org.apache.derby.impl.sql.conn
Class GenericStatementContext

java.lang.Object
  org.apache.derby.iapi.services.context.ContextImpl
      org.apache.derby.impl.sql.conn.GenericStatementContext

All Implemented Interfaces:

Context, StatementContext

final class GenericStatementContext
extends ContextImpl
implements StatementContext

GenericStatementContext is pushed/popped around a statement prepare and execute so that any statement specific clean up can be performed.

Nested Class Summary

private static class

GenericStatementContext.CancelQueryTask This is a TimerTask that is responsible for timing out statements, typically when an application has called Statement.setQueryTimeout().

Field Summary

private Activation	activation The activation associated with this context, or null
private boolean	cancellationFlag
private GenericStatementContext.CancelQueryTask	cancelTask
private java.util.ArrayList	dependencies
private java.lang.String	internalSavePointName
private boolean	inUse
private boolean	isAtomic
private boolean	isForReadOnly
private boolean	isSystemCode
private LanguageConnectionContext	lcc
private NoPutResultSet[]	materializedSubqueries
private boolean	parentInTrigger
private ParameterValueSet	pvs
private boolean	rollbackParentContext
private boolean	setSavePoint
private short	sqlAllowed Set to one of RoutineAliasInfo.
private SQLSessionContext	sqlSessionContext The SQLSessionContext associated with a statement context.
private boolean	statementWasInvalidated
private java.lang.String	stmtText
private NoPutResultSet[]	subqueryTrackingArray
private ResultSet	topResultSet

Constructor Summary

GenericStatementContext(LanguageConnectionContext lcc)

Method Summary

void	addDependency(Dependency dy) Track a Dependency within this StatementContext.
java.lang.StringBuffer	appendErrorInfo()
void	cancel() Cancels the statement which has allocated this StatementContext object.
void	cleanupOnError(java.lang.Throwable error) Close down the top ResultSet, if relevant, and rollback to the internal savepoint, if one was set.
void	clearInUse() Mark this context as not in use.
void	clearSavePoint() Clear the save point for the current statement.
Activation	getActivation() Get activation associated with this statement context, if any.
short	getSQLAllowed() Get the setting of the SQL allowed state.
SQLSessionContext	getSQLSessionContext() Get the current SQL session context
java.lang.String	getStatementText() Return the text of the current statement.
boolean	getStatementWasInvalidated() Tells if this statement has been invalidated.
NoPutResultSet[]	getSubqueryTrackingArray() Get the subquery tracking array for this query.
boolean	getSystemCode() Return true if this statement is system code.
boolean	inTrigger() Returns whether we started from within the context of a trigger or not.
boolean	inUse() Is this statement context in use or not.
boolean	isAtomic() Indicates whether the statement needs to be executed atomically or not, i.e., whether a commit/rollback is permitted by a connection nested in this statement.
boolean	isCancelled() Tests whether the statement which has allocated this StatementContext object has been cancelled.
boolean	isForReadOnly() Is this statement for a read only, non-updatable ResultSet
boolean	isLastHandler(int severity) Return whether or not this context is the "last" handler for a the specified severity level.
boolean	onStack() Reports whether this StatementContext is on the context stack.
private void	pleaseBeOnStack() Raise an exception if this Context is not in use, that is, on the Context Stack.
void	resetSavePoint() Resets the savepoint to the current spot if it is set, otherwise, noop.
void	setActivation(Activation a) Mark this statement context as associated with this activation.
void	setInUse(boolean parentInTrigger, boolean isAtomic, boolean isForReadOnly, java.lang.String stmtText, ParameterValueSet pvs, long timeoutMillis) Mark this context as being in use.
void	setParentRollback() Indicate that, in the event of a statement-level exception, this context is NOT the last one that needs to be rolled back--rather, it is nested within some other statement context, and that other context needs to be rolled back, too.
void	setSavePoint() Set a save point for the current statement.
void	setSQLAllowed(short allow, boolean force) Set the level of SQL allowed in this and subsequent nested statements due to a routine call.
void	setSQLSessionContext(SQLSessionContext ctx) Set the current SQL session context
void	setSubqueryResultSet(int subqueryNumber, NoPutResultSet subqueryResultSet, int numSubqueries) Set the appropriate entry in the subquery tracking array for the specified subquery.
void	setSystemCode() Set to indicate statement is system code.
void	setTopResultSet(ResultSet topResultSet, NoPutResultSet[] subqueryTrackingArray) Set the top ResultSet in the ResultSet tree for close down on an error.
private void	stuffTopResultSet(ResultSet topResultSet, NoPutResultSet[] subqueryTrackingArray) Private minion of setTopResultSet() and clearInUse()

