Files
futur4j/futur-api/src/main/java/dev/tommyjs/futur/promise/AbstractPromise.java
2024-05-25 21:13:20 +02:00

498 lines
16 KiB
Java

package dev.tommyjs.futur.promise;
import dev.tommyjs.futur.executor.PromiseExecutor;
import dev.tommyjs.futur.function.ExceptionalConsumer;
import dev.tommyjs.futur.function.ExceptionalFunction;
import dev.tommyjs.futur.function.ExceptionalRunnable;
import dev.tommyjs.futur.function.ExceptionalSupplier;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.slf4j.Logger;
import java.util.Collection;
import java.util.LinkedList;
import java.util.Objects;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.function.Consumer;
public abstract class AbstractPromise<T, F> implements Promise<T> {
private Collection<PromiseListener<T>> listeners;
private final AtomicReference<PromiseCompletion<T>> completion;
private final CountDownLatch latch;
private final Lock lock;
public AbstractPromise() {
this.completion = new AtomicReference<>();
this.latch = new CountDownLatch(1);
this.lock = new ReentrantLock();
}
protected static <V> void propagateResult(Promise<V> from, Promise<V> to) {
from.addDirectListener(to::complete, to::completeExceptionally);
}
protected static void propagateCancel(Promise<?> from, Promise<?> to) {
from.onCancel(to::completeExceptionally);
}
private <V> @NotNull Runnable createRunnable(T result, @NotNull Promise<V> promise, @NotNull ExceptionalFunction<T, V> task) {
return () -> {
if (promise.isCompleted()) return;
try {
V nextResult = task.apply(result);
promise.complete(nextResult);
} catch (Throwable e) {
promise.completeExceptionally(e);
}
};
}
public abstract @NotNull AbstractPromiseFactory<F> getFactory();
protected @NotNull PromiseExecutor<F> getExecutor() {
return getFactory().getExecutor();
}
protected @NotNull Logger getLogger() {
return getFactory().getLogger();
}
@Override
public T awaitInterruptibly() throws InterruptedException {
this.latch.await();
return joinCompletion(Objects.requireNonNull(getCompletion()));
}
@Override
public T awaitInterruptibly(long timeoutMillis) throws TimeoutException, InterruptedException {
boolean success = this.latch.await(timeoutMillis, TimeUnit.MILLISECONDS);
if (!success) {
throw new TimeoutException("Promise stopped waiting after " + timeoutMillis + "ms");
}
return joinCompletion(Objects.requireNonNull(getCompletion()));
}
@Override
public T await() {
try {
return awaitInterruptibly();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
@Override
public T await(long timeoutMillis) throws TimeoutException {
try {
return awaitInterruptibly(timeoutMillis);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
private T joinCompletion(PromiseCompletion<T> completion) {
if (completion.isError())
throw new RuntimeException(completion.getException());
return completion.getResult();
}
@Override
public @NotNull Promise<Void> thenRunSync(@NotNull ExceptionalRunnable task) {
return thenApplySync(result -> {
task.run();
return null;
});
}
@Override
public @NotNull Promise<Void> thenRunDelayedSync(@NotNull ExceptionalRunnable task, long delay, @NotNull TimeUnit unit) {
return thenApplyDelayedSync(result -> {
task.run();
return null;
}, delay, unit);
}
@Override
public @NotNull Promise<Void> thenConsumeSync(@NotNull ExceptionalConsumer<T> task) {
return thenApplySync(result -> {
task.accept(result);
return null;
});
}
@Override
public @NotNull Promise<Void> thenConsumeDelayedSync(@NotNull ExceptionalConsumer<T> task, long delay, @NotNull TimeUnit unit) {
return thenApplyDelayedSync(result -> {
task.accept(result);
return null;
}, delay, unit);
}
@Override
public <V> @NotNull Promise<V> thenSupplySync(@NotNull ExceptionalSupplier<V> task) {
return thenApplySync(result -> task.get());
}
@Override
public <V> @NotNull Promise<V> thenSupplyDelayedSync(@NotNull ExceptionalSupplier<V> task, long delay, @NotNull TimeUnit unit) {
return thenApplyDelayedSync(result -> task.get(), delay, unit);
}
@Override
public <V> @NotNull Promise<V> thenApplySync(@NotNull ExceptionalFunction<T, V> task) {
Promise<V> promise = getFactory().unresolved();
addDirectListener(
res -> {
try {
Runnable runnable = createRunnable(res, promise, task);
F future = getExecutor().runSync(runnable);
promise.onCancel((e) -> getExecutor().cancel(future));
} catch (RejectedExecutionException e) {
promise.completeExceptionally(e);
}
},
promise::completeExceptionally
);
propagateCancel(promise, this);
return promise;
}
@Override
public <V> @NotNull Promise<V> thenApplyDelayedSync(@NotNull ExceptionalFunction<T, V> task, long delay, @NotNull TimeUnit unit) {
Promise<V> promise = getFactory().unresolved();
addDirectListener(
res -> {
try {
Runnable runnable = createRunnable(res, promise, task);
F future = getExecutor().runSync(runnable, delay, unit);
promise.onCancel((e) -> getExecutor().cancel(future));
} catch (RejectedExecutionException e) {
promise.completeExceptionally(e);
}
},
promise::completeExceptionally
);
propagateCancel(promise, this);
return promise;
}
@Override
public <V> @NotNull Promise<V> thenComposeSync(@NotNull ExceptionalFunction<T, Promise<V>> task) {
Promise<V> promise = getFactory().unresolved();
thenApplySync(task).addDirectListener(
nestedPromise -> {
if (nestedPromise == null) {
promise.complete(null);
} else {
propagateResult(nestedPromise, promise);
propagateCancel(promise, nestedPromise);
}
},
promise::completeExceptionally
);
propagateCancel(promise, this);
return promise;
}
@Override
public @NotNull Promise<Void> thenRunAsync(@NotNull ExceptionalRunnable task) {
return thenApplyAsync(result -> {
task.run();
return null;
});
}
@Override
public @NotNull Promise<Void> thenRunDelayedAsync(@NotNull ExceptionalRunnable task, long delay, @NotNull TimeUnit unit) {
return thenApplyDelayedAsync(result -> {
task.run();
return null;
}, delay, unit);
}
@Override
public @NotNull Promise<Void> thenConsumeAsync(@NotNull ExceptionalConsumer<T> task) {
return thenApplyAsync(result -> {
task.accept(result);
return null;
});
}
@Override
public @NotNull Promise<Void> thenConsumeDelayedAsync(@NotNull ExceptionalConsumer<T> task, long delay, @NotNull TimeUnit unit) {
return thenApplyDelayedAsync(result -> {
task.accept(result);
return null;
}, delay, unit);
}
@Override
public <V> @NotNull Promise<V> thenSupplyAsync(@NotNull ExceptionalSupplier<V> task) {
return thenApplyAsync(result -> task.get());
}
@Override
public <V> @NotNull Promise<V> thenSupplyDelayedAsync(@NotNull ExceptionalSupplier<V> task, long delay, @NotNull TimeUnit unit) {
return thenApplyDelayedAsync(result -> task.get(), delay, unit);
}
@Override
public @NotNull Promise<T> thenPopulateReference(@NotNull AtomicReference<T> reference) {
return thenApplyAsync((result) -> {
reference.set(result);
return result;
});
}
@Override
public <V> @NotNull Promise<V> thenApplyAsync(@NotNull ExceptionalFunction<T, V> task) {
Promise<V> promise = getFactory().unresolved();
addDirectListener(
(res) -> {
try {
Runnable runnable = createRunnable(res, promise, task);
F future = getExecutor().runAsync(runnable);
promise.onCancel((e) -> getExecutor().cancel(future));
} catch (RejectedExecutionException e) {
promise.completeExceptionally(e);
}
},
promise::completeExceptionally
);
propagateCancel(promise, this);
return promise;
}
@Override
public <V> @NotNull Promise<V> thenApplyDelayedAsync(@NotNull ExceptionalFunction<T, V> task, long delay, @NotNull TimeUnit unit) {
Promise<V> promise = getFactory().unresolved();
addDirectListener(
res -> {
try {
Runnable runnable = createRunnable(res, promise, task);
F future = getExecutor().runAsync(runnable, delay, unit);
promise.onCancel((e) -> getExecutor().cancel(future));
} catch (RejectedExecutionException e) {
promise.completeExceptionally(e);
}
},
promise::completeExceptionally
);
propagateCancel(promise, this);
return promise;
}
@Override
public <V> @NotNull Promise<V> thenComposeAsync(@NotNull ExceptionalFunction<T, Promise<V>> task) {
Promise<V> promise = getFactory().unresolved();
thenApplyAsync(task).addDirectListener(
nestedPromise -> {
if (nestedPromise == null) {
promise.complete(null);
} else {
propagateResult(nestedPromise, promise);
propagateCancel(promise, nestedPromise);
}
},
promise::completeExceptionally
);
propagateCancel(promise, this);
return promise;
}
@Override
public @NotNull Promise<Void> erase() {
return thenSupplyAsync(() -> null);
}
@Override
public @NotNull Promise<T> addAsyncListener(@NotNull AsyncPromiseListener<T> listener) {
return addAnyListener(listener);
}
