org.apache.hadoop.hbase.types

类 FixedLengthWrapper<T>

java.lang.Object

org.apache.hadoop.hbase.types.FixedLengthWrapper<T>

所有已实现的接口:

DataType<T>

直接已知子类:

RawBytesFixedLength, RawStringFixedLength

@InterfaceAudience.Public
public class FixedLengthWrapper<T>
extends Object
implements DataType<T>

Wraps an existing DataType implementation as a fixed-length version of itself. This has the useful side-effect of turning an existing DataType which is not skippable into a skippable variant.

字段概要

字段

限定符和类型	字段和说明
protected DataType<T>	base
protected int	length

构造器概要

构造器

构造器和说明
FixedLengthWrapper(DataType<T> base, int length) Create a fixed-length version of the wrapped.

方法概要

限定符和类型	方法和说明
T	decode(PositionedByteRange src) Read an instance of T from the buffer src.
int	encode(PositionedByteRange dst, T val) Write instance val into buffer dst.
Class<T>	encodedClass() Inform consumers over what type this DataType operates.
int	encodedLength(T val) Inform consumers how long the encoded byte[] will be.
int	getLength() Retrieve the maximum length (in bytes) of encoded values.
Order	getOrder() Retrieve the sort Order imposed by this data type, or null when natural ordering is not preserved.
boolean	isNullable() Indicates whether this instance supports encoding null values.
boolean	isOrderPreserving() Indicates whether this instance writes encoded byte[]'s which preserve the natural sort order of the unencoded value.
boolean	isSkippable() Indicates whether this instance is able to skip over it's encoded value.
int	skip(PositionedByteRange src) Skip src's position forward over one encoded value.

从类继承的方法 java.lang.Object

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

字段详细资料

base

protected final DataType<T> base

length

protected final int length

构造器详细资料

FixedLengthWrapper

public FixedLengthWrapper(DataType<T> base,
                          int length)

Create a fixed-length version of the wrapped.

参数:

base - the DataType to restrict to a fixed length.

length - the maximum length (in bytes) for encoded values.

方法详细资料

getLength

public int getLength()

Retrieve the maximum length (in bytes) of encoded values.

isOrderPreserving

public boolean isOrderPreserving()

从接口复制的说明: DataType

Indicates whether this instance writes encoded byte[]'s which preserve the natural sort order of the unencoded value.

指定者:

isOrderPreserving 在接口中 DataType<T>

返回:

true when natural order is preserved, false otherwise.

getOrder

public Order getOrder()

从接口复制的说明: DataType

Retrieve the sort Order imposed by this data type, or null when natural ordering is not preserved. Value is either ascending or descending. Default is assumed to be Order.ASCENDING.

指定者:

getOrder 在接口中 DataType<T>

isNullable

public boolean isNullable()

从接口复制的说明: DataType

Indicates whether this instance supports encoding null values. This depends on the implementation details of the encoding format. All DataTypes that support null should treat null as comparing less than any non-null value for default sort ordering purposes.

指定者:

isNullable 在接口中 DataType<T>

返回:

true when null is supported, false otherwise.

isSkippable

public boolean isSkippable()

从接口复制的说明: DataType

Indicates whether this instance is able to skip over it's encoded value. DataTypes that are not skippable can only be used as the right-most field of a Struct.

指定者:

isSkippable 在接口中 DataType<T>

encodedLength

public int encodedLength(T val)

从接口复制的说明: DataType

Inform consumers how long the encoded byte[] will be.

指定者:

encodedLength 在接口中 DataType<T>

参数:

val - The value to check.

返回:

the number of bytes required to encode val.a

encodedClass

public Class<T> encodedClass()

从接口复制的说明: DataType

Inform consumers over what type this DataType operates. Useful when working with bare DataType instances.

指定者:

encodedClass 在接口中 DataType<T>

skip

public int skip(PositionedByteRange src)

从接口复制的说明: DataType

Skip src's position forward over one encoded value.

指定者:

skip 在接口中 DataType<T>

参数:

src - the buffer containing the encoded value.

返回:

number of bytes skipped.

decode

public T decode(PositionedByteRange src)

从接口复制的说明: DataType

Read an instance of T from the buffer src.

指定者:

decode 在接口中 DataType<T>

参数:

src - the buffer containing the encoded value.

encode

public int encode(PositionedByteRange dst,
                  T val)

从接口复制的说明: DataType

Write instance val into buffer dst.

指定者:

encode 在接口中 DataType<T>

参数:

dst - the buffer containing the encoded value.

val - the value to encode onto dst.

返回:

number of bytes written.