com.goldencode.p2j.persist.trigger

Class DatabaseTriggerManager

java.lang.Object

com.goldencode.p2j.persist.trigger.DatabaseTriggerManager

All Implemented Interfaces:

Scopeable

public class DatabaseTriggerManager
extends java.lang.Object
implements Scopeable

This class handles the management of trigger system for a database. For session triggers, it maintains a stack of scopes (a layer of triggers for each subroutine block).
An additional independent virtual level for generic triggers (which are executed first, non-vetoable) is composed of the genericXXXXTriggers maps. These can be null if no such triggers were registered.
There is a last layer formed by the schema triggers. If defined, they are executed last, and only if not overridden by the session trigger. They are not stored here but the code to be executed is dynamically computed based on annotation declared in DMO and current PROPATH.

One instance of this class is associated with a user context and, because this class implements Scopeable it is initialized in StandardServer.invoke(), before the topmost "startup" scope is pushed. The DatabaseTriggerManager is notified when the execution enters and leaves subroutine blocks, so it can do the management of session trigger layers.

Field Summary

Fields

Modifier and Type	Field and Description
private static ContextLocal<DatabaseTriggerManager>	context Context local map of instances of this class, mapped by theirs database name .
private java.util.Map<java.lang.Class<? extends Buffer>,java.util.HashMap<java.lang.Long,java.util.Deque<DatabaseEventType>>>	executing The stack of currently executing triggers in this context for each record id.
private java.util.Map<java.lang.String,java.util.Map<java.lang.String,TriggerData>>	genericAssignTriggers The data for ASSIGN generic triggers mapped by database and then by property name.
private java.util.Map<java.lang.String,TriggerData>	genericCreateTriggers The data for CREATE generic triggers mapped by database.
private java.util.Map<java.lang.String,TriggerData>	genericDeleteTriggers The data for DELETE generic triggers mapped by database.
private java.util.Map<java.lang.String,TriggerData>	genericFindTriggers The data for FIND generic triggers mapped by database.
private java.util.Map<java.lang.String,TriggerData>	genericWriteTriggers The data for WRITE generic triggers mapped by database.
private boolean	isTrigAbsolutePath Indicates whether the client trigger path is an absolute path or not.
private static CentralLogger	LOG Logger
private static int	logCluteringProtection The number of times we attempted to write the log on generic trigger old-buffer not being handled properly
private static int	logCluteringThreshold A rate at which we attempt to slow-down the logs on generic trigger old-buffer not being handled properly.
private java.util.Map<java.lang.Object,TriggerBlockLayer>	persistentTriggers The mapping of registered triggers for a persistent procedure.
private ProcedureManager.ProcedureHelper	pm Helper to use the ProcedureManager without any context local lookups.
private java.util.Map<java.lang.String,java.lang.Class<?>>	proceduresClassMap Procedure name to java class map.
private java.util.Deque<java.lang.Object>	programs The order of the persistentTriggers.
private java.util.Deque<TriggerBlockLayer>	stack The stack of all layer of triggers handled by this manager.
private TransactionManager.TransactionHelper	tm Helper to use the TM without any context local lookups.
private java.lang.String[]	triggerSearchPaths The paths to search for the trigger procedures, either an absolute path given at startup, or the relative trigger path concatenated to the propath.
private java.util.Optional<java.lang.String>	trigPath The trig parameter path specified by the client, with absolute prefix removed if necessary.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	DatabaseTriggerManager() Private constructor.

