RollCycle (OpenHFT/Chronicle-Queue 5.23ea3 API)

All Known Implementing Classes:

RollCycles
```
public interface RollCycle
```

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`int`	`current(net.openhft.chronicle.core.time.TimeProvider time, long epoch)` Returns the current cycle.
`int`	`defaultIndexCount()`
`int`	`defaultIndexSpacing()` Returns the space between excerpts that are explicitly indexed.
`@NotNull String`	`format()` Returns the format that is to be applied when file names are calculated for a new roll cycle.
`int`	`lengthInMillis()` Returns the length in milliseconds (i.e.
`long`	`maxMessagesPerCycle()`
`int`	`toCycle(long index)` Returns the cycle for the given `index`.
`long`	`toIndex(int cycle, long sequenceNumber)` Returns the index for the provided `cycle` and `sequenceNumber`.
`long`	`toSequenceNumber(long index)` Returns the sequence number for the provided `index`.

- Method Detail
  - format
```
@NotNull
@NotNull String format()
```
    Returns the format that is to be applied when file names are calculated for a new roll cycle.
    For example, the following formats can be returned:
    - "yyyyMMdd-HHmm" (MINUTELY)
    - "yyyyMMdd" (DAILY)
    Lexicographical order of formatted cycles must preserve chronological order, i.e. if cycle1 < cycle2, the same relation must be kept for their string representations.
    Returns:
    
    the format that is to be applied when file names are calculated for a new roll cycle
  - lengthInMillis
```
int lengthInMillis()
```
    Returns the length in milliseconds (i.e. the maximum duration) for a roll cycle.
    For example, the following lengths can be returned:
    - 60 * 1,000 = 60,000 (MINUTELY)
    - 24 * 60 * 60 * 1,000 = 86,400,000 (DAILY)
    Returns:
    
    the length in milliseconds (i.e. the maximum duration) for a roll cycle
  - defaultIndexCount
```
int defaultIndexCount()
```
    Returns:
    
    the size of each index array, note: indexCount^2 is the maximum number of index queue entries.
  - defaultIndexSpacing
```
int defaultIndexSpacing()
```
    Returns the space between excerpts that are explicitly indexed.
    A higher number means higher sequential write performance but slower random access read. The sequential read performance is not affected by this property.
    For example, the following default index spacing can be returned:
    - 16 (MINUTELY)
    - 64 (DAILY)
    Returns:
    
    the space between excerpts that are explicitly indexed
  - current
```
int current(net.openhft.chronicle.core.time.TimeProvider time,
            long epoch)
```
    Returns the current cycle. Default epoch is 0 so for a DAILY cycle this will return the number of days since 1970-01-01T00:00:00Z.
    
    Parameters:
    
    epoch - an EPOCH offset, to all the user to define their own epoch
    
    Returns:
    
    the current cycle
  - toIndex
```
long toIndex(int cycle,
             long sequenceNumber)
```
    Returns the index for the provided cycle and sequenceNumber.
    An index is made up of cycle shifted left + sequenceNumber. sequenceNumber starts at 0 for each new cycle. DAILY cycle has cycleShift=32 and sequenceMask=0xFFFFFFFF so the top 32 bits are for cycle and bottom 32 bits are for sequence. This means you can only store 2^32 entries per day. HUGE_DAILY has shift=48 and mask=0xFFFFFFFFFFFF thus allowing 2^48 entries per day.
    
    Parameters:
    
    cycle - to be composed into an index
    
    sequenceNumber - to be composed into an index
    
    Returns:
    
    the index for the given cycle and sequenceNumber
  - toSequenceNumber
```
long toSequenceNumber(long index)
```
    Returns the sequence number for the provided index.
    An index is comprised of both a cycle and a sequence number but the way the index is composed of said properties may vary. This method decomposes the provided index and extracts the sequence number.
    
    Parameters:
    
    index - to use to extract the sequence number
    
    Returns:
    
    the sequence number for the provided index
  - toCycle
```
int toCycle(long index)
```
    Returns the cycle for the given index.
    An index is comprised of both a cycle and a sequence number but the way the index is composed of said properties may vary. This method decomposes the provided index and extracts the cycle.
    
    Parameters:
    
    index - to use when extracting the cycle
    
    Returns:
    
    the sequence number for the given index
  - maxMessagesPerCycle
```
long maxMessagesPerCycle()
```
    Returns:
    
    the maximum number of messages per cycle

Interface RollCycle

Method Summary

Method Detail

format

lengthInMillis

defaultIndexCount

defaultIndexSpacing

current

toIndex

toSequenceNumber

toCycle

maxMessagesPerCycle