jadex.rules.state.javaimpl.OAVNameIdGenerator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jadex-rules Show documentation
Show all versions of jadex-rules Show documentation
Jadex Rules is a small lightweight rule engine, which currently
employs the well-known Rete algorithm for highly efficient rule
matching. Jadex rules is therefore similar to other rule engines
like JESS and Drools. Despite the similarities there are also
important differences between these systems:
* Jadex Rules is very small and
intended to be used as component
of other software. Even though rules can be specified in a Java
dialect as well as (a small variation of) the CLIPS language
its primary usage is on the API level. Jadex Rules is currently
the core component of the Jadex BDI reasoning engine.
* Jadex Rules cleanly separates between state and rule representation.
This allows the state implementation as well as the matcher to be
flexibly exchanged. Some experiments have e.g. been conducted with
a Jena representation. Regarding the matcher, it is planned to
support also the Treat algorithm, which has a lower memory footprint
than Rete.
* Jadex Rules pays close attention to rule debugging. The state as
well as the rete engine can be observed at runtime. The rule debugger
provides functionalities to execute a rule program stepwise and also
use rule breakpoints to stop the execution at those points.
package jadex.rules.state.javaimpl;
import jadex.rules.state.IOAVState;
import jadex.rules.state.OAVObjectType;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* Id generator using easy to read names and numbers.
*/
public class OAVNameIdGenerator implements IOAVIdGenerator
{
//-------- attributes --------
/** The id counter map (type -> count). */
protected Map counters;
/** The flag indicating if content ids should be produced. */
protected boolean iscontentid;
//-------- constructors --------
/**
* Create a new id generator.
*/
public OAVNameIdGenerator()
{
this(false);
}
/**
* Create a new id generator.
*/
public OAVNameIdGenerator(boolean iscontentid)
{
this.counters = new HashMap();
this.iscontentid = iscontentid;
}
/**
* Create a unique id.
* @param state The state.
* @param type The object type.
* @return The new id.
*/
public Object createId(IOAVState state, OAVObjectType type)
{
long start = 1;
if(counters.containsKey(type))
{
start = ((Long)counters.get(type)).longValue();
}
long id = start;
Object ret = iscontentid? new OAVContentId(type, id++): new OAVObjectId(type, id++);
if(state.containsObject(ret))
System.out.println("Warning, id overflow.");
while(state.containsObject(ret) && id!=start)
{
ret = new OAVObjectId(/*state,*/ type, id++);
}
if(state.containsObject(ret))
throw new RuntimeException("No free id available.");
counters.put(type, new Long(id));
return ret;
}
/**
* Test if an object is an id.
* @param state The state.
* @param type The object type.
* @return The new id.
*/
public boolean isId(Object id)
{
return id!=null && id instanceof OAVObjectId;
}
//-------- helper classes --------
/**
* An id for an OAV object.
*/
private static class OAVObjectId
{
//-------- attributes --------
/** The state. */
// protected IOAVState state;
/** The object type. */
protected OAVObjectType type;
/** The id value. */
protected long id;
//-------- constructors --------
/**
* Create an OAV object id with the given id value.
* @param id The id value.
*/
public OAVObjectId(/*IOAVState state,*/ OAVObjectType type, long id)
{
// this.state = state;
this.type = type;
this.id = id;
}
//-------- methods --------
/**
* Create a string representation of this OAV object id.
*/
public String toString()
{
return type.getName()+"_"+id;
}
/**
* Test if two object are equal.
* @param object The object to compare to.
* /
public boolean equals(Object object)
{
boolean ret = object instanceof OAVObjectId;
if(ret)
{
OAVObjectId other = (OAVObjectId)object;
ret = this.id==other.id
&& this.state.equals(other.state)
&& this.type.equals(((OAVObjectId)object).type);
}
return ret;
}*/
/**
* Return the hashcode for this id.
* @return The hashcode for this id.
* /
public int hashCode()
{
int ret = 31 + (int)(id ^ (id >>> 32));
ret = 31 * ret + type.hashCode();
return ret;
}*/
}
/**
* An id for an OAV object.
*/
private static class OAVContentId extends OAVObjectId implements IOAVContentId
{
//-------- attributes --------
/** The content map. */
protected Map content;
//-------- constructors --------
/**
* Create an OAV object id with the given id value.
* @param id The id value.
*/
public OAVContentId(OAVObjectType type, long id)
{
super(type, id);
this.content = new LinkedHashMap();
}
//-------- methods --------
/**
* Get the content.
* @return The content.
*/
public Map getContent()
{
return content;
}
}
}