Method Summary

Modifier and Type	Method and Description
(package private) boolean	areAssignTriggersEnabled(java.lang.Class<? extends Buffer> bufferCls) Indicate whether assign triggers are enabled for the given buffer class at this block level.
private void	computeTriggerSearchPaths() Compute the locations where the search for the trigger procedures will happen depending on the trig path value.
private static Buffer	createWriteOldBuffer(java.lang.Class<?> def, java.lang.Class<? extends Buffer> bufferCls, Record oldDmoValue) Extract only the DMO schema-specific interface (i.e., exclude the Buffer interface)
static void	deregisterDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls) Unregister a session database trigger for the given event type and buffer class.
static void	deregisterDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.String property) Unregister a session database trigger for the given event type and buffer class.
(package private) java.lang.String	deregisterGenericAssignTrigger(java.lang.String database, java.lang.String property) Unregister a session database trigger for the given event type and buffer class.
(package private) java.lang.String	deregisterGenericTrigger(java.lang.String eventName, java.lang.String database) Unregister a previously set generic trigger given the event type and database.
static boolean	disableDumpTriggers(java.lang.Class<? extends Buffer> bufferCls) Disables dump triggers (FIND events) for the current block and any block of a callee from this block (function, internal/external procedure).
static boolean	disableLoadTriggers(java.lang.Class<? extends Buffer> bufferCls) Disables load triggers (CREATE,ASSIGN, WRITE events) for the current block.
static boolean	disableLoadTriggers(java.lang.Class<? extends Buffer> bufferCls, boolean allowReplication) Disables load triggers (CREATE, ASSIGN, WRITE events) for the current block.
private static boolean	fireAssignTrigger(TriggerData triggerData, Buffer newRecord, java.lang.String property, BaseDataType oldValue) Instantiates an object of the ASSIGN trigger and fires it.
private static void	fireTrigger(DatabaseEventType det, TriggerData triggerData, Buffer buffer, Buffer oldValue) Instantiates a trigger object associated with the specified database event type and fires it.
static DatabaseTriggerManager	get() Obtain the context-local DatabaseTriggerManager object.
(package private) java.util.Deque<DatabaseEventType>	getExecutingTriggerStack(java.lang.Class<? extends Buffer> bufferClass, java.lang.Long rowId, boolean create) Get the set of triggers that are currently executed for a specified record.
private TriggerData	getGenericTrigger(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls, java.lang.String database, java.lang.String property) Look for a specific generic trigger and return it if one was registered.
static DatabaseEventType	getReplicationEvent(DatabaseEventType det) Convert a base database event into the replication event.
(package private) static TriggerData	getReplicationSchemaTrigger(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls) Obtain the container that hold information for instantiating a schema trigger object for the replication version of the det event.
(package private) static TriggerData	getSchemaTrigger(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls, java.lang.String property) Obtain the container that holds information for instantiating a schema trigger object responsible for a det event.
ScopeId	getScopeId() Get the ScopeId for the instance.
private TriggerBlockLayer.EnableStatus	getTriggerStatus(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls) Looks into the stack of layers and check if a trigger is enabled for a database event.
private static boolean	guardedExec(java.lang.Runnable code) Execute a piece of code, checking whether it raised an ERROR.
static void	handleError(int errId, DatabaseEventType det, java.lang.String tableOrBufferName, java.lang.String fieldName) Handle trigger- related errors.
private static DatabaseTrigger<Buffer>	instantiateTrigger(TriggerData triggerData) Create a trigger object instance based on information from a TriggerData container.
(package private) boolean	isAssignTrigger(java.lang.Class<? extends Buffer> bufferCls, java.lang.String property, java.lang.String database) Indicate whether an assign trigger (session or schema) is registered for the given buffer class and DMO property at the current block level.
private static boolean	isSchemaTriggerOverrideable(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls) Tests if a schema trigger is overrideable.
(package private) boolean	isTriggerEnabled(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls, java.lang.String database) Indicate whether any trigger (session or schema) of the specified type is registered for the given buffer class at the current block level.
private TriggerData	peekTrigger(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls, java.lang.String property) Implementation of the trigger search algorithm in the stack of triggers.
static void	registerDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls, java.lang.Object container) Register a session database trigger within the current scope.
static void	registerDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls, java.lang.Object container, boolean override) Register a session database trigger within the current scope.
static void	registerDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls, java.lang.Object container, boolean override, boolean hasOldBuffer) Register a session database trigger within the current scope.
static void	registerDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.String property, java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls, java.lang.Object container) Register an ASSIGN session database trigger within the current scope.
static void	registerDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.String property, java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls, java.lang.Object container, boolean override) Register an ASSIGN session database trigger within the current scope.
static void	registerDatabaseTrigger(DatabaseEventType event, java.lang.Class<? extends Buffer> bufferCls, java.lang.String property, java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls, java.lang.Object container, boolean override, boolean hasOldValue) Register an ASSIGN session database trigger within the current scope.
(package private) java.lang.String	registerGenericTrigger(java.lang.String eventName, java.lang.String database, java.lang.String triggerClassName) Register a generic trigger for a specific event.
(package private) java.lang.String	registerGenericTrigger(java.lang.String eventName, java.lang.String database, java.lang.String triggerClassName, java.lang.String property) Register a generic trigger for a ASSIGN event.
(package private) void	removeExecutingTriggerStack(java.lang.Class<? extends Buffer> bufferClass, java.lang.Long rowId) Cleanup.
private void	removeGenericTrigger(DatabaseEventType det, java.lang.String database, java.lang.String property) Removes a generic trigger from the associated map.
void	scopeDeleted() Provides a notification that an external scope is about to be deleted.
void	scopeFinished() Provides a notification that a scope is about to be exited.
void	scopeStart(BlockDefinition block) Provides a notification that a new scope is about to be entered.
static boolean	trigger(DatabaseEventType det, java.lang.Class<? extends Buffer> bufferCls, Buffer newVal, Record oldDmoValue, java.lang.String database) Executes trigger suite for a base event (except for ASSIGN triggers).
static boolean	triggerAssign(java.lang.Class<? extends Buffer> bufferCls, Buffer newVal, java.lang.String property, BaseDataType oldValue, java.lang.String ldb) Executes an ASSIGN trigger.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final CentralLogger LOG

