AbstractRecord (Narayana: ArjunaJTA narayana-jta 5.0.0.CR1 API)

java.lang.Object
- com.arjuna.ats.arjuna.StateManager
- - com.arjuna.ats.arjuna.coordinator.AbstractRecord

```
public abstract class AbstractRecord
extends StateManager
```
Abstract Record Class This class provides an abstract template that defines the interface that the atomic action system uses to notify objects that various state transitions have occurred as the 2PC protocol executes. Record types derived from this class manage certain properties of objects such as recovery information, concurrency control information etc, and all must redefine the operations defined here as abstract to take appropriate action. Many functions are declared pure virtual to force a definition to occur in any derived class. These are currently all functions dealing with atomic action coordination as well as the following list management functions: typeIs: returns the record type of the instance. This is one of the values of the enumerated type Record_type value: Some arbitrary value associated with the record instance merge: Used when two records need to merge together. Currently this is only used by CadaverRecords to merge information from PersistenceRecords shouldAdd: returns TRUE is the record should be added to the list FALSE if it should be discarded shouldMerge: returns TRUE is the two records should be merged into a single record, FALSE if it should be discarded shouldReplace: returns TRUE if the record should replace an existing one, FALSE otherwise.

Since:

1.0.

Version:

$Id: AbstractRecord.java 2342 2006-03-30 13:06:17Z $

Author:

Mark Little (mark@arjuna.com)

Field Summary
- Fields inherited from class com.arjuna.ats.arjuna.StateManager
  modifyingActions, objectModel, objectUid, usingActions

Constructor Summary

Constructors
Modifier	Constructor and Description
	`AbstractRecord()` Creates a 'blank' abstract record.
`protected`	`AbstractRecord(Uid storeUid)` Create a new instance with the specified paramaters.
`protected`	`AbstractRecord(Uid storeUid, String objType, int otype)` Create a new instance with the specified parameters.

Method Summary

Methods
Modifier and Type	Method and Description
`abstract void`	`alter(AbstractRecord a)` Alter the current record with the one presented.
`static AbstractRecord`	`create(int type)`
`boolean`	`doSave()` Should this record be saved in the intentions list? If the record is saved, then it may be recovered later in the event of a failure.
`boolean`	`equals(AbstractRecord ar)` Determine if two records are equal in that both are the same type and have the same order value (determined via 'order()').
`boolean`	`forgetHeuristic()` Forget any heuristic outcome which this implementation may have produced.
`protected AbstractRecord`	`getNext()`
`protected AbstractRecord`	`getPrevious()` These few functions are link manipulation primitives used by the RecordList processing software to chain instances together.
`String`	`getTypeOfObject()` Return the type of the abstract record.
`boolean`	`greaterThan(AbstractRecord ar)` Determine if two records are greater than in that both are the same type and their Uids are greater than.
`boolean`	`lessThan(AbstractRecord ar)` Determine if two records are less than in that both are the same type and their Uids are less than.
`abstract void`	`merge(AbstractRecord a)` Merge the current record with the one presented.
`abstract int`	`nestedAbort()` A rollback of a nested transaction has occurred.
`int`	`nestedCleanup()` Cleanup is called if a nested is detected to be an orphan.
`abstract int`	`nestedCommit()` A commit of a nested transaction has occurred.
`int`	`nestedOnePhaseCommit()` Perform a nested one phase commit.
`abstract int`	`nestedPrepare()` A prepare for a nested transaction has occurred.
`Uid`	`order()` Return the Uid of this abstract record so that it can be ordered in the intentions list.
`void`	`print(PrintWriter strm)` Write information about this specific instance to the specified stream.
`boolean`	`propagateOnAbort()` Determine if records are discarded on action abort or must be propagated to parents.
`boolean`	`propagateOnCommit()` Determine if records are discarded on action commit or must be propagated to parents.
`void`	`replace(AbstractRecord a)` The current record is about to replace the one presented.
`boolean`	`restore_state(InputObjectState os, int i)` During recovery, the transaction log is given to the recovery system and it will recreate a transaction instance to perform necessary recovery actions.
`boolean`	`save_state(OutputObjectState os, int i)` When the transaction is required to make the intentions list persistent, it scans the list and asks each record whether or not it requires state to be saved (by calling doSave).
`protected void`	`setNext(AbstractRecord ar)` Set the next element in the list to the specified instance.
`protected void`	`setPrevious(AbstractRecord ar)` Set the previous element in the list to the specified instance.
`abstract void`	`setValue(Object o)`
`abstract boolean`	`shouldAdd(AbstractRecord a)` Should we add the record presented to the intentions list?
`abstract boolean`	`shouldAlter(AbstractRecord a)` Should we alter the current record with the one presented?
`abstract boolean`	`shouldMerge(AbstractRecord a)` Should we merge the current record with the one presented?
`abstract boolean`	`shouldReplace(AbstractRecord a)` Should we replace the record presented with the current record?
`abstract int`	`topLevelAbort()` A rollback of a top-level transaction has occurred.
`int`	`topLevelCleanup()` Cleanup is called if a top-level action is detected to be an orphan.
`abstract int`	`topLevelCommit()` A commit of a top-level transaction has occurred.
`int`	`topLevelOnePhaseCommit()` Perform a top-level one phase commit.
`abstract int`	`topLevelPrepare()` A prepare for a top-level transaction has occurred.
`String`	`type()` Re-implementation of abstract methods inherited from base class.
`abstract int`	`typeIs()`
`abstract Object`	`value()` If this abstract record caused a heuristic then it should return an object which implements `HeuristicInformation`

