Class XactId

java.lang.Object

org.apache.derby.impl.store.raw.xact.XactId

All Implemented Interfaces:

Externalizable, Serializable, Formatable, TypedFormat, TransactionId

public class XactId
extends Object
implements TransactionId

Use this class for a short hand representation of the transaction. This value is only guarentee to be unique within one continuous operation of the raw store, in other words, every reboot may reuse the same value. Whereas GlobalXactId is unique for all times across all raw store, a XactId is only unique within a particular rawstore and may be reused. XactId keeps track of the outstanding transactionId and is responsible for dispensing new transactionIds

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private long	id

Constructor Summary

Constructors

Constructor	Description
XactId()
XactId(long id)

Method Summary

Modifier and Type	Method	Description
static long	compare(TransactionId a, TransactionId b)	Return 0 if a == b, +ve number if a > b -ve number if a < b
boolean	equals(Object other)
protected long	getId()
int	getMaxStoredSize()	TransactionId method
int	getTypeFormatId()	Return my format identifier.
int	hashCode()
void	readExternal(ObjectInput in)	Read this in
String	toString()
void	writeExternal(ObjectOutput out)	Write this out.

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

id

private long id

Constructor Details

XactId

public XactId(long id)

XactId

public XactId()

Method Details

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Write this out.

Specified by:

writeExternal in interface Externalizable

Throws:

IOException - error writing to log stream

readExternal

public void readExternal(ObjectInput in)
                  throws IOException

Read this in

Specified by:

readExternal in interface Externalizable

Throws:

IOException - error reading from log stream

getTypeFormatId

public int getTypeFormatId()

Return my format identifier.

Specified by:

getTypeFormatId in interface TypedFormat

Returns:

The identifier. (A UUID stuffed in an array of 16 bytes).

getMaxStoredSize

public int getMaxStoredSize()

TransactionId method

Specified by:

getMaxStoredSize in interface TransactionId

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

compare

public static long compare(TransactionId a,
 TransactionId b)

Return 0 if a == b, +ve number if a > b -ve number if a < b

getId

protected long getId()

toString

public String toString()

Overrides:

toString in class Object