⚡️ Speed up method ShortValue.equals by 8%

[codeflash-ai]

📄 8% (0.08x) speedup for ShortValue.equals in client/src/com/aerospike/client/Value.java

⏱️ Runtime : 195 microseconds → 181 microseconds (best of 5 runs)

📝 Explanation and details

The optimized code achieves a 7% runtime improvement (from 195 to 181 microseconds) by applying two key optimizations to the equals() method:

1. Fast-path reference equality check:

if (this == other) {
    return true;
}

This early-return optimization immediately handles the common case where an object is compared to itself, avoiding all subsequent checks. This is particularly beneficial in scenarios involving collections (HashMaps, HashSets) or caching, where self-comparisons frequently occur.

2. Direct class comparison instead of reflective check:

// Original: this.getClass().equals(other.getClass())
// Optimized: other.getClass() != ShortValue.class

The optimized version replaces a reflective getClass().equals() call with a direct class identity check (!= ShortValue.class). This eliminates:

• The cost of calling getClass() on this
• The virtual method invocation of equals() on the Class object
• The overhead of comparing Class objects

Since ShortValue is a final class, the direct comparison is safe and semantically equivalent while being significantly faster.

Performance characteristics based on test results:

• Self-comparison tests (testSameInstance_equalsTrue) benefit maximally from the reference check
• High-volume comparison tests (testManyComparisons_performanceNoException with 100K iterations) demonstrate the cumulative speedup
• The optimization maintains correctness across all edge cases (null checks, type mismatches, boundary values)

The changes are especially valuable if ShortValue.equals() is called frequently in data serialization paths, collection operations, or protocol handling—typical use cases for value objects in wire protocol implementations.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 34 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	No coverage data found for equals

🌀 Click to see Generated Regression Tests

package com.aerospike.client;

import org.junit.Test;
import org.junit.Before;
import static org.junit.Assert.*;
import com.aerospike.client.Value;

/**
 * Unit tests for Value.ShortValue.equals(...)
 *
 * Note: These tests exercise the equals implementation of the nested
 * ShortValue class in com.aerospike.client.Value.
 */
public class ValueTest {
    private Value.ShortValue instance;

    @Before
    public void setUp() {
        instance = new Value.ShortValue((short) 5);
    }

    @Test
    public void testSameInstance_equalsTrue() {
        // same instance should be equal to itself
        assertTrue(instance.equals(instance));
    }

    @Test
    public void testEqualValues_symmetry() {
        // two distinct ShortValue instances with same short value should be equal (symmetry)
        Value.ShortValue a = new Value.ShortValue((short) 123);
        Value.ShortValue b = new Value.ShortValue((short) 123);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
    }

    @Test
    public void testDifferentValues_equalsFalse() {
        Value.ShortValue a = new Value.ShortValue((short) 10);
        Value.ShortValue b = new Value.ShortValue((short) 11);
        assertFalse(a.equals(b));
    }

    @Test
    public void testNullComparison_returnsFalse() {
        // comparing to null must return false
        assertFalse(instance.equals(null));
    }

    @Test
    public void testDifferentType_returnsFalse() {
        // comparing to an unrelated type (e.g., java.lang.Short) must return false
        Short boxed = (short) 5;
        assertFalse(instance.equals(boxed));
    }

    @Test
    public void testBoundaryMin_equalsTrue() {
        Value.ShortValue a = new Value.ShortValue(Short.MIN_VALUE);
        Value.ShortValue b = new Value.ShortValue(Short.MIN_VALUE);
        assertTrue(a.equals(b));
    }

    @Test
    public void testBoundaryMax_equalsTrue() {
        Value.ShortValue a = new Value.ShortValue(Short.MAX_VALUE);
        Value.ShortValue b = new Value.ShortValue(Short.MAX_VALUE);
        assertTrue(a.equals(b));
    }

