Add m-esr52 at 52.6.0

1 files changed, 957 insertions, 0 deletions

diff --git a/widget/gonk/libui/InputTransport.cpp b/widget/gonk/libui/InputTransport.cpp
new file mode 100644
index 000000000..3f0fcb047
--- /dev/null
+++ b/widget/gonk/libui/InputTransport.cpp
@@ -0,0 +1,957 @@
+//
+// Copyright 2010 The Android Open Source Project
+//
+// Provides a shared memory transport for input events.
+//
+#define LOG_TAG "InputTransport"
+
+//#define LOG_NDEBUG 0
+
+// Log debug messages about channel messages (send message, receive message)
+#define DEBUG_CHANNEL_MESSAGES 0
+
+// Log debug messages whenever InputChannel objects are created/destroyed
+#define DEBUG_CHANNEL_LIFECYCLE 0
+
+// Log debug messages about transport actions
+#define DEBUG_TRANSPORT_ACTIONS 0
+
+// Log debug messages about touch event resampling
+#define DEBUG_RESAMPLING 0
+
+
+#include "cutils_log.h"
+#include <cutils/properties.h>
+#include <errno.h>
+#include <fcntl.h>
+#include "InputTransport.h"
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <math.h>
+
+
+namespace android {
+
+// Socket buffer size.  The default is typically about 128KB, which is much larger than
+// we really need.  So we make it smaller.  It just needs to be big enough to hold
+// a few dozen large multi-finger motion events in the case where an application gets
+// behind processing touches.
+static const size_t SOCKET_BUFFER_SIZE = 32 * 1024;
+
+// Nanoseconds per milliseconds.
+static const nsecs_t NANOS_PER_MS = 1000000;
+
+// Latency added during resampling.  A few milliseconds doesn't hurt much but
+// reduces the impact of mispredicted touch positions.
+static const nsecs_t RESAMPLE_LATENCY = 5 * NANOS_PER_MS;
+
+// Minimum time difference between consecutive samples before attempting to resample.
+static const nsecs_t RESAMPLE_MIN_DELTA = 2 * NANOS_PER_MS;
+
+// Maximum time to predict forward from the last known state, to avoid predicting too
+// far into the future.  This time is further bounded by 50% of the last time delta.
+static const nsecs_t RESAMPLE_MAX_PREDICTION = 8 * NANOS_PER_MS;
+
+template<typename T>
+inline static T min(const T& a, const T& b) {
+    return a < b ? a : b;
+}
+
+inline static float lerp(float a, float b, float alpha) {
+    return a + alpha * (b - a);
+}
+
+// --- InputMessage ---
+
+bool InputMessage::isValid(size_t actualSize) const {
+    if (size() == actualSize) {
+        switch (header.type) {
+        case TYPE_KEY:
+            return true;
+        case TYPE_MOTION:
+            return body.motion.pointerCount > 0
+                    && body.motion.pointerCount <= MAX_POINTERS;
+        case TYPE_FINISHED:
+            return true;
+        }
+    }
+    return false;
+}
+
+size_t InputMessage::size() const {
+    switch (header.type) {
+    case TYPE_KEY:
+        return sizeof(Header) + body.key.size();
+    case TYPE_MOTION:
+        return sizeof(Header) + body.motion.size();
+    case TYPE_FINISHED:
+        return sizeof(Header) + body.finished.size();
+    }
+    return sizeof(Header);
+}
+
+
+// --- InputChannel ---
+
+InputChannel::InputChannel(const String8& name, int fd) :
+        mName(name), mFd(fd) {
+#if DEBUG_CHANNEL_LIFECYCLE
+    ALOGD("Input channel constructed: name='%s', fd=%d",
+            mName.string(), fd);
+#endif
+
+    int result = fcntl(mFd, F_SETFL, O_NONBLOCK);
+    LOG_ALWAYS_FATAL_IF(result != 0, "channel '%s' ~ Could not make socket "
