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https://issues.apache.org/jira/browse/HBASE-16624?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=15486459#comment-15486459
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deepankar edited comment on HBASE-16624 at 9/13/16 6:46 AM:
Function is nested deep inside the HFileScannerImpl and it was hard to come up
with a UT. But if you can pass the sequenceId above the Integer.MAX_VALUE you
would immediately see the issue, to confirm the issue I have changed the
function as below and tested it with values passed below
{code}
/**
* Actually do the mvcc read. Does no checks.
* @param offsetFromPos
*/
private long _readMvccVersion(ByteBuff blockBuffer) {
long currMemstoreTS = 0;
int offsetFromPos = 0;
// This is Bytes#bytesToVint inlined so can save a few instructions in
this hot method; i.e.
// previous if one-byte vint, we'd redo the vint call to find int size.
// Also the method is kept small so can be inlined.
byte firstByte = blockBuffer.getByteAfterPosition(offsetFromPos);
int len = WritableUtils.decodeVIntSize(firstByte);
if (len == 1) {
currMemstoreTS = firstByte;
} else {
int remaining = len -1;
long i = 0;
offsetFromPos++;
if (remaining >= Bytes.SIZEOF_INT) {
// The int read has to be converted to unsigned long so the & op
i = (blockBuffer.getIntAfterPosition(offsetFromPos) &
0xL);
remaining -= Bytes.SIZEOF_INT;
offsetFromPos += Bytes.SIZEOF_INT;
}
if (remaining >= Bytes.SIZEOF_SHORT) {
short s = blockBuffer.getShortAfterPosition(offsetFromPos);
i = i << 16;
i = i | (s & 0x);
remaining -= Bytes.SIZEOF_SHORT;
offsetFromPos += Bytes.SIZEOF_SHORT;
}
for (int idx = 0; idx < remaining; idx++) {
byte b = blockBuffer.getByteAfterPosition(offsetFromPos + idx);
i = i << 8;
i = i | (b & 0xFF);
}
currMemstoreTS = (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
}
return currMemstoreTS;
}
{code}
And I passed the byteBuff I got from
{code}
ByteArrayDataOutput out = ByteStreams.newDataOutput();
WritableUtils.writeVLong(out, 3085788160L);
new SingleByteBuff(ByteBuffer.wrap(out.toByteArray()))
{code}
was (Author: dvdreddy):
Function is nested deep inside the HFileScannerImpl and it was hard to come up
with a UT. But if you can cross the sequenceId above the Integer.MAX_VALUE you
would immediately see the issue, to confirm the issue I have changed the
function
{code}
/**
* Actually do the mvcc read. Does no checks.
* @param offsetFromPos
*/
private long _readMvccVersion(ByteBuff blockBuffer) {
long currMemstoreTS = 0;
int offsetFromPos = 0;
// This is Bytes#bytesToVint inlined so can save a few instructions in
this hot method; i.e.
// previous if one-byte vint, we'd redo the vint call to find int size.
// Also the method is kept small so can be inlined.
byte firstByte = blockBuffer.getByteAfterPosition(offsetFromPos);
int len = WritableUtils.decodeVIntSize(firstByte);
if (len == 1) {
currMemstoreTS = firstByte;
} else {
int remaining = len -1;
long i = 0;
offsetFromPos++;
if (remaining >= Bytes.SIZEOF_INT) {
// The int read has to be converted to unsigned long so the & op
i = (blockBuffer.getIntAfterPosition(offsetFromPos) &
0xL);
remaining -= Bytes.SIZEOF_INT;
offsetFromPos += Bytes.SIZEOF_INT;
}
if (remaining >= Bytes.SIZEOF_SHORT) {
short s = blockBuffer.getShortAfterPosition(offsetFromPos);
i = i << 16;
i = i | (s & 0x);
remaining -= Bytes.SIZEOF_SHORT;
offsetFromPos += Bytes.SIZEOF_SHORT;
}
for (int idx = 0; idx < remaining; idx++) {
byte b = blockBuffer.getByteAfterPosition(offsetFromPos + idx);
i = i << 8;
i = i | (b & 0xFF);
}
currMemstoreTS = (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
}
return currMemstoreTS;
}
{code}
And I passed the byteBuff I got from
{code}
ByteArrayDataOutput out = ByteStreams.newDataOutput();
WritableUtils.writeVLong(out, 3085788160L);
new SingleByteBuff(ByteBuffer.wrap(out.toByteArray()))
{code}
> MVCC DeSerialization bug in the HFileScannerImpl
>
>
> Key: HBASE-16624
> URL:
