org.elasticsearch.common.util

Class LongHash

java.lang.Object

org.elasticsearch.common.util.LongHash

All Implemented Interfaces:

AutoCloseable, Releasable

public final class LongHash
extends Object

Specialized hash table implementation similar to BytesRefHash that maps long values to ids. Collisions are resolved with open addressing and linear probing, growth is smooth thanks to BigArrays and capacity is always a multiple of 2 for faster identification of buckets. This class is not thread-safe.

Constructor Summary

Constructors

Constructor and Description
LongHash(long capacity, BigArrays bigArrays)
LongHash(long capacity, float maxLoadFactor, BigArrays bigArrays)

Method Summary

Methods

Modifier and Type	Method and Description
long	add(long key) Try to add key.
long	capacity() Return the number of allocated slots to store this hash table.
void	close()
long	find(long key) Get the id associated with key or -1 if the key is not contained in the hash.
long	get(long id) Return the key at 0 <= index <= capacity().
protected void	grow()
long	id(long index) Get the id associated with key at 0 <= index <= capacity() or -1 if this slot is unused.
protected long	id(long index, long id)
protected void	removeAndAdd(long index) Remove the entry at the given index and add it back
protected void	resize(long capacity) Resize to the given capacity.
long	size() Return the number of longs in this hash table.
protected boolean	used(long bucket)

Methods inherited from class java.lang.Object

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

Constructor Detail

LongHash

public LongHash(long capacity,
        BigArrays bigArrays)

LongHash

public LongHash(long capacity,
        float maxLoadFactor,
        BigArrays bigArrays)

Method Detail

get

public long get(long id)

Return the key at 0 <= index <= capacity(). The result is undefined if the slot is unused.

find

public long find(long key)

Get the id associated with key or -1 if the key is not contained in the hash.

add

public long add(long key)

Try to add key. Return its newly allocated id if it wasn't in the hash table yet, or -1-id if it was already present in the hash table.

removeAndAdd

protected void removeAndAdd(long index)

Remove the entry at the given index and add it back

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Releasable

id

public long id(long index)

Get the id associated with key at 0 <= index <= capacity() or -1 if this slot is unused.

id

protected final long id(long index,
      long id)

resize

protected void resize(long capacity)

Resize to the given capacity.

used

protected boolean used(long bucket)

capacity

public long capacity()

Return the number of allocated slots to store this hash table.

size

public long size()

Return the number of longs in this hash table.

grow

protected final void grow()