XactId (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.store.raw.xact.XactId

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, Formatable, TypedFormat, TransactionId
```
public class XactId
extends java.lang.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

Fields
Modifier and Type	Field	Description
`private long`	`id`

Constructor Summary

Constructors
Constructor Description

XactId()

XactId(long id)

Constructors
Constructor	Description
`XactId()`
`XactId(long id)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
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(java.lang.Object other)`
`protected long`	`getId()`
`int`	`getMaxStoredSize()`	TransactionId method
`int`	`getTypeFormatId()`	Return my format identifier.
`int`	`hashCode()`
`void`	`readExternal(java.io.ObjectInput in)`	Read this in
`java.lang.String`	`toString()`
`void`	`writeExternal(java.io.ObjectOutput out)`	Write this out.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - id
```
private long id
```
- Constructor Detail
  - XactId
```
public XactId(long id)
```
  - XactId
```
public XactId()
```
- Method Detail
  - writeExternal
```
public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
```
    Write this out.
    
    Specified by:
    
    writeExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.IOException - error writing to log stream
  - readExternal
```
public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException
```
    Read this in
    
    Specified by:
    
    readExternal in interface java.io.Externalizable
    
    Throws:
    
    java.io.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(java.lang.Object other)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.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 java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class XactId

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

id

Constructor Detail

XactId

XactId

Method Detail

writeExternal

readExternal

getTypeFormatId

getMaxStoredSize

equals

hashCode

compare

getId

toString