org.apache.hadoop.io

类 CompressedWritable

java.lang.Object

org.apache.hadoop.io.CompressedWritable

所有已实现的接口:

Writable

public abstract class CompressedWritable
extends Object
implements Writable

A base-class for Writables which store themselves compressed and lazily inflate on field access. This is useful for large objects whose fields are not be altered during a map or reduce operation: leaving the field data compressed makes copying the instance from one file to another much faster.

构造器概要

构造器

构造器和说明
CompressedWritable()

方法概要

方法

限定符和类型	方法和说明
protected void	ensureInflated() Must be called by all methods which access fields to ensure that the data has been uncompressed.
void	readFields(DataInput in) Deserialize the fields of this object from in.
protected abstract void	readFieldsCompressed(DataInput in) Subclasses implement this instead of readFields(DataInput).
void	write(DataOutput out) Serialize the fields of this object to out.
protected abstract void	writeCompressed(DataOutput out) Subclasses implement this instead of write(DataOutput).

从类继承的方法 java.lang.Object

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

构造器详细资料

CompressedWritable

public CompressedWritable()

方法详细资料

readFields

public final void readFields(DataInput in)
                      throws IOException

从接口复制的说明: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

指定者:

readFields 在接口中 Writable

参数:

in - DataInput to deseriablize this object from.

抛出:

IOException

ensureInflated

protected void ensureInflated()

Must be called by all methods which access fields to ensure that the data has been uncompressed.

readFieldsCompressed

protected abstract void readFieldsCompressed(DataInput in)
                                      throws IOException

Subclasses implement this instead of readFields(DataInput).

抛出:

IOException

write

public final void write(DataOutput out)
                 throws IOException

从接口复制的说明: Writable

Serialize the fields of this object to out.

指定者:

write 在接口中 Writable

参数:

out - DataOuput to serialize this object into.

抛出:

IOException

writeCompressed

protected abstract void writeCompressed(DataOutput out)
                                 throws IOException

Subclasses implement this instead of write(DataOutput).

抛出:

IOException