package com.almende.eve.agent.log;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;
import com.almende.eve.agent.Agent;
import com.almende.eve.rpc.jsonrpc.JSONRequest;
public class LogAgent extends Agent {
private static long TIME_TO_LIVE = 20 * 60 * 1000; // milliseconds
public void log(Log log) {
@SuppressWarnings("unchecked")
// TODO: use a database instead of the state - when you register
// more and more logs this will be very unreliable.
List<Log> logs = (List<Log>) getState().get("logs");
if (logs == null) {
logs = new ArrayList<Log>();
}
logs.add(log);
// TODO: limit to a maximum number and age of the logs?
getState().put("logs", logs);
}
public List<Log> getLogs(Long since) throws Exception {
@SuppressWarnings("unchecked")
List<Log> logs = (List<Log>) getState().get("logs");
// TODO: use a database for the logs. It is very inefficient to
// retrieve them all and then filter them.
List<Log> output = new ArrayList<Log>();
if (logs != null) {
for (Log log : logs) {
if (((since == null) || (log.getTimestamp() > since))) {
output.add(log);
}
}
}
// reset the time to live for the agent. It will stay alive when
// regularly requested for logs
setTimeToLive(TIME_TO_LIVE);
return output;
}
/**
* Remove existing time to live
*/
public void cancelTimeToLive() {
String timeoutId = (String) getState().get("timeoutId");
if (timeoutId != null) {
getScheduler().cancelTask(timeoutId);
}
getState().remove("timeoutId");
}
/**
* Set a time-to-live for the LogAgent. After this timeout, it will
* delete itself.
* This is useful for a temporary LogAgent used for a single session in a
* browser.
* @param interval interval in milliseconds
* @throws Exception
*/
public void setTimeToLive(long interval)
throws Exception {
// remove existing timeout
cancelTimeToLive();
// create a new timeout
JSONRequest request = new JSONRequest("killMe", null);
String timeoutId = getScheduler().createTask(request, interval);
getState().put("timeoutId", timeoutId);
}
/**
* Delete the log agent.
* @throws Exception
*/
public void killMe () throws Exception {
getAgentFactory().deleteAgent(getId());
}
@Override
public String getDescription() {
return "The LogAgent can temporarily log events of an agent. " +
"The agent is meant for internal use by the AgentFactory.";
}
@Override
public String getVersion() {
return "0.1";
}
Logger logger = Logger.getLogger(this.getClass().getSimpleName());
}