org.apache.hadoop.hbase.regionserver

Interface InternalScanner

All Superinterfaces:

AutoCloseable, Closeable

All Known Subinterfaces:

RegionScanner

All Known Implementing Classes:

DelegatingInternalScanner, HRegion.RegionScannerImpl, KeyValueHeap, MobStoreScanner, ReversedKeyValueHeap, ReversedMobStoreScanner, ReversedRegionScannerImpl, ReversedStoreScanner, StoreScanner

@InterfaceAudience.LimitedPrivate(value="Coprocesssor")
 @InterfaceStability.Evolving
public interface InternalScanner
extends Closeable

Internal scanners differ from client-side scanners in that they operate on HStoreKeys and byte[] instead of RowResults. This is because they are actually close to how the data is physically stored, and therefore it is more convenient to interact with them that way. It is also much easier to merge the results across SortedMaps than RowResults.

Additionally, we need to be able to determine if the scanner is doing wildcard column matches (when only a column family is specified or if a column regex is specified) or if multiple members of the same column family were specified. If so, we need to ignore the timestamp to ensure that we get all the family members, as they may have been last updated at different times.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the scanner and releases any resources it has allocated
default boolean	next(List<Cell> result) Grab the next row's worth of values.
boolean	next(List<Cell> result, ScannerContext scannerContext) Grab the next row's worth of values.

Method Detail

next

default boolean next(List<Cell> result)
              throws IOException

Grab the next row's worth of values.

Parameters:

result - return output array

Returns:

true if more rows exist after this one, false if scanner is done

Throws:

IOException - e

next

boolean next(List<Cell> result,
             ScannerContext scannerContext)
      throws IOException

Grab the next row's worth of values.

Parameters:

result - return output array

scannerContext -

Returns:

true if more rows exist after this one, false if scanner is done

Throws:

IOException - e

close

void close()
    throws IOException

Closes the scanner and releases any resources it has allocated

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException