it.unimi.dsi.mg4j.index
Interface CompressionFlags

All Known Implementing Classes:
Index, IndexReader, IndexWriter, SecondPass

public interface CompressionFlags

This interface provides constants to be used as compression flags for the constructors of the IndexReader and IndexWriter classes.

Of course, this is an instance of the constant interface antipattern. Blame it on Sun for having made static members access so ugly.

Since:
0.6
Author:
Paolo Boldi, Sebastiano Vigna
See Also:
IndexWriter

Field Summary
static int ARITH
          Arithmetic coding (see ArithmeticCoder).
static String[] CODING_NAME
           
static long COUNTS_DEFAULT
          Flag: default value for count coding (γ).
static long COUNTS_DELTA
          Flag: write counts of occurrence lists using δ coding.
static long COUNTS_GAMMA
          Flag: write counts of occurrence lists using γ coding (default).
static int COUNTS_SHIFT
          The mask shift for count coding.
static int DELTA
          δ coding (see OutputBitStream.writeDelta(int)).
static long FREQUENCIES_DEFAULT
          Flag: default value for frequency coding (γ).
static long FREQUENCIES_DELTA
          Flag: write the term frequency using δ coding.
static long FREQUENCIES_GAMMA
          Flag: write the term frequency using γ coding.
static int FREQUENCIES_SHIFT
          The mask shift for frequency coding.
static int GAMMA
          γ coding (see OutputBitStream.writeGamma(int)).
static int GOLOMB
          Golomb coding (see OutputBitStream.writeGolomb(int,int)).
static int INTERP
          Interpolative coding (see InterpolativeCoding).
static int NIBBLE
          Variable-length nibble coding (see OutputBitStream.writeNibble(int)).
static long NO_COUNTS
          Flag: do not write counts (and thus, a fortiori, positions).
static long NO_POSITIONS
          Flag: do not write positions.
static int NONE
          A special value used to denote absence of a feature.
static long POINTERS_DEFAULT
          Flag: default value for pointer coding (Golomb).
static long POINTERS_DELTA
          Flag: write document pointers using δ coding.
static long POINTERS_GAMMA
          Flag: write document pointers using γ coding.
static long POINTERS_GOLOMB
          Flag: write document pointers using Golomb coding with parameter Fast.golombModulus(freq/N) (default).
static int POINTERS_SHIFT
          The mask shift for pointer coding.
static long POSITIONS_ARITH
          Flag: write positions in a document using arithmetic coding.
static long POSITIONS_DEFAULT
          Flag: default value for position coding (Golomb).
static long POSITIONS_DELTA
          Flag: write positions in a document using δ coding.
static long POSITIONS_GAMMA
          Flag: write positions in a document using γ coding.
static long POSITIONS_GOLOMB
          Flag: write positions in a document using Golomb coding with parameter Fast.golombModulus(count/docSize) (default).
static long POSITIONS_INTERP
          Flag: write positions in a document using interpolative coding.
static int POSITIONS_SHIFT
          The mask shift for position coding.
static long POSITIONS_SKEWED_GOLOMB
          Flag: write positions in a document using skewed Golomb coding with parameter Fast.golombModulus(median/docSize).
static int SKEWED_GOLOMB
          Skewed Golomb coding (see OutputBitStream.writeSkewedGolomb(int,int)).
static int UNARY
          Unary coding (see OutputBitStream.writeUnary(int)).
static int ZETA
          ζk coding (see OutputBitStream.writeZeta(int,int)).
 

Field Detail

DELTA

public static final int DELTA
δ coding (see OutputBitStream.writeDelta(int)).

See Also:
Constant Field Values

GAMMA

public static final int GAMMA
γ coding (see OutputBitStream.writeGamma(int)).

See Also:
Constant Field Values

GOLOMB

public static final int GOLOMB
Golomb coding (see OutputBitStream.writeGolomb(int,int)).

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Constant Field Values

SKEWED_GOLOMB

public static final int SKEWED_GOLOMB
Skewed Golomb coding (see OutputBitStream.writeSkewedGolomb(int,int)).

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Constant Field Values

ARITH

public static final int ARITH
Arithmetic coding (see ArithmeticCoder).

