zeus.actors
Class ResourceDb

java.lang.Object
  java.util.Dictionary
      java.util.Hashtable
          zeus.actors.ResourceDb

All Implemented Interfaces:

java.lang.Cloneable, java.util.Map, java.io.Serializable

public class ResourceDb

extends java.util.Hashtable

This class implements the Resource Database component, whose role is to store the resources owned by the agent, (which are Fact objects). The Resource Database is simply an extended Hashtable with the fact objects held indexed by their types.

Developers will probably interact the Resource Database on a regular basis, as it both contains the agent's knowledge and provides a means of altering it. A reference to the Resource Database can be obtained from the agent's AgentContext object, allowing access to the methods described below; (The methods without descriptions are primarily used by other agent components and so are unlikely to be useful to developers).

Change log

19/08/00 - added some code to the any(Fact) method at about line 580 - 590 this is to stop an unnecessary exception being thrown, the new behavior is that if the method is called and there are no facts of that type in the resourcedb then a new fact of that type will be returned instead.

Change log ---------- 13/06/01 added a number of fields (name,planner,ontologyDb, gensym,externaldb) which are used to store references that would be obtained from the AgentContext object, but cannot be if the context is not available at initialisation. I hope that this will enable better extensibility, but it might cause problems if the agent architecture is altered at run time. Added isSet method to allow programmers to check to see if Added setPlanner to permit this reference to be updated easily Added setName Added setOntologyDb Added setGenSym

See Also:

Serialized Form

Nested Class Summary

Nested classes inherited from class java.util.Hashtable

Field Summary

private static int	ACCESS
private static int	ADD
protected AgentContext	context
private static int	DELETE
private HSet[]	eventMonitor
protected GenSym	gensym
private static int	MODIFY
protected java.lang.String	name
protected OntologyDb	ontologyDb
protected Planner	planner

Fields inherited from class java.util.Hashtable

Constructor Summary

ResourceDb()

ResourceDb(AgentContext context)

Method Summary

ResourceItem	add(Fact fact) The primary method for adding new facts to the Resource Database was synchronized
ResourceItem	add(Fact[] List) was synchronized
ResourceItem	add(java.util.Vector List) was synchronized
void	addFactMonitor(FactMonitor monitor, long event_type)
void	addFactMonitor(FactMonitor monitor, long event_type, boolean notify_previous) Use this if your code needs to react to changes in the Resource Database.
Fact[]	all(Fact fact) Use this to retrieve all the facts in the database that match the parameter
Fact[]	all(java.lang.String type)
Goal	allocateResource(PlanRecord rec, int position, int required)
java.util.Vector	allocateResources(PlanRecord rec)
Fact	any(Fact fact) Use this to randomly retrieve a fact that matches the parameter
Fact	any(java.lang.String type) Randomly retrieves a fact with the same type as the parameter
void	consume(DataRec rec)
boolean	contains(Fact fact, int start) Use this to test whether a particular fact exists in the database
Fact	debit(double amount) Special purpose method to decrease the value of the amount attribute of MONEY facts
private void	debug(java.lang.String str)
void	del(Fact fact) The primary method for permanently removing facts from the Resource Database
void	del(Fact[] List)
void	del(java.util.Vector List)
void	deleteAll(java.lang.String type) Deletes all facts matching the parameter type, should obviously be used with caution
Fact	evalLocal(Fact fact)
boolean	evalNegative(Fact fact)
int	findAll(PlanRecord rec, int precond_position, int required)
void	free(DataRec rec)
AgentContext	getAgentContext() Use this to obtain handles to the other internal components of agent
boolean	isContextSet() check that the AgentContext context field is set.
boolean	isGenSymSet() check that the gensym refernece is set
boolean	isNameSet() check that the name refernce is set
boolean	isOntologyDbSet() check that the ontologyDb reference is set
boolean	isPlannerSet() check that the planner reference is set
boolean	isSet() check to see if all necessary fields are set
void	modify(Fact f1, Fact f2) Use this if facts have changed and you need to update the Resource Database
private void	notifyMonitors(ResourceItem item, int type)
void	removeFactMonitor(FactMonitor monitor, long event_type)
(package private) void	replaceOrAdd(Fact fact) was synchronized
int	reserve(DataRec datarec, int start, int required)
int	reserve(DataRec datarec, PlanRecord rec, int start, int required) Enables a resource to be secured at a certain time period, (this is provided primarily for internal use)
void	setGenSym(GenSym gensym) this allows you to set the gensym referencce
void	setName(java.lang.String name) this allows you to set the name reference
void	setOntologyDb(OntologyDb ontologyDb) this allows you to set the ontolgyDb reference
void	setPlanner(Planner planner) this allows you to set the planner reference

