Camera2: Add support for offline session callbacks
Add blocking offline session callback support which can
track the state transitions.
Bug: 135142453
Test: Camera CTS
Change-Id: Ia42d4a96564c433eddfd3e8ba27b0483f6f3c5ac
diff --git a/camera2/public/src/com/android/ex/camera2/blocking/BlockingOfflineSessionCallback.java b/camera2/public/src/com/android/ex/camera2/blocking/BlockingOfflineSessionCallback.java
new file mode 100644
index 0000000..021dcd7
--- /dev/null
+++ b/camera2/public/src/com/android/ex/camera2/blocking/BlockingOfflineSessionCallback.java
@@ -0,0 +1,254 @@
+/*
+ * Copyright 2020 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.ex.camera2.blocking;
+
+import android.hardware.camera2.CameraDevice;
+import android.hardware.camera2.CameraOfflineSession;
+import android.hardware.camera2.CameraOfflineSession.CameraOfflineSessionCallback;
+import android.os.Handler;
+import android.os.SystemClock;
+import android.util.Log;
+
+import com.android.ex.camera2.exceptions.TimeoutRuntimeException;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A camera offline session listener that implements blocking operations on state changes.
+ *
+ * <p>Provides wait calls that block until the next unobserved state of the
+ * requested type arrives. Unobserved states are states that have occurred since
+ * the last wait, or that will be received from the camera device in the
+ * future.</p>
+ *
+ * <p>Pass-through all offline callbacks to the proxy.</p>
+ *
+ */
+public class BlockingOfflineSessionCallback
+ extends CameraOfflineSession.CameraOfflineSessionCallback {
+ private static final String TAG = "BlockingOfflineSessionCallback";
+ private static final boolean VERBOSE = Log.isLoggable(TAG, Log.VERBOSE);
+
+ private final CameraOfflineSession.CameraOfflineSessionCallback mProxy;
+
+ // Guards mWaiting
+ private final Object mLock = new Object();
+ private boolean mWaiting = false;
+
+ private final LinkedBlockingQueue<Integer> mRecentStates =
+ new LinkedBlockingQueue<Integer>();
+
+ private void setCurrentState(int state) {
+ if (VERBOSE) Log.v(TAG, "Offline session state now " + stateToString(state));
+ try {
+ mRecentStates.put(state);
+ } catch (InterruptedException e) {
+ throw new RuntimeException("Unable to set offline session state", e);
+ }
+ }
+
+ private static final String[] mStateNames = {
+ "STATE_UNINITIALIZED",
+ "STATE_READY",
+ "STATE_IDLE",
+ "STATE_CLOSED",
+ "STATE_ERROR",
+ "STATE_SWITCH_FAILED",
+ };
+
+ /**
+ * Offline session has not reported any state yet
+ */
+ public static final int STATE_UNINITIALIZED = -1;
+
+ /**
+ * The offline session moves to ready state in case of successful offline switch
+ */
+ public static final int STATE_READY = 0;
+
+ /**
+ * The offline session moves to idle state once all offline capture requests complete
+ */
+ public static final int STATE_IDLE = 1;
+
+ /**
+ * The offline session is closed
+ */
+ public static final int STATE_CLOSED = 2;
+
+ /**
+ * The offline session has encountered a fatal error
+ */
+ public static final int STATE_ERROR = 3;
+
+ /**
+ * The offline session failed during the offline switch
+ */
+ public static final int STATE_SWITCH_FAILED = 4;
+
+ /**
+ * Total number of reachable states
+ */
+ private static final int NUM_STATES = 5;
+
+ public BlockingOfflineSessionCallback() {
+ mProxy = null;
+ }
+
+ public BlockingOfflineSessionCallback(
+ CameraOfflineSession.CameraOfflineSessionCallback listener) {
+ mProxy = listener;
+ }
+
+ @Override
+ public void onReady(CameraOfflineSession session) {
+ if (mProxy != null) {
+ mProxy.onReady(session);
+ }
+ setCurrentState(STATE_READY);
+ }
+
+ @Override
+ public void onSwitchFailed(CameraOfflineSession session) {
+ if (mProxy != null) {
+ mProxy.onSwitchFailed(session);
+ }
+ setCurrentState(STATE_SWITCH_FAILED);
+ }
+
+ @Override
+ public void onIdle(CameraOfflineSession session) {
+ if (mProxy != null) {
+ mProxy.onIdle(session);
+ }
+ setCurrentState(STATE_IDLE);
+ }
+
+ @Override
+ public void onError(CameraOfflineSession session, int error) {
+ if (mProxy != null) {
+ mProxy.onError(session, error);
+ }
+ setCurrentState(STATE_ERROR);
+ }
+
+ @Override
+ public void onClosed(CameraOfflineSession session) {
+ if (mProxy != null) {
+ mProxy.onClosed(session);
+ }
+ setCurrentState(STATE_CLOSED);
+ }
+
+ /**
+ * Wait until the desired state is observed, checking all state
+ * transitions since the last state that was waited on.
