astra.util.TupleSpace Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of astra-apis Show documentation
Show all versions of astra-apis Show documentation
Base project for ASTRA applications
package astra.util;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import astra.core.Module;
import astra.formula.Formula;
import astra.formula.Predicate;
import astra.term.ListTerm;
import astra.term.Primitive;
import astra.term.Term;
/**
* This class implements an in JVM tuple space.
*
*
* Tuple spaces are shared spaces are an alternative (to message passing) mechanism for
* implementing coordination mechanisms in multi-agent systems. This class implements
* an in JVM tuple space.
*
*
*
* To use this class, you will need to import this class and add it as a module:
*
*
*
* package ts;
*
* import astra.util.TupleSpace;
*
* agent Template {
* module TupleSpace ts;
* }
*
*
* @author Rem Collier
*
*/
public class TupleSpace extends Module {
private class Tuple {
private List participants = new LinkedList();
private Map tuples = new HashMap();
public void join(String name) {
participants.add(name);
}
public void leave(String name) {
participants.remove(name);
}
public boolean isParticipant(String name) {
return participants.contains(name);
}
public boolean putValue(String name, String key, Object value) {
if (!isParticipant(name)) throw new UnsupportedOperationException("You are not in this tuple space: " + name);
tuples.put(key, value);
return true;
}
public Object getValue(String name, String key) {
if (!isParticipant(name)) throw new UnsupportedOperationException("You are not in this tuple space: " + name);
return tuples.get(key);
}
public String toString() {
return participants + " / " + tuples;
}
public boolean hasParticipants() {
return !participants.isEmpty();
}
}
static Map spaces = new HashMap();
static Map> agents = new HashMap>();
/**
* Action that lets the agent join a tuple space
*
*
* This action should be used to connect an agent to a tuple space. If a tuple space
* with the given id exists, then the agent joins that space, alternatively, the space
* is first created and then the agent joins it.
*
*
* @param id the id of the tuple space that the agent is to join.
* @return true if the action succeeds, false otherwise
*/
@ACTION
public synchronized boolean join(String id) {
List list = agents.get(agent.name());
if (list == null) {
agents.put(agent.name(), list = new LinkedList());
}
if (list.contains(id)) {
throw new UnsupportedOperationException("Agent: " + agent.name() + " has already joined space: " + id);
}
Tuple tuple = spaces.get(id);
if (tuple == null) {
spaces.put(id, tuple = new Tuple());
}
tuple.join(agent.name());
list.add(id);
return true;
}
/**
* Action for an agent to leave a tuple space
*
* This action should be used when an agent wants to leave a tuple space. If the tuple space is
* empty after the agent has left, then the space is deleted.
*
*
* This action fails if:
*
*
* - The space does not exist.
*
- The agent is not in the space.
*
*
* @param id the id of the space.
* @return true if the action succeeds, false otherwise
*/
@ACTION
public synchronized boolean leave(String id) {
List list = agents.get(agent.name());
if (list == null) {
throw new UnsupportedOperationException("Agent: " + agent.name() + " is not in any spaces");
}
if (!list.contains(id)) {
throw new UnsupportedOperationException("Agent: " + agent.name() + " is not in space: " + id);
}
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
tuple.leave(agent.name());
list.remove(agent.name());
if (!tuple.hasParticipants()) spaces.remove(id);
return true;
}
/**
* Action to post an object to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the object will be stored under
* @param value the object
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, Object value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), id, value);
}
/**
* Action to post a string to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the string will be stored under
* @param value the string
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, String value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post an int to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the int will be stored under
* @param value the int
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, int value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post an long to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the long will be stored under
* @param value the long
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, long value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post an float bject to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the float will be stored under
* @param value the float
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, float value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post an double to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the double will be stored under
* @param value the double
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, double value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post a char to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the char will be stored under
* @param value the char
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, char value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post a boolean to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the boolean will be stored under
* @param value the boolean
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, boolean value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Action to post an list to the specified space.
*
*
* This action will fail if the space does not exist.
*
*
* @param id the space id
* @param key the key that the list will be stored under
* @param value the list
* @return true if the action succeeds, false otherwise
*/
@ACTION
public boolean post(String id, String key, ListTerm value) {
Tuple tuple = spaces.get(id);
if (tuple == null) return false;
return tuple.putValue(agent.name(), key, value);
}
/**
* Term to retrieve a string from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public String getString(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (String) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve an int from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public Integer getInt(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (Integer) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve a long from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public Long getLong(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (Long) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve a float from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public Float getFloat(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (Float) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve a double from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public Double getDouble(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (Double) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve a list from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public ListTerm getList(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (ListTerm) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve an object from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public Object getObject(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve a char from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public char getChar(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (Character) tuple.getValue(agent.name(), key);
}
/**
* Term to retrieve a boolean from a space stored under a given key
*
* This term fails if there is not tuple space with the given id.
*
*
* @param id the space id
* @param key the key that the value is stored under
* @return the value associated with key
*/
@TERM
public Boolean getBoolean(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) throw new UnsupportedOperationException("There is no tuple space: " + id);
return (Boolean) tuple.getValue(agent.name(), key);
}
/**
* Formula to check whether a space contains a key
*
* @param id the space id
* @param key the key
* @return returns formuala TRUE if the tuple space has the given key, the formula FALSE otherwise
*/
@FORMULA
public Formula hasTuple(String id, String key) {
Tuple tuple = spaces.get(id);
if (tuple == null) return Predicate.FALSE;
return tuple.getValue(agent.name(), key) != null ? Predicate.TRUE:Predicate.FALSE;
}
/**
* Formula to check whether a space exists
*
* @param id the space id
* @return returns formuala TRUE if the tuple space exists, the formula FALSE otherwise
*/
@FORMULA
public Formula hasSpace(String id) {
return spaces.get(id) != null ? Predicate.TRUE:Predicate.FALSE;
}
/**
* Return a list of the spaces that the agent has joined.
*
* @return returns an ASTRA list of tuple space ids
*/
@TERM
public ListTerm getSpaceList() {
List list = agents.get(agent.name());
if (list == null) {
return new ListTerm(new Term[] {});
}
Term[] terms = new Term[list.size()];
for (int i=0; i