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Fix AbsatractByteBufferProxy.compareBuff #170

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Merged
merged 1 commit into from
Mar 12, 2021
Merged

Fix AbsatractByteBufferProxy.compareBuff #170

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4 changes: 2 additions & 2 deletions src/main/java/org/lmdbjava/ByteBufferProxy.java
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Original file line number Diff line number Diff line change
Expand Up @@ -133,7 +133,7 @@ public static int compareBuff(final ByteBuffer o1, final ByteBuffer o2) {
final int minWords = minLength / Long.BYTES;

final boolean reverse1 = o1.order() == LITTLE_ENDIAN;
final boolean reverse2 = o1.order() == LITTLE_ENDIAN;
final boolean reverse2 = o2.order() == LITTLE_ENDIAN;
for (int i = 0; i < minWords * Long.BYTES; i += Long.BYTES) {
final long lw = reverse1 ? reverseBytes(o1.getLong(i)) : o1.getLong(i);
final long rw = reverse2 ? reverseBytes(o2.getLong(i)) : o2.getLong(i);
Expand All @@ -152,7 +152,7 @@ public static int compareBuff(final ByteBuffer o1, final ByteBuffer o2) {
}
}

return o1.capacity() - o2.capacity();
return o1.remaining() - o2.remaining();
}

static Field findField(final Class<?> c, final String name) {
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36 changes: 33 additions & 3 deletions src/test/java/org/lmdbjava/ComparatorTest.java
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Expand Up @@ -33,6 +33,7 @@
import static org.lmdbjava.DirectBufferProxy.PROXY_DB;

import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Comparator;

import com.google.common.primitives.SignedBytes;
Expand Down Expand Up @@ -156,9 +157,38 @@ private static class ByteBufferRunner implements ComparatorRunner {

@Override
public int compare(final byte[] o1, final byte[] o2) {
final ByteBuffer o1b = ByteBuffer.wrap(o1);
final ByteBuffer o2b = ByteBuffer.wrap(o2);
return PROXY_OPTIMAL.compare(o1b, o2b);
// Convert arrays to buffers that are larger than the array, with
// limit set at the array length. One buffer bigger than the other.
ByteBuffer o1b = arrayToBuffer(o1, o1.length * 3);
ByteBuffer o2b = arrayToBuffer(o2, o2.length * 2);
final int result = PROXY_OPTIMAL.compare(o1b, o2b);

// Now swap which buffer is bigger
o1b = arrayToBuffer(o1, o1.length * 2);
o2b = arrayToBuffer(o2, o2.length * 3);
final int result2 = PROXY_OPTIMAL.compare(o1b, o2b);

assertThat(result2, is(result));

// Now try with buffers sized to the array.
o1b = ByteBuffer.wrap(o1);
o2b = ByteBuffer.wrap(o2);
final int result3 = PROXY_OPTIMAL.compare(o1b, o2b);

assertThat(result3, is(result));

return result;
}

private ByteBuffer arrayToBuffer(final byte[] arr, final int bufferCapacity) {
if (bufferCapacity < arr.length) {
throw new IllegalArgumentException("bufferCapacity < arr.length");
}
final byte[] newArr = Arrays.copyOf(arr, bufferCapacity);
final ByteBuffer byteBuffer = ByteBuffer.wrap(newArr);
byteBuffer.limit(arr.length);
byteBuffer.position(0);
return byteBuffer;
}
}

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