Package org.apache.commons.compress.compressors.lz77support

Class Parameters

  • public final class Parameters
extends java.lang.Object
    Parameters of the compressor.

    • Field Detail

      • TRUE_MIN_BACK_REFERENCE_LENGTH

        public static final int TRUE_MIN_BACK_REFERENCE_LENGTH
        The hard-coded absolute minimal length of a back-reference.
        See Also:
        Constant Field Values

    • Method Detail

      • builder

        public static Parameters.Builder builder​(int windowSize)
        Initializes the builder for the compressor's parameters with a minBackReferenceLength of 3 and max*Length equal to windowSize - 1.

        It is recommended to not use this method directly but rather tune a pre-configured builder created by a format specific factory like SnappyCompressorOutputStream.createParameterBuilder(int).

        Parameters:
        windowSize - the size of the sliding window - this determines the maximum offset a back-reference can take. Must be a power of two.
        Returns:
        a builder configured for the given window size
        Throws:
        java.lang.IllegalArgumentException - if windowSize is not a power of two.

      • getWindowSize

        public int getWindowSize()
        Gets the size of the sliding window - this determines the maximum offset a back-reference can take.
        Returns:
        the size of the sliding window

      • getMinBackReferenceLength

        public int getMinBackReferenceLength()
        Gets the minimal length of a back-reference found.
        Returns:
        the minimal length of a back-reference found

      • getMaxBackReferenceLength

        public int getMaxBackReferenceLength()
        Gets the maximal length of a back-reference found.
        Returns:
        the maximal length of a back-reference found

      • getMaxOffset

        public int getMaxOffset()
        Gets the maximal offset of a back-reference found.
        Returns:
        the maximal offset of a back-reference found

      • getMaxLiteralLength

        public int getMaxLiteralLength()
        Gets the maximal length of a literal block.
        Returns:
        the maximal length of a literal block

      • getNiceBackReferenceLength

        public int getNiceBackReferenceLength()
        Gets the length of a back-reference that is considered nice enough to stop searching for longer ones.
        Returns:
        the length of a back-reference that is considered nice enough to stop searching

      • getMaxCandidates

        public int getMaxCandidates()
        Gets the maximum number of back-reference candidates to consider.
        Returns:
        the maximum number of back-reference candidates to consider

      • getLazyMatching

        public boolean getLazyMatching()
        Gets whether to perform lazy matching.
        Returns:
        whether to perform lazy matching

      • getLazyMatchingThreshold

        public int getLazyMatchingThreshold()
        Gets the threshold for lazy matching.
        Returns:
        the threshold for lazy matching