Methods inherited from class java.util.Hashtable

clear, clone, contains, containsKey, containsValue, elements, entrySet, equals, get, hashCode, isEmpty, keys, keySet, put, putAll, rehash, remove, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

eventMonitor

private HSet[] eventMonitor

ADD

private static final int ADD

See Also:

Constant Field Values

MODIFY

private static final int MODIFY

See Also:

Constant Field Values

DELETE

private static final int DELETE

See Also:

Constant Field Values

ACCESS

private static final int ACCESS

See Also:

Constant Field Values

context

protected AgentContext context

name

protected java.lang.String name

planner

protected Planner planner

ontologyDb

protected OntologyDb ontologyDb

gensym

protected GenSym gensym

Constructor Detail

ResourceDb

public ResourceDb()

ResourceDb

public ResourceDb(AgentContext context)

Method Detail

setPlanner

public void setPlanner(Planner planner)

this allows you to set the planner reference

setName

public void setName(java.lang.String name)

this allows you to set the name reference

setGenSym

public void setGenSym(GenSym gensym)

this allows you to set the gensym referencce

setOntologyDb

public void setOntologyDb(OntologyDb ontologyDb)

this allows you to set the ontolgyDb reference

isNameSet

public boolean isNameSet()

check that the name refernce is set

isGenSymSet

public boolean isGenSymSet()

check that the gensym refernece is set

isPlannerSet

public boolean isPlannerSet()

check that the planner reference is set

isOntologyDbSet

public boolean isOntologyDbSet()

check that the ontologyDb reference is set

isContextSet

public boolean isContextSet()

check that the AgentContext context field is set. Note: this is not necessary for the rdb to function, but is included so that

isSet

public boolean isSet()

check to see if all necessary fields are set

getAgentContext

public AgentContext getAgentContext()

Use this to obtain handles to the other internal components of agent

add

public ResourceItem add(java.util.Vector List)

was synchronized

add

public ResourceItem add(Fact[] List)

was synchronized

add

public ResourceItem add(Fact fact)

The primary method for adding new facts to the Resource Database was synchronized

replaceOrAdd

void replaceOrAdd(Fact fact)

was synchronized

del

public void del(java.util.Vector List)

del

public void del(Fact[] List)

del

public void del(Fact fact)

The primary method for permanently removing facts from the Resource Database

modify

public void modify(Fact f1,
                   Fact f2)

Use this if facts have changed and you need to update the Resource Database

free

public void free(DataRec rec)

consume

public void consume(DataRec rec)

findAll

public int findAll(PlanRecord rec,
                   int precond_position,
                   int required)

reserve

public int reserve(DataRec datarec,
                   PlanRecord rec,
                   int start,
                   int required)

Enables a resource to be secured at a certain time period, (this is provided primarily for internal use)

reserve

public int reserve(DataRec datarec,
                   int start,
                   int required)

allocateResources

public java.util.Vector allocateResources(PlanRecord rec)

allocateResource

public Goal allocateResource(PlanRecord rec,
                             int position,
                             int required)

debit

public Fact debit(double amount)

Special purpose method to decrease the value of the amount attribute of MONEY facts

evalLocal

public Fact evalLocal(Fact fact)

evalNegative

public boolean evalNegative(Fact fact)

all

public Fact[] all(java.lang.String type)

all

public Fact[] all(Fact fact)

Use this to retrieve all the facts in the database that match the parameter

deleteAll

public void deleteAll(java.lang.String type)

Deletes all facts matching the parameter type, should obviously be used with caution

any

public Fact any(java.lang.String type)

Randomly retrieves a fact with the same type as the parameter

any

public Fact any(Fact fact)

Use this to randomly retrieve a fact that matches the parameter

contains

public boolean contains(Fact fact,
                        int start)

Use this to test whether a particular fact exists in the database

addFactMonitor

public void addFactMonitor(FactMonitor monitor,
                           long event_type,
                           boolean notify_previous)

Use this if your code needs to react to changes in the Resource Database. This provides a programatic alternative to writing reaction rules

addFactMonitor

public void addFactMonitor(FactMonitor monitor,
                           long event_type)

removeFactMonitor

public void removeFactMonitor(FactMonitor monitor,
                              long event_type)

notifyMonitors

private void notifyMonitors(ResourceItem item,
                            int type)

debug

private void debug(java.lang.String str)