Methods inherited from class org.apache.derby.iapi.services.context.ContextImpl

getContextManager, getIdName, popMe, pushMe

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.services.context.Context

getContextManager, getIdName, popMe, pushMe

Field Detail

setSavePoint

private boolean setSavePoint

internalSavePointName

private java.lang.String internalSavePointName

topResultSet

private ResultSet topResultSet

dependencies

private java.util.ArrayList dependencies

subqueryTrackingArray

private NoPutResultSet[] subqueryTrackingArray

materializedSubqueries

private NoPutResultSet[] materializedSubqueries

lcc

private final LanguageConnectionContext lcc

inUse

private boolean inUse

cancellationFlag

private volatile boolean cancellationFlag

cancelTask

private GenericStatementContext.CancelQueryTask cancelTask

parentInTrigger

private boolean parentInTrigger

isForReadOnly

private boolean isForReadOnly

isAtomic

private boolean isAtomic

isSystemCode

private boolean isSystemCode

rollbackParentContext

private boolean rollbackParentContext

statementWasInvalidated

private boolean statementWasInvalidated

stmtText

private java.lang.String stmtText

pvs

private ParameterValueSet pvs

sqlAllowed

private short sqlAllowed

Set to one of RoutineAliasInfo.{MODIFIES_SQL_DATA, READS_SQL_DATA, CONTAINS_SQL, NO_SQL}

activation

private Activation activation

The activation associated with this context, or null

sqlSessionContext

private SQLSessionContext sqlSessionContext

The SQLSessionContext associated with a statement context.

Constructor Detail

GenericStatementContext

GenericStatementContext(LanguageConnectionContext lcc)

Method Detail

setInUse

public void setInUse(boolean parentInTrigger,
                     boolean isAtomic,
                     boolean isForReadOnly,
                     java.lang.String stmtText,
                     ParameterValueSet pvs,
                     long timeoutMillis)

Description copied from interface: StatementContext

Mark this context as being in use.

Specified by:

setInUse in interface StatementContext

Parameters:

parentInTrigger - true if the parent started in the context of a trigger

isAtomic - true if the statement must be executed atomically

isForReadOnly - true if the statement is for producing non-updatable resultset

stmtText - the text of the statement. Needed for any language statement (currently, for any statement that can cause a trigger to fire). Please set this unless you are some funky jdbc setXXX method or something.

pvs - parameter value set, if it has one

timeoutMillis - timeout value for the statement, in milliseconds. Zero means no timeout.

clearInUse

public void clearInUse()

Description copied from interface: StatementContext

Mark this context as not in use. This is important because we always leave the top statement context on the stack, and we don't want to clean it up if a statement level exception happens while the context is not in use.

Specified by:

clearInUse in interface StatementContext

setSavePoint

public void setSavePoint()
                  throws StandardException

Description copied from interface: StatementContext

Set a save point for the current statement. NOTE: This needs to be off of the StatementContext so that it gets cleared on a statement error.

Specified by:

setSavePoint in interface StatementContext

Throws:

StandardException - Thrown on error

See Also:

StatementContext.setSavePoint()

resetSavePoint

public void resetSavePoint()
                    throws StandardException

Resets the savepoint to the current spot if it is set, otherwise, noop. Used when a commit is done on a nested connection.

Specified by:

resetSavePoint in interface StatementContext

Throws:

StandardException - Thrown on error

See Also:

StatementContext.resetSavePoint()

clearSavePoint

public void clearSavePoint()
                    throws StandardException

Description copied from interface: StatementContext

Clear the save point for the current statement.

