components/nvs: make some methods const

components/nvs_flash/src/compressed_enum_table.hpp

@@ -33,7 +33,7 @@ public:
         return mData;
     }
 
-    Tenum get(size_t index)
+    Tenum get(size_t index) const
     {
         assert(index >= 0 && index < Nitems);
         size_t wordIndex = index / ITEMS_PER_WORD;

components/nvs_flash/src/nvs_page.cpp

@@ -536,7 +536,7 @@ esp_err_t Page::alterPageState(PageState state)
     return ESP_OK;
 }
 
-esp_err_t Page::readEntry(size_t index, Item& dst)
+esp_err_t Page::readEntry(size_t index, Item& dst) const
 {
     auto rc = spi_flash_read(getEntryAddress(index), reinterpret_cast<uint32_t*>(&dst), sizeof(dst));
     if (rc != ESP_OK) {
@@ -658,7 +658,7 @@ void Page::invalidateCache()
     mFindInfo = CachedFindInfo();
 }
     
-void Page::debugDump()
+void Page::debugDump() const
 {
     printf("state=%x addr=%x seq=%d\nfirstUsed=%d nextFree=%d used=%d erased=%d\n", mState, mBaseAddress, mSeqNumber, static_cast<int>(mFirstUsedEntry), static_cast<int>(mNextFreeEntry), mUsedEntryCount, mErasedEntryCount);
     size_t skip = 0;

components/nvs_flash/src/nvs_page.hpp

@@ -162,7 +162,7 @@ public:
 
     void invalidateCache();
     
-    void debugDump();
+    void debugDump() const;
 
 protected:
 
@@ -195,7 +195,7 @@ protected:
 
     esp_err_t alterPageState(PageState state);
 
-    esp_err_t readEntry(size_t index, Item& dst);
+    esp_err_t readEntry(size_t index, Item& dst) const;
 
     esp_err_t writeEntry(const Item& item);
 
@@ -210,7 +210,7 @@ protected:
         return static_cast<uint8_t>(type) & 0x0f;
     }
 
-    uint32_t getEntryAddress(size_t entry)
+    uint32_t getEntryAddress(size_t entry) const
     {
         assert(entry < ENTRY_COUNT);
         return mBaseAddress + ENTRY_DATA_OFFSET + static_cast<uint32_t>(entry) * ENTRY_SIZE;