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:

Serializable, MapJoinTableContainer

public class HashMapWrapper
extends AbstractMapJoinTableContainer
implements 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

Constructor Summary

HashMapWrapper()

HashMapWrapper(int threshold)

HashMapWrapper(int threshold, float loadFactor)
Constructor.

HashMapWrapper(Map<String,String> metaData)

Method Summary

void	clear()
Set<Map.Entry<MapJoinKey,MapJoinRowContainer>>	entrySet()
MapJoinRowContainer	get(MapJoinKey key)
MapJoinKey	getAnyKey()
void	put(MapJoinKey key, MapJoinRowContainer value)
int	size()

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

getMetaData

Methods inherited from class java.lang.Object

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

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(Map<String,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 Set<Map.Entry<MapJoinKey,MapJoinRowContainer>> entrySet()

Specified by:

entrySet in interface MapJoinTableContainer

clear

public void clear()

Specified by:

clear in interface MapJoinTableContainer

getAnyKey

public MapJoinKey getAnyKey()

Specified by:

getAnyKey in interface MapJoinTableContainer