--- /dev/null
+package org.argeo.util.register;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+public class Component {
+ private final static AtomicBoolean started = new AtomicBoolean(false);
+ private final static IdentityHashMap<Object, Component> components = new IdentityHashMap<>();
+
+ private static synchronized void registerComponent(Component component) {
+ if (started.get()) // TODO make it rellay dynamic
+ throw new IllegalStateException("Already activated");
+ if (components.containsKey(component.instance))
+ throw new IllegalArgumentException("Already registered as component");
+ components.put(component.instance, component);
+ }
+
+ static synchronized Component get(Object instance) {
+ if (!components.containsKey(instance))
+ throw new IllegalArgumentException("Not registered as component");
+ return components.get(instance);
+ }
+
+ public synchronized static void activate() {
+ if (started.get())
+ throw new IllegalStateException("Already activated");
+ for (Component component : components.values()) {
+ component.activationStarted.complete(null);
+ }
+ started.set(true);
+ }
+
+ public synchronized static void deactivate() {
+ if (!started.get())
+ throw new IllegalStateException("Not activated");
+ for (Component component : components.values()) {
+ component.deactivationStarted.complete(null);
+ }
+ started.set(false);
+ }
+
+ private final Object instance;
+
+ private Runnable init;
+ private Runnable close;
+
+ private final Map<Class<?>, PublishedType<?>> types;
+ private final Set<Dependency<?>> dependencies;
+
+ private CompletableFuture<Void> activationStarted = new CompletableFuture<Void>();
+ private CompletableFuture<Void> activated = new CompletableFuture<Void>();
+
+ private CompletableFuture<Void> deactivationStarted = new CompletableFuture<Void>();
+ private CompletableFuture<Void> deactivated = new CompletableFuture<Void>();
+
+ private Set<Dependency<?>> dependants = new HashSet<>();
+
+ Component(Object instance, Runnable init, Runnable close, Set<Dependency<?>> dependencies, Set<Class<?>> classes) {
+ assert instance != null;
+ assert init != null;
+ assert close != null;
+ assert dependencies != null;
+ assert classes != null;
+
+ this.instance = instance;
+ this.init = init;
+ this.close = close;
+
+ // types
+ Map<Class<?>, PublishedType<?>> types = new HashMap<>(classes.size());
+ for (Class<?> clss : classes) {
+ if (!clss.isAssignableFrom(instance.getClass()))
+ throw new IllegalArgumentException(
+ "Type " + clss.getName() + " is not compatible with " + instance.getClass().getName());
+ types.put(clss, new PublishedType<>(clss));
+ }
+ this.types = Collections.unmodifiableMap(types);
+
+ // dependencies
+ this.dependencies = Collections.unmodifiableSet(new HashSet<>(dependencies));
+ for (Dependency<?> dependency : this.dependencies) {
+ dependency.setDependantComponent(this);
+ }
+
+ // future activation
+ activated = activationStarted //
+ .thenCompose(this::dependenciesActivated) //
+ .thenRun(this.init);
+
+ // future deactivation
+ deactivated = deactivationStarted //
+ .thenCompose(this::dependantsDeactivated) //
+ .thenRun(this.close);
+
+ registerComponent(this);
+ }
+
+ CompletableFuture<Void> dependenciesActivated(Void v) {
+ Set<CompletableFuture<?>> constraints = new HashSet<>(this.dependencies.size());
+ for (Dependency<?> dependency : this.dependencies) {
+ CompletableFuture<Void> dependencyActivated = dependency.getPublisher().activated //
+ .thenCompose(dependency::set);
+ constraints.add(dependencyActivated);
+ }
+ return CompletableFuture.allOf(constraints.toArray(new CompletableFuture[constraints.size()]));
+ }
