Package org.elasticsearch.common.util

Class BytesRefHash

java.lang.Object
org.elasticsearch.common.util.BytesRefHash
All Implemented Interfaces:
java.io.Closeable, java.lang.AutoCloseable, Releasable
public final class BytesRefHash
extends java.lang.Object
Specialized hash table implementation similar to Lucene's BytesRefHash that maps BytesRef values to ids. Collisions are resolved with open addressing and linear probing, growth is smooth thanks to BigArrays, hashes are cached for faster re-hashing and capacity is always a multiple of 2 for faster identification of buckets. This class is not thread-safe.

  • Constructor Summary

    Constructors 
    Constructor Description
    BytesRefHash​(long capacity, float maxLoadFactor, BigArrays bigArrays)  
    BytesRefHash​(long capacity, BigArrays bigArrays)  

  • Method Summary

    Modifier and Type Method Description
    long add​(org.apache.lucene.util.BytesRef key)
    Sugar to add(key, key.hashCode().
    long add​(org.apache.lucene.util.BytesRef key, int code)
    Try to add key.
    long capacity()
    Return the number of allocated slots to store this hash table.
    void close()  
    long find​(org.apache.lucene.util.BytesRef key)
    Sugar for find(key, key.hashCode()
    long find​(org.apache.lucene.util.BytesRef key, int code)
    Get the id associated with key
    org.apache.lucene.util.BytesRef get​(long id, org.apache.lucene.util.BytesRef dest)
    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 Details

  • Method Details

    • get

      public org.apache.lucene.util.BytesRef get​(long id, org.apache.lucene.util.BytesRef dest)
      Return the key at 0 <= index <= capacity(). The result is undefined if the slot is unused.

      Beware that the content of the BytesRef may become invalid as soon as close() is called

    • find

      public long find​(org.apache.lucene.util.BytesRef key, int code)
      Get the id associated with key

    • find

      public long find​(org.apache.lucene.util.BytesRef key)
      Sugar for find(key, key.hashCode()

    • add

      public long add​(org.apache.lucene.util.BytesRef key, int code)
      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.

    • add

      public long add​(org.apache.lucene.util.BytesRef key)
      Sugar to add(key, key.hashCode().

    • 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 java.lang.AutoCloseable
      Specified by:
      close in interface java.io.Closeable
      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()