Move InputConsumer into separate files

This helps to keep track of things, and it also allows easier deletion
in the future.

Bug: 311142655
Test: none
Change-Id: Iece2bf6857ab05f86072031a4cf3a36f843b1634

1 files changed, 249 insertions, 0 deletions

diff --git a/include/input/InputConsumer.h b/include/input/InputConsumer.h
new file mode 100644
index 0000000000..560e804c68
--- /dev/null
+++ b/include/input/InputConsumer.h
@@ -0,0 +1,249 @@
+/*
+ * 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
+
+/*
+ * Native input transport.
+ *
+ * The InputConsumer is used by the application to receive events from the input dispatcher.
+ */
+
+#include "InputTransport.h"
+
+namespace android {
+
+/*
+ * Consumes input events from an input channel.
+ */
+class InputConsumer {
+public:
+    /* Create a consumer associated with an input channel. */
+    explicit InputConsumer(const std::shared_ptr<InputChannel>& channel);
+    /* Create a consumer associated with an input channel, override resampling system property */
+    explicit InputConsumer(const std::shared_ptr<InputChannel>& channel,
+                           bool enableTouchResampling);
+
+    /* Destroys the consumer and releases its input channel. */
+    ~InputConsumer();
+
+    /* Gets the underlying input channel. */
+    inline std::shared_ptr<InputChannel> getChannel() { return mChannel; }
+
+    /* Consumes an input event from the input channel and copies its contents into
+     * an InputEvent object created using the specified factory.
+     *
+     * Tries to combine a series of move events into larger batches whenever possible.
+     *
+     * If consumeBatches is false, then defers consuming pending batched events if it
+     * is possible for additional samples to be added to them later.  Call hasPendingBatch()
+     * to determine whether a pending batch is available to be consumed.
+     *
+     * If consumeBatches is true, then events are still batched but they are consumed
+     * immediately as soon as the input channel is exhausted.
+     *
+     * The frameTime parameter specifies the time when the current display frame started
+     * rendering in the CLOCK_MONOTONIC time base, or -1 if unknown.
+     *
+     * The returned sequence number is never 0 unless the operation failed.
+     *
+     * Returns OK on success.
+     * Returns WOULD_BLOCK if there is no event present.
+     * Returns DEAD_OBJECT if the channel's peer has been closed.
+     * Returns NO_MEMORY if the event could not be created.
+     * Other errors probably indicate that the channel is broken.
+     */
+    status_t consume(InputEventFactoryInterface* factory, bool consumeBatches, nsecs_t frameTime,
+                     uint32_t* outSeq, InputEvent** outEvent);
+
+    /* Sends a finished signal to the publisher to inform it that the message
+     * with the specified sequence number has finished being process and whether
+     * the message was handled by the consumer.
+     *
+     * Returns OK on success.
+     * Returns BAD_VALUE if seq is 0.
+     * Other errors probably indicate that the channel is broken.
+     */
+    status_t sendFinishedSignal(uint32_t seq, bool handled);
+
+    status_t sendTimeline(int32_t inputEventId,
+                          std::array<nsecs_t, GraphicsTimeline::SIZE> timeline);
+
+    /* Returns true if there is a pending batch.
+     *
+     * Should be called after calling consume() with consumeBatches == false to determine
+     * whether consume() should be called again later on with consumeBatches == true.
+     */
+    bool hasPendingBatch() const;
+
+    /* Returns the source of first pending batch if exist.
+     *
+     * Should be called after calling consume() with consumeBatches == false to determine
+     * whether consume() should be called again later on with consumeBatches == true.
+     */
+    int32_t getPendingBatchSource() const;
+
+    /* 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 dump() const;
+
+private:
+    // True if touch resampling is enabled.
+    const bool mResampleTouch;
+
+    std::shared_ptr<InputChannel> mChannel;
+
+    // The current input message.
+    InputMessage mMsg;
+
+    // True if mMsg contains a valid input message that was deferred from the previous
+    // call to consume and that still needs to be handled.
+    bool mMsgDeferred;
+
+    // Batched motion events per device and source.
+    struct Batch {
+        std::vector<InputMessage> samples;
+    };
+    std::vector<Batch> mBatches;
+
+    // Touch state per device and source, only for sources of class pointer.
+    struct History {
+        nsecs_t eventTime;
+        BitSet32 idBits;