    @Test
    public void testManyComparisons_performanceNoException() {
        // Perform a large number of comparisons to ensure stability/performance.
        // This is not a strict performance benchmark, but helps detect issues under load.
        Value.ShortValue a = new Value.ShortValue((short) 42);
        Value.ShortValue b = new Value.ShortValue((short) 42);
        for (int i = 0; i < 100_000; i++) {
            // single assertion per loop would be too slow; just ensure equals returns true each time
            if (!a.equals(b)) {
                fail("Equality failed during repeated comparisons at iteration: " + i);
            }
        }
        // If loop completes, consider test passed.
        assertTrue(true);
    }
}

package com.aerospike.client;

import org.junit.Test;
import org.junit.Before;
import static org.junit.Assert.*;
import com.aerospike.client.Value;

public class ValueTest {
    private Value shortOne;

    @Before
    public void setUp() {
        // Create a Value instance representing a short. Use factory method to obtain concrete implementation.
        shortOne = Value.get((short)1);
    }

    @Test
    public void testShortValue_Equals_SameInstance_True() {
        // same instance must be equal to itself
        assertTrue(shortOne.equals(shortOne));
    }

    @Test
    public void testShortValue_Equals_SameValueDifferentInstances_True() {
        // Two distinct Value instances created for the same short value should be equal.
        Value a = Value.get((short)42);
        Value b = Value.get((short)42);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a)); // symmetry
    }

    @Test
    public void testShortValue_Equals_DifferentShortValues_False() {
        // Values with different short contents must not be equal.
        Value a = Value.get((short)42);
        Value b = Value.get((short)43);
        assertFalse(a.equals(b));
        assertFalse(b.equals(a));
    }

    @Test
    public void testShortValue_Equals_Null_False() {
        // equals with null must return false
        Value v = Value.get((short)0);
        assertFalse(v.equals(null));
    }

    @Test
    public void testShortValue_Equals_DifferentNumericType_False() {
        // A short Value should not be equal to an int Value even if numeric values are the same.
        Value shortVal = Value.get((short)1);
        Value intVal = Value.get(1); // int factory
        assertFalse(shortVal.equals(intVal));
        assertFalse(intVal.equals(shortVal));
    }

    @Test
    public void testShortValue_Equals_OtherObjectType_False() {
        // equals must return false for arbitrary other object types
        Value v = Value.get((short)5);
        Object other = new Object();
        assertFalse(v.equals(other));
    }

    @Test
    public void testShortValue_Equals_BoundaryValues() {
        // Test boundary short values
        Value minValA = Value.get(Short.MIN_VALUE);
        Value minValB = Value.get((short)Short.MIN_VALUE);
        Value maxValA = Value.get(Short.MAX_VALUE);
        Value maxValB = Value.get((short)Short.MAX_VALUE);

        assertTrue(minValA.equals(minValB));
        assertTrue(minValB.equals(minValA));
        assertTrue(maxValA.equals(maxValB));
        assertTrue(maxValB.equals(maxValA));

        assertFalse(minValA.equals(maxValA));
        assertFalse(maxValA.equals(minValA));
    }

    @Test
    public void testShortValue_Equals_Transitivity() {
        // If a == b and b == c then a == c
        Value a = Value.get((short)123);
        Value b = Value.get((short)123);
        Value c = Value.get((short)123);

        assertTrue(a.equals(b));
        assertTrue(b.equals(c));
        assertTrue(a.equals(c));
    }

    @Test
    public void testShortValue_Equals_LargeScale_RepeatedComparisons() {
        // Run repeated equality checks to simulate large-scale usage.
        // This is not a strict performance benchmark but verifies consistent behavior under load.
        Value v1 = Value.get((short)100);
        // Pre-create an array of same-value Value objects to compare against.
        final int iterations = 10000;
        Value[] arr = new Value[iterations];
        for (int i = 0; i < iterations; i++) {
            arr[i] = Value.get((short)100);
        }

        for (int i = 0; i < iterations; i++) {
            if (!v1.equals(arr[i])) {
                fail("Equality mismatch at iteration " + i);
            }
        }

        // Final assertion to indicate test passed if no failures occurred.
        assertTrue(true);
    }
}

To edit these changes git checkout codeflash/optimize-ShortValue.equals-ml8a80ed and push.