Logger

context

private static final ContextLocal<DatabaseTriggerManager> context

Context local map of instances of this class, mapped by theirs database name .

logCluteringProtection

private static int logCluteringProtection

The number of times we attempted to write the log on generic trigger old-buffer not being handled properly

logCluteringThreshold

private static int logCluteringThreshold

A rate at which we attempt to slow-down the logs on generic trigger old-buffer not being handled properly. This is increasing periodically to reduce the number of logs.

pm

private final ProcedureManager.ProcedureHelper pm

Helper to use the ProcedureManager without any context local lookups.

tm

private final TransactionManager.TransactionHelper tm

Helper to use the TM without any context local lookups.

stack

private final java.util.Deque<TriggerBlockLayer> stack

The stack of all layer of triggers handled by this manager.

persistentTriggers

private final java.util.Map<java.lang.Object,TriggerBlockLayer> persistentTriggers

The mapping of registered triggers for a persistent procedure.

programs

private final java.util.Deque<java.lang.Object> programs

The order of the persistentTriggers.

executing

private final java.util.Map<java.lang.Class<? extends Buffer>,java.util.HashMap<java.lang.Long,java.util.Deque<DatabaseEventType>>> executing

The stack of currently executing triggers in this context for each record id.

triggerSearchPaths

private java.lang.String[] triggerSearchPaths

The paths to search for the trigger procedures, either an absolute path given at startup, or the relative trigger path concatenated to the propath.

trigPath

private java.util.Optional<java.lang.String> trigPath

The trig parameter path specified by the client, with absolute prefix removed if necessary.

isTrigAbsolutePath

private boolean isTrigAbsolutePath

Indicates whether the client trigger path is an absolute path or not.

proceduresClassMap

private final java.util.Map<java.lang.String,java.lang.Class<?>> proceduresClassMap

Procedure name to java class map.

genericFindTriggers

private java.util.Map<java.lang.String,TriggerData> genericFindTriggers

The data for FIND generic triggers mapped by database.

genericCreateTriggers

private java.util.Map<java.lang.String,TriggerData> genericCreateTriggers

The data for CREATE generic triggers mapped by database.

genericWriteTriggers

private java.util.Map<java.lang.String,TriggerData> genericWriteTriggers

The data for WRITE generic triggers mapped by database.

genericDeleteTriggers

private java.util.Map<java.lang.String,TriggerData> genericDeleteTriggers

The data for DELETE generic triggers mapped by database.

genericAssignTriggers

private java.util.Map<java.lang.String,java.util.Map<java.lang.String,TriggerData>> genericAssignTriggers

The data for ASSIGN generic triggers mapped by database and then by property name.