+            "non-blocking.  errno=%d", mName.string(), errno);
+}
+
+InputChannel::~InputChannel() {
+#if DEBUG_CHANNEL_LIFECYCLE
+    ALOGD("Input channel destroyed: name='%s', fd=%d",
+            mName.string(), mFd);
+#endif
+
+    ::close(mFd);
+}
+
+status_t InputChannel::openInputChannelPair(const String8& name,
+        sp<InputChannel>& outServerChannel, sp<InputChannel>& outClientChannel) {
+    int sockets[2];
+    if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets)) {
+        status_t result = -errno;
+        ALOGE("channel '%s' ~ Could not create socket pair.  errno=%d",
+                name.string(), errno);
+        outServerChannel.clear();
+        outClientChannel.clear();
+        return result;
+    }
+
+    int bufferSize = SOCKET_BUFFER_SIZE;
+    setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
+    setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
+    setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
+    setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
+
+    String8 serverChannelName = name;
+    serverChannelName.append(" (server)");
+    outServerChannel = new InputChannel(serverChannelName, sockets[0]);
+
+    String8 clientChannelName = name;
+    clientChannelName.append(" (client)");
+    outClientChannel = new InputChannel(clientChannelName, sockets[1]);
+    return OK;
+}
+
+status_t InputChannel::sendMessage(const InputMessage* msg) {
+    size_t msgLength = msg->size();
+    ssize_t nWrite;
+    do {
+        nWrite = ::send(mFd, msg, msgLength, MSG_DONTWAIT | MSG_NOSIGNAL);
+    } while (nWrite == -1 && errno == EINTR);
+
+    if (nWrite < 0) {
+        int error = errno;
+#if DEBUG_CHANNEL_MESSAGES
+        ALOGD("channel '%s' ~ error sending message of type %d, errno=%d", mName.string(),
+                msg->header.type, error);
+#endif
+        if (error == EAGAIN || error == EWOULDBLOCK) {
+            return WOULD_BLOCK;
+        }
+        if (error == EPIPE || error == ENOTCONN) {
+            return DEAD_OBJECT;
+        }
+        return -error;
+    }
+
+    if (size_t(nWrite) != msgLength) {
+#if DEBUG_CHANNEL_MESSAGES
+        ALOGD("channel '%s' ~ error sending message type %d, send was incomplete",
+                mName.string(), msg->header.type);
+#endif
+        return DEAD_OBJECT;
+    }
+
+#if DEBUG_CHANNEL_MESSAGES
+    ALOGD("channel '%s' ~ sent message of type %d", mName.string(), msg->header.type);
+#endif
+    return OK;
+}
+
+status_t InputChannel::receiveMessage(InputMessage* msg) {
+    ssize_t nRead;
+    do {
+        nRead = ::recv(mFd, msg, sizeof(InputMessage), MSG_DONTWAIT);
+    } while (nRead == -1 && errno == EINTR);
+
+    if (nRead < 0) {
+        int error = errno;
+#if DEBUG_CHANNEL_MESSAGES
+        ALOGD("channel '%s' ~ receive message failed, errno=%d", mName.string(), errno);
+#endif
+        if (error == EAGAIN || error == EWOULDBLOCK) {
+            return WOULD_BLOCK;
+        }
+        if (error == EPIPE || error == ENOTCONN) {
+            return DEAD_OBJECT;
+        }
+        return -error;
+    }
+
+    if (nRead == 0) { // check for EOF
+#if DEBUG_CHANNEL_MESSAGES
+        ALOGD("channel '%s' ~ receive message failed because peer was closed", mName.string());
+#endif
+        return DEAD_OBJECT;
+    }
+
+    if (!msg->isValid(nRead)) {
+#if DEBUG_CHANNEL_MESSAGES
+        ALOGD("channel '%s' ~ received invalid message", mName.string());
+#endif