Methods inherited from class com.arjuna.ats.arjuna.StateManager
activate, activate, cleanup, createLists, deactivate, deactivate, deactivate, destroy, disable, forgetAction, get_uid, getMutex, getObjectModel, getStore, getStoreRoot, loadObjectState, lockMutex, modified, objectType, packHeader, persist, rememberAction, setStatus, setupStore, setupStore, setupStore, status, terminate, tryLockMutex, unlockMutex, unpackHeader

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

- Constructor Detail
  - AbstractRecord
```
protected AbstractRecord(Uid storeUid,
              String objType,
              int otype)
```
    Create a new instance with the specified parameters.
    
    Parameters:
    storeUid - the unique id for this instance.
    objType - the type of the instance.
    otype - the ObjectType of the object.
    See Also:
    ObjectType
  - AbstractRecord
```
protected AbstractRecord(Uid storeUid)
```
    Create a new instance with the specified paramaters.
    
    Parameters:
    storeUid - the unique id for this instance.
  - AbstractRecord
```
public AbstractRecord()
```
    Creates a 'blank' abstract record. This is used during crash recovery when recreating the prepared list of a server atomic action.
- Method Detail
  - typeIs
```
public abstract int typeIs()
```
    Returns:
    RecordType value.
  - value
```
public abstract Object value()
```
    If this abstract record caused a heuristic then it should return an object which implements HeuristicInformation
    
    Returns:
    Object to be used to order.
  - setValue
```
public abstract void setValue(Object o)
```
  - nestedAbort
```
public abstract int nestedAbort()
```
    A rollback of a nested transaction has occurred.
    
    Returns:
    TwoPhaseOutcome to indicate success/failure.
    See Also:
    TwoPhaseOutcome
  - nestedCommit
```
public abstract int nestedCommit()
```
    A commit of a nested transaction has occurred.
    
    Returns:
    TwoPhaseOutcome to indicate success/failure.
    See Also:
    TwoPhaseOutcome
  - nestedPrepare
```
public abstract int nestedPrepare()
```
    A prepare for a nested transaction has occurred.
    
    Returns:
    TwoPhaseOutcome to indicate success/failure.
    See Also:
    TwoPhaseOutcome
  - topLevelAbort
```
public abstract int topLevelAbort()
```
    A rollback of a top-level transaction has occurred.
    
    Returns:
    TwoPhaseOutcome to indicate success/failure.
    See Also:
    TwoPhaseOutcome
  - topLevelCommit
```
public abstract int topLevelCommit()
```
    A commit of a top-level transaction has occurred.
    
    Returns:
    TwoPhaseOutcome to indicate success/failure.
    See Also:
    TwoPhaseOutcome
  - topLevelPrepare
```
public abstract int topLevelPrepare()
```
    A prepare for a top-level transaction has occurred.
    
    Returns:
    TwoPhaseOutcome to indicate success/failure.
    See Also:
    TwoPhaseOutcome
  - order
```
public Uid order()
```
    Return the Uid of this abstract record so that it can be ordered in the intentions list. This is also the Uid that the record was saved with in the object store.
    