+ *
+ * <p>Note: Only one waiter allowed at a time!</p>
+ *
+ * @param state state to observe a transition to
+ * @param timeout how long to wait in milliseconds
+ *
+ * @throws TimeoutRuntimeException if the desired state is not observed before timeout.
+ */
+ public void waitForState(int state, long timeout) {
+ Integer[] stateArray = { state };
+
+ waitForAnyOfStates(Arrays.asList(stateArray), timeout);
+ }
+
+ /**
+ * Wait until the one of the desired states is observed, checking all
+ * state transitions since the last state that was waited on.
+ *
+ * <p>Note: Only one waiter allowed at a time!</p>
+ *
+ * @param states Set of desired states to observe a transition to.
+ * @param timeout how long to wait in milliseconds
+ *
+ * @return the state reached
+ * @throws TimeoutRuntimeException if none of the states is observed before timeout.
+ *
+ */
+ public int waitForAnyOfStates(Collection<Integer> states, final long timeout) {
+ synchronized (mLock) {
+ if (mWaiting) {
+ throw new IllegalStateException("Only one waiter allowed at a time");
+ }
+ mWaiting = true;
+ }
+ if (VERBOSE) {
+ StringBuilder s = new StringBuilder("Waiting for state(s) ");
+ appendStates(s, states);
+ Log.v(TAG, s.toString());
+ }
+
+ Integer nextState = null;
+ long timeoutLeft = timeout;
+ long startMs = SystemClock.elapsedRealtime();
+ try {
+ while ((nextState = mRecentStates.poll(timeoutLeft, TimeUnit.MILLISECONDS))
+ != null) {
+ if (VERBOSE) {
+ Log.v(TAG, " Saw transition to " + stateToString(nextState));
+ }
+ if (states.contains(nextState)) break;
+ long endMs = SystemClock.elapsedRealtime();
+ timeoutLeft -= (endMs - startMs);
+ startMs = endMs;
+ }
+ } catch (InterruptedException e) {
+ throw new UnsupportedOperationException("Does not support interrupts on waits", e);
+ }
+
+ synchronized (mLock) {
+ mWaiting = false;
+ }
+
+ if (!states.contains(nextState)) {
+ StringBuilder s = new StringBuilder("Timed out after ");
+ s.append(timeout);
+ s.append(" ms waiting for state(s) ");
+ appendStates(s, states);
+
+ throw new TimeoutRuntimeException(s.toString());
+ }
+
+ return nextState;
+ }
+
+ /**
+ * Convert state integer to a String
+ */
+ public static String stateToString(int state) {
+ return mStateNames[state + 1];
+ }
+
+ /**
+ * Append all states to string
+ */
+ public static void appendStates(StringBuilder s, Collection<Integer> states) {
+ boolean start = true;
+ for (Integer state : states) {
+ if (!start) s.append(" ");
+ s.append(stateToString(state));
+ start = false;
+ }
+ }
+}
