org.opends.server.backends.pluggable.spi

Interface Cursor<K,V>

Type Parameters:

K - Type of the record's key

V - Type of the record's value

All Superinterfaces:

AutoCloseable, Closeable, SequentialCursor<K,V>

All Known Implementing Classes:

EmptyCursor

public interface Cursor<K,V>
extends SequentialCursor<K,V>

Sequential cursor extended with navigation methods.

Method Summary

Modifier and Type	Method and Description
boolean	positionToIndex(int index) Positions the cursor to the specified index within the tree.
boolean	positionToKey(ByteSequence key) Positions the cursor to the provided key if it exists in the tree.
boolean	positionToKeyOrNext(ByteSequence key) Positions the cursor to the provided key if it exists in the tree, or else the lesser key greater than the provided key in the tree.
boolean	positionToLastKey() Positions the cursor to the last key in the tree.

Methods inherited from interface org.opends.server.backends.pluggable.spi.SequentialCursor

close, delete, getKey, getValue, isDefined, next

Method Detail

positionToKey

boolean positionToKey(ByteSequence key)

Positions the cursor to the provided key if it exists in the tree.

Parameters:

key - the key where to position the cursor

Returns:

true if the cursor could be positioned to the key, false otherwise

positionToKeyOrNext

boolean positionToKeyOrNext(ByteSequence key)

Positions the cursor to the provided key if it exists in the tree, or else the lesser key greater than the provided key in the tree.

Parameters:

key - the key where to position the cursor

Returns:

true if the cursor could be positioned to the key or the next one, false otherwise

positionToLastKey

boolean positionToLastKey()

Positions the cursor to the last key in the tree.

Returns:

true if the cursor could be positioned to the last key, false otherwise

positionToIndex

boolean positionToIndex(int index)

Positions the cursor to the specified index within the tree. Implementations may take advantage of optimizations provided by the underlying storage, such as counted B-Trees.

Parameters:

index - the index where the cursor should be positioned, (0 is the first record).

Returns:

true if the cursor could be positioned to the index, false otherwise