Class 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.
    • Method Summary

      Modifier and Type Method Description
      long add​(org.apache.lucene.util.BytesRef key)
      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)
      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 Detail

      • BytesRefHash

        public BytesRefHash​(long capacity,
                            BigArrays bigArrays)
      • BytesRefHash

        public BytesRefHash​(long capacity,
                            float maxLoadFactor,
                            BigArrays bigArrays)
    • Method Detail

      • 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
      • 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.
      • 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()