com.amazon.carbonado.sequence

Interface SequenceValueProducer

All Known Implementing Classes:

AbstractSequenceValueProducer, SequenceValueGenerator

public interface SequenceValueProducer

Produces values for sequences.

Since:

1.2

Author:

Brian S O'Neill, bcastill

See Also:

Sequence

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.String	nextDecimalValue() Returns the next decimal string value from the sequence, which remains positive.
int	nextIntValue() Returns the next value from the sequence, which may wrap negative if all positive values are exhausted.
long	nextLongValue() Returns the next value from the sequence, which may wrap negative if all positive values are exhausted.
java.lang.String	nextNumericalValue(int radix, int minLength) Returns the next numerical string value from the sequence, which remains positive.
boolean	returnReservedValues() Allow any unused reserved values to be returned for re-use.

Method Detail

nextLongValue

long nextLongValue()
                   throws PersistException

Returns the next value from the sequence, which may wrap negative if all positive values are exhausted. When sequence wraps back to initial value, the sequence is fully exhausted, and an exception is thrown to indicate this.

Note: this method throws PersistException even for fetch failures since this method is called by insert operations. Insert operations can only throw a PersistException.

Throws:

PersistException - for fetch/persist failure or if sequence is exhausted.

nextIntValue

int nextIntValue()
                 throws PersistException

Returns the next value from the sequence, which may wrap negative if all positive values are exhausted. When sequence wraps back to initial value, the sequence is fully exhausted, and an exception is thrown to indicate this.

Note: this method throws PersistException even for fetch failures since this method is called by insert operations. Insert operations can only throw a PersistException.

Throws:

PersistException - for fetch/persist failure or if sequence is exhausted for int values.

nextDecimalValue

java.lang.String nextDecimalValue()
                                  throws PersistException

Returns the next decimal string value from the sequence, which remains positive. When sequence wraps back to initial value, the sequence is fully exhausted, and an exception is thrown to indicate this.

Note: this method throws PersistException even for fetch failures since this method is called by insert operations. Insert operations can only throw a PersistException.

Throws:

PersistException - for fetch/persist failure or if sequence is exhausted.

nextNumericalValue

java.lang.String nextNumericalValue(int radix,
                                  int minLength)
                                    throws PersistException

Returns the next numerical string value from the sequence, which remains positive. When sequence wraps back to initial value, the sequence is fully exhausted, and an exception is thrown to indicate this.

Note: this method throws PersistException even for fetch failures since this method is called by insert operations. Insert operations can only throw a PersistException.

Parameters:

radix - use 2 for binary, 10 for decimal, 16 for hex. Max is 36.

minLength - ensure string is at least this long (padded with zeros if necessary) to ensure proper string sort

Throws:

PersistException - for fetch/persist failure or if sequence is exhausted.

returnReservedValues

boolean returnReservedValues()
                             throws FetchException,
                                    PersistException

Allow any unused reserved values to be returned for re-use. If the repository is shared by other processes, then reserved values might not be returnable.

This method should be called during the shutdown process of a repository, although calling it does not invalidate this SequenceValueGenerator. If getNextValue is called again, it will reserve values again.

Returns:

true if reserved values were returned

Throws:

FetchException

PersistException