zeus.agents
Class PersistentStore

java.lang.Object
  zeus.agents.PersistentStore

Direct Known Subclasses:

FlatFile

public abstract class PersistentStore

extends java.lang.Object

This abstract class provides an interface to storage platforms so that messaging data (i.e. communication sessions among agents) may be stored for future playback and manipulation. It acts a bridge between a ZEUS database proxy (i.e. DbProxy) and and a persistent storage mechanism (e.g. a flat file or a database such as Oracle). Typically a ZEUS Visualiser agent talks to a DbProxy which in turn forwards the requests to subclasses of this abstract class. A class that extends this abstract class should provide implementations for following methods:

  public  abstract void createSession(String replyKey, String agent,
                  String sessionType, String sessionId, String accessKey);
  public abstract void deleteSession(String replyKey, String agent,
                                     String sessionType, String sessionId);
  public abstract void getAllSessions(String replyKey, String agent,
                                        String sessionType);
  public abstract void deleteSessionType(String replyKey, String agent,
                                         String sessionType);
  public abstract void openSession(String replyKey, String agent,
                    String sessionType, String sessionId, String accessKey);

  public abstract void saveRecord(String replyKey, String agent,
                                  String accessKey, String record);
  public  void closeSession(String replyKey,String agent,String accessKey);
  public abstract void nextRecord(String replyKey,String agent,String accessKey);
  public abstract void priorRecord(String replyKey,String agent,String accessKey);
  public abstract void beginSession(String replyKey,String agent,String accessKey);
  public abstract void endSession(String replyKey,String agent,String accessKey);
  public abstract void getAgents(String replyKey,String agent,String accessKey);
  public abstract void countRecords(String replyKey,String agent,String accessKey);

  

The methods have all or some of the following arguments:
String replyKey Recipient's (i.e.the ZEUS Visualiser agent) conversation key.
String agent The name of the ZEUS Visualiser agent who wants the communication sessions saved for future playback.
String sessionType The type of information being saved for future playback (i.e. the tool within which the communication session is taken place. Tools can be one of the following: Society Viewer, Report Viewer, Statistics Viewer, Remote Viewer and Control Tool Viewer.
String sessionId A unique identifier (typically the name of the persistent storage i.e. flat file or database) representing a communication session.
String accessKey A handle representing an agent and session id used by subclasses of this abstract class to access the persistent storage.
Each implemented method should return a Zeus Performative object ( using proxy.sendMsg(msg) where msg is a Performative object ) by specifying whether the operation failed or succeeds. If the operation succeeds then instantiate a Performative class with "inform" or "failure" if it failed. Instantiating a Performative class should follow this format:
Performative msg = new Performative("failure");
msg.setReceiver(agent);
msg.setInReplyTo(replyKey);
msg.setContent("reason for failure or success");
proxy.sendMsg(msg);

Field Summary

private OrderedHashtable	knownAgents
protected DbProxy	proxy
private boolean	verifyAccess

Constructor Summary

PersistentStore()

Method Summary

abstract void	beginSession(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Go to the beginning of a session identified by accessKey.
abstract void	closeSession(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Close a session identified by accessKey.
abstract void	countRecords(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Returns the number of records in a session identified by accessKey.
abstract void	createSession(java.lang.String replyKey, java.lang.String agent, java.lang.String sessionType, java.lang.String sessionId, java.lang.String accessKey) Its purpose is to create a new session (i.e. a flat file or database table).
abstract void	deleteSession(java.lang.String replyKey, java.lang.String agent, java.lang.String sessionType, java.lang.String sessionId) Given a session type, delete the session type with the name sessionId.
abstract void	deleteSessionType(java.lang.String replyKey, java.lang.String agent, java.lang.String sessionType) Delete a session type with its associated sessions (i.e. tables).
abstract void	endSession(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Go to the end of a session identified by accessKey.
abstract void	getAgents(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Returns all known agents associated with a given session identified by accessKey.
abstract void	getAllSessions(java.lang.String replyKey, java.lang.String agent, java.lang.String sessionType) Given a session type, list all sessions (tables) associated with that type.
protected boolean	isAccessible()
abstract void	nextRecord(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Returns the next record in a session identified by accessKey.
abstract void	openSession(java.lang.String replyKey, java.lang.String agent, java.lang.String sessionType, java.lang.String sessionId, java.lang.String accessKey) Given a session type, open the session with name sessionId.
abstract void	priorRecord(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey) Returns the previous record in a session identified by accessKey.
abstract void	saveRecord(java.lang.String replyKey, java.lang.String agent, java.lang.String accessKey, java.lang.String record) Save the record in a session identified by accessKey.
void	setAccess(boolean access) Sets access level.
void	setProxy(DbProxy proxy) Sets the proxy.

