org.apache.hadoop.hbase.client.ScanResultCache Maven / Gradle / Ivy
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* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.hadoop.hbase.client;
import java.io.IOException;
import org.apache.yetus.audience.InterfaceAudience;
/**
* 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:
*
* - Get results from ScanResponse proto.
* - Pass them to ScanResultCache and get something back.
* - If we actually get something back, then pass it to ScanConsumer.
*
*/
@InterfaceAudience.Private
interface ScanResultCache {
static final Result[] EMPTY_RESULT_ARRAY = new Result[0];
/**
* Add the given results to cache and get valid results back.
* @param results the results of a scan next. Must not be null.
* @param isHeartbeatMessage indicate whether the results is gotten from a heartbeat response.
* @return valid results, never null.
*/
Result[] addAndGet(Result[] results, boolean isHeartbeatMessage) throws IOException;
/**
* Clear the cached result if any. Called when scan error and we will start from a start of a row
* again.
*/
void clear();
/**
* Return the number of complete rows. Used to implement limited scan.
*/
int numberOfCompleteRows();
}