Module org.apache.lucene.core
Package org.apache.lucene.util.compress

Class LZ4.HighCompressionHashTable

java.lang.Object
org.apache.lucene.util.compress.LZ4.HashTable
org.apache.lucene.util.compress.LZ4.HighCompressionHashTable
Enclosing class:
LZ4
public static final class LZ4.HighCompressionHashTable extends LZ4.HashTable
A higher-precision LZ4.HashTable. It stores up to 256 occurrences of 4-bytes sequences in the last 2^16 bytes, which makes it much more likely to find matches than LZ4.FastCompressionHashTable.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private int
    attempts
     
    private int
    base
     
    private byte[]
    bytes
     
    private final short[]
    chainTable
     
    private int
    end
     
    private final int[]
    hashTable
     
    private static final int
    MASK
     
    private static final int
    MAX_ATTEMPTS
     
    private int
    next
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    HighCompressionHashTable()
    Sole constructor

  • Method Summary

    Modifier and Type
    Method
    Description
    private void
    addHash(int off)
     
    (package private) boolean
    assertReset()
     
    (package private) int
    get(int off)
    Advance the cursor to off and return an index that stored the same 4 bytes as b[o:o+4).
    (package private) void
    initDictionary(int dictLen)
    Init dictLen bytes to be used as a dictionary.
    (package private) int
    previous(int off)
    Return an index that less than off and stores the same 4 bytes.
    (package private) void
    reset(byte[] bytes, int off, int len)
    Reset this hash table in order to compress the given content.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • MAX_ATTEMPTS

      private static final int MAX_ATTEMPTS
      See Also:

    • MASK

      private static final int MASK
      See Also:

    • bytes

      private byte[] bytes

    • base

      private int base

    • next

      private int next

    • end

      private int end

    • hashTable

      private final int[] hashTable

    • chainTable

      private final short[] chainTable

    • attempts

      private int attempts

  • Constructor Details

    • HighCompressionHashTable

      public HighCompressionHashTable()
      Sole constructor

  • Method Details

    • reset

      void reset(byte[] bytes, int off, int len)
      Description copied from class: LZ4.HashTable
      Reset this hash table in order to compress the given content.
      Specified by:
      reset in class LZ4.HashTable

    • initDictionary

      void initDictionary(int dictLen)
      Description copied from class: LZ4.HashTable
      Init dictLen bytes to be used as a dictionary.
      Specified by:
      initDictionary in class LZ4.HashTable

    • get

      int get(int off)
      Description copied from class: LZ4.HashTable
      Advance the cursor to off and return an index that stored the same 4 bytes as b[o:o+4). This may only be called on strictly increasing sequences of offsets. A return value of -1 indicates that no other index could be found.
      Specified by:
      get in class LZ4.HashTable

    • addHash

      private void addHash(int off)

    • previous

      int previous(int off)
      Description copied from class: LZ4.HashTable
      Return an index that less than off and stores the same 4 bytes. Unlike LZ4.HashTable.get(int), it doesn't need to be called on increasing offsets. A return value of -1 indicates that no other index could be found.
      Specified by:
      previous in class LZ4.HashTable

    • assertReset

      boolean assertReset()
      Specified by:
      assertReset in class LZ4.HashTable