See Also:
Constant Field Values

INTERP

public static final int INTERP
Interpolative coding (see InterpolativeCoding).

See Also:
Constant Field Values

UNARY

public static final int UNARY
Unary coding (see OutputBitStream.writeUnary(int)).

See Also:
Constant Field Values

ZETA

public static final int ZETA
ζk coding (see OutputBitStream.writeZeta(int,int)).

See Also:
Constant Field Values

NIBBLE

public static final int NIBBLE
Variable-length nibble coding (see OutputBitStream.writeNibble(int)).

See Also:
Constant Field Values

NONE

public static final int NONE
A special value used to denote absence of a feature.

See Also:
Constant Field Values

CODING_NAME

public static final String[] CODING_NAME

FREQUENCIES_SHIFT

public static final int FREQUENCIES_SHIFT
The mask shift for frequency coding.

See Also:
Constant Field Values

FREQUENCIES_DEFAULT

public static final long FREQUENCIES_DEFAULT
Flag: default value for frequency coding (γ).

See Also:
Constant Field Values

FREQUENCIES_GAMMA

public static final long FREQUENCIES_GAMMA
Flag: write the term frequency using γ coding.

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Constant Field Values

FREQUENCIES_DELTA

public static final long FREQUENCIES_DELTA
Flag: write the term frequency using δ coding.

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Constant Field Values

POINTERS_SHIFT

public static final int POINTERS_SHIFT
The mask shift for pointer coding.

See Also:
Constant Field Values

POINTERS_DEFAULT

public static final long POINTERS_DEFAULT
Flag: default value for pointer coding (Golomb).

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Constant Field Values

POINTERS_GOLOMB

public static final long POINTERS_GOLOMB
Flag: write document pointers using Golomb coding with parameter Fast.golombModulus(freq/N) (default).

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Constant Field Values

POINTERS_GAMMA

public static final long POINTERS_GAMMA
Flag: write document pointers using γ coding.

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Constant Field Values

POINTERS_DELTA

public static final long POINTERS_DELTA
Flag: write document pointers using δ coding.

See Also:
Constant Field Values

COUNTS_SHIFT

public static final int COUNTS_SHIFT
The mask shift for count coding.

See Also:
Constant Field Values

COUNTS_DEFAULT

public static final long COUNTS_DEFAULT
Flag: default value for count coding (γ).

See Also:
Constant Field Values

COUNTS_GAMMA

public static final long COUNTS_GAMMA
Flag: write counts of occurrence lists using γ coding (default).

See Also:
Constant Field Values

COUNTS_DELTA

public static final long COUNTS_DELTA
Flag: write counts of occurrence lists using δ coding.

See Also:
Constant Field Values

NO_COUNTS

public static final long NO_COUNTS
Flag: do not write counts (and thus, a fortiori, positions).

See Also:
Constant Field Values

POSITIONS_SHIFT

public static final int POSITIONS_SHIFT
The mask shift for position coding.

See Also:
Constant Field Values

POSITIONS_DEFAULT

public static final long POSITIONS_DEFAULT
Flag: default value for position coding (Golomb).

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Constant Field Values

POSITIONS_GOLOMB

public static final long POSITIONS_GOLOMB
Flag: write positions in a document using Golomb coding with parameter Fast.golombModulus(count/docSize) (default).

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Constant Field Values

POSITIONS_SKEWED_GOLOMB

public static final long POSITIONS_SKEWED_GOLOMB
Flag: write positions in a document using skewed Golomb coding with parameter Fast.golombModulus(median/docSize).

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Constant Field Values

POSITIONS_GAMMA

public static final long POSITIONS_GAMMA
Flag: write positions in a document using γ coding.

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Constant Field Values

POSITIONS_DELTA

public static final long POSITIONS_DELTA
Flag: write positions in a document using δ coding.

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Constant Field Values

POSITIONS_ARITH

public static final long POSITIONS_ARITH
Flag: write positions in a document using arithmetic coding.

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Constant Field Values

POSITIONS_INTERP

public static final long POSITIONS_INTERP
Flag: write positions in a document using interpolative coding.

See Also:
Constant Field Values

NO_POSITIONS

public static final long NO_POSITIONS
Flag: do not write positions.

See Also:
Constant Field Values