Constructor Detail

DatabaseTriggerManager

private DatabaseTriggerManager()

Private constructor. An instance of this class can be obtained only using get() method. Registers this object with TransactionManager as a Scopeable instance.

Method Detail

computeTriggerSearchPaths

private void computeTriggerSearchPaths()

Compute the locations where the search for the trigger procedures will happen depending on the trig path value. If the trig path is an absolute path, the search happens only in it. If the trig path is relative, it is concatenated to the end of every propath path, so the search is done in this modified propath.

getSchemaTrigger

static TriggerData getSchemaTrigger(DatabaseEventType det,
                                    java.lang.Class<? extends Buffer> bufferCls,
                                    java.lang.String property)

Obtain the container that holds information for instantiating a schema trigger object responsible for a det event. If such trigger does not exist, or the procedure defined is invalid, a null object is returned.

Parameters:

det - The database event to which the trigger responds to.

bufferCls - The class that defines the table for which the trigger applies to.

property - Optionally, for ASSIGN triggers the name of the property (field) for which the trigger was declared. Otherwise, it is ignored.

Returns:

The container that holds information of how to create an instance of the specified trigger and how to apply it or null if such schema trigger has not been declared.

getReplicationSchemaTrigger

static TriggerData getReplicationSchemaTrigger(DatabaseEventType det,
                                               java.lang.Class<? extends Buffer> bufferCls)

Obtain the container that hold information for instantiating a schema trigger object for the replication version of the det event. This call is only valid for events that have replication equivalent. If these conditions are not met or no such replication trigger was defined, then a null object is returned.

Parameters:

det - The database event whose replication equivalent trigger responds to.

bufferCls - The buffer class for the dmo that fired the trigger.

Returns:

The container that holds information of how to create an instance of the replication schema trigger.

get

public static DatabaseTriggerManager get()

Obtain the context-local DatabaseTriggerManager object.

Returns:

the DatabaseTriggerManager for current context.

registerDatabaseTrigger

public static void registerDatabaseTrigger(DatabaseEventType event,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls,
                                           java.lang.Object container)

Register a session database trigger within the current scope. Any previously registered session trigger on current block is silently removed. This overloaded method is always not overriding the schema trigger and is not declaring an OLD [BUFFER].

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

triggerCls - The class of the trigger.

container - The containing object (all triggers are implemented as non-static inner classes, so they must have a reference to the containing class).

registerDatabaseTrigger

public static void registerDatabaseTrigger(DatabaseEventType event,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls,
                                           java.lang.Object container,
                                           boolean override)

Register a session database trigger within the current scope. Any previously registered session trigger on current block is silently removed. This overloaded method not declaring an OLD [BUFFER].

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

triggerCls - The class of the trigger.

container - The containing object (all triggers are implemented as non-static inner classes, so they must have a reference to the containing class).

override - true if OVERRIDE keyword is specified.

registerDatabaseTrigger

public static void registerDatabaseTrigger(DatabaseEventType event,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls,
                                           java.lang.Object container,
                                           boolean override,
                                           boolean hasOldBuffer)

Register a session database trigger within the current scope. Any previously registered session trigger on current block is silently removed.

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

triggerCls - The class of the trigger.

container - The containing object (all triggers are implemented as non-static inner classes, so they must have a reference to the containing class).

override - true if OVERRIDE keyword is specified.

hasOldBuffer - true if an OLD [BUFFER] keyword is specified.

registerDatabaseTrigger

public static void registerDatabaseTrigger(DatabaseEventType event,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           java.lang.String property,
                                           java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls,
                                           java.lang.Object container)

Register an ASSIGN session database trigger within the current scope. Any previously registered session trigger on current block is silently removed. This overloaded method is always not overriding the schema trigger and is not declaring an OLD [VALUE].