+        int32_t idToIndex[MAX_POINTER_ID + 1];
+        PointerCoords pointers[MAX_POINTERS];
+
+        void initializeFrom(const InputMessage& msg) {
+            eventTime = msg.body.motion.eventTime;
+            idBits.clear();
+            for (uint32_t i = 0; i < msg.body.motion.pointerCount; i++) {
+                uint32_t id = msg.body.motion.pointers[i].properties.id;
+                idBits.markBit(id);
+                idToIndex[id] = i;
+                pointers[i].copyFrom(msg.body.motion.pointers[i].coords);
+            }
+        }
+
+        void initializeFrom(const History& other) {
+            eventTime = other.eventTime;
+            idBits = other.idBits; // temporary copy
+            for (size_t i = 0; i < other.idBits.count(); i++) {
+                uint32_t id = idBits.clearFirstMarkedBit();
+                int32_t index = other.idToIndex[id];
+                idToIndex[id] = index;
+                pointers[index].copyFrom(other.pointers[index]);
+            }
+            idBits = other.idBits; // final copy
+        }
+
+        const PointerCoords& getPointerById(uint32_t id) const { return pointers[idToIndex[id]]; }
+
+        bool hasPointerId(uint32_t id) const { return idBits.hasBit(id); }
+    };
+    struct TouchState {
+        int32_t deviceId;
+        int32_t source;
+        size_t historyCurrent;
+        size_t historySize;
+        History history[2];
+        History lastResample;
+
+        void initialize(int32_t incomingDeviceId, int32_t incomingSource) {
+            deviceId = incomingDeviceId;
+            source = incomingSource;
+            historyCurrent = 0;
+            historySize = 0;
+            lastResample.eventTime = 0;
+            lastResample.idBits.clear();
+        }
+
+        void addHistory(const InputMessage& msg) {
+            historyCurrent ^= 1;
+            if (historySize < 2) {
+                historySize += 1;
+            }
+            history[historyCurrent].initializeFrom(msg);
+        }
+
+        const History* getHistory(size_t index) const {
+            return &history[(historyCurrent + index) & 1];
+        }
+
+        bool recentCoordinatesAreIdentical(uint32_t id) const {
+            // Return true if the two most recently received "raw" coordinates are identical
+            if (historySize < 2) {
+                return false;
+            }
+            if (!getHistory(0)->hasPointerId(id) || !getHistory(1)->hasPointerId(id)) {
+                return false;
+            }
+            float currentX = getHistory(0)->getPointerById(id).getX();
+            float currentY = getHistory(0)->getPointerById(id).getY();
+            float previousX = getHistory(1)->getPointerById(id).getX();
+            float previousY = getHistory(1)->getPointerById(id).getY();
+            if (currentX == previousX && currentY == previousY) {
+                return true;
+            }
+            return false;
+        }
+    };
+    std::vector<TouchState> mTouchStates;
+
+    // Chain of batched sequence numbers.  When multiple input messages are combined into
+    // a batch, we append a record here that associates the last sequence number in the
+    // batch with the previous one.  When the finished signal is sent, we traverse the
+    // chain to individually finish all input messages that were part of the batch.
+    struct SeqChain {
+        uint32_t seq;   // sequence number of batched input message
+        uint32_t chain; // sequence number of previous batched input message
+    };
+    std::vector<SeqChain> mSeqChains;
+
+    // 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;
+
+    status_t consumeBatch(InputEventFactoryInterface* factory, nsecs_t frameTime, uint32_t* outSeq,
+                          InputEvent** outEvent);
+    status_t consumeSamples(InputEventFactoryInterface* factory, Batch& batch, size_t count,
+                            uint32_t* outSeq, InputEvent** outEvent);
+
+    void updateTouchState(InputMessage& msg);
+    void resampleTouchState(nsecs_t frameTime, MotionEvent* event, const InputMessage* next);
+
+    ssize_t findBatch(int32_t deviceId, int32_t source) const;
+    ssize_t findTouchState(int32_t deviceId, int32_t source) const;
+
+    nsecs_t getConsumeTime(uint32_t seq) const;
+    void popConsumeTime(uint32_t seq);
+    status_t sendUnchainedFinishedSignal(uint32_t seq, bool handled);
+
+    static void rewriteMessage(TouchState& state, InputMessage& msg);
+    static bool canAddSample(const Batch& batch, const InputMessage* msg);
+    static ssize_t findSampleNoLaterThan(const Batch& batch, nsecs_t time);
+
+    static bool isTouchResamplingEnabled();
+};
+
+} // namespace android