Examples of org.apache.lucene.util.encoding.EightFlagsIntEncoder

org.apache.lucene.util.encoding.EightFlagsIntEncoder

A {@link ChunksIntEncoder} which encodes data in chunks of 8. Every group starts with a singlebyte (called indicator) which represents 8 - 1 bit flags, where the value:

1 means the encoded value is '1'
0 means the value is encoded using {@link VInt8IntEncoder}, and the encoded bytes follow the indicator.
Since value 0 is illegal, and 1 is encoded in the indicator, the actual value that is encoded is value-2, which saves some more bits.

Encoding example:

Original values: 6, 16, 5, 9, 7, 1
After sorting: 1, 5, 6, 7, 9, 16
D-Gap computing: 1, 4, 1, 1, 2, 5 (so far - done by {@link DGapIntEncoder})
Encoding: 1,0,1,1,0,0,0,0 as the indicator, by 2 (4-2), 0 (2-2), 3 (5-2).
Binary encode: 0 | 0 | 0 | 0 | 1 | 1 | 0 | 1 00000010 00000000 00000011 (indicator is underlined).
NOTE: the order of the values in the indicator is lsb ⇒ msb, which allows for more efficient decoding.

@lucene.experimental

    System.out.println(separator);


    encoderTest(new VInt8IntEncoder(), facetIDs, loopFactor);
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new VInt8IntEncoder())), facetIDs, loopFactor);
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new VInt8IntEncoder()))), facetIDs, loopFactor);
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new EightFlagsIntEncoder()))), facetIDs, loopFactor);
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new FourFlagsIntEncoder()))), facetIDs, loopFactor);
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new NOnesIntEncoder(3)))), facetIDs, loopFactor);
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new NOnesIntEncoder(4)))), facetIDs, loopFactor);


    System.out.println();

    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new VInt8IntEncoder()))));
  }


  @Test
  public void testSortingUniqueDGapEightFlags() {
    encoderTest(new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new EightFlagsIntEncoder()))));
  }

Related Classes of org.apache.lucene.util.encoding.EightFlagsIntEncoder

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