[Java] Call bound check instead of capacity expansion in AbstractMuta…

…bleDirectBuffer.getInt (#285)
real-logic · Aug 30, 2023 · a2b406f · a2b406f
1 parent ba5935b
commit a2b406f
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Showing 2 changed files with 20 additions and 1 deletion.
diff --git a/agrona/src/main/java/org/agrona/AbstractMutableDirectBuffer.java b/agrona/src/main/java/org/agrona/AbstractMutableDirectBuffer.java
@@ -182,7 +182,10 @@ public void putLong(final int index, final long value)
      */
     public int getInt(final int index, final ByteOrder byteOrder)
     {
-        ensureCapacity(index, SIZE_OF_INT);
+        if (SHOULD_BOUNDS_CHECK)
+        {
+            boundsCheck0(index, SIZE_OF_INT);
+        }
 
         int bits = UNSAFE.getInt(byteArray, addressOffset + index);
         if (NATIVE_BYTE_ORDER != byteOrder)

diff --git a/agrona/src/test/java/org/agrona/ExpandableArrayBufferTest.java b/agrona/src/test/java/org/agrona/ExpandableArrayBufferTest.java
@@ -15,6 +15,7 @@
  */
 package org.agrona;
 
+import java.nio.ByteOrder;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
@@ -144,4 +145,19 @@ void checkLimitIncreaseBufferCapacity(final int limit)
         assertTrue(limit <= buffer.capacity());
         assertNotSame(originalArray, buffer.byteArray());
     }
+
+    @Test
+    void shouldThrowExceptionForReadingIntAboveCapacity()
+    {
+        final MutableDirectBuffer buffer = newBuffer(3);
+        assertThrows(IndexOutOfBoundsException.class, () -> buffer.getInt(4, ByteOrder.BIG_ENDIAN));
+    }
+
+    @Test
+    void shouldThrowExceptionForReadingLongAboveCapacity()
+    {
+        final MutableDirectBuffer buffer = newBuffer(3);
+        assertThrows(IndexOutOfBoundsException.class, () -> buffer.getLong(4, ByteOrder.BIG_ENDIAN));
+    }
+
 }