Refine first component implementation

[lgpl/argeo-commons.git] / org.argeo.enterprise / src / org / argeo / util / register / StaticRegister.java

diff --git a/org.argeo.enterprise/src/org/argeo/util/register/StaticRegister.java b/org.argeo.enterprise/src/org/argeo/util/register/StaticRegister.java
new file mode 100644 (file)
index 0000000..0c55bdd
--- /dev/null
+++ b/org.argeo.enterprise/src/org/argeo/util/register/StaticRegister.java
@@ -0,0 +1,65 @@
+package org.argeo.util.register;
+
+import java.util.HashSet;
+import java.util.IdentityHashMap;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/** A minimal component register. */
+public class StaticRegister {
+       private final static AtomicBoolean started = new AtomicBoolean(false);
+       private final static IdentityHashMap<Object, Component<?>> components = new IdentityHashMap<>();
+
+       static synchronized void registerComponent(Component<?> component) {
+               if (started.get()) // TODO make it really dynamic
+                       throw new IllegalStateException("Already activated");
+               if (components.containsKey(component.getInstance()))
+                       throw new IllegalArgumentException("Already registered as component");
+               components.put(component.getInstance(), component);
+       }
+
+       static synchronized Component<?> get(Object instance) {
+               if (!components.containsKey(instance))
+                       throw new IllegalArgumentException("Not registered as component");
+               return components.get(instance);
+       }
+
+       synchronized static void activate() {
+               if (started.get())
+                       throw new IllegalStateException("Already activated");
+               Set<CompletableFuture<?>> constraints = new HashSet<>();
+               for (Component<?> component : components.values()) {
+                       component.startActivating();
+                       constraints.add(component.getActivated());
+               }
+
+               // wait
+               try {
+                       CompletableFuture.allOf(constraints.toArray(new CompletableFuture[0])).thenRun(() -> started.set(true))
+                                       .get();
+               } catch (ExecutionException | InterruptedException e) {
+                       throw new RuntimeException(e);
+               }
+       }
+
+       synchronized static void deactivate() {
+               if (!started.get())
+                       throw new IllegalStateException("Not activated");
+               Set<CompletableFuture<?>> constraints = new HashSet<>();
+               for (Component<?> component : components.values()) {
+                       component.startDeactivating();
+                       constraints.add(component.getDeactivated());
+               }
+
+               // wait
+               try {
+                       CompletableFuture.allOf(constraints.toArray(new CompletableFuture[0])).thenRun(() -> started.set(false))
+                                       .get();
+               } catch (ExecutionException | InterruptedException e) {
+                       throw new RuntimeException(e);
+               }
+       }
+
+}