org.apache.hadoop.hive.ql.exec.persistence

Class HashMapWrapper

java.lang.Object

org.apache.hadoop.hive.ql.exec.persistence.AbstractMapJoinTableContainer

org.apache.hadoop.hive.ql.exec.persistence.HashMapWrapper

All Implemented Interfaces:

java.io.Serializable, MapJoinTableContainer

public class HashMapWrapper
extends AbstractMapJoinTableContainer
implements java.io.Serializable

Simple wrapper for persistent Hashmap implementing only the put/get/remove/clear interface. The main memory hash table acts as a cache and all put/get will operate on it first. If the size of the main memory hash table exceeds a certain threshold, new elements will go into the persistent hash table.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.commons.logging.Log	LOG

Constructor Summary

Constructors

Constructor and Description
HashMapWrapper()
HashMapWrapper(int threshold)
HashMapWrapper(int threshold, float loadFactor) Constructor.
HashMapWrapper(java.util.Map<java.lang.String,java.lang.String> metaData)

Method Summary

Modifier and Type	Method and Description
void	clear()
java.util.Set<java.util.Map.Entry<MapJoinKey,MapJoinRowContainer>>	entrySet()
MapJoinRowContainer	get(MapJoinKey key)
void	put(MapJoinKey key, MapJoinRowContainer value)
int	size()

Methods inherited from class org.apache.hadoop.hive.ql.exec.persistence.AbstractMapJoinTableContainer

getMetaData, putMetaData

Methods inherited from class java.lang.Object

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

Field Detail

LOG

protected static final org.apache.commons.logging.Log LOG

Constructor Detail

HashMapWrapper

public HashMapWrapper(int threshold,
                      float loadFactor)

Constructor.

Parameters:

threshold - User specified threshold to store new values into persistent storage.

HashMapWrapper

public HashMapWrapper(java.util.Map<java.lang.String,java.lang.String> metaData)

HashMapWrapper

public HashMapWrapper(int threshold)

HashMapWrapper

public HashMapWrapper()

Method Detail

get

public MapJoinRowContainer get(MapJoinKey key)

Specified by:

get in interface MapJoinTableContainer

put

public void put(MapJoinKey key,
                MapJoinRowContainer value)

Specified by:

put in interface MapJoinTableContainer

size

public int size()

Specified by:

size in interface MapJoinTableContainer

entrySet

public java.util.Set<java.util.Map.Entry<MapJoinKey,MapJoinRowContainer>> entrySet()

Specified by:

entrySet in interface MapJoinTableContainer

clear

public void clear()

Specified by:

clear in interface MapJoinTableContainer