org.exist.numbering
Class DLNFactory

java.lang.Object
  org.exist.numbering.DLNFactory

All Implemented Interfaces:

NodeIdFactory

public class DLNFactory
extends Object
implements NodeIdFactory

Implementation of NodeIdFactory for DLN-based node ids.

Constructor Summary

DLNFactory()

Method Summary

NodeId	createFromData(int sizeHint, byte[] data, int startOffset) Read a NodeId from the given byte array.
NodeId	createFromStream(NodeId previous, VariableByteInput is) Read a NodeId from the given input stream.
NodeId	createFromStream(VariableByteInput is) Read a NodeId from the given input stream.
NodeId	createFromString(String string) Create a NodeId instance from its string representation.
NodeId	createInstance() Create a new NodeId, initialized with a default value.
NodeId	createInstance(int id) Create a new NodeId, initialized with the given base id.
NodeId	documentNodeId() Returns a NodeId representing the document node of a document.
int	lengthInBytes(int units, byte[] data, int startOffset) Returns the number of bytes occupied by the NodeId stored in the byte array at the given startOffset.
void	writeEndOfDocument(VariableByteOutputStream os)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DLNFactory

public DLNFactory()

Method Detail

createInstance

public NodeId createInstance()

Description copied from interface: NodeIdFactory

Create a new NodeId, initialized with a default value.

Specified by:

createInstance in interface NodeIdFactory

Returns:

a new NodeId.

createInstance

public NodeId createInstance(int id)

Description copied from interface: NodeIdFactory

Create a new NodeId, initialized with the given base id.

Specified by:

createInstance in interface NodeIdFactory

Returns:

nodeId

createFromStream

public NodeId createFromStream(VariableByteInput is)
                        throws IOException

Description copied from interface: NodeIdFactory

Read a NodeId from the given input stream.

Specified by:

createFromStream in interface NodeIdFactory

Parameters:

is - the input stream to read from

Returns:

the NodeId read

Throws:

IOException - if there's a problem with the underlying input stream

See Also:

NodeId.write(org.exist.storage.io.VariableByteOutputStream)

createFromStream

public NodeId createFromStream(NodeId previous,
                               VariableByteInput is)
                        throws IOException

Description copied from interface: NodeIdFactory

Read a NodeId from the given input stream. Assumes that the node id was stored with prefix-compression, i.e. only the bytes differing from the previous node were written out.

Specified by:

createFromStream in interface NodeIdFactory

Parameters:

previous - the previous node id read or null if there is none

is - the input stream to read from

Returns:

the NodeId read

Throws:

IOException - if there's a problem with the underlying input stream

See Also:

NodeId.write(NodeId, org.exist.storage.io.VariableByteOutputStream)

createFromData

public NodeId createFromData(int sizeHint,
                             byte[] data,
                             int startOffset)

Description copied from interface: NodeIdFactory

Read a NodeId from the given byte array. Start to read at startOffset. sizeHint indicates the length of the id in an implementation dependent manner. Some implementations may require sizeHint to be specified, others not.

Specified by:

createFromData in interface NodeIdFactory

Parameters:

sizeHint - a hint about the expected length of the id

data - the byte array to read from

startOffset - offset into the byte array

Returns:

the NodeId read

createFromString

public NodeId createFromString(String string)

Description copied from interface: NodeIdFactory

Create a NodeId instance from its string representation.

Specified by:

createFromString in interface NodeIdFactory

Parameters:

string - the string representation of the node id as returned by Object.toString()

Returns:

nodeId

documentNodeId

public NodeId documentNodeId()

Description copied from interface: NodeIdFactory

Returns a NodeId representing the document node of a document. Usually, this will be a singleton object.

Specified by:

documentNodeId in interface NodeIdFactory

Returns:

the document node id.

lengthInBytes

public int lengthInBytes(int units,
                         byte[] data,
                         int startOffset)

Description copied from interface: NodeIdFactory

Returns the number of bytes occupied by the NodeId stored in the byte array at the given startOffset. This method is similar to NodeIdFactory.createFromData(int, byte[], int), but it just returns the number of bytes.

Specified by:

lengthInBytes in interface NodeIdFactory

Returns:

number of bytes

writeEndOfDocument

public void writeEndOfDocument(VariableByteOutputStream os)

Specified by:

writeEndOfDocument in interface NodeIdFactory