+        return BAD_VALUE;
+    }
+
+#if DEBUG_CHANNEL_MESSAGES
+    ALOGD("channel '%s' ~ received message of type %d", mName.string(), msg->header.type);
+#endif
+    return OK;
+}
+
+sp<InputChannel> InputChannel::dup() const {
+    int fd = ::dup(getFd());
+    return fd >= 0 ? new InputChannel(getName(), fd) : NULL;
+}
+
+
+// --- InputPublisher ---
+
+InputPublisher::InputPublisher(const sp<InputChannel>& channel) :
+        mChannel(channel) {
+}
+
+InputPublisher::~InputPublisher() {
+}
+
+status_t InputPublisher::publishKeyEvent(
+        uint32_t seq,
+        int32_t deviceId,
+        int32_t source,
+        int32_t action,
+        int32_t flags,
+        int32_t keyCode,
+        int32_t scanCode,
+        int32_t metaState,
+        int32_t repeatCount,
+        nsecs_t downTime,
+        nsecs_t eventTime) {
+#if DEBUG_TRANSPORT_ACTIONS
+    ALOGD("channel '%s' publisher ~ publishKeyEvent: seq=%u, deviceId=%d, source=0x%x, "
+            "action=0x%x, flags=0x%x, keyCode=%d, scanCode=%d, metaState=0x%x, repeatCount=%d,"
+            "downTime=%lld, eventTime=%lld",
+            mChannel->getName().string(), seq,
+            deviceId, source, action, flags, keyCode, scanCode, metaState, repeatCount,
+            downTime, eventTime);
+#endif
+
+    if (!seq) {
+        ALOGE("Attempted to publish a key event with sequence number 0.");
+        return BAD_VALUE;
+    }
+
+    InputMessage msg;
+    msg.header.type = InputMessage::TYPE_KEY;
+    msg.body.key.seq = seq;
+    msg.body.key.deviceId = deviceId;
+    msg.body.key.source = source;
+    msg.body.key.action = action;
+    msg.body.key.flags = flags;
+    msg.body.key.keyCode = keyCode;
+    msg.body.key.scanCode = scanCode;
+    msg.body.key.metaState = metaState;
+    msg.body.key.repeatCount = repeatCount;
+    msg.body.key.downTime = downTime;
+    msg.body.key.eventTime = eventTime;
+    return mChannel->sendMessage(&msg);
+}
+
+status_t InputPublisher::publishMotionEvent(
+        uint32_t seq,
+        int32_t deviceId,
+        int32_t source,
+        int32_t action,
+        int32_t flags,
+        int32_t edgeFlags,
+        int32_t metaState,
+        int32_t buttonState,
+        float xOffset,
+        float yOffset,
+        float xPrecision,
+        float yPrecision,
+        nsecs_t downTime,
+        nsecs_t eventTime,
+        size_t pointerCount,
+        const PointerProperties* pointerProperties,
+        const PointerCoords* pointerCoords) {
+#if DEBUG_TRANSPORT_ACTIONS
+    ALOGD("channel '%s' publisher ~ publishMotionEvent: seq=%u, deviceId=%d, source=0x%x, "
+            "action=0x%x, flags=0x%x, edgeFlags=0x%x, metaState=0x%x, buttonState=0x%x, "
+            "xOffset=%f, yOffset=%f, "
+            "xPrecision=%f, yPrecision=%f, downTime=%lld, eventTime=%lld, "
+            "pointerCount=%d",
+            mChannel->getName().string(), seq,
+            deviceId, source, action, flags, edgeFlags, metaState, buttonState,
+            xOffset, yOffset, xPrecision, yPrecision, downTime, eventTime, pointerCount);
+#endif
+
+    if (!seq) {
+        ALOGE("Attempted to publish a motion event with sequence number 0.");
+        return BAD_VALUE;
+    }
+
+    if (pointerCount > MAX_POINTERS || pointerCount < 1) {
+        ALOGE("channel '%s' publisher ~ Invalid number of pointers provided: %d.",
+                mChannel->getName().string(), pointerCount);
+        return BAD_VALUE;
+    }
