Add InputConsumerNoResampling, which is a rewrite of InputConsumer (2b920275) · Commits · e / os / android_frameworks_native

include/input/InputConsumerNoResampling.h

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		/**
		* Copyright 2024 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.
		*/

		#pragma once

		#include <utils/Looper.h>
		#include "InputTransport.h"

		namespace android {

		/**
		* An interface to receive batched input events. Even if you don't want batching, you still have to
		* use this interface, and some of the events will be batched if your implementation is slow to
		* handle the incoming input.
		*/
		class InputConsumerCallbacks {
		public:
		virtual ~InputConsumerCallbacks(){};
		virtual void onKeyEvent(KeyEvent&& event, uint32_t seq) = 0;
		virtual void onMotionEvent(MotionEvent&& event, uint32_t seq) = 0;
		/**
		* When you receive this callback, you must (eventually) call "consumeBatchedInputEvents".
		* If you don't want batching, then call "consumeBatchedInputEvents" immediately with
		* std::nullopt frameTime to receive the pending motion event(s).
		* @param pendingBatchSource the source of the pending batch.
		*/
		virtual void onBatchedInputEventPending(int32_t pendingBatchSource) = 0;
		virtual void onFocusEvent(FocusEvent&& event, uint32_t seq) = 0;
		virtual void onCaptureEvent(CaptureEvent&& event, uint32_t seq) = 0;
		virtual void onDragEvent(DragEvent&& event, uint32_t seq) = 0;
		virtual void onTouchModeEvent(TouchModeEvent&& event, uint32_t seq) = 0;
		};

		/**
		* Consumes input events from an input channel.
		*
		* This is a re-implementation of InputConsumer that does not have resampling at the current moment.
		* A lot of the higher-level logic has been folded into this class, to make it easier to use.
		* In the legacy class, InputConsumer, the consumption logic was partially handled in the jni layer,
		* as well as various actions like adding the fd to the Choreographer.
		*
		* TODO(b/297226446): use this instead of "InputConsumer":
		* - Add resampling to this class
		* - Allow various resampling strategies to be specified
		* - Delete the old "InputConsumer" and use this class instead, renaming it to "InputConsumer".
		* - Add tracing
		* - Update all tests to use the new InputConsumer
		*
		* This class is not thread-safe. We are currently allowing the constructor to run on any thread,
		* but all of the remaining APIs should be invoked on the looper thread only.
		*/
		class InputConsumerNoResampling final {
		public:
		explicit InputConsumerNoResampling(const std::shared_ptr<InputChannel>& channel,
		sp<Looper> looper, InputConsumerCallbacks& callbacks);
		~InputConsumerNoResampling();

		/**
		* Must be called exactly once for each event received through the callbacks.
		*/
		void finishInputEvent(uint32_t seq, bool handled);
		void reportTimeline(int32_t inputEventId, nsecs_t gpuCompletedTime, nsecs_t presentTime);
		/**
		* If you want to consume all events immediately (disable batching), the you still must call
		* this. For frameTime, use a std::nullopt.
		* @param frameTime the time up to which consume the events. When there's double (or triple)
		* buffering, you may want to not consume all events currently available, because you could be
		* still working on an older frame, but there could already have been events that arrived that
		* are more recent.
		* @return whether any events were actually consumed
		*/
		bool consumeBatchedInputEvents(std::optional<nsecs_t> frameTime);
		/**
		* Returns true when there is likely a pending batch or a pending event in the channel.
		*
		* This is only a performance hint and may return false negative results. Clients should not
		* rely on availability of the message based on the return value.
		*/
		bool probablyHasInput() const;

		std::string getName() { return mChannel->getName(); }

		std::string dump() const;

		private:
		std::shared_ptr<InputChannel> mChannel;
		sp<Looper> mLooper;
		InputConsumerCallbacks& mCallbacks;

		// Looper-related infrastructure
		/**
		* This class is needed to associate the function "handleReceiveCallback" with the provided
		* looper. The callback sent to the looper is RefBase - based, so we can't just send a reference
		* of this class directly to the looper.
		*/
		class LooperEventCallback : public LooperCallback {
		public:
		LooperEventCallback(std::function<int(int events)> callback) : mCallback(callback) {}
		int handleEvent(int /fd/, int events, void* /data/) override {
		return mCallback(events);
		}

		private:
		std::function<int(int events)> mCallback;
		};
		sp<LooperEventCallback> mCallback;
		/**
		* The actual code that executes when the looper encounters available data on the InputChannel.
		*/
		int handleReceiveCallback(int events);
		int mFdEvents;
		void setFdEvents(int events);

		void ensureCalledOnLooperThread(const char* func) const;

