org.apache.hadoop.hbase.client

Interface ScanResultCache

All Known Implementing Classes:

AllowPartialScanResultCache, BatchScanResultCache, CompleteScanResultCache

@InterfaceAudience.Private
interface ScanResultCache

Used to separate the row constructing logic.

After we add heartbeat support for scan, RS may return partial result even if allowPartial is false and batch is 0. With this interface, the implementation now looks like:

1. Get results from ScanResponse proto.
2. Pass them to ScanResultCache and get something back.
3. If we actually get something back, then pass it to ScanConsumer.

Field Summary

Fields

Modifier and Type	Field and Description
static Result[]	EMPTY_RESULT_ARRAY

Method Summary

Modifier and Type	Method and Description
Result[]	addAndGet(Result[] results, boolean isHeartbeatMessage) Add the given results to cache and get valid results back.
void	clear() Clear the cached result if any.
int	numberOfCompleteRows() Return the number of complete rows.

Field Detail

EMPTY_RESULT_ARRAY

static final Result[] EMPTY_RESULT_ARRAY

Method Detail

addAndGet

Result[] addAndGet(Result[] results,
                   boolean isHeartbeatMessage)
            throws IOException

Add the given results to cache and get valid results back.

Parameters:

results - the results of a scan next. Must not be null.

isHeartbeatMessage - indicate whether the results is gotten from a heartbeat response.

Returns:

valid results, never null.

Throws:

IOException

clear

void clear()

Clear the cached result if any. Called when scan error and we will start from a start of a row again.

numberOfCompleteRows

int numberOfCompleteRows()

Return the number of complete rows. Used to implement limited scan.