org.apache.hadoop.hbase

Class KeyValue.KVComparator

java.lang.Object

org.apache.hadoop.hbase.KeyValue.KVComparator

All Implemented Interfaces:

Comparator<Cell>, KeyValue.SamePrefixComparator<byte[]>, org.apache.hadoop.io.RawComparator<Cell>

Direct Known Subclasses:

KeyValue.MetaComparator, KeyValue.RawBytesComparator

Enclosing class:

KeyValue

public static class KeyValue.KVComparator
extends Object
implements org.apache.hadoop.io.RawComparator<Cell>, KeyValue.SamePrefixComparator<byte[]>

Compare KeyValues. When we compare KeyValues, we only compare the Key portion. This means two KeyValues with same Key but different Values are considered the same as far as this Comparator is concerned.

Constructor Summary

Constructors

Constructor and Description
KeyValue.KVComparator()

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	calcIndexKey(byte[] lastKeyOfPreviousBlock, byte[] firstKeyInBlock)
protected Object	clone()
int	compare(byte[] l, int loff, int llen, byte[] r, int roff, int rlen)
int	compare(Cell left, Cell right) Compares the Key of a cell -- with fields being more significant in this order: rowkey, colfam/qual, timestamp, type, mvcc
protected int	compareColumns(byte[] left, int loffset, int llength, int lfamilylength, byte[] right, int roffset, int rlength, int rfamilylength)
int	compareFlatKey(byte[] left, byte[] right)
int	compareFlatKey(byte[] left, int loffset, int llength, byte[] right, int roffset, int rlength) Compares left to right assuming that left,loffset,llength and right,roffset,rlength are full KVs laid out in a flat byte[]s.
int	compareIgnoringPrefix(int commonPrefix, byte[] left, int loffset, int llength, byte[] right, int roffset, int rlength) Overridden
protected int	compareRowKey(Cell left, Cell right) Compares the only the user specified portion of a Key.
int	compareRows(byte[] left, int loffset, int llength, byte[] right, int roffset, int rlength) Get the b[],o,l for left and right rowkey portions and compare.
int	compareRows(KeyValue left, KeyValue right)
int	compareTimestamps(KeyValue left, KeyValue right)
String	getLegacyKeyComparatorName() The HFileV2 file format's trailer contains this class name.
byte[]	getShortMidpointKey(byte[] leftKey, byte[] rightKey) This is a HFile block index key optimization.
boolean	matchingRowColumn(KeyValue left, KeyValue right) Compares the row and column of two keyvalues for equality
boolean	matchingRows(byte[] left, int loffset, int llength, byte[] right, int roffset, int rlength) Compare rows.
boolean	matchingRows(KeyValue left, KeyValue right) Compares the row of two keyvalues for equality

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

KeyValue.KVComparator

public KeyValue.KVComparator()

Method Detail

getLegacyKeyComparatorName

public String getLegacyKeyComparatorName()

The HFileV2 file format's trailer contains this class name. We reinterpret this and instantiate the appropriate comparator. TODO: With V3 consider removing this.

Returns:

legacy class name for FileFileTrailer#comparatorClassName

compare

public int compare(byte[] l,
          int loff,
          int llen,
          byte[] r,
          int roff,
          int rlen)

Specified by:

compare in interface org.apache.hadoop.io.RawComparator<Cell>

compareRowKey

protected int compareRowKey(Cell left,
                Cell right)

Compares the only the user specified portion of a Key. This is overridden by MetaComparator.

Parameters:

left -

right -

Returns:

0 if equal, <0 if left smaller, >0 if right smaller

compareFlatKey

public int compareFlatKey(byte[] left,
                 int loffset,
                 int llength,
                 byte[] right,
                 int roffset,
                 int rlength)

Compares left to right assuming that left,loffset,llength and right,roffset,rlength are full KVs laid out in a flat byte[]s.

Parameters:

left -

loffset -

llength -

right -

roffset -

rlength -

Returns:

0 if equal, <0 if left smaller, >0 if right smaller

compareFlatKey

public int compareFlatKey(byte[] left,
                 byte[] right)

compare

public int compare(Cell left,
          Cell right)

Compares the Key of a cell -- with fields being more significant in this order: rowkey, colfam/qual, timestamp, type, mvcc

Specified by:

compare in interface Comparator<Cell>

compareTimestamps

public int compareTimestamps(KeyValue left,
                    KeyValue right)

compareRows

public int compareRows(KeyValue left,
              KeyValue right)

Parameters:

left -

right -

Returns:

Result comparing rows.

compareRows

public int compareRows(byte[] left,
              int loffset,
              int llength,
              byte[] right,
              int roffset,
              int rlength)

Get the b[],o,l for left and right rowkey portions and compare.

Parameters:

left -

loffset -

llength -

right -

roffset -

rlength -

Returns:

0 if equal, <0 if left smaller, >0 if right smaller

compareColumns

protected int compareColumns(byte[] left,
                 int loffset,
                 int llength,
                 int lfamilylength,
                 byte[] right,
                 int roffset,
                 int rlength,
                 int rfamilylength)

compareIgnoringPrefix

public int compareIgnoringPrefix(int commonPrefix,
                        byte[] left,
                        int loffset,
                        int llength,
                        byte[] right,
                        int roffset,
                        int rlength)

Overridden

Specified by:

compareIgnoringPrefix in interface KeyValue.SamePrefixComparator<byte[]>

Parameters:

commonPrefix -

left -

loffset -

llength -

right -

roffset -

rlength -

Returns:

0 if equal, <0 if left smaller, >0 if right smaller

matchingRowColumn

public boolean matchingRowColumn(KeyValue left,
                        KeyValue right)

Compares the row and column of two keyvalues for equality

Parameters:

left -

right -

Returns:

True if same row and column.

matchingRows

public boolean matchingRows(KeyValue left,
                   KeyValue right)

Compares the row of two keyvalues for equality

Parameters:

left -

right -

Returns:

True if rows match.

matchingRows

public boolean matchingRows(byte[] left,
                   int loffset,
                   int llength,
                   byte[] right,
                   int roffset,
                   int rlength)

Compare rows. Just calls Bytes.equals, but it's good to have this encapsulated.

Parameters:

left - Left row array.

loffset - Left row offset.

llength - Left row length.

right - Right row array.

roffset - Right row offset.

rlength - Right row length.

Returns:

Whether rows are the same row.

calcIndexKey

public byte[] calcIndexKey(byte[] lastKeyOfPreviousBlock,
                  byte[] firstKeyInBlock)

getShortMidpointKey

public byte[] getShortMidpointKey(byte[] leftKey,
                         byte[] rightKey)

This is a HFile block index key optimization.

Parameters:

leftKey -

rightKey -

Returns:

0 if equal, <0 if left smaller, >0 if right smaller

clone

protected Object clone()
                throws CloneNotSupportedException

Overrides:

clone in class Object

Throws:

CloneNotSupportedException