		// Event-reading infrastructure
		/**
		* A fifo queue of events to be sent to the InputChannel. We can't send all InputMessages to
		* the channel immediately when they are produced, because it's possible that the InputChannel
		* is blocked (if the channel buffer is full). When that happens, we don't want to drop the
		* events. Therefore, events should only be erased from the queue after they've been
		* successfully written to the InputChannel.
		*/
		std::queue<InputMessage> mOutboundQueue;
		/**
		* Try to send all of the events in mOutboundQueue over the InputChannel. Not all events might
		* actually get sent, because it's possible that the channel is blocked.
		*/
		void processOutboundEvents();

		/**
		* The time at which each event with the sequence number 'seq' was consumed.
		* This data is provided in 'finishInputEvent' so that the receiving end can measure the latency
		* This collection is populated when the event is received, and the entries are erased when the
		* events are finished. It should not grow infinitely because if an event is not ack'd, ANR
		* will be raised for that connection, and no further events will be posted to that channel.
		*/
		std::unordered_map<uint32_t /seq/, nsecs_t /consumeTime/> mConsumeTimes;
		/**
		* Find and return the consumeTime associated with the provided sequence number. Crashes if
		* the provided seq number is not found.
		*/
		nsecs_t popConsumeTime(uint32_t seq);

		// Event reading and processing
		/**
		* Read all of the available events from the InputChannel
		*/
		std::vector<InputMessage> readAllMessages();

		/**
		* Send InputMessage to the corresponding InputConsumerCallbacks function.
		* @param msg
		*/
		void handleMessage(const InputMessage& msg) const;

		// Batching
		/**
		* Batch messages that can be batched. When an unbatchable message is encountered, send it
		* to the InputConsumerCallbacks immediately. If there are batches remaining,
		* notify InputConsumerCallbacks.
		*/
		void handleMessages(std::vector<InputMessage>&& messages);
		/**
		* Batched InputMessages, per deviceId.
		* For each device, we are storing a queue of batched messages. These will all be collapsed into
		* a single MotionEvent (up to a specific frameTime) when the consumer calls
		* `consumeBatchedInputEvents`.
		*/
		std::map<DeviceId, std::queue<InputMessage>> mBatches;
		/**
		* A map from a single sequence number to several sequence numbers. This is needed because of
		* batching. When batching is enabled, a single MotionEvent will contain several samples. Each
		* sample came from an individual InputMessage of Type::Motion, and therefore will have to be
		* finished individually. Therefore, when the app calls "finish" on a (possibly batched)
		* MotionEvent, we will need to check this map in case there are multiple sequence numbers
		* associated with a single number that the app provided.
		*
		* For example:
		* Suppose we received 4 InputMessage's of type Motion, with action MOVE:
		* InputMessage(MOVE) InputMessage(MOVE) InputMessage(MOVE) InputMessage(MOVE)
		* seq=10 seq=11 seq=12 seq=13
		* The app consumed them all as a batch, which means that the app received a single MotionEvent
		* with historySize=3 and seq = 10.
		*
		* This map will look like:
		* {
		* 10: [11, 12, 13],
		* }
		* So the sequence number 10 will have 3 other sequence numbers associated with it.
		* When the app calls 'finish' for seq=10, we need to call 'finish' 4 times total, for sequence
		* numbers 10, 11, 12, 13. The app is not aware of the sequence numbers of each sample inside
		* the batched MotionEvent that it received.
		*/
		std::map<uint32_t, std::vector<uint32_t>> mBatchedSequenceNumbers;
		};

		} // namespace android

libs/input/Android.bp

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		@@ -205,6 +205,7 @@ cc_library {
		"AccelerationCurve.cpp",
		"Input.cpp",
		"InputConsumer.cpp",
		"InputConsumerNoResampling.cpp",
		"InputDevice.cpp",
		"InputEventLabels.cpp",
		"InputTransport.cpp",

libs/input/InputConsumerNoResampling.cpp

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libs/input/tests/Android.bp

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		@@ -19,6 +19,7 @@ cc_test {
		"InputDevice_test.cpp",
		"InputEvent_test.cpp",
		"InputPublisherAndConsumer_test.cpp",
		"InputPublisherAndConsumerNoResampling_test.cpp",
		"InputVerifier_test.cpp",
		"MotionPredictor_test.cpp",
		"MotionPredictorMetricsManager_test.cpp",

libs/input/tests/InputPublisherAndConsumerNoResampling_test.cpp

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