+
+    InputMessage msg;
+    msg.header.type = InputMessage::TYPE_MOTION;
+    msg.body.motion.seq = seq;
+    msg.body.motion.deviceId = deviceId;
+    msg.body.motion.source = source;
+    msg.body.motion.action = action;
+    msg.body.motion.flags = flags;
+    msg.body.motion.edgeFlags = edgeFlags;
+    msg.body.motion.metaState = metaState;
+    msg.body.motion.buttonState = buttonState;
+    msg.body.motion.xOffset = xOffset;
+    msg.body.motion.yOffset = yOffset;
+    msg.body.motion.xPrecision = xPrecision;
+    msg.body.motion.yPrecision = yPrecision;
+    msg.body.motion.downTime = downTime;
+    msg.body.motion.eventTime = eventTime;
+    msg.body.motion.pointerCount = pointerCount;
+    for (size_t i = 0; i < pointerCount; i++) {
+        msg.body.motion.pointers[i].properties.copyFrom(pointerProperties[i]);
+        msg.body.motion.pointers[i].coords.copyFrom(pointerCoords[i]);
+    }
+    return mChannel->sendMessage(&msg);
+}
+
+status_t InputPublisher::receiveFinishedSignal(uint32_t* outSeq, bool* outHandled) {
+#if DEBUG_TRANSPORT_ACTIONS
+    ALOGD("channel '%s' publisher ~ receiveFinishedSignal",
+            mChannel->getName().string());
+#endif
+
+    InputMessage msg;
+    status_t result = mChannel->receiveMessage(&msg);
+    if (result) {
+        *outSeq = 0;
+        *outHandled = false;
+        return result;
+    }
+    if (msg.header.type != InputMessage::TYPE_FINISHED) {
+        ALOGE("channel '%s' publisher ~ Received unexpected message of type %d from consumer",
+                mChannel->getName().string(), msg.header.type);
+        return UNKNOWN_ERROR;
+    }
+    *outSeq = msg.body.finished.seq;
+    *outHandled = msg.body.finished.handled;
+    return OK;
+}
+
+// --- InputConsumer ---
+
+InputConsumer::InputConsumer(const sp<InputChannel>& channel) :
+        mResampleTouch(isTouchResamplingEnabled()),
+        mChannel(channel), mMsgDeferred(false) {
+}
+
+InputConsumer::~InputConsumer() {
+}
+
+bool InputConsumer::isTouchResamplingEnabled() {
+    char value[PROPERTY_VALUE_MAX];
+    int length = property_get("debug.inputconsumer.resample", value, NULL);
+    if (length > 0) {
+        if (!strcmp("0", value)) {
+            return false;
+        }
+        if (strcmp("1", value)) {
+            ALOGD("Unrecognized property value for 'debug.inputconsumer.resample'.  "
+                    "Use '1' or '0'.");
+        }
+    }
+    return true;
+}
+
+status_t InputConsumer::consume(InputEventFactoryInterface* factory,
+        bool consumeBatches, nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent) {
+#if DEBUG_TRANSPORT_ACTIONS
+    ALOGD("channel '%s' consumer ~ consume: consumeBatches=%s, frameTime=%lld",
+            mChannel->getName().string(), consumeBatches ? "true" : "false", frameTime);
+#endif
+
+    *outSeq = 0;
+    *outEvent = NULL;
+
+    // Fetch the next input message.
+    // Loop until an event can be returned or no additional events are received.
+    while (!*outEvent) {
+        if (mMsgDeferred) {
+            // mMsg contains a valid input message from the previous call to consume
+            // that has not yet been processed.
+            mMsgDeferred = false;
+        } else {
+            // Receive a fresh message.
+            status_t result = mChannel->receiveMessage(&mMsg);
+            if (result) {
+                // Consume the next batched event unless batches are being held for later.
