org.apache.hadoop.hbase

类 CellComparatorImpl

java.lang.Object

org.apache.hadoop.hbase.CellComparatorImpl

所有已实现的接口:

Comparator<Cell>, CellComparator

直接已知子类:

CellComparatorImpl.MetaCellComparator

@InterfaceAudience.Private
 @InterfaceStability.Evolving
public class CellComparatorImpl
extends Object
implements CellComparator

Compare two HBase cells. Do not use this method comparing -ROOT- or hbase:meta cells. Cells from these tables need a specialized comparator, one that takes account of the special formatting of the row where we have commas to delimit table from regionname, from row. See KeyValue for how it has a special comparator to do hbase:meta cells and yet another for -ROOT-.

While using this comparator for {compareRows(Cell, Cell) et al, the hbase:meta cells format should be taken into consideration, for which the instance of this comparator should be used. In all other cases the static APIs in this comparator would be enough

HOT methods. We spend a good portion of CPU comparing. Anything that makes the compare faster will likely manifest at the macro level. See also BBKVComparator. Use it when mostly ByteBufferKeyValues.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	CellComparatorImpl.MetaCellComparator A CellComparatorImpl for hbase:meta catalog table KeyValues.

字段概要

字段

限定符和类型	字段和说明
static CellComparatorImpl	COMPARATOR Comparator for plain key/values; i.e. non-catalog table key/values.
static CellComparatorImpl	META_COMPARATOR A CellComparatorImpl for hbase:meta catalog table KeyValues.

构造器概要

构造器

构造器和说明
CellComparatorImpl()

方法概要

限定符和类型	方法和说明
int	compare(Cell a, Cell b) Lexographically compares two cells.
int	compare(Cell a, Cell b, boolean ignoreSequenceid) Compare cells.
int	compareColumns(Cell left, Cell right) Compares the family and qualifier part of the cell
int	compareFamilies(Cell left, Cell right) Compare the families of left and right cell
int	compareQualifiers(Cell left, Cell right) Compare the qualifiers part of the left and right cells.
int	compareRows(Cell left, byte[] right, int roffset, int rlength) Compares the row part of the cell with a simple plain byte[] like the stopRow in Scan.
int	compareRows(Cell left, Cell right) Compares the rows of the left and right cell.
int	compareTimestamps(Cell left, Cell right) Compares cell's timestamps in DESCENDING order.
int	compareTimestamps(long ltimestamp, long rtimestamp) Compares cell's timestamps in DESCENDING order.
int	compareWithoutRow(Cell left, Cell right) Lexographically compares the two cells excluding the row part.
Comparator	getSimpleComparator()

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.hadoop.hbase.CellComparator

getInstance

从接口继承的方法 java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

字段详细资料

COMPARATOR

public static final CellComparatorImpl COMPARATOR

Comparator for plain key/values; i.e. non-catalog table key/values. Works on Key portion of KeyValue only.

META_COMPARATOR

public static final CellComparatorImpl META_COMPARATOR

A CellComparatorImpl for hbase:meta catalog table KeyValues.

构造器详细资料

CellComparatorImpl

public CellComparatorImpl()

方法详细资料

compare

public final int compare(Cell a,
                         Cell b)

从接口复制的说明: CellComparator

Lexographically compares two cells. The key part of the cell is taken for comparison which includes row, family, qualifier, timestamp and type

指定者:

compare 在接口中 Comparator<Cell>

指定者:

compare 在接口中 CellComparator

参数:

a - the left hand side cell

b - the right hand side cell

返回:

greater than 0 if leftCell is bigger, less than 0 if rightCell is bigger, 0 if both cells are equal

compare

public int compare(Cell a,
                   Cell b,
                   boolean ignoreSequenceid)

从接口复制的说明: CellComparator

Compare cells.

指定者:

compare 在接口中 CellComparator

ignoreSequenceid - True if we are to compare the key portion only and ignore the sequenceid. Set to false to compare key and consider sequenceid.