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

triggerCls - The class of the trigger.

container - The containing object (all triggers are implemented as non-static inner classes, so they must have a reference to the containing class).

registerDatabaseTrigger

public static void registerDatabaseTrigger(DatabaseEventType event,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           java.lang.String property,
                                           java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls,
                                           java.lang.Object container,
                                           boolean override)

Register an ASSIGN session database trigger within the current scope. Any previously registered session trigger on current block is silently removed. This overloaded method is not declaring an OLD [VALUE].

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

triggerCls - The class of the trigger.

container - The containing object (all triggers are implemented as non-static inner classes, so they must have a reference to the containing class).

override - true if OVERRIDE keyword is specified.

registerDatabaseTrigger

public static void registerDatabaseTrigger(DatabaseEventType event,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           java.lang.String property,
                                           java.lang.Class<? extends DatabaseTrigger<? extends Buffer>> triggerCls,
                                           java.lang.Object container,
                                           boolean override,
                                           boolean hasOldValue)

Register an ASSIGN session database trigger within the current scope. Any previously registered session trigger on current block is silently removed.

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

triggerCls - The class of the trigger.

container - The containing object (all triggers are implemented as non-static inner classes, so they must have a reference to the containing class).

override - true if OVERRIDE keyword is specified.

deregisterDatabaseTrigger

public static void deregisterDatabaseTrigger(DatabaseEventType event,
                                             java.lang.Class<? extends Buffer> bufferCls,
                                             java.lang.String property)

Unregister a session database trigger for the given event type and buffer class. This is only called when a ON Assign OF <table.field> REVERT.

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

property - The property that is deregistered from ASSIGN trigger.

deregisterDatabaseTrigger

public static void deregisterDatabaseTrigger(DatabaseEventType event,
                                             java.lang.Class<? extends Buffer> bufferCls)

Unregister a session database trigger for the given event type and buffer class. This is only called when a ON <event> OF <table> REVERT.

Parameters:

event - Database event type.

bufferCls - The class of the buffer to which the event is applied.

disableDumpTriggers

public static boolean disableDumpTriggers(java.lang.Class<? extends Buffer> bufferCls)

Disables dump triggers (FIND events) for the current block and any block of a callee from this block (function, internal/external procedure).

Parameters:

bufferCls - The buffer for which to disable dump triggers.

Returns:

true if the filter was successfully applied. If false is returned then the internal stack is broken because of bad block management.

disableLoadTriggers

public static boolean disableLoadTriggers(java.lang.Class<? extends Buffer> bufferCls)

Disables load triggers (CREATE,ASSIGN, WRITE events) for the current block. The replication triggers are also disabled.

Parameters:

bufferCls - The buffer for which to disable load triggers.

Returns:

true if the filter was successfully applied. If false is returned then the internal stack is broken because of bad block management.

disableLoadTriggers

public static boolean disableLoadTriggers(java.lang.Class<? extends Buffer> bufferCls,
                                          boolean allowReplication)

Disables load triggers (CREATE, ASSIGN, WRITE events) for the current block.

Parameters:

bufferCls - The buffer for which to disable load triggers.

allowReplication - If true the replication triggers will not be disabled for this block.

Returns:

true if the filter was successfully applied. If false is returned then the internal stack is broken because of bad block management.

trigger

public static boolean trigger(DatabaseEventType det,
                              java.lang.Class<? extends Buffer> bufferCls,
                              Buffer newVal,
                              Record oldDmoValue,
                              java.lang.String database)

Executes trigger suite for a base event (except for ASSIGN triggers). The suite includes the session, simple schema and replication triggers that have been defined/assigned for the det base event. The order in which they execute depends on det: session triggers are always executed first and replication triggers last, except for the FIND triggers, where schema triggers execute before session triggers and there is no replication trigger to execute.

