ml.shifu.guagua.util
类 MemoryDiskList<T extends Serializable>

java.lang.Object
  ml.shifu.guagua.util.MemoryDiskList<T>

所有已实现的接口：

Iterable<T>, AppendList<T>

public class MemoryDiskList<T extends Serializable>
extends Object
implements AppendList<T>

A list to store data firstly into memory then into disk if over threshold.

Only two stages support in such kind of list. The first one is WRITE, the next is read. So far random WRITE and READ are not supported in this list.

WARNING: close() should be called at last to release file descriptor.

User should provide fileName in constructor and only one file is used to store data.

作者：

Zhang David (pengzhang@paypal.com)

嵌套类摘要

从接口 ml.shifu.guagua.util.AppendList 继承的嵌套类/接口

AppendList.State

构造方法摘要

MemoryDiskList()
Default constructor.

MemoryDiskList(List<T> delegationList)
Constructor with only memory delegationList.

MemoryDiskList(long maxSize)
Constructor with only memory bytes size limit.

MemoryDiskList(long maxSize, List<T> delegationList)
Constructor with max bytes size of memory and delegationList.

MemoryDiskList(long maxSize, List<T> delegationList, String fileName)
Constructor with max bytes size of memory and delegationList and disk file name in current working dir.

MemoryDiskList(long maxSize, String fileName)
Constructor with max bytes size of memory and disk file name in current working dir.

方法摘要

boolean	append(T t) Append object to this list
void	clear() Clear all elements.
void	close() Close disk stream.
Iterator<T>	iterator()
void	reOpen() Reopen stream for iteration.
long	size() Return size of this list.
void	switchState() After appending, switch state from WRITE to READ to allow iterating.

从类 java.lang.Object 继承的方法

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

构造方法详细信息

MemoryDiskList

public MemoryDiskList(long maxSize,
                      List<T> delegationList)

Constructor with max bytes size of memory and delegationList. Disk file name is random filename in current working dir.

MemoryDiskList

public MemoryDiskList(List<T> delegationList)

Constructor with only memory delegationList. By default no limit of bytes size in memory.

MemoryDiskList

public MemoryDiskList(long maxSize,
                      List<T> delegationList,
                      String fileName)

Constructor with max bytes size of memory and delegationList and disk file name in current working dir.

MemoryDiskList

public MemoryDiskList(long maxSize,
                      String fileName)

Constructor with max bytes size of memory and disk file name in current working dir. By default LinkedList is used for memory list.

MemoryDiskList

public MemoryDiskList(long maxSize)

Constructor with only memory bytes size limit.

MemoryDiskList

public MemoryDiskList()

Default constructor. By default no memory limit, LinkedList and random file name.

方法详细信息

append

public boolean append(T t)

从接口 AppendList 复制的描述

Append object to this list

指定者：

接口 AppendList<T extends Serializable> 中的 append

参数：

t - the object to append

返回：

whether appending object successful

close

public void close()

Close disk stream. Should be called at the end of usage of MemoryDiskList.

reOpen

public void reOpen()

Reopen stream for iteration.

iterator

public Iterator<T> iterator()

指定者：

接口 Iterable<T extends Serializable> 中的 iterator

switchState

public void switchState()

从接口 AppendList 复制的描述

After appending, switch state from WRITE to READ to allow iterating.

指定者：

接口 AppendList<T extends Serializable> 中的 switchState

size

public long size()

从接口 AppendList 复制的描述

Return size of this list.

指定者：

接口 AppendList<T extends Serializable> 中的 size

clear

public void clear()

从接口 AppendList 复制的描述

Clear all elements.

指定者：

接口 AppendList<T extends Serializable> 中的 clear