Specified by:

clearSavePoint in interface StatementContext

Throws:

StandardException - Thrown on error

See Also:

StatementContext.clearSavePoint()

setTopResultSet

public void setTopResultSet(ResultSet topResultSet,
                            NoPutResultSet[] subqueryTrackingArray)
                     throws StandardException

Set the top ResultSet in the ResultSet tree for close down on an error.

Specified by:

setTopResultSet in interface StatementContext

Parameters:

topResultSet - The top ResultSet in the ResultSet tree

subqueryTrackingArray - (Sparse) of tops of subquery ResultSet trees

Throws:

StandardException - thrown on error.

stuffTopResultSet

private void stuffTopResultSet(ResultSet topResultSet,
                               NoPutResultSet[] subqueryTrackingArray)

Private minion of setTopResultSet() and clearInUse()

Parameters:

topResultSet - make this the top result set

subqueryTrackingArray - where to keep track of subqueries in this statement

setSubqueryResultSet

public void setSubqueryResultSet(int subqueryNumber,
                                 NoPutResultSet subqueryResultSet,
                                 int numSubqueries)
                          throws StandardException

Set the appropriate entry in the subquery tracking array for the specified subquery. Useful for closing down open subqueries on an exception.

Specified by:

setSubqueryResultSet in interface StatementContext

Parameters:

subqueryNumber - The subquery # for this subquery

subqueryResultSet - The ResultSet at the top of the subquery

numSubqueries - The total # of subqueries in the entire query

Throws:

StandardException - thrown on error.

getSubqueryTrackingArray

public NoPutResultSet[] getSubqueryTrackingArray()
                                          throws StandardException

Get the subquery tracking array for this query. (Useful for runtime statistics.)

Specified by:

getSubqueryTrackingArray in interface StatementContext

Returns:

NoPutResultSet[] The (sparse) array of tops of subquery ResultSet trees

Throws:

StandardException - thrown on error.

addDependency

public void addDependency(Dependency dy)
                   throws StandardException

Track a Dependency within this StatementContext. (We need to clear any dependencies added within this context on an error.

Specified by:

addDependency in interface StatementContext

Parameters:

dy - The dependency to track.

Throws:

StandardException - thrown on error.

inTrigger

public boolean inTrigger()

Returns whether we started from within the context of a trigger or not.

Specified by:

inTrigger in interface StatementContext

Returns:

true if we are in a trigger context

cleanupOnError

public void cleanupOnError(java.lang.Throwable error)
                    throws StandardException

Close down the top ResultSet, if relevant, and rollback to the internal savepoint, if one was set.

Specified by:

cleanupOnError in interface Context

Throws:

StandardException - thrown on error. REVISIT: don't want cleanupOnError's to throw exceptions.

isLastHandler

public boolean isLastHandler(int severity)

Description copied from interface: Context

Return whether or not this context is the "last" handler for a the specified severity level. Previously, the context manager would march through all of the contexts in cleanupOnError() and call each of their cleanupOnError() methods. That did not work with server side JDBC, especially for a StatementException, because outer contexts could get cleaned up incorrectly. This functionality is specific to the Language system. Any non-language system contexts should return ExceptionSeverity.NOT_APPLICABLE_SEVERITY. NOTE: Both the LanguageConnectionContext and the JDBC Connection Context are interested in session level errors because they both have clean up to do. This method allows both of them to return false so that all such handlers under them can do their clean up.

Specified by:

isLastHandler in interface Context

Overrides:

isLastHandler in class ContextImpl

See Also:

Context.isLastHandler(int)

onStack

public boolean onStack()

Reports whether this StatementContext is on the context stack.

Specified by:

onStack in interface StatementContext

Returns:

true if this StatementContext is on the context stack. false otherwise.

isAtomic

public boolean isAtomic()

Indicates whether the statement needs to be executed atomically or not, i.e., whether a commit/rollback is permitted by a connection nested in this statement.

Specified by:

isAtomic in interface StatementContext

Returns:

true if needs to be atomic

getStatementText

public java.lang.String getStatementText()

Return the text of the current statement. Note that this may be null. It is currently not set up correctly for ResultSets that aren't single row result sets (e.g SELECT), replication, and setXXXX/getXXXX jdbc methods.