+
+ CompletableFuture<Void> dependantsDeactivated(Void v) {
+ Set<CompletableFuture<?>> constraints = new HashSet<>(this.dependants.size());
+ for (Dependency<?> dependant : this.dependants) {
+ CompletableFuture<Void> dependantDeactivated = dependant.getDependantComponent().deactivated //
+ .thenCompose(dependant::unset);
+ constraints.add(dependantDeactivated);
+ }
+ CompletableFuture<Void> dependantsDeactivated = CompletableFuture
+ .allOf(constraints.toArray(new CompletableFuture[constraints.size()]));
+ return dependantsDeactivated;
+
+ }
+
+ void addDependant(Dependency<?> dependant) {
+ dependants.add(dependant);
+ }
+
+ public <T> PublishedType<T> getType(Class<T> clss) {
+ if (!types.containsKey(clss))
+ throw new IllegalArgumentException(clss.getName() + " is not a type published by this component");
+ return (PublishedType<T>) types.get(clss);
+ }
+
+ public class PublishedType<T> {
+ private Class<T> clss;
+
+ private CompletableFuture<T> value;
+
+ public PublishedType(Class<T> clss) {
+ this.clss = clss;
+
+ value = CompletableFuture.completedFuture((T) Component.this.instance);
+ }
+
+ Component getPublisher() {
+ return Component.this;
+ }
+
+ Class<T> getType() {
+ return clss;
+ }
+ }
+
+ public static class Builder<I> {
+ private final I instance;
+
+ private Runnable init;
+ private Runnable close;
+
+ private Set<Dependency<?>> dependencies = new HashSet<>();
+ private Set<Class<?>> types = new HashSet<>();
+
+ public Builder(I instance) {
+ this.instance = instance;
+ }
+
+ public Component build() {
+ if (types.isEmpty()) {
+ types.add(instance.getClass());
+ }
+
+ if (init == null)
+ init = () -> {
+ };
+ if (close == null)
+ close = () -> {
+ };
+
+ Component component = new Component(instance, init, close, dependencies, types);
+ for (Dependency<?> dependency : dependencies) {
+ dependency.type.getPublisher().addDependant(dependency);
+ }
+ return component;
+ }
+
+ public Builder<I> addType(Class<?>... classes) {
+ types.addAll(Arrays.asList(classes));
+ return this;
+ }
+
+ public Builder<I> addInit(Runnable init) {
+ if (this.init != null)
+ throw new IllegalArgumentException("init method is already set");
+ this.init = init;
+ return this;
+ }
+
+ public Builder<I> addClose(Runnable close) {
+ if (this.close != null)
+ throw new IllegalArgumentException("close method is already set");
+ this.close = close;
+ return this;
+ }
+
+ public <D> Builder<I> addDependency(PublishedType<D> type, Predicate<?> filter, Consumer<D> set,
+ Consumer<D> unset) {
+ dependencies.add(new Dependency<D>(type, filter, set, unset));
+ return this;
+ }
+
+ public I get() {
+ return instance;
+ }
+
+ }
+
+ static class Dependency<D> {
+ private PublishedType<D> type;
+ private Predicate<?> filter;
+ private Consumer<D> set;
+ private Consumer<D> unset;
+
+ // live
+ Component dependantComponent;
+ CompletableFuture<Void> setStage;
+ CompletableFuture<Void> unsetStage;
+
+ public Dependency(PublishedType<D> types, Predicate<?> filter, Consumer<D> set, Consumer<D> unset) {
+ super();
+ this.type = types;
+ this.filter = filter;
+ this.set = set;
+ this.unset = unset != null ? unset : (v) -> set.accept(null);
+ }
+
+ // live
+ void setDependantComponent(Component component) {
+ this.dependantComponent = component;
+ }
+
+ Component getPublisher() {
+ return type.getPublisher();
+ }
+
+ Component getDependantComponent() {
+ return dependantComponent;
+ }
+
+ CompletableFuture<Void> set(Void v) {
+ return type.value.thenAccept(set);
+ }
+
+ CompletableFuture<Void> unset(Void v) {
+ return type.value.thenAccept(unset);
+ }
+
+ }
+}
+
projects / lgpl / argeo-commons.git / blobdiff