HBASE-18757 Fix improper bitwise & in bucketcache offset calculation

This correctly casts the operand to a long to avoid negative offsets created by sign extending the integer operand.

Signed-off-by: tedyu <yuzhihong@gmail.com>
This commit is contained in:
Zach York 2017-08-31 10:25:32 -07:00 committed by tedyu
parent 7e1517545c
commit cd1b964bb7
2 changed files with 11 additions and 2 deletions

View File

@ -1285,8 +1285,8 @@ public class BucketCache implements BlockCache, HeapSize {
}
long offset() { // Java has no unsigned numbers
long o = ((long) offsetBase) & 0xFFFFFFFF;
o += (((long) (offset1)) & 0xFF) << 32;
long o = ((long) offsetBase) & 0xFFFFFFFFL; //This needs the L cast otherwise it will be sign extended as a negative number.
o += (((long) (offset1)) & 0xFF) << 32; //The 0xFF here does not need the L cast because it is treated as a positive int.
return o << 8;
}

View File

@ -388,4 +388,13 @@ public class TestBucketCache {
long expectedOutput = (long) Math.floor(bucketCache.getAllocator().getTotalSize() * partitionFactor * minFactor);
assertEquals(expectedOutput, bucketCache.getPartitionSize(partitionFactor));
}
@Test
public void testOffsetProducesPositiveOutput() {
//This number is picked because it produces negative output if the values isn't ensured to be positive.
//See HBASE-18757 for more information.
long testValue = 549888460800L;
BucketCache.BucketEntry bucketEntry = new BucketCache.BucketEntry(testValue, 10, 10L, true);
assertEquals(testValue, bucketEntry.offset());
}
}