io.lambdacube.aspecio.internal.service.ServicePool Maven / Gradle / Ivy
package io.lambdacube.aspecio.internal.service;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.function.Supplier;
public final class ServicePool {
private final Map originalToProxy = new IdentityHashMap<>();
private final Map proxyToOriginal = new IdentityHashMap<>();
private final Map proxyToCount = new IdentityHashMap<>();
public synchronized T get(Object originalService, Supplier proxyFactory) {
T proxy = originalToProxy.computeIfAbsent(originalService, k -> proxyFactory.get());
proxyToOriginal.putIfAbsent(proxy, originalService);
proxyToCount.compute(proxy, (k, v) -> {
if (v == null) {
return 1;
} else {
return v + 1;
}
});
return proxy;
}
public synchronized boolean unget(T proxy) {
Integer count = proxyToCount.compute(proxy, (k, v) -> {
if (v == null) {
return 0;
} else {
return v - 1;
}
});
if (count > 0) {
return false;
}
// clean-up
proxyToCount.remove(proxy);
Object original = proxyToOriginal.remove(proxy);
T proxyX = originalToProxy.remove(original);
assert proxy == proxyX;
return true;
}
}