Parameters:

det - The trigger type to be executed.

bufferCls - The buffer class for the dmo that fired the trigger.

newVal - The buffer that fired the trigger.

oldDmoValue - When the (WRITE) trigger declares an 'old' buffer value, this is passed to trigger procedure as r/o buffer.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

Returns:

true if no trigger was executed, or they executed with success. The method will return false if the trigger vetoed the operation (by returning error).

getReplicationEvent

public static DatabaseEventType getReplicationEvent(DatabaseEventType det)

Convert a base database event into the replication event. If they are already replication events, they are returned. If they do not have a replication event associated, null is returned.

Parameters:

det - The base trigger event.

Returns:

The replication event of det. For FIND and ASSIGN, null is returned.

triggerAssign

public static boolean triggerAssign(java.lang.Class<? extends Buffer> bufferCls,
                                    Buffer newVal,
                                    java.lang.String property,
                                    BaseDataType oldValue,
                                    java.lang.String ldb)

Executes an ASSIGN trigger.

Parameters:

bufferCls - The buffer class for the dmo that fired the trigger.

newVal - The buffer that contains the field that fired the trigger.

oldValue - When the ASSIGN trigger declares an 'old' value, this is passed to trigger procedure. The procedure code is allowed to modify this value without generating any error, however, they are lost as only a duplicate is passed on.

ldb - The database where the buffer reside.

Returns:

true if no trigger was executed, or they executed with success. The method will return false if the trigger vetoed the operation (by returning error).

scopeStart

public void scopeStart(BlockDefinition block)

Provides a notification that a new scope is about to be entered. The manager only acts on top-level scope. Each time a new scope is entered a fresh new layer of triggers is added to internal stack.

Specified by:

scopeStart in interface Scopeable

Parameters:

block - The explicit block definition which required this notification.

scopeDeleted

public void scopeDeleted()

Provides a notification that an external scope is about to be deleted.

Specified by:

scopeDeleted in interface Scopeable

getScopeId

public ScopeId getScopeId()

Get the ScopeId for the instance.

Specified by:

getScopeId in interface Scopeable

Returns:

ScopeId.DATABASE_TRIGGER_MANAGER.

scopeFinished

public void scopeFinished()

Provides a notification that a scope is about to be exited. The manager only acts on top-level scope. Each time a scope is exited the last layer of triggers is removed from internal stack.

Specified by:

scopeFinished in interface Scopeable

registerGenericTrigger

java.lang.String registerGenericTrigger(java.lang.String eventName,
                                        java.lang.String database,
                                        java.lang.String triggerClassName)

Register a generic trigger for a specific event. When such trigger is registered, it will be fired for all events of that type, of all tables from specified database before any other configured session or schema trigger. The execution of the latter two is unaffected of the presence or execution of the generic trigger.

Parameters:

eventName - The event as case-insensitive string.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

triggerClassName - The trigger class which implements the method for handling the respective event in a generic manner.

Returns:

null if the operation is successful and a short description of the problem otherwise.

deregisterGenericTrigger

java.lang.String deregisterGenericTrigger(java.lang.String eventName,
                                          java.lang.String database)

Unregister a previously set generic trigger given the event type and database. This is the equivalent of ON <event> OF <table> REVERT but for generic triggers.

Parameters:

eventName - The event as case-insensitive string.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

Returns:

null if the operation is successful and a short description of the problem otherwise.

registerGenericTrigger

java.lang.String registerGenericTrigger(java.lang.String eventName,
                                        java.lang.String database,
                                        java.lang.String triggerClassName,
                                        java.lang.String property)

Register a generic trigger for a ASSIGN event. When such trigger is registered, it will be fired for all ASSIGN events, of all tables from specified database BEFORE any other configured session or schema triggers. The execution of the latter two is unaffected of the presence or execution of the generic trigger.

Parameters:

eventName - The event as case-insensitive string.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

triggerClassName - The trigger class which implements the method for handling the respective event in a generic manner.

property - The property name of the affected field.

Returns:

null if the operation is successful and a short description of the problem otherwise.

deregisterGenericAssignTrigger

java.lang.String deregisterGenericAssignTrigger(java.lang.String database,
                                                java.lang.String property)

Unregister a session database trigger for the given event type and buffer class. This is the equivalent of ON Assign OF <table> REVERT but for generic triggers.