Specified by:

getStatementText in interface StatementContext

Returns:

the statement text

pleaseBeOnStack

private void pleaseBeOnStack()
                      throws StandardException

Raise an exception if this Context is not in use, that is, on the Context Stack.

Throws:

StandardException - thrown on error.

inUse

public boolean inUse()

Description copied from interface: StatementContext

Is this statement context in use or not.

Specified by:

inUse in interface StatementContext

Returns:

true if in use

isForReadOnly

public boolean isForReadOnly()

Description copied from interface: StatementContext

Is this statement for a read only, non-updatable ResultSet

Specified by:

isForReadOnly in interface StatementContext

Returns:

true if the statement is for creating a read only, non-updatable ResultSet

isCancelled

public boolean isCancelled()

Tests whether the statement which has allocated this StatementContext object has been cancelled. This method is typically called from the thread which is executing the statement, to test whether execution should continue or stop.

Specified by:

isCancelled in interface StatementContext

Returns:

whether the statement which has allocated this StatementContext object has been cancelled.

cancel

public void cancel()

Cancels the statement which has allocated this StatementContext object. This is done by setting a flag in the StatementContext object. For this to have any effect, it is the responsibility of the executing statement to check this flag regularly.

Specified by:

cancel in interface StatementContext

setSQLAllowed

public void setSQLAllowed(short allow,
                          boolean force)

Description copied from interface: StatementContext

Set the level of SQL allowed in this and subsequent nested statements due to a routine call. Value must be one of RoutineAliasInfo.{MODIFIES_SQL_DATA, READS_SQL_DATA, CONTAINS_SQL, NO_SQL}

Specified by:

setSQLAllowed in interface StatementContext

force - set to true to override more restrictive setting. Used to reset the permissions after a function call.

getSQLAllowed

public short getSQLAllowed()

Description copied from interface: StatementContext

Get the setting of the SQL allowed state.

Specified by:

getSQLAllowed in interface StatementContext

setParentRollback

public void setParentRollback()

Indicate that, in the event of a statement-level exception, this context is NOT the last one that needs to be rolled back--rather, it is nested within some other statement context, and that other context needs to be rolled back, too.

Specified by:

setParentRollback in interface StatementContext

setSystemCode

public void setSystemCode()

Set to indicate statement is system code. For example a system procedure, view, function etc.

Specified by:

setSystemCode in interface StatementContext

getSystemCode

public boolean getSystemCode()

Return true if this statement is system code.

Specified by:

getSystemCode in interface StatementContext

appendErrorInfo

public java.lang.StringBuffer appendErrorInfo()

Overrides:

appendErrorInfo in class ContextImpl

setActivation

public void setActivation(Activation a)

Description copied from interface: StatementContext

Mark this statement context as associated with this activation.

Specified by:

setActivation in interface StatementContext

Parameters:

a - activation

See Also:

StatementContext.setActivation(Activation a)

getActivation

public Activation getActivation()

Description copied from interface: StatementContext

Get activation associated with this statement context, if any. Used to link up stack of activations of calls in nested connections, see GenericPreparedStatement#getActivation.

Specified by:

getActivation in interface StatementContext

See Also:

StatementContext.getActivation()

getSQLSessionContext

public SQLSessionContext getSQLSessionContext()

Description copied from interface: StatementContext

Get the current SQL session context

Specified by:

getSQLSessionContext in interface StatementContext

See Also:

StatementContext.getSQLSessionContext()

setSQLSessionContext

public void setSQLSessionContext(SQLSessionContext ctx)

Description copied from interface: StatementContext

Set the current SQL session context

Specified by:

setSQLSessionContext in interface StatementContext

Parameters:

ctx - the SQL session context

See Also:

StatementContext.setSQLSessionContext(SQLSessionContext ctx)

getStatementWasInvalidated

public boolean getStatementWasInvalidated()

Description copied from interface: StatementContext

Tells if this statement has been invalidated.

Specified by:

getStatementWasInvalidated in interface StatementContext

Returns:

true if the statement was invalidated.