Camera: add OFFLINE_PROCESSING APIs
Also a typo fix in metadata doc.
Test: N/A. New API skeleton, no implementation yet.
Bug: 135142453
Change-Id: I4852ee28242afabe81b02cfef39994c5d2705359
diff --git a/camera/device/3.6/ICameraOfflineSession.hal b/camera/device/3.6/ICameraOfflineSession.hal
new file mode 100644
index 0000000..03cea64
--- /dev/null
+++ b/camera/device/3.6/ICameraOfflineSession.hal
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2019 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 android.hardware.camera.device@3.6;
+
+import @3.5::ICameraDeviceCallback;
+
+/**
+ * Camera device offline session interface.
+ *
+ * Obtained via ICameraDeviceSession::switchToOffline(), this interface contains
+ * the methods and callback interfaces that define how camera service interacts
+ * with an offline session.
+ *
+ * An offline session contains some unfinished capture requests that were submitted
+ * to the parent ICameraDeviceSession before calling switchToOffline, and is
+ * responsible for delivering these capture results back to camera service regardless
+ * of whether the parent camera device is still opened or not. An offline session must
+ * not have access to the camera device's image sensor. During switchToOffline
+ * call, camera HAL must capture all necessary frames from the image sensor that
+ * is needed for completing the requests offline later.
+ */
+interface ICameraOfflineSession {
+ /**
+ * Set the callbacks for offline session to communicate with camera service.
+ *
+ * Offline session is responsible to store all callbacks the camera HAL
+ * generated after the return of ICameraDeviceSession::switchToOffline, and
+ * send them to camera service once this method is called.
+ *
+ * Camera service must not call this method more than once, so these
+ * callbacks can be assumed to be constant after the first setCallback call.
+ */
+ setCallback(ICameraDeviceCallback cb);
+
+ /**
+ * getCaptureResultMetadataQueue:
+ *
+ * Retrieves the queue used along with
+ * ICameraDeviceCallback#processCaptureResult.
+ *
+ * Clients to ICameraOfflineSession must:
+ * - Call getCaptureRequestMetadataQueue to retrieve the fast message queue;
+ * - In implementation of ICameraDeviceCallback, test whether
+ * .fmqResultSize field is zero.
+ * - If .fmqResultSize != 0, read result metadata from the fast message
+ * queue;
+ * - otherwise, read result metadata in CaptureResult.result.
+ *
+ * @return queue the queue that implementation writes result metadata to.
+ */
+ getCaptureResultMetadataQueue() generates (fmq_sync<uint8_t> queue);
+
+ /**
+ * Close the offline session and release all resources.
+ *
+ * Camera service may call this method before or after the offline session
+ * has finished all requests it needs to handle. If there are still unfinished
+ * requests when close is called, camera HAL must send ERROR_REQUEST for
+ * all unfinished requests and return all buffers via
+ * ICameraDeviceCallback#processCaptureResult or
+ * ICameraDeviceCallback#returnStreamBuffers.
+ * Also, all buffer caches maintained by the offline session must be erased
+ * before the close call returns.
+ */
+ close();
+};