+                if (consumeBatches || result != WOULD_BLOCK) {
+                    result = consumeBatch(factory, frameTime, outSeq, outEvent);
+                    if (*outEvent) {
+#if DEBUG_TRANSPORT_ACTIONS
+                        ALOGD("channel '%s' consumer ~ consumed batch event, seq=%u",
+                                mChannel->getName().string(), *outSeq);
+#endif
+                        break;
+                    }
+                }
+                return result;
+            }
+        }
+
+        switch (mMsg.header.type) {
+        case InputMessage::TYPE_KEY: {
+            KeyEvent* keyEvent = factory->createKeyEvent();
+            if (!keyEvent) return NO_MEMORY;
+
+            initializeKeyEvent(keyEvent, &mMsg);
+            *outSeq = mMsg.body.key.seq;
+            *outEvent = keyEvent;
+#if DEBUG_TRANSPORT_ACTIONS
+            ALOGD("channel '%s' consumer ~ consumed key event, seq=%u",
+                    mChannel->getName().string(), *outSeq);
+#endif
+            break;
+        }
+
+        case AINPUT_EVENT_TYPE_MOTION: {
+            ssize_t batchIndex = findBatch(mMsg.body.motion.deviceId, mMsg.body.motion.source);
+            if (batchIndex >= 0) {
+                Batch& batch = mBatches.editItemAt(batchIndex);
+                if (canAddSample(batch, &mMsg)) {
+                    batch.samples.push(mMsg);
+#if DEBUG_TRANSPORT_ACTIONS
+                    ALOGD("channel '%s' consumer ~ appended to batch event",
+                            mChannel->getName().string());
+#endif
+                    break;
+                } else {
+                    // We cannot append to the batch in progress, so we need to consume
+                    // the previous batch right now and defer the new message until later.
+                    mMsgDeferred = true;
+                    status_t result = consumeSamples(factory,
+                            batch, batch.samples.size(), outSeq, outEvent);
+                    mBatches.removeAt(batchIndex);
+                    if (result) {
+                        return result;
+                    }
+#if DEBUG_TRANSPORT_ACTIONS
+                    ALOGD("channel '%s' consumer ~ consumed batch event and "
+                            "deferred current event, seq=%u",
+                            mChannel->getName().string(), *outSeq);
+#endif
+                    break;
+                }
+            }
+
+            // Start a new batch if needed.
+            if (mMsg.body.motion.action == AMOTION_EVENT_ACTION_MOVE
+                    || mMsg.body.motion.action == AMOTION_EVENT_ACTION_HOVER_MOVE) {
+                mBatches.push();
+                Batch& batch = mBatches.editTop();
+                batch.samples.push(mMsg);
+#if DEBUG_TRANSPORT_ACTIONS
+                ALOGD("channel '%s' consumer ~ started batch event",
+                        mChannel->getName().string());
+#endif
+                break;
+            }
+
+            MotionEvent* motionEvent = factory->createMotionEvent();
+            if (! motionEvent) return NO_MEMORY;
+
+            updateTouchState(&mMsg);
+            initializeMotionEvent(motionEvent, &mMsg);
+            *outSeq = mMsg.body.motion.seq;
+            *outEvent = motionEvent;
+#if DEBUG_TRANSPORT_ACTIONS
+            ALOGD("channel '%s' consumer ~ consumed motion event, seq=%u",
+                    mChannel->getName().string(), *outSeq);
+#endif
+            break;
+        }
+
+        default:
+            ALOGE("channel '%s' consumer ~ Received unexpected message of type %d",
+                    mChannel->getName().string(), mMsg.header.type);
+            return UNKNOWN_ERROR;
+        }
+    }
+    return OK;
+}
+
+status_t InputConsumer::consumeBatch(InputEventFactoryInterface* factory,
+        nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent) {
+    status_t result;
+    for (size_t i = mBatches.size(); i-- > 0; ) {
+        Batch& batch = mBatches.editItemAt(i);
