Package org.apache.hadoop.hbase.regionserver.querymatcher

Class NormalUserScanQueryMatcher

java.lang.Object

org.apache.hadoop.hbase.regionserver.querymatcher.ScanQueryMatcher

org.apache.hadoop.hbase.regionserver.querymatcher.UserScanQueryMatcher

org.apache.hadoop.hbase.regionserver.querymatcher.NormalUserScanQueryMatcher

All Implemented Interfaces:

ShipperListener

@Private
public abstract class NormalUserScanQueryMatcher
extends UserScanQueryMatcher

Query matcher for normal user scan.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.regionserver.querymatcher.ScanQueryMatcher

ScanQueryMatcher.MatchCode

Field Summary

Fields

Modifier and Type	Field	Description
private final boolean	canSeekOnDeleteMarker	Whether seek optimization for range delete markers is applicable
private final DeleteTracker	deletes	Keeps track of deletes
private final boolean	get	True if we are doing a 'Get' Scan.
private ExtendedCell	lastDelete	Last range delete cell, for qualifier comparison across consecutive markers
private int	rangeDeleteCount	Count of consecutive range delete markers seen for the same column
(package private) static final int	SEEK_ON_DELETE_MARKER_THRESHOLD	Number of consecutive range delete markers (DeleteColumn/DeleteFamily) to skip before switching to seek.
protected final boolean	seePastDeleteMarkers	whether time range queries can see rows "behind" a delete

Fields inherited from class org.apache.hadoop.hbase.regionserver.querymatcher.UserScanQueryMatcher

filter, hasNullColumn, stopRow, tr

Fields inherited from class org.apache.hadoop.hbase.regionserver.querymatcher.ScanQueryMatcher

columns, currentRow, now, oldestUnexpiredTS, rowComparator, startKey

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NormalUserScanQueryMatcher(Scan scan, ScanInfo scanInfo, ColumnTracker columns, boolean hasNullColumn, DeleteTracker deletes, long oldestUnexpiredTS, long now)

Method Summary

Modifier and Type	Method	Description
void	beforeShipped()	The action that needs to be performed before Shipper.shipped() is performed
static NormalUserScanQueryMatcher	create(Scan scan, ScanInfo scanInfo, ColumnTracker columns, DeleteTracker deletes, boolean hasNullColumn, long oldestUnexpiredTS, long now)
protected boolean	isGet()
ScanQueryMatcher.MatchCode	match(ExtendedCell cell)	Determines if the caller should do one of several things: seek/skip to the next row (MatchCode.SEEK_NEXT_ROW) seek/skip to the next column (MatchCode.SEEK_NEXT_COL) include the current KeyValue (MatchCode.INCLUDE) ignore the current KeyValue (MatchCode.SKIP) got to the next row (MatchCode.DONE)
protected void	reset()

Methods inherited from class org.apache.hadoop.hbase.regionserver.querymatcher.UserScanQueryMatcher

create, getFilter, getNextKeyHint, hasNullColumnInQuery, isUserScan, matchColumn, moreRowsMayExistAfter, moreRowsMayExistsAfter

Methods inherited from class org.apache.hadoop.hbase.regionserver.querymatcher.ScanQueryMatcher

checkColumn, checkDeleted, clearCurrentRow, compareKeyForNextColumn, compareKeyForNextRow, createStartKeyFromRow, currentRow, getKeyForNextColumn, getStartKey, getTrackers, preCheck, preCheckRaw, setToNewRow

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

SEEK_ON_DELETE_MARKER_THRESHOLD

static final int SEEK_ON_DELETE_MARKER_THRESHOLD

Number of consecutive range delete markers (DeleteColumn/DeleteFamily) to skip before switching to seek. Seeking is more expensive than skipping for a single marker, but much faster when markers accumulate. This threshold avoids the seek overhead for the common case (one delete per row/column) while still kicking in when markers pile up.

See Also:

• Constant Field Values

deletes

private final DeleteTracker deletes

Keeps track of deletes

get

private final boolean get

True if we are doing a 'Get' Scan. Every Get is actually a one-row Scan.

seePastDeleteMarkers

protected final boolean seePastDeleteMarkers

whether time range queries can see rows "behind" a delete

canSeekOnDeleteMarker

private final boolean canSeekOnDeleteMarker

Whether seek optimization for range delete markers is applicable

rangeDeleteCount

private int rangeDeleteCount

Count of consecutive range delete markers seen for the same column

lastDelete

private ExtendedCell lastDelete

Last range delete cell, for qualifier comparison across consecutive markers

Constructor Details

NormalUserScanQueryMatcher

protected NormalUserScanQueryMatcher(Scan scan,
 ScanInfo scanInfo,
 ColumnTracker columns,
 boolean hasNullColumn,
 DeleteTracker deletes,
 long oldestUnexpiredTS,
 long now)

Method Details

beforeShipped

public void beforeShipped()
                   throws IOException

Description copied from interface: ShipperListener

The action that needs to be performed before Shipper.shipped() is performed

Specified by:

beforeShipped in interface ShipperListener

Overrides:

beforeShipped in class UserScanQueryMatcher

Throws:

IOException

match

public ScanQueryMatcher.MatchCode match(ExtendedCell cell)
                                 throws IOException

Description copied from class: ScanQueryMatcher

Determines if the caller should do one of several things:

• seek/skip to the next row (MatchCode.SEEK_NEXT_ROW)
• seek/skip to the next column (MatchCode.SEEK_NEXT_COL)
• include the current KeyValue (MatchCode.INCLUDE)
• ignore the current KeyValue (MatchCode.SKIP)
• got to the next row (MatchCode.DONE)

Specified by:

match in class ScanQueryMatcher

Parameters:

cell - KeyValue to check

Returns:

The match code instance.

Throws:

IOException - in case there is an internal consistency problem caused by a data corruption.

reset

protected void reset()

Specified by:

reset in class ScanQueryMatcher

isGet

protected boolean isGet()

Specified by:

isGet in class UserScanQueryMatcher

create

public static NormalUserScanQueryMatcher create(Scan scan,
 ScanInfo scanInfo,
 ColumnTracker columns,
 DeleteTracker deletes,
 boolean hasNullColumn,
 long oldestUnexpiredTS,
 long now)
                                         throws IOException

Throws:

IOException