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Diffstat (limited to 'bundles/org.eclipse.equinox.log.stream/osgi/src/org/osgi/util/pushstream/PushEvent.java')
| -rw-r--r-- | bundles/org.eclipse.equinox.log.stream/osgi/src/org/osgi/util/pushstream/PushEvent.java | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/bundles/org.eclipse.equinox.log.stream/osgi/src/org/osgi/util/pushstream/PushEvent.java b/bundles/org.eclipse.equinox.log.stream/osgi/src/org/osgi/util/pushstream/PushEvent.java deleted file mode 100644 index 028f0a392..000000000 --- a/bundles/org.eclipse.equinox.log.stream/osgi/src/org/osgi/util/pushstream/PushEvent.java +++ /dev/null @@ -1,205 +0,0 @@ -/* - * Copyright (c) OSGi Alliance (2015, 2016). 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. - */ - -package org.osgi.util.pushstream; - -import static org.osgi.util.pushstream.PushEvent.EventType.*; - -/** - * A PushEvent is an immutable object that is transferred through a - * communication channel to push information to a downstream consumer. The event - * has three different types: - * <ul> - * <li>{@link EventType#DATA} – Provides access to a typed data element in the - * stream. - * <li>{@link EventType#CLOSE} – The stream is closed. After receiving this - * event, no more events will follow. - * <li>{@link EventType#ERROR} – The stream ran into an unrecoverable problem - * and is sending the reason downstream. The stream is closed and no more events - * will follow after this event. - * </ul> - * - * @param <T> The payload type of the event. - * @Immutable - */ -public abstract class PushEvent<T> { - - /** - * The type of a {@link PushEvent}. - */ - public static enum EventType { - /** - * A data event forming part of the stream - */ - DATA, - /** - * An error event that indicates streaming has failed and that no more - * events will arrive - */ - ERROR, - /** - * An event that indicates that the stream has terminated normally - */ - CLOSE - } - - /** - * Package private default constructor. - */ - PushEvent() {} - - /** - * Get the type of this event. - * - * @return The type of this event. - */ - public abstract EventType getType(); - - /** - * Return the data for this event. - * - * @return The data payload. - * @throws IllegalStateException if this event is not a - * {@link EventType#DATA} event. - */ - public T getData() throws IllegalStateException { - throw new IllegalStateException( - "Not a DATA event, the event type is " + getType()); - } - - /** - * Return the error that terminated the stream. - * - * @return The error that terminated the stream. - * @throws IllegalStateException if this event is not an - * {@link EventType#ERROR} event. - */ - public Exception getFailure() throws IllegalStateException { - throw new IllegalStateException( - "Not an ERROR event, the event type is " + getType()); - } - - /** - * Answer if no more events will follow after this event. - * - * @return {@code false} if this is a data event, otherwise {@code true}. - */ - public boolean isTerminal() { - return true; - } - - /** - * Create a new data event. - * - * @param <T> The payload type. - * @param payload The payload. - * @return A new data event wrapping the specified payload. - */ - public static <T> PushEvent<T> data(T payload) { - return new DataEvent<T>(payload); - } - - /** - * Create a new error event. - * - * @param <T> The payload type. - * @param e The error. - * @return A new error event with the specified error. - */ - public static <T> PushEvent<T> error(Exception e) { - return new ErrorEvent<T>(e); - } - - /** - * Create a new close event. - * - * @param <T> The payload type. - * @return A new close event. - */ - public static <T> PushEvent<T> close() { - return new CloseEvent<T>(); - } - - /** - * Convenience to cast a close/error event to another payload type. Since - * the payload type is not needed for these events this is harmless. This - * therefore allows you to forward the close/error event downstream without - * creating anew event. - * - * @param <X> The new payload type. - * @return The current error or close event mapped to a new payload type. - * @throws IllegalStateException if the event is a {@link EventType#DATA} - * event. - */ - public <X> PushEvent<X> nodata() throws IllegalStateException { - @SuppressWarnings("unchecked") - PushEvent<X> result = (PushEvent<X>) this; - return result; - } - - static final class DataEvent<T> extends PushEvent<T> { - private final T data; - - DataEvent(T data) { - this.data = data; - } - - @Override - public T getData() throws IllegalStateException { - return data; - } - - @Override - public EventType getType() { - return DATA; - } - - @Override - public boolean isTerminal() { - return false; - } - - @Override - public <X> PushEvent<X> nodata() throws IllegalStateException { - throw new IllegalStateException("This event is a DATA event"); - } - } - - static final class ErrorEvent<T> extends PushEvent<T> { - private final Exception error; - - ErrorEvent(Exception error) { - this.error = error; - } - - @Override - public Exception getFailure() { - return error; - } - - @Override - public EventType getType() { - return ERROR; - } - } - - static final class CloseEvent<T> extends PushEvent<T> { - @Override - public EventType getType() { - return CLOSE; - } - } -} |