+        if (frameTime < 0) {
+            result = consumeSamples(factory, batch, batch.samples.size(),
+                    outSeq, outEvent);
+            mBatches.removeAt(i);
+            return result;
+        }
+
+        nsecs_t sampleTime = frameTime - RESAMPLE_LATENCY;
+        ssize_t split = findSampleNoLaterThan(batch, sampleTime);
+        if (split < 0) {
+            continue;
+        }
+
+        result = consumeSamples(factory, batch, split + 1, outSeq, outEvent);
+        const InputMessage* next;
+        if (batch.samples.isEmpty()) {
+            mBatches.removeAt(i);
+            next = NULL;
+        } else {
+            next = &batch.samples.itemAt(0);
+        }
+        if (!result) {
+            resampleTouchState(sampleTime, static_cast<MotionEvent*>(*outEvent), next);
+        }
+        return result;
+    }
+
+    return WOULD_BLOCK;
+}
+
+status_t InputConsumer::consumeSamples(InputEventFactoryInterface* factory,
+        Batch& batch, size_t count, uint32_t* outSeq, InputEvent** outEvent) {
+    MotionEvent* motionEvent = factory->createMotionEvent();
+    if (! motionEvent) return NO_MEMORY;
+
+    uint32_t chain = 0;
+    for (size_t i = 0; i < count; i++) {
+        InputMessage& msg = batch.samples.editItemAt(i);
+        updateTouchState(&msg);
+        if (i) {
+            SeqChain seqChain;
+            seqChain.seq = msg.body.motion.seq;
+            seqChain.chain = chain;
+            mSeqChains.push(seqChain);
+            addSample(motionEvent, &msg);
+        } else {
+            initializeMotionEvent(motionEvent, &msg);
+        }
+        chain = msg.body.motion.seq;
+    }
+    batch.samples.removeItemsAt(0, count);
+
+    *outSeq = chain;
+    *outEvent = motionEvent;
+    return OK;
+}
+
+void InputConsumer::updateTouchState(InputMessage* msg) {
+    if (!mResampleTouch ||
+            !(msg->body.motion.source & AINPUT_SOURCE_CLASS_POINTER)) {
+        return;
+    }
+
+    int32_t deviceId = msg->body.motion.deviceId;
+    int32_t source = msg->body.motion.source;
+    nsecs_t eventTime = msg->body.motion.eventTime;
+
+    // Update the touch state history to incorporate the new input message.
+    // If the message is in the past relative to the most recently produced resampled
+    // touch, then use the resampled time and coordinates instead.
+    switch (msg->body.motion.action & AMOTION_EVENT_ACTION_MASK) {
+    case AMOTION_EVENT_ACTION_DOWN: {
+        ssize_t index = findTouchState(deviceId, source);
+        if (index < 0) {
+            mTouchStates.push();
+            index = mTouchStates.size() - 1;
+        }
+        TouchState& touchState = mTouchStates.editItemAt(index);
+        touchState.initialize(deviceId, source);
+        touchState.addHistory(msg);
+        break;
+    }
+
+    case AMOTION_EVENT_ACTION_MOVE: {
+        ssize_t index = findTouchState(deviceId, source);
+        if (index >= 0) {
+            TouchState& touchState = mTouchStates.editItemAt(index);
+            touchState.addHistory(msg);
+            if (eventTime < touchState.lastResample.eventTime) {
+                rewriteMessage(touchState, msg);
+            } else {
+                touchState.lastResample.idBits.clear();
+            }
+        }
+        break;
+    }
+
+    case AMOTION_EVENT_ACTION_POINTER_DOWN: {
+        ssize_t index = findTouchState(deviceId, source);
+        if (index >= 0) {
+            TouchState& touchState = mTouchStates.editItemAt(index);
+            touchState.lastResample.idBits.clearBit(msg->body.motion.getActionId());
+            rewriteMessage(touchState, msg);
+        }
+        break;
+    }
+
+    case AMOTION_EVENT_ACTION_POINTER_UP: {
+        ssize_t index = findTouchState(deviceId, source);
+        if (index >= 0) {
+            TouchState& touchState = mTouchStates.editItemAt(index);
+            rewriteMessage(touchState, msg);
