/*
* Copyright (C) 2014 The Android Open Source Project
*
* 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 com.android.camera.one.v2.sharedimagereader.imagedistributor;
import com.android.camera.async.BufferQueue;
import com.android.camera.one.v2.camera2proxy.ImageProxy;
import com.android.camera.one.v2.core.CaptureStream;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* An interface for {@link CaptureStream}s which route images into a
* {@link BufferQueue}.
*
* For example, an implementation of this may be added to a
* {@link com.android.camera.one.v2.core.RequestBuilder} to then get Images
* corresponding to that request as a queue.
*
* Note that images always arrive in order. Different implementations may behave
* differently with respect to how images are dropped. For example, some may act
* like a ring-buffer and automatically drop the oldest image when a new image
* arrives. Others may close new images immediately if no capacity is available.
*/
public interface ImageStream extends BufferQueue, CaptureStream {
/**
* Closes the ImageStream. After being closed, no more images will be
* available and any images left in the stream are closed.
*/
@Override
public void close();
/**
* Blocks, returning the next available image.
*
* @return The next available image.
* @throws InterruptedException If interrupted while waiting for the next
* image.
* @throws com.android.camera.async.BufferQueue.BufferQueueClosedException
* If the stream is closed and no more images will be available.
*/
@Override
public ImageProxy getNext() throws InterruptedException, BufferQueueClosedException;
/**
* Blocks, returning the next available image.
*
* @param timeout The maximum amount of time to wait.
* @param unit The unit associated with the timeout.
* @return The next available image.
* @throws InterruptedException If interrupted while waiting for the next
* image.
* @throws com.android.camera.async.BufferQueue.BufferQueueClosedException
* If the stream is closed and no more images will be available.
* @throws TimeoutException If no new image is made available within the
* specified time limit.
*/
@Override
public ImageProxy getNext(long timeout, TimeUnit unit) throws InterruptedException,
TimeoutException,
BufferQueueClosedException;
/**
* Immediately returns the next available image without removing it from the
* stream. Note that the ImageStream still owns the image, so the caller
* MUST NOT close it.
*
* @return The next available value if one exists, or null if no value
* exists yet or the stream is closed.
*/
@Override
public ImageProxy peekNext();
/**
* Immediately discards the next available image, if one exists.
*/
@Override
public void discardNext();
/**
* @return True if the stream has been closed by either the producer or the
* consumer.
*/
@Override
public boolean isClosed();
}