jetbrains.exodus.entitystore

Interface Sequence

public interface Sequence

Sequence allows to get unique successive non-negative long numbers. Sequences are named, you can request a sequence by name using methods StoreTransaction.getSequence(String) or StoreTransaction.getSequence(String, long). Sequences are persistent, any flushed or committed transaction saves all dirty (mutated) sequences which were requested by transactions created against current PersistentEntityStore.

PersistentEntityStore implementation uses Sequences to generate EntityId instances.

See Also:

StoreTransaction.getSequence(String), StoreTransaction.getSequence(String, long)

Method Summary

Modifier and Type	Method and Description
long	get() Returns current number obtained by last call to increment().
long	increment() Returns next non-negative number.
void	set(long l) Sets current number.

Method Detail

increment

long increment()

Returns next non-negative number. For a Sequence created by method StoreTransaction.getSequence(String), it starts with 0. For a Sequence created by method StoreTransaction.getSequence(String, long), it starts with specified initial value.

Returns:

next number

get

long get()

Returns current number obtained by last call to increment(). If increment() was never called it returns -1.

Returns:

current number obtained by last call to increment() or -1

set

void set(long l)

Sets current number. Next call to increment() will return l + 1.

Parameters:

l - current number