Parameters:

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

property - The property that is deregistered from ASSIGN trigger.

Returns:

null if the operation is successful and a short description of the problem otherwise.

isSchemaTriggerOverrideable

private static boolean isSchemaTriggerOverrideable(DatabaseEventType event,
                                                   java.lang.Class<? extends Buffer> bufferCls)

Tests if a schema trigger is overrideable. In case the trigger is declared as overrideable, true is returned. Otherwise, 3223 code is recordOrThrowError(). If no error is acting false will be returned.

Parameters:

event - The database event of the trigger to be tested.

bufferCls - The class buf for the table the trigger is defined.

Returns:

true if respective trigger can be overridden by a session trigger.

instantiateTrigger

private static DatabaseTrigger<Buffer> instantiateTrigger(TriggerData triggerData)

Create a trigger object instance based on information from a TriggerData container.

Parameters:

triggerData - The container that holds information about the trigger to be built.

Returns:

An instance of the trigger as configured in triggerData.

createWriteOldBuffer

private static Buffer createWriteOldBuffer(java.lang.Class<?> def,
                                           java.lang.Class<? extends Buffer> bufferCls,
                                           Record oldDmoValue)

Extract only the DMO schema-specific interface (i.e., exclude the Buffer interface)

Parameters:

def - The source-definition class for the trigger.

bufferCls - Interface which defines DMO's public API plus all Buffer methods.

oldDmoValue - The read-only value.

Returns:

A temporary read-only buffer that can be used as the OLD 'parameter' in a WRITE trigger.

fireAssignTrigger

private static boolean fireAssignTrigger(TriggerData triggerData,
                                         Buffer newRecord,
                                         java.lang.String property,
                                         BaseDataType oldValue)

Instantiates an object of the ASSIGN trigger and fires it.

Parameters:

triggerData - Information about how the trigger will be built.

newRecord - The buffer that contains the field that fired the trigger.

property - Optionally, for ASSIGN triggers the name of the property (field) for which the trigger was declared. Otherwise, it is ignored.

oldValue - The old value of the field. May be null if the trigger did not declare it.

Returns:

true if no trigger was executed, or they executed with success. The method will return false if the trigger vetoed the operation (by returning error).

fireTrigger

private static void fireTrigger(DatabaseEventType det,
                                TriggerData triggerData,
                                Buffer buffer,
                                Buffer oldValue)

Instantiates a trigger object associated with the specified database event type and fires it.

Parameters:

det - The database event type to be fired.

triggerData - Information about how the trigger will be built.

buffer - The buffer that fired the trigger.

oldValue - The old value of the buffer. May be null if the trigger did not declare it.

handleError

public static void handleError(int errId,
                               DatabaseEventType det,
                               java.lang.String tableOrBufferName,
                               java.lang.String fieldName)

Handle trigger- related errors. The error is displayed in status bar then the execution of the procedure is abruptly interrupted because all trigger errors are fatal errors.

Parameters:

errId - The id of the error.

det - The database event that caused the error.

tableOrBufferName - The name of the table (or buffer in some cases) that caused the error

fieldName - In the case of ASSIGN trigger the field that caused the error.

isTriggerEnabled

boolean isTriggerEnabled(DatabaseEventType det,
                         java.lang.Class<? extends Buffer> bufferCls,
                         java.lang.String database)

Indicate whether any trigger (session or schema) of the specified type is registered for the given buffer class at the current block level.

Parameters:

det - Trigger type.

bufferCls - Buffer class.

database - The database where the buffer reside. If null try to autodetect using the buffer DMO.

Returns:

true if a registered trigger is found, else false.

areAssignTriggersEnabled

boolean areAssignTriggersEnabled(java.lang.Class<? extends Buffer> bufferCls)

Indicate whether assign triggers are enabled for the given buffer class at this block level.

Parameters:

bufferCls - Buffer class.

Returns:

See above.

isAssignTrigger

boolean isAssignTrigger(java.lang.Class<? extends Buffer> bufferCls,
                        java.lang.String property,
                        java.lang.String database)

Indicate whether an assign trigger (session or schema) is registered for the given buffer class and DMO property at the current block level.