Methods inherited from class java.lang.Object

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

Field Detail

proxy

protected DbProxy proxy

verifyAccess

private boolean verifyAccess

knownAgents

private OrderedHashtable knownAgents

Constructor Detail

PersistentStore

public PersistentStore()

Method Detail

setProxy

public void setProxy(DbProxy proxy)

Sets the proxy.

setAccess

public void setAccess(boolean access)

Sets access level.

createSession

public abstract void createSession(java.lang.String replyKey,
                                   java.lang.String agent,
                                   java.lang.String sessionType,
                                   java.lang.String sessionId,
                                   java.lang.String accessKey)

Its purpose is to create a new session (i.e. a flat file or database table). Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.
If the session exists open it for appending and return done.
If the session doesn't exit create it for writing and return done.
If aforementioned operations fails return failure.

deleteSession

public abstract void deleteSession(java.lang.String replyKey,
                                   java.lang.String agent,
                                   java.lang.String sessionType,
                                   java.lang.String sessionId)

Given a session type, delete the session type with the name sessionId. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

getAllSessions

public abstract void getAllSessions(java.lang.String replyKey,
                                    java.lang.String agent,
                                    java.lang.String sessionType)

Given a session type, list all sessions (tables) associated with that type. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

deleteSessionType

public abstract void deleteSessionType(java.lang.String replyKey,
                                       java.lang.String agent,
                                       java.lang.String sessionType)

Delete a session type with its associated sessions (i.e. tables). Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

openSession

public abstract void openSession(java.lang.String replyKey,
                                 java.lang.String agent,
                                 java.lang.String sessionType,
                                 java.lang.String sessionId,
                                 java.lang.String accessKey)

Given a session type, open the session with name sessionId. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

saveRecord

public abstract void saveRecord(java.lang.String replyKey,
                                java.lang.String agent,
                                java.lang.String accessKey,
                                java.lang.String record)

Save the record in a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

closeSession

public abstract void closeSession(java.lang.String replyKey,
                                  java.lang.String agent,
                                  java.lang.String accessKey)

Close a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

nextRecord

public abstract void nextRecord(java.lang.String replyKey,
                                java.lang.String agent,
                                java.lang.String accessKey)

Returns the next record in a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

priorRecord

public abstract void priorRecord(java.lang.String replyKey,
                                 java.lang.String agent,
                                 java.lang.String accessKey)

Returns the previous record in a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

beginSession

public abstract void beginSession(java.lang.String replyKey,
                                  java.lang.String agent,
                                  java.lang.String accessKey)

Go to the beginning of a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

endSession

public abstract void endSession(java.lang.String replyKey,
                                java.lang.String agent,
                                java.lang.String accessKey)

Go to the end of a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

getAgents

public abstract void getAgents(java.lang.String replyKey,
                               java.lang.String agent,
                               java.lang.String accessKey)

Returns all known agents associated with a given session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

countRecords

public abstract void countRecords(java.lang.String replyKey,
                                  java.lang.String agent,
                                  java.lang.String accessKey)

Returns the number of records in a session identified by accessKey. Returns done as the content of a Performative object if the operation succeeds else return reasons for failure to the specified agent with the replyKey as agent's conversation key.

isAccessible

protected boolean isAccessible()