_handle);
+    } else {
+        err = nvs_open(name, readOnly?NVS_READONLY:NVS_READWRITE, &_handle);
+    }
     if(err){
         log_e("nvs_open failed: %s", nvs_error(err));
         return false;

libraries/Preferences/src/Preferences.h

@@ -29,7 +29,7 @@ class Preferences {
         Preferences();
         ~Preferences();
 
-        bool begin(const char * name, bool readOnly=false);
+        bool begin(const char * name, bool readOnly=false, const char* partition_label=NULL);
         void end();
 
         bool clear();