Parameters:

bufferCls - Buffer class.

property - DMO property name.

database - The database where the buffer reside. If null try to autodetect using the buffer DMO.

Returns:

true if a registered trigger is found, else false.

getExecutingTriggerStack

java.util.Deque<DatabaseEventType> getExecutingTriggerStack(java.lang.Class<? extends Buffer> bufferClass,
                                                            java.lang.Long rowId,
                                                            boolean create)

Get the set of triggers that are currently executed for a specified record.

Parameters:

bufferClass - The dmo buffer interface.

rowId - The id of the record.

create - If the specified stack does not exist, make sure it is created.

Returns:

The stack of execution triggers. May be null if stack does not exist and creation of a new one was not requested.

removeExecutingTriggerStack

void removeExecutingTriggerStack(java.lang.Class<? extends Buffer> bufferClass,
                                 java.lang.Long rowId)

Cleanup. Removes a trigger stack for a specified record. The stack must exist and be empty, otherwise there the pop/push are not balanced.

Parameters:

bufferClass - The dmo buffer interface.

rowId - The id of the record.

getTriggerStatus

private TriggerBlockLayer.EnableStatus getTriggerStatus(DatabaseEventType det,
                                                        java.lang.Class<? extends Buffer> bufferCls)

Looks into the stack of layers and check if a trigger is enabled for a database event. If the trigger was not disabled at all, EnableStatus.ENABLED is returned. If the trigger was disabled, the EnableStatus.DISABLED is returned unless the events has a replication pair, and it was not disable using ALLOW-REPLICATION, when EnableStatus.REPLICATION_ONLY is returned.

FIND/ASSIGN/CREATE/WRITE events won't return ENABLED here, they will return either DISABLED or UNKNOWN. Thus, we check the entire stack until DISABLED is found and if DISABLED is never returned, then we are implicitly ENABLED.

Parameters:

det - The database (base) event.

bufferCls - The buffer.

Returns:

the status of the trigger on the buffer.

peekTrigger

private TriggerData peekTrigger(DatabaseEventType det,
                                java.lang.Class<? extends Buffer> bufferCls,
                                java.lang.String property)

Implementation of the trigger search algorithm in the stack of triggers. Each layer of the stack is inspected for det type of trigger associated with buff. If found it is returned, otherwise the search continue with the next level from the stack. If no such trigger can be found, null is returned. This method takes into account if respective trigger event was disabled and, in this case, a special singleton object is returned.

Parameters:

det - The database trigger type.

bufferCls - The buffer that raised the trigger event.

property - In the case of ASSIGN trigger, the name of the property that fired the trigger

Returns:

The top-level instance of the trigger data of the det type associated with buff.

removeGenericTrigger

private void removeGenericTrigger(DatabaseEventType det,
                                  java.lang.String database,
                                  java.lang.String property)

Removes a generic trigger from the associated map.

Parameters:

det - The event type of the trigger to be reverted

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

property - The property that is unregistered from ASSIGN trigger, otherwise ignored.

getGenericTrigger

private TriggerData getGenericTrigger(DatabaseEventType det,
                                      java.lang.Class<? extends Buffer> bufferCls,
                                      java.lang.String database,
                                      java.lang.String property)

Look for a specific generic trigger and return it if one was registered.

Parameters:

det - The trigger type to be executed.

bufferCls - The buffer class for the dmo that fired the trigger. Currently, unused. It will be used when the buffer pattern will be added to generic trigger registration.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

property - The modified property, in case of ASSIGN triggers.

Returns:

the trigger data necessary for firing the specified trigger, or null if none was found.

guardedExec

private static boolean guardedExec(java.lang.Runnable code)

Execute a piece of code, checking whether it raised an ERROR. In the event this happens, false is returned if already in silent mode, otherwise the exception will propagate to the caller.

Parameters:

code - The code to be executed.

Returns:

true if the code executed normally, and false if it raised an error while in silent mode.

Throws:

ErrorConditionException - if an error condition was raised while not in silent mode