@InterfaceAudience.Public public class TerminatedWrapper<T> extends Object implements DataType<T>
DataType implementation as a terminated
version of itself. This has the useful side-effect of turning an existing
DataType which is not skippable into a
skippable variant.| 构造器和说明 |
|---|
TerminatedWrapper(DataType<T> wrapped,
byte[] term)
Create a terminated version of the
wrapped. |
TerminatedWrapper(DataType<T> wrapped,
String term)
Create a terminated version of the
wrapped. |
| 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. |
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. |
protected int |
terminatorPosition(PositionedByteRange src)
Return the position at which
term begins within src,
or -1 if term is not found. |
public TerminatedWrapper(DataType<T> wrapped, byte[] term)
wrapped.IllegalArgumentException - when term is null or empty.public TerminatedWrapper(DataType<T> wrapped, String term)
wrapped.
term is converted to a byte[] using
Bytes.toBytes(String).IllegalArgumentException - when term is null or empty.public boolean isOrderPreserving()
DataTypebyte[]'s
which preserve the natural sort order of the unencoded value.isOrderPreserving 在接口中 DataType<T>true when natural order is preserved,
false otherwise.public Order getOrder()
DataTypeOrder 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.public boolean isNullable()
DataTypeDataTypes that support null should treat null as comparing
less than any non-null value for default sort ordering purposes.isNullable 在接口中 DataType<T>true when null is supported, false otherwise.public boolean isSkippable()
DataTypeDataTypes that are not skippable can only be used as the
right-most field of a Struct.isSkippable 在接口中 DataType<T>public int encodedLength(T val)
DataTypebyte[] will be.encodedLength 在接口中 DataType<T>val - The value to check.val.apublic Class<T> encodedClass()
DataTypeDataType operates. Useful
when working with bare DataType instances.encodedClass 在接口中 DataType<T>protected int terminatorPosition(PositionedByteRange src)
term begins within src,
or -1 if term is not found.public int skip(PositionedByteRange src)
src's position forward over one encoded value.skip 在接口中 DataType<T>src - the buffer containing the encoded value.IllegalArgumentException - when the terminator sequence is not found.public T decode(PositionedByteRange src)
DataTypeT from the buffer src.public int encode(PositionedByteRange dst, T val)
val into buffer dst.encode 在接口中 DataType<T>dst - the buffer containing the encoded value.val - the value to encode onto dst.IllegalArgumentException - when the encoded representation of
val contains the term sequence.Copyright © 2007–2019 The Apache Software Foundation. All rights reserved.