EndpointState

EndpointState.java

import java.util.Collections;
import java.util.EnumMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReference;

public class EndpointState {

    private volatile HeartBeatState hbState;
    private final AtomicReference<Map<ApplicationState, VersionedValue>> applicationState;

    /* fields below do not get serialized */
    private volatile long updateTimestamp;
    private volatile boolean isAlive;

    public EndpointState(HeartBeatState initialHbState) {
        this(initialHbState, new EnumMap<ApplicationState, VersionedValue>(ApplicationState.class));
    }
    EndpointState(HeartBeatState initialHbState, Map<ApplicationState, VersionedValue> states) {
        hbState = initialHbState;
        applicationState = new AtomicReference<Map<ApplicationState, VersionedValue>>(new EnumMap<ApplicationState,VersionedValue>(states));
        updateTimestamp = System.nanoTime();
        isAlive = true;
    }

    HeartBeatState getHeartBeatState() {
        return hbState;
    }
    void setHeartBeatState(HeartBeatState newHbState) { 
        updateTimestamp(); hbState = newHbState;
    }

    public VersionedValue getApplicationState(ApplicationState key) {
        return applicationState.get().get(key);
    }
    public Set<Map.Entry<ApplicationState, VersionedValue>> states() {
        return applicationState.get().entrySet();
    }
    public void addApplicationState(ApplicationState key, VersionedValue value) {
        addApplicationStates(Collections.singletonMap(key, value));
    }
    public void addApplicationStates(Map<ApplicationState, VersionedValue> values) {
        addApplicationStates(values.entrySet());
    }
    public void addApplicationStates(Set<Map.Entry<ApplicationState, VersionedValue>> values) 
    {
        while (true) {
           Map<ApplicationState, VersionedValue> orig = applicationState.get();
           Map<ApplicationState, VersionedValue> copy = new EnumMap<ApplicationState, VersionedValue>(orig);

           for (Map.Entry<ApplicationState, VersionedValue> value : values)
                copy.put(value.getKey(), value.getValue());

           if (applicationState.compareAndSet(orig, copy))
                return;
        }
    }
    public long getUpdateTimestamp() { 
        return updateTimestamp; 
    }
    void updateTimestamp() { 
        updateTimestamp = System.nanoTime(); 
    }
    public boolean isNormalState() {
        return getStatus().equals(VersionedValue.STATUS_NORMAL);
    }
    public String getStatus() {
        VersionedValue status = getApplicationState(ApplicationState.STATUS_WITH_PORT);
        return status.value;
    }
    public String toString() {
        return "EndpointState: HeartBeatState = " + hbState + ", AppStateMap = " + applicationState.get();
    }
}