[heap-data] add Matches() to compare Heap::Data with a given buffer (#9740)

Also updates the unit test to validate the new method.

src/core/common/heap_data.cpp

@@ -78,6 +78,25 @@ void Data::SetFrom(Data &&aData)
     TakeFrom(aData);
 }
 
+bool Data::Matches(const uint8_t *aBuffer, uint16_t aLength) const
+{
+    bool matches = false;
+
+    VerifyOrExit(aLength == mData.GetLength());
+
+    if (IsNull())
+    {
+        matches = (aLength == 0);
+    }
+    else
+    {
+        matches = mData.MatchesBytesIn(aBuffer);
+    }
+
+exit:
+    return matches;
+}
+
 void Data::Free(void)
 {
     Heap::Free(mData.GetBytes());

src/core/common/heap_data.hpp

@@ -169,6 +169,18 @@ public:
      */
     void CopyBytesTo(uint8_t *aBuffer) const { return mData.CopyBytesTo(aBuffer); }
 
+    /**
+     * Compares the `Data` content with the bytes from a given buffer.
+     *
+     * @param[in] aBuffer   A pointer to a buffer to compare with the data.
+     * @param[in] aLength   The length of @p aBuffer.
+     *
+     * @retval TRUE   The `Data` content matches the bytes in @p aBuffer.
+     * @retval FALSE  The `Data` content does not match the byes in @p aBuffer.
+     *
+     */
+    bool Matches(const uint8_t *aBuffer, uint16_t aLength) const;
+
     /**
      * Frees any buffer allocated by the `Heap::Data`.
      *

tests/unit/test_heap_string.cpp

@@ -171,11 +171,15 @@ void VerifyData(const Heap::Data &aData, const uint8_t *aBytes, uint16_t aLength
 
     PrintData(aData);
 
+    VerifyOrQuit(aData.Matches(aBytes, aLength));
+    VerifyOrQuit(!aData.Matches(aBytes, aLength + 1));
+
     if (aLength == 0)
     {
         VerifyOrQuit(aData.IsNull());
         VerifyOrQuit(aData.GetBytes() == nullptr);
         VerifyOrQuit(aData.GetLength() == 0);
+        VerifyOrQuit(aData.Matches(nullptr, 0));
     }
     else
     {
@@ -186,6 +190,10 @@ void VerifyData(const Heap::Data &aData, const uint8_t *aBytes, uint16_t aLength
 
         aData.CopyBytesTo(buffer);
         VerifyOrQuit(memcmp(buffer, aBytes, aLength) == 0, "CopyBytesTo() failed");
+
+        VerifyOrQuit(aData.Matches(buffer, aLength));
+        buffer[aLength - 1]++;
+        VerifyOrQuit(!aData.Matches(buffer, aLength));
     }
 }
 
@@ -223,6 +231,10 @@ void TestHeapData(void)
     printf("After constructor\n");
     VerifyData(data, nullptr, 0);
 
+    VerifyOrQuit(data.Matches(nullptr, 0));
+    VerifyOrQuit(data.Matches(kData1, 0));
+    VerifyOrQuit(!data.Matches(kData1, 1));
+
     printf("------------------------------------------------------------------------------------\n");
     printf("SetFrom(aBuffer, aLength)\n");