nl.topicus.jdbc.shaded.io.grpc.internal.InUseStateAggregator Maven / Gradle / Ivy
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package nl.topicus.jdbc.shaded.io.grpc.internal;
import java.util.HashSet;
import nl.topicus.jdbc.shaded.javax.annotation.concurrent.NotThreadSafe;
/**
* Aggregates the in-use state of a set of objects.
*/
@NotThreadSafe
abstract class InUseStateAggregator {
private final HashSet inUseObjects = new HashSet();
/**
* Update the in-use state of an object. Initially no object is in use.
*
* This may call into {@link #handleInUse} or {@link #handleNotInUse} when appropriate.
*/
final void updateObjectInUse(T object, boolean inUse) {
int origSize = inUseObjects.size();
if (inUse) {
inUseObjects.add(object);
if (origSize == 0) {
handleInUse();
}
} else {
boolean removed = inUseObjects.remove(object);
if (removed && origSize == 1) {
handleNotInUse();
}
}
}
final boolean isInUse() {
return !inUseObjects.isEmpty();
}
/**
* Called when the aggregated in-use state has changed to true, which means at least one object is
* in use.
*/
abstract void handleInUse();
/**
* Called when the aggregated in-use state has changed to false, which means no object is in use.
*/
abstract void handleNotInUse();
}