Package org.apache.derby.impl.sql.execute

Class GenericRIChecker

java.lang.Object

org.apache.derby.impl.sql.execute.GenericRIChecker

Direct Known Subclasses:

ForeignKeyRIChecker, ReferencedKeyRIChecker

public abstract class GenericRIChecker
extends java.lang.Object

Generic implementation of a Referential Integrity checker. Abstract.

Field Summary

Fields

Modifier and Type	Field	Description
protected BackingStoreHashtable	deferredRowsHashTable	Cached value (for efficiency) of the intermediate table of violations we use in the presence of deferred FK constraints.
protected DynamicCompiledOpenConglomInfo[]	fkDcocis
protected FKInfo	fkInfo
protected StaticCompiledOpenConglomInfo[]	fkScocis
protected int[]	identityMap
(package private) IndexRow	indexQualifierRow
protected LanguageConnectionContext	lcc
protected int	numColumns
protected DynamicCompiledOpenConglomInfo	refDcoci
protected StaticCompiledOpenConglomInfo	refScoci
private java.util.Hashtable<java.lang.Long,ScanController>	scanControllers
protected TransactionController	tc

Constructor Summary

Constructors

Constructor	Description
GenericRIChecker(LanguageConnectionContext lcc, TransactionController tc, FKInfo fkinfo)

Method Summary

Modifier and Type	Method	Description
(package private) void	close()	Clean up all scan controllers
(package private) abstract void	doCheck(Activation a, ExecRow row, boolean restrictCheckOnly, int deferredRowReq)	Check the validity of this row
(package private) int	getRICheckIsolationLevel()	Get the isolation level for the scan for the RI check.
protected ScanController	getScanController(long conglomNumber, StaticCompiledOpenConglomInfo scoci, DynamicCompiledOpenConglomInfo dcoci, ExecRow searchRow)	Get a scan controller positioned using searchRow as the start/stop position.
(package private) boolean	isAnyFieldNull(ExecRow baseRow)	Are any of the fields null in the row passed in.
private void	setupQualifierRow(ExecRow baseRow)

Methods inherited from class java.lang.Object

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

Field Detail

fkInfo

protected FKInfo fkInfo

fkDcocis

protected DynamicCompiledOpenConglomInfo[] fkDcocis

fkScocis

protected StaticCompiledOpenConglomInfo[] fkScocis

refDcoci

protected DynamicCompiledOpenConglomInfo refDcoci

refScoci

protected StaticCompiledOpenConglomInfo refScoci

tc

protected TransactionController tc

lcc

protected LanguageConnectionContext lcc

deferredRowsHashTable

protected BackingStoreHashtable deferredRowsHashTable

Cached value (for efficiency) of the intermediate table of violations we use in the presence of deferred FK constraints.

scanControllers

private final java.util.Hashtable<java.lang.Long,ScanController> scanControllers

numColumns

protected final int numColumns

identityMap

protected int[] identityMap

indexQualifierRow

final IndexRow indexQualifierRow

Constructor Detail

GenericRIChecker

GenericRIChecker(LanguageConnectionContext lcc,
                 TransactionController tc,
                 FKInfo fkinfo)
          throws StandardException

Parameters:

lcc - the language connection context

tc - the xact controller

fkinfo - the foreign key information

Throws:

StandardException - Thrown on failure

Method Detail

doCheck

abstract void doCheck(Activation a,
                      ExecRow row,
                      boolean restrictCheckOnly,
                      int deferredRowReq)
               throws StandardException

Check the validity of this row

Parameters:

a - The activation

row - The row to check

restrictCheckOnly - true if the check is relevant only for RESTRICTED referential action.

deferredRowReq - For referenced keys: The required number of duplicates that need to be present. Only used if postCheck==false.

Throws:

StandardException - on error

getScanController

protected ScanController getScanController(long conglomNumber,
                                           StaticCompiledOpenConglomInfo scoci,
                                           DynamicCompiledOpenConglomInfo dcoci,
                                           ExecRow searchRow)
                                    throws StandardException

Get a scan controller positioned using searchRow as the start/stop position. The assumption is that searchRow is of the same format as the index being opened. The scan is set up to return no columns. NOTE: We only need an instantaneous lock on the table that we are probing as we are just checking for the existence of a row. All updaters, whether to the primary or foreign key tables, will hold an X lock on the table that they are updating and will be probing the other table, so instantaneous locks will not change the semantics. RESOLVE: Due to the current RI implementation we cannot always get instantaneous locks. We will call a method to find out what kind of locking to do until the implementation changes.

Parameters:

conglomNumber - the particular conglomerate we are interested in

scoci -

dcoci -

searchRow - the row to match

Returns:

scan controller

Throws:

StandardException - on error

setupQualifierRow

private void setupQualifierRow(ExecRow baseRow)

isAnyFieldNull

boolean isAnyFieldNull(ExecRow baseRow)

Are any of the fields null in the row passed in. The only fields that are checked are those corresponding to the colArray in fkInfo.

Parameters:

baseRow - the row to check for null fields

Returns:

true if any are null

close

void close()
    throws StandardException

Clean up all scan controllers

Throws:

StandardException - on error

getRICheckIsolationLevel

int getRICheckIsolationLevel()

Get the isolation level for the scan for the RI check. NOTE: The level will eventually be instantaneous locking once the implementation changes.

Returns:

The isolation level for the scan for the RI check.