返回:

0 if equal, -1 if a < b, and +1 if a > b.

compareColumns

public final int compareColumns(Cell left,
                                Cell right)

Compares the family and qualifier part of the cell

返回:

0 if both cells are equal, 1 if left cell is bigger than right, -1 otherwise

compareFamilies

public final int compareFamilies(Cell left,
                                 Cell right)

Compare the families of left and right cell

指定者:

compareFamilies 在接口中 CellComparator

参数:

left - the left hand side cell

right - the right hand side cell

返回:

0 if both cells are equal, 1 if left cell is bigger than right, -1 otherwise

compareQualifiers

public final int compareQualifiers(Cell left,
                                   Cell right)

Compare the qualifiers part of the left and right cells.

指定者:

compareQualifiers 在接口中 CellComparator

参数:

left - the left hand side cell

right - the right hand side cell

返回:

0 if both cells are equal, 1 if left cell is bigger than right, -1 otherwise

compareRows

public int compareRows(Cell left,
                       Cell right)

Compares the rows of the left and right cell. For the hbase:meta case this method is overridden such that it can handle hbase:meta cells. The caller should ensure using the appropriate comparator for hbase:meta.

指定者:

compareRows 在接口中 CellComparator

参数:

left - the left hand side cell

right - the right hand side cell

返回:

0 if both cells are equal, 1 if left cell is bigger than right, -1 otherwise

compareRows

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

Compares the row part of the cell with a simple plain byte[] like the stopRow in Scan. This should be used with context where for hbase:meta cells the {META_COMPARATOR should be used

指定者:

compareRows 在接口中 CellComparator

参数:

left - the cell to be compared

right - the kv serialized byte[] to be compared with

roffset - the offset in the byte[]

rlength - the length in the byte[]

返回:

0 if both cell and the byte[] are equal, 1 if the cell is bigger than byte[], -1 otherwise

compareWithoutRow

public final int compareWithoutRow(Cell left,
                                   Cell right)

从接口复制的说明: CellComparator

Lexographically compares the two cells excluding the row part. It compares family, qualifier, timestamp and the type

指定者:

compareWithoutRow 在接口中 CellComparator

参数:

left - the left hand side cell

right - the right hand side cell

返回:

greater than 0 if leftCell is bigger, less than 0 if rightCell is bigger, 0 if both cells are equal

compareTimestamps

public int compareTimestamps(Cell left,
                             Cell right)

从接口复制的说明: CellComparator

Compares cell's timestamps in DESCENDING order. The below older timestamps sorting ahead of newer timestamps looks wrong but it is intentional. This way, newer timestamps are first found when we iterate over a memstore and newer versions are the first we trip over when reading from a store file.

指定者:

compareTimestamps 在接口中 CellComparator

参数:

left - the left hand side cell

right - the right hand side cell

返回:

1 if left's timestamp < right's timestamp -1 if left's timestamp > right's timestamp 0 if both timestamps are equal

compareTimestamps

public int compareTimestamps(long ltimestamp,
                             long rtimestamp)

从接口复制的说明: CellComparator

Compares cell's timestamps in DESCENDING order. The below older timestamps sorting ahead of newer timestamps looks wrong but it is intentional. This way, newer timestamps are first found when we iterate over a memstore and newer versions are the first we trip over when reading from a store file.

指定者:

compareTimestamps 在接口中 CellComparator

参数:

ltimestamp - the left cell's timestamp

rtimestamp - the right cell's timestamp

返回:

1 if left's timestamp < right's timestamp -1 if left's timestamp > right's timestamp 0 if both timestamps are equal

getSimpleComparator

public Comparator getSimpleComparator()

指定者:

getSimpleComparator 在接口中 CellComparator

返回:

A dumbed-down, fast comparator for hbase2 base-type, the ByteBufferKeyValue. Create an instance when you make a new memstore, when you know only BBKVs will be passed. Do not pollute with types other than BBKV if can be helped; the Comparator will slow.