    Returns:
    Uid for this instance.
    See Also:
    Uid
  getTypeOfObject public String getTypeOfObject() Return the type of the abstract record. Used in ordering the instances in the intentions list. This is also the type that the record was saved with in the object store. Returns: String representing type. propagateOnAbort public boolean propagateOnAbort() Determine if records are discarded on action abort or must be propagated to parents. Returns: true if the record should be propagated to the parent transaction if the current transaction rolls back, false otherwise. The default is false. propagateOnCommit public boolean propagateOnCommit() Determine if records are discarded on action commit or must be propagated to parents. Returns: true if the record should be propagated to the parent transaction if the current transaction commits, false otherwise. The default is true. equals public final boolean equals(AbstractRecord ar) Determine if two records are equal in that both are the same type and have the same order value (determined via 'order()'). Returns: true if equal, false otherwise. lessThan public final boolean lessThan(AbstractRecord ar) Determine if two records are less than in that both are the same type and their Uids are less than. Returns: true if equal, false otherwise. greaterThan public final boolean greaterThan(AbstractRecord ar) Determine if two records are greater than in that both are the same type and their Uids are greater than. Returns: true if equal, false otherwise. topLevelCleanup public int topLevelCleanup() Cleanup is called if a top-level action is detected to be an orphan. NOTE nested actions are never orphans since their parents would be aborted we may as well abort them as well. Returns: TwoPhaseOutcome as default is the same as topLevelAbort. nestedCleanup public int nestedCleanup() Cleanup is called if a nested is detected to be an orphan. NOTE nested actions are never orphans since their parents would be aborted we may as well abort them as well. Returns: TwoPhaseOutcome as default is the same as nestedAbort. doSave public boolean doSave() Should this record be saved in the intentions list? If the record is saved, then it may be recovered later in the event of a failure. Note, however, that the size of the intentions list on disk is critical to the performance of the system (disk I/O is a bottleneck). Returns: true if it should be saved, false otherwise. false is the default. type public String type() Re-implementation of abstract methods inherited from base class. Overrides: type in class StateManager print public void print(PrintWriter strm) Write information about this specific instance to the specified stream. Overrides: print in class StateManager Parameters: strm - the stream on which to output. save_state public boolean save_state(OutputObjectState os, int i) When the transaction is required to make the intentions list persistent, it scans the list and asks each record whether or not it requires state to be saved (by calling doSave). If the answer is yes, then save_state is called and the record instance must save enough information to enable it to be restored from that state later. The basic AbstractRecord save_state will save common data that is required by the base class during recovery. If a derived class calls super.save_state then it must be called before packing any other data item. Overrides: save_state in class StateManager Returns: true if successful, false otherwise. restore_state public boolean restore_state(InputObjectState os, int i) During recovery, the transaction log is given to the recovery system and it will recreate a transaction instance to perform necessary recovery actions. This transaction will recreate the intentions list and give each recreated AbstractRecord the state that that was saved during transaction persistence. The base class will restore information that it needs from the log. Data items must be unpacked in the same order that they were packed. Overrides: restore_state in class StateManager Returns: true if successful, false otherwise. forgetHeuristic public boolean forgetHeuristic() Forget any heuristic outcome which this implementation may have produced. Returns: true by default. If false is returned then the instance must be remembered by the transaction (in the log) in order for recovery to retry later or for a system administrator to be able to determine which resources have not been successfully completed. nestedOnePhaseCommit public int nestedOnePhaseCommit() Perform a nested one phase commit. Returns: TwoPhaseOutcome to indicate success/failure. See Also: TwoPhaseOutcome topLevelOnePhaseCommit public int topLevelOnePhaseCommit() Perform a top-level one phase commit. Returns: TwoPhaseOutcome to indicate success/failure. See Also: TwoPhaseOutcome create public static AbstractRecord create(int type) merge public abstract void merge(AbstractRecord a) Merge the current record with the one presented. Parameters: a - the record with which to merge. alter public abstract void alter(AbstractRecord a) Alter the current record with the one presented. Parameters: a - the record with which to alter. shouldAdd public abstract boolean shouldAdd(AbstractRecord a) Should we add the record presented to the intentions list? Parameters: a - The record to try to add. Returns: true if the record should be added, false otherwise. shouldAlter public abstract boolean shouldAlter(AbstractRecord a) Should we alter the current record with the one presented? Parameters: a - The record to try to alter. Returns: true if the record should be altered, false otherwise. shouldMerge public abstract boolean shouldMerge(AbstractRecord a) Should we merge the current record with the one presented? Parameters: a - The record to try to merge. Returns: true if the record should be merged, false otherwise. shouldReplace public abstract boolean shouldReplace(AbstractRecord a) Should we replace the record presented with the current record? Parameters: a - The record to try to replace. Returns: true if the record should be replaced, false otherwise. replace public void replace(AbstractRecord a) The current record is about to replace the one presented. This method is invoked to give the current record a chance to copy information, for example, from the record being replaced. Parameters: a - the record that will replace this instance. getPrevious protected final AbstractRecord getPrevious() These few functions are link manipulation primitives used by the RecordList processing software to chain instances together. Returns: the previous element in the intentions list, or null. getNext protected final AbstractRecord getNext() Returns: the next element in the intentions list, or null. setPrevious protected final void setPrevious(AbstractRecord ar) Set the previous element in the list to the specified instance. Parameters: ar - the instance to become previous. setNext protected final void setNext(AbstractRecord ar) Set the next element in the list to the specified instance. Parameters: ar - the instance to become next.

Class AbstractRecord

Field Summary

Fields inherited from class com.arjuna.ats.arjuna.StateManager

Constructor Summary

Method Summary

Methods inherited from class com.arjuna.ats.arjuna.StateManager

Methods inherited from class java.lang.Object

Constructor Detail

AbstractRecord

AbstractRecord

AbstractRecord

Method Detail

typeIs

value

setValue

nestedAbort

nestedCommit

nestedPrepare

topLevelAbort

topLevelCommit

topLevelPrepare

order

getTypeOfObject

propagateOnAbort

propagateOnCommit

equals

lessThan

greaterThan

topLevelCleanup

nestedCleanup

doSave

type

print

save_state

restore_state

forgetHeuristic

nestedOnePhaseCommit

topLevelOnePhaseCommit

create

merge

alter

shouldAdd

shouldAlter

shouldMerge

shouldReplace

replace

getPrevious

getNext

setPrevious

setNext