/*
 * Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package reactor.core.publisher;

import java.util.Objects;
import java.util.function.Function;

import org.reactivestreams.Subscription;
import reactor.core.CoreSubscriber;
import reactor.core.Fuseable;
import reactor.util.annotation.Nullable;

Maps the values of the source publisher one-on-one via a mapper function.

This variant allows composing fuseable stages.

Type parameters:
  • <T> – the source value type
  • <R> – the result value type
See Also:
/** * Maps the values of the source publisher one-on-one via a mapper function. * <p> * This variant allows composing fuseable stages. * * @param <T> the source value type * @param <R> the result value type * * @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a> */
final class FluxMapFuseable<T, R> extends FluxOperator<T, R> implements Fuseable { final Function<? super T, ? extends R> mapper;
Constructs a FluxMap instance with the given source and mapper.
Params:
  • source – the source Publisher instance
  • mapper – the mapper function
Throws:
/** * Constructs a FluxMap instance with the given source and mapper. * * @param source the source Publisher instance * @param mapper the mapper function * * @throws NullPointerException if either {@code source} or {@code mapper} is null. */
FluxMapFuseable(Flux<? extends T> source, Function<? super T, ? extends R> mapper) { super(source); this.mapper = Objects.requireNonNull(mapper, "mapper"); } @Override @SuppressWarnings("unchecked") public void subscribe(CoreSubscriber<? super R> actual) { if (actual instanceof ConditionalSubscriber) { ConditionalSubscriber<? super R> cs = (ConditionalSubscriber<? super R>) actual; source.subscribe(new MapFuseableConditionalSubscriber<>(cs, mapper)); return; } source.subscribe(new MapFuseableSubscriber<>(actual, mapper)); } static final class MapFuseableSubscriber<T, R> implements InnerOperator<T, R>, QueueSubscription<R> { final CoreSubscriber<? super R> actual; final Function<? super T, ? extends R> mapper; boolean done; QueueSubscription<T> s; int sourceMode; MapFuseableSubscriber(CoreSubscriber<? super R> actual, Function<? super T, ? extends R> mapper) { this.actual = actual; this.mapper = mapper; } @SuppressWarnings("unchecked") @Override public void onSubscribe(Subscription s) { if (Operators.validate(this.s, s)) { this.s = (QueueSubscription<T>) s; actual.onSubscribe(this); } } @Override public void onNext(T t) { if (sourceMode == ASYNC) { actual.onNext(null); } else { if (done) { Operators.onNextDropped(t, actual.currentContext()); return; } R v; try { v = Objects.requireNonNull(mapper.apply(t), "The mapper returned a null value."); } catch (Throwable e) { Throwable e_ = Operators.onNextError(t, e, actual.currentContext(), s); if (e_ != null) { onError(e_); } else { s.request(1); } return; } actual.onNext(v); } } @Override public void onError(Throwable t) { if (done) { Operators.onErrorDropped(t, actual.currentContext()); return; } done = true; actual.onError(t); } @Override public void onComplete() { if (done) { return; } done = true; actual.onComplete(); } @Override public Object scanUnsafe(Attr key) { if (key == Attr.PARENT) return s; if (key == Attr.TERMINATED) return done; return InnerOperator.super.scanUnsafe(key); } @Override public CoreSubscriber<? super R> actual() { return actual; } @Override public void request(long n) { s.request(n); } @Override public void cancel() { s.cancel(); } @Override @Nullable public R poll() { for(;;) { T v = s.poll(); if (v != null) { try { return Objects.requireNonNull(mapper.apply(v)); } catch (Throwable t) { RuntimeException e_ = Operators.onNextPollError(v, t, currentContext()); if (e_ != null) { throw e_; } else { continue; } } } return null; } } @Override public boolean isEmpty() { return s.isEmpty(); } @Override public void clear() { s.clear(); } @Override public int requestFusion(int requestedMode) { int m; if ((requestedMode & Fuseable.THREAD_BARRIER) != 0) { return Fuseable.NONE; } else { m = s.requestFusion(requestedMode); } sourceMode = m; return m; } @Override public int size() { return s.size(); } } static final class MapFuseableConditionalSubscriber<T, R> implements ConditionalSubscriber<T>, InnerOperator<T, R>, QueueSubscription<R> { final ConditionalSubscriber<? super R> actual; final Function<? super T, ? extends R> mapper; boolean done; QueueSubscription<T> s; int sourceMode; MapFuseableConditionalSubscriber(ConditionalSubscriber<? super R> actual, Function<? super T, ? extends R> mapper) { this.actual = actual; this.mapper = mapper; } @Override @Nullable public Object scanUnsafe(Attr key) { if (key == Attr.PARENT) return s; if (key == Attr.TERMINATED) return done; return InnerOperator.super.scanUnsafe(key); } @SuppressWarnings("unchecked") @Override public void onSubscribe(Subscription s) { if (Operators.validate(this.s, s)) { this.s = (QueueSubscription<T>) s; actual.onSubscribe(this); } } @Override public void onNext(T t) { if (sourceMode == ASYNC) { actual.onNext(null); } else { if (done) { Operators.onNextDropped(t, actual.currentContext()); return; } R v; try { v = Objects.requireNonNull(mapper.apply(t), "The mapper returned a null value."); } catch (Throwable e) { Throwable e_ = Operators.onNextError(t, e, actual.currentContext(), s); if (e_ != null) { onError(e_); } else { s.request(1); } return; } actual.onNext(v); } } @Override public boolean tryOnNext(T t) { if (done) { Operators.onNextDropped(t, actual.currentContext()); return true; } R v; try { v = Objects.requireNonNull(mapper.apply(t), "The mapper returned a null value."); return actual.tryOnNext(v); } catch (Throwable e) { Throwable e_ = Operators.onNextError(t, e, actual.currentContext(), s); if (e_ != null) { onError(e_); return true; } else { return false; } } } @Override public void onError(Throwable t) { if (done) { Operators.onErrorDropped(t, actual.currentContext()); return; } done = true; actual.onError(t); } @Override public void onComplete() { if (done) { return; } done = true; actual.onComplete(); } @Override public CoreSubscriber<? super R> actual() { return actual; } @Override public void request(long n) { s.request(n); } @Override public void cancel() { s.cancel(); } @Override @Nullable public R poll() { for(;;) { T v = s.poll(); if (v != null) { try { return Objects.requireNonNull(mapper.apply(v)); } catch (Throwable t) { RuntimeException e_ = Operators.onNextPollError(v, t, currentContext()); if (e_ != null) { throw e_; } else { continue; } } } return null; } } @Override public boolean isEmpty() { return s.isEmpty(); } @Override public void clear() { s.clear(); } @Override public int requestFusion(int requestedMode) { int m; if ((requestedMode & Fuseable.THREAD_BARRIER) != 0) { return Fuseable.NONE; } else { m = s.requestFusion(requestedMode); } sourceMode = m; return m; } @Override public int size() { return s.size(); } } }