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Java library for persisted low latency messaging (Java 8+)

There is a newer version: 5.27ea0

package net.openhft.chronicle.queue.rollcycles;

import net.openhft.chronicle.queue.RollCycle;

/**
 * These are largely used for testing and benchmarks to almost turn off indexing.
 */
public enum SparseRollCycles implements RollCycle {
    /**
     * 0x20000000 entries per day, indexing every 8th entry
     */
    SMALL_DAILY(/*-----*/"yyyyMMdd'S'", 24 * 60 * 60 * 1000, 8 << 10, 8),
    /**
     * 0x3ffffffff entries per hour with sparse indexing (every 1024th entry)
     */
    LARGE_HOURLY_SPARSE("yyyyMMdd-HH'LS'", 60 * 60 * 1000, 4 << 10, 1024),
    /**
     * 0x3ffffffffff entries per hour with super-sparse indexing (every (2^20)th entry)
     */
    LARGE_HOURLY_XSPARSE("yyyyMMdd-HH'LX'", 60 * 60 * 1000, 2 << 10, 1 << 20),
    /**
     * 0xffffffffffff entries per day with super-sparse indexing (every (2^20)th entry)
     */
    HUGE_DAILY_XSPARSE("yyyyMMdd'HX'", 24 * 60 * 60 * 1000, 16 << 10, 1 << 20),
    ;

    private final String format;
    private final int lengthInMillis;
    private final RollCycleArithmetic arithmetic;

    SparseRollCycles(String format, int lengthInMillis, int indexCount, int indexSpacing) {
        this.format = format;
        this.lengthInMillis = lengthInMillis;
        this.arithmetic = RollCycleArithmetic.of(indexCount, indexSpacing);
    }

    public long maxMessagesPerCycle() {
        return arithmetic.maxMessagesPerCycle();
    }

    @Override
    public String format() {
        return this.format;
    }

    @Override
    public int lengthInMillis() {
        return this.lengthInMillis;
    }

    /**
     * @return this is the size of each index array, note: indexCount^2 is the maximum number of index queue entries.
     */
    @Override
    public int defaultIndexCount() {
        return arithmetic.indexCount();
    }

    @Override
    public int defaultIndexSpacing() {
        return arithmetic.indexSpacing();
    }

    @Override
    public long toIndex(int cycle, long sequenceNumber) {
        return arithmetic.toIndex(cycle, sequenceNumber);
    }

    @Override
    public long toSequenceNumber(long index) {
        return arithmetic.toSequenceNumber(index);
    }

    @Override
    public int toCycle(long index) {
        return arithmetic.toCycle(index);
    }
}