@Override
public @NotNull Promise<T> addAsyncListener(@Nullable Consumer<T> successListener, @Nullable Consumer<Throwable> errorListener) {
return addAsyncListener((res) -> {
if (res.isError()) {
if (errorListener != null) errorListener.accept(res.getException());
} else {
if (successListener != null) successListener.accept(res.getResult());
}
});
}
@Override
public @NotNull Promise<T> addDirectListener(@NotNull PromiseListener<T> listener) {
return addAnyListener(listener);
}
@Override
public @NotNull Promise<T> addDirectListener(@Nullable Consumer<T> successListener, @Nullable Consumer<Throwable> errorListener) {
return addDirectListener((res) -> {
if (res.isError()) {
if (errorListener != null) errorListener.accept(res.getException());
} else {
if (successListener != null) successListener.accept(res.getResult());
}
});
}
private @NotNull Promise<T> addAnyListener(PromiseListener<T> listener) {
PromiseCompletion<T> completion;
lock.lock();
try {
completion = getCompletion();
if (completion == null) {
if (listeners == null) listeners = new LinkedList<>();
listeners.add(listener);
return this;
}
} finally {
lock.unlock();
}
callListener(listener, completion);
return this;
}
private void callListener(PromiseListener<T> listener, PromiseCompletion<T> ctx) {
if (listener instanceof AsyncPromiseListener) {
try {
getExecutor().runAsync(() -> callListenerNow(listener, ctx));
} catch (RejectedExecutionException ignored) {
}
} else {
callListenerNow(listener, ctx);
}
}
private void callListenerNow(PromiseListener<T> listener, PromiseCompletion<T> ctx) {
try {
listener.handle(ctx);
} catch (Exception e) {
getLogger().error("Exception caught in promise listener", e);
}
}
@Override
public @NotNull Promise<T> onSuccess(@NotNull Consumer<T> listener) {
return addAsyncListener(listener, null);
}
@Override
public @NotNull Promise<T> onError(@NotNull Consumer<Throwable> listener) {
return addAsyncListener(null, listener);
}
@Override
public @NotNull Promise<T> logExceptions(@NotNull String message) {
return onError(e -> getLogger().error(message, e));
}
@Override
public <E extends Throwable> @NotNull Promise<T> onError(@NotNull Class<E> clazz, @NotNull Consumer<E> listener) {
return onError((e) -> {
if (clazz.isAssignableFrom(e.getClass())) {
//noinspection unchecked
listener.accept((E) e);
}
});
}
@Override
public @NotNull Promise<T> onCancel(@NotNull Consumer<CancellationException> listener) {
return onError(CancellationException.class, listener);
}
@Deprecated
@Override
public @NotNull Promise<T> timeout(long time, @NotNull TimeUnit unit) {
return maxWaitTime(time, unit);
}
@Override
public @NotNull Promise<T> maxWaitTime(long time, @NotNull TimeUnit unit) {
try {
Exception e = new TimeoutException("Promise stopped waiting after " + time + " " + unit);
F future = getExecutor().runAsync(() -> completeExceptionally(e), time, unit);
return addDirectListener((_v) -> getExecutor().cancel(future));
} catch (RejectedExecutionException e) {
completeExceptionally(e);
return this;
}
}
private void handleCompletion(@NotNull PromiseCompletion<T> ctx) {
lock.lock();
try {
if (!setCompletion(ctx)) return;
this.latch.countDown();
if (listeners != null) {
for (PromiseListener<T> listener : listeners) {
callListener(listener, ctx);
}
}
} finally {
lock.unlock();
}
}
private boolean setCompletion(PromiseCompletion<T> completion) {
return this.completion.compareAndSet(null, completion);
}
@Override
public void cancel(@Nullable String message) {
completeExceptionally(new CancellationException(message));
}
@Override
public void complete(@Nullable T result) {
handleCompletion(new PromiseCompletion<>(result));
}
@Override
public void completeExceptionally(@NotNull Throwable result) {
handleCompletion(new PromiseCompletion<>(result));
}
@Override
public boolean isCompleted() {
return completion.get() != null;
}
@Override
public @Nullable PromiseCompletion<T> getCompletion() {
return completion.get();
}
@Override
public @NotNull CompletableFuture<T> toFuture() {
CompletableFuture<T> future = new CompletableFuture<>();
this.addDirectListener(future::complete, future::completeExceptionally);
future.whenComplete((res, e) -> {
if (e instanceof CancellationException) {
this.cancel();
}
});
return future;
}
}