/*
* Copyright (C) 2006-2016 DLR, Germany
*
* All rights reserved
*
* http://www.rcenvironment.de/
*/
package de.rcenvironment.core.log;
import java.util.Enumeration;
import java.util.List;
import org.osgi.service.log.LogEntry;
import org.osgi.service.log.LogListener;
import org.osgi.service.log.LogReaderService;
import org.osgi.service.log.LogService;
import de.rcenvironment.core.communication.common.InstanceNodeSessionId;
/**
* Service that serves as an abstraction of the {@link RemotableLogReaderService}s of the whole distributed system. It provides convenient
* access to local and remote {@link RemotableLogReaderService}s.
*
* @author Doreen Seider
*/
// TODO rename
public interface DistributedLogReaderService {
/**
* Subscribes to LogEntry objects.
*
* This method registers a {@link LogListener} object with a {@link LogReaderService} of the given platform. The
* LogListener.logged(LogEntry) method will be called for each {@link LogEntry} object placed into the log.
*
* @param logListener The {@link SerializableLogListener} object to register.
* @param nodeId The {@link InstanceNodeSessionId} of the platform to register.
*
* @see LogReaderService#addLogListener(LogListener).
*/
void addLogListener(SerializableLogListener logListener, InstanceNodeSessionId nodeId);
/**
* Returns an {@link Enumeration} of all {@link LogEntry} objects in the log.
*
* Each element of the enumeration is a {@link LogEntry} object, ordered with the most recent entry first. Whether the enumeration is of
* all {@link LogEntry} objects since the {@link LogService} was started or some recent past is implementation-specific. Also
* implementation-specific is whether informational and debug {@link LogEntry} objects are included in the enumeration.
*
* @param nodeId The {@link InstanceNodeSessionId} of the platform to get the log from.
* @return The {@link List} of {@link SerializableLogEntry} objects.
*
* @see LogReaderService#getLog().
*/
List<SerializableLogEntry> getLog(InstanceNodeSessionId nodeId);
/**
* Unsubscribes from LogEntry objects.
*
* This method unregisters a LogListener object from the Log Reader Service.
*
* @param logListener The {@link SerializableLogListener} object to unregister.
* @param nodeId The {@link InstanceNodeSessionId} of the platform to unregister.
*
* @see LogReaderService#removeLogListener().
*/
void removeLogListener(SerializableLogListener logListener, InstanceNodeSessionId nodeId);
}