+            touchState.lastResample.idBits.clearBit(msg->body.motion.getActionId());
+        }
+        break;
+    }
+
+    case AMOTION_EVENT_ACTION_SCROLL: {
+        ssize_t index = findTouchState(deviceId, source);
+        if (index >= 0) {
+            const TouchState& touchState = mTouchStates.itemAt(index);
+            rewriteMessage(touchState, msg);
+        }
+        break;
+    }
+
+    case AMOTION_EVENT_ACTION_UP:
+    case AMOTION_EVENT_ACTION_CANCEL: {
+        ssize_t index = findTouchState(deviceId, source);
+        if (index >= 0) {
+            const TouchState& touchState = mTouchStates.itemAt(index);
+            rewriteMessage(touchState, msg);
+            mTouchStates.removeAt(index);
+        }
+        break;
+    }
+    }
+}
+
+void InputConsumer::rewriteMessage(const TouchState& state, InputMessage* msg) {
+    for (size_t i = 0; i < msg->body.motion.pointerCount; i++) {
+        uint32_t id = msg->body.motion.pointers[i].properties.id;
+        if (state.lastResample.idBits.hasBit(id)) {
+            PointerCoords& msgCoords = msg->body.motion.pointers[i].coords;
+            const PointerCoords& resampleCoords = state.lastResample.getPointerById(id);
+#if DEBUG_RESAMPLING
+            ALOGD("[%d] - rewrite (%0.3f, %0.3f), old (%0.3f, %0.3f)", id,
+                    resampleCoords.getAxisValue(AMOTION_EVENT_AXIS_X),
+                    resampleCoords.getAxisValue(AMOTION_EVENT_AXIS_Y),
+                    msgCoords.getAxisValue(AMOTION_EVENT_AXIS_X),
+                    msgCoords.getAxisValue(AMOTION_EVENT_AXIS_Y));
+#endif
+            msgCoords.setAxisValue(AMOTION_EVENT_AXIS_X, resampleCoords.getX());
+            msgCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, resampleCoords.getY());
+        }
+    }
+}
+
+void InputConsumer::resampleTouchState(nsecs_t sampleTime, MotionEvent* event,
+    const InputMessage* next) {
+    if (!mResampleTouch
+            || !(event->getSource() & AINPUT_SOURCE_CLASS_POINTER)
+            || event->getAction() != AMOTION_EVENT_ACTION_MOVE) {
+        return;
+    }
+
+    ssize_t index = findTouchState(event->getDeviceId(), event->getSource());
+    if (index < 0) {
+#if DEBUG_RESAMPLING
+        ALOGD("Not resampled, no touch state for device.");
+#endif
+        return;
+    }
+
+    TouchState& touchState = mTouchStates.editItemAt(index);
+    if (touchState.historySize < 1) {
+#if DEBUG_RESAMPLING
+        ALOGD("Not resampled, no history for device.");
+#endif
+        return;
+    }
+
+    // Ensure that the current sample has all of the pointers that need to be reported.
+    const History* current = touchState.getHistory(0);
+    size_t pointerCount = event->getPointerCount();
+    for (size_t i = 0; i < pointerCount; i++) {
+        uint32_t id = event->getPointerId(i);
+        if (!current->idBits.hasBit(id)) {
+#if DEBUG_RESAMPLING
+            ALOGD("Not resampled, missing id %d", id);
+#endif
+            return;
+        }
+    }
+
+    // Find the data to use for resampling.
+    const History* other;
+    History future;
+    float alpha;
+    if (next) {
+        // Interpolate between current sample and future sample.
+        // So current->eventTime <= sampleTime <= future.eventTime.
+        future.initializeFrom(next);
+        other = &future;
+        nsecs_t delta = future.eventTime - current->eventTime;
+        if (delta < RESAMPLE_MIN_DELTA) {
+#if DEBUG_RESAMPLING
+            ALOGD("Not resampled, delta time is %lld ns.", delta);
+#endif
+            return;
+        }
+        alpha = float(sampleTime - current->eventTime) / delta;
+    } else if (touchState.historySize >= 2) {
+        // Extrapolate future sample using current sample and past sample.
+        // So other->eventTime <= current->eventTime <= sampleTime.
+        other = touchState.getHistory(1);
+        nsecs_t delta = current->eventTime - other->eventTime;
+        if (delta < RESAMPLE_MIN_DELTA) {
+#if DEBUG_RESAMPLING
+            ALOGD("