package com.ajjpj.asysmon;
import com.ajjpj.asysmon.config.AStaticSysMonConfig;
import com.ajjpj.asysmon.config.ASysMonConfig;
import com.ajjpj.asysmon.data.ACorrelationId;
import com.ajjpj.asysmon.data.AGlobalDataPoint;
import com.ajjpj.asysmon.data.AHierarchicalData;
import com.ajjpj.asysmon.measure.*;
import com.ajjpj.asysmon.measure.global.AGlobalMeasurer;
import com.ajjpj.asysmon.datasink.ADataSink;
import com.ajjpj.asysmon.util.timer.ATimer;
import java.util.*;
/**
* This class is the point of contact for an application to ASysMon. There are basically two ways to use it:
*
* <ul>
* <li> Use the static get() method to access it as a singleton. That is simple and convenient, and it is
* sufficient for many applications. If it is used that way, all configuration must be done through
* the static methods of AStaticSysMonConfig. </li>
* <li> Create and manage your own instance (or instances) by calling the constructor, passing in your
* configuration. This is for maximum flexibility, but you lose some convenience. </li>
* </ul>
*
* @author arno
*/
public class ASysMon {
private final ATimer timer;
private final List<? extends ADataSink> handlers;
private final List<? extends AGlobalMeasurer> globalMeasurers;
private final ThreadLocal<AMeasurementHierarchy> hierarchyPerThread = new ThreadLocal<AMeasurementHierarchy>();
public static ASysMon get() {
// this class has the sole purpose of providing really lazy init of the singleton instance
return ASysMonInstanceHolder.INSTANCE;
}
public ASysMon(ASysMonConfig config) {
this.timer = config.getTimer();
this.handlers = new ArrayList<ADataSink>(config.getHandlers());
this.globalMeasurers = new ArrayList<AGlobalMeasurer> (config.getGlobalMeasurers());
}
private AMeasurementHierarchy getMeasurementHierarchy() {
final AMeasurementHierarchy candidate = hierarchyPerThread.get();
if(candidate != null) {
return candidate;
}
final AMeasurementHierarchy result = new AMeasurementHierarchyImpl(timer, new ADataSink() {
@Override public void onStartedHierarchicalMeasurement() {
for(ADataSink handler: handlers) {
handler.onStartedHierarchicalMeasurement();
}
}
@Override public void onFinishedHierarchicalMeasurement(AHierarchicalData data, Collection<ACorrelationId> startedFlows, Collection<ACorrelationId> joinedFlows) {
hierarchyPerThread.remove();
for(ADataSink handler: handlers) {
handler.onFinishedHierarchicalMeasurement(data, startedFlows, joinedFlows);
}
}
});
hierarchyPerThread.set(result);
return result;
}
public <R, E extends Exception> R measure(String identifier, AMeasureCallback<R,E> callback) throws E {
final ASimpleMeasurement m = start(identifier);
try {
return callback.call(m);
} finally {
m.finish();
}
}
public ASimpleMeasurement start(String identifier) {
return start(identifier, true);
}
public ASimpleMeasurement start(String identifier, boolean serial) {
return getMeasurementHierarchy().start(identifier, serial);
}
public ACollectingMeasurement startCollectingMeasurement(String identifier) {
return startCollectingMeasurement(identifier, true);
}
public ACollectingMeasurement startCollectingMeasurement(String identifier, boolean serial) {
return getMeasurementHierarchy().startCollectingMeasurement(identifier, serial);
}
public Map<String, AGlobalDataPoint> getGlobalMeasurements() {
if(AStaticSysMonConfig.isGloballyDisabled()) {
return new HashMap<String, AGlobalDataPoint>();
}
final Map<String, AGlobalDataPoint> result = new HashMap<String, AGlobalDataPoint>();
for(AGlobalMeasurer measurer: globalMeasurers) {
measurer.contributeMeasurements(result);
}
return result;
}
/**
* this class has the sole purpose of providing really lazy init of the singleton instance
*/
private static class ASysMonInstanceHolder {
public static final ASysMon INSTANCE = new ASysMon(AStaticSysMonConfig.get());
}
}