Package org.opends.server.backends.pluggable.spi

Interface ReadableTransaction

All Known Subinterfaces:

WriteableTransaction

public interface ReadableTransaction

Represents a readable transaction on a storage engine.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	ReadableTransaction.ReadOption	Options applicable to openCursor(TreeName, ReadOption...).

Method Summary

Modifier and Type	Method	Description
default long	getRecordCount(TreeName treeName)	Returns the number of key/value pairs in the provided tree.
default Cursor<ByteString,ByteString>	openCursor(TreeName treeName, ReadableTransaction.ReadOption... options)	Opens a non-positioned cursor on the tree whose name is provided.
default ByteString	read(TreeName treeName, ByteSequence key)	Reads the record's value associated to the provided key, in the tree whose name is provided.

Method Detail

read

default ByteString read(TreeName treeName,
                        ByteSequence key)

Reads the record's value associated to the provided key, in the tree whose name is provided.

Parameters:

treeName - the tree name

key - the record's key

Returns:

the record's value, or null if none exists or if the tree does not exist.

openCursor

default Cursor<ByteString,ByteString> openCursor(TreeName treeName,
                                                       ReadableTransaction.ReadOption... options)

Opens a non-positioned cursor on the tree whose name is provided. The cursor will then have to be positioned (e.g: by invoking SequentialCursor.next()) to be defined.

Parameters:

treeName - the tree name

options - the options to apply to the opened cursor.

Returns:

a new non-positioned cursor or an empty cursor if the tree does not exist.

getRecordCount

default long getRecordCount(TreeName treeName)

Returns the number of key/value pairs in the provided tree.

Parameters:

treeName - the tree name

Returns:

the number of key/value pairs in the provided tree or 0 if the tree does not exist.