net.sf.farrago.ddl
Class DdlReloadTableStmt

java.lang.Object
  net.sf.farrago.ddl.DdlStmt
      net.sf.farrago.ddl.DdlReloadTableStmt

All Implemented Interfaces:

DdlMultipleTransactionStmt, FarragoSessionDdlStmt

Direct Known Subclasses:

DdlAlterTableStructureStmt, DdlRebuildTableStmt

public abstract class DdlReloadTableStmt
extends DdlStmt
implements DdlMultipleTransactionStmt

DdlReloadTableStmt is an abstract base for statements which need to self-insert data from an existing table. Currently this includes ALTER TABLE REBUILD and ALTER TABLE ADD COLUMN.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/ddl/DdlReloadTableStmt.java#8 $

Author:

John Pham, John Sichi

Nested Class Summary

private class

DdlReloadTableStmt.ReloadTableIndexMap A special index map used when rebuildIndexes=true.

Field Summary

private FarragoSessionIndexMap	baseIndexMap
private boolean	rebuildingIndexes
private FarragoSessionIndexMap	rebuildMap
private String	recoveryRefMofId
private String	reloadSql
private FarragoRepos	repos
private CwmTable	table
private RefClass	tableClass
private String	tableMofId
private FarragoDataWrapperCache	wrapperCache
private Map<String,Long>	writeIndexMap

Constructor Summary

DdlReloadTableStmt(CwmTable table)
Constructs a DdlReloadTableStmt.

Method Summary

void	completeAfterExecuteUnlocked(FarragoSessionDdlValidator ddlValidator, FarragoSession session, boolean success) Provides access to the repository after execution of the DDL.
boolean	completeRequiresWriteTxn() Checks whether the DdlMultipleTransactionStmt.completeAfterExecuteUnlocked( FarragoSessionDdlValidator, FarragoSession, boolean) method requires a repository write transaction.
private void	crashIfTrapSet()
void	executeUnlocked(FarragoSessionDdlValidator ddlValidator, FarragoSession session) Executes long-running DDL actions.
protected CwmTable	getOldTableStructureForIndexMap()
protected abstract String	getReloadDml(SqlPrettyWriter writer) Generates the SQL to be used to reload the table.
protected CwmTable	getTable()
void	prepForExecuteUnlocked(FarragoSessionDdlValidator ddlValidator, FarragoSession session) Provides access to the repository in preparation for the execution of DdlStmt.
protected void	recoverFromFailure(FarragoSessionDdlValidator ddlValidator, FarragoSession session) Called after an exception is thrown during the execution phase.
protected void	setRecoveryRef(FemRecoveryReference recoveryRef) Sets up a recovery reference to be used in the event of a crash.
protected boolean	shouldRebuildIndexes(FarragoSessionDdlValidator ddlValidator) Determines whether statement execution should rebuild all indexes on the table.
private void	sleepIfTrapSet()
void	visit(DdlVisitor visitor) Invokes a visitor on this statement.

Methods inherited from class net.sf.farrago.ddl.DdlStmt

getModelElement, isDropRestricted, postCommit, postExecute, preExecute, preValidate, requiresCommit, runsAsDml

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.farrago.session.FarragoSessionDdlStmt

getModelElement, isDropRestricted, postCommit, postExecute, preExecute, preValidate, requiresCommit, runsAsDml

Field Detail

table

private CwmTable table

tableMofId

private String tableMofId

tableClass

private RefClass tableClass

repos

private FarragoRepos repos

baseIndexMap

private FarragoSessionIndexMap baseIndexMap

wrapperCache

private FarragoDataWrapperCache wrapperCache

writeIndexMap

private Map<String,Long> writeIndexMap

rebuildMap

private FarragoSessionIndexMap rebuildMap

reloadSql

private String reloadSql

rebuildingIndexes

private boolean rebuildingIndexes

recoveryRefMofId

private String recoveryRefMofId

Constructor Detail

DdlReloadTableStmt

public DdlReloadTableStmt(CwmTable table)

Constructs a DdlReloadTableStmt.

Parameters:

table - target table

Method Detail

visit

public void visit(DdlVisitor visitor)

Description copied from class: DdlStmt

Invokes a visitor on this statement.

Specified by:

visit in class DdlStmt

Parameters:

visitor - DdlVisitor to invoke

prepForExecuteUnlocked

public void prepForExecuteUnlocked(FarragoSessionDdlValidator ddlValidator,
                                   FarragoSession session)

Description copied from interface: DdlMultipleTransactionStmt

Provides access to the repository in preparation for the execution of DdlStmt. This method is invoked within the context the original repository transaction for the DDL statement. Whether that transaction is a write transaction depends on the DDL statement being executed.

Specified by:

prepForExecuteUnlocked in interface DdlMultipleTransactionStmt

Parameters:

ddlValidator - DDL validator for this statement

See Also:

FarragoReposTxnContext

executeUnlocked

public void executeUnlocked(FarragoSessionDdlValidator ddlValidator,
                            FarragoSession session)

Description copied from interface: DdlMultipleTransactionStmt

Executes long-running DDL actions. This method is invoked outside the context of any repository transaction.

Specified by:

executeUnlocked in interface DdlMultipleTransactionStmt

Parameters:

ddlValidator - DDL validator for this statement

session - reentrant Farrago session which may be used to execute DML statements

sleepIfTrapSet

private void sleepIfTrapSet()

completeRequiresWriteTxn

public boolean completeRequiresWriteTxn()

Description copied from interface: DdlMultipleTransactionStmt

Checks whether the DdlMultipleTransactionStmt.completeAfterExecuteUnlocked( FarragoSessionDdlValidator, FarragoSession, boolean) method requires a repository write transaction.

Specified by:

completeRequiresWriteTxn in interface DdlMultipleTransactionStmt

Returns:

true if a write txn must be started before executing the completion step, false if a read txn is sufficient

recoverFromFailure

protected void recoverFromFailure(FarragoSessionDdlValidator ddlValidator,
                                  FarragoSession session)

Called after an exception is thrown during the execution phase.

Parameters:

ddlValidator - DDL validator for this statement

session - reentrant Farrago session

completeAfterExecuteUnlocked

public void completeAfterExecuteUnlocked(FarragoSessionDdlValidator ddlValidator,
                                         FarragoSession session,
                                         boolean success)

Description copied from interface: DdlMultipleTransactionStmt

Provides access to the repository after execution of the DDL. Typically implementations of this method modify the repository to store the results of DdlMultipleTransactionStmt.executeUnlocked(FarragoSessionDdlValidator, FarragoSession). This method is invoked in a locked repository transaction. The method DdlMultipleTransactionStmt.completeRequiresWriteTxn() controls whether the transaction read-only or not. This method may not access and/or modify repository objects loaded in a previous transaction unless they are reloaded by MOF ID. Be aware that objects may have been modified by another session unless some external mechanism (for instance, the "table-in-use" collection) guarantees that they have not been modified by another statement.

Note that any repository modifications made during the execution of this method will not be post-processed by DdlValidator. For instance, DdlValidator.checkJmiConstraints(RefObject) is not called, and therefore any mandatory default primitives are not automatically set, which will cause errors later if the attributes have not been explicitly initialized. See JmiObjUtil.setMandatoryPrimitiveDefaults(javax.jmi.reflect.RefObject).

Specified by:

completeAfterExecuteUnlocked in interface DdlMultipleTransactionStmt

Parameters:

ddlValidator - DDL validator for this statement

session - reentrant Farrago session which may be used to execute DML statements

success - whether the execution succeeded; detection of failure can be used to recover

crashIfTrapSet

private void crashIfTrapSet()

shouldRebuildIndexes

protected boolean shouldRebuildIndexes(FarragoSessionDdlValidator ddlValidator)

Determines whether statement execution should rebuild all indexes on the table. Some ooptimzed reloads may be able to avoid this.

Parameters:

ddlValidator - validator for this DDL statement

Returns:

whether to rebuild

getReloadDml

protected abstract String getReloadDml(SqlPrettyWriter writer)

Generates the SQL to be used to reload the table. Note that this is called from prepForExecuteUnlocked, so it is allowed to call getTable().

Parameters:

writer - writer to uses for generating SQL

Returns:

DML statement which accomplishes reload

setRecoveryRef

protected void setRecoveryRef(FemRecoveryReference recoveryRef)

Sets up a recovery reference to be used in the event of a crash.

Parameters:

recoveryRef - recovery reference for this operation

getTable

protected CwmTable getTable()

Returns:

the table affected by this statement

getOldTableStructureForIndexMap

protected CwmTable getOldTableStructureForIndexMap()

Returns:

the old table structure if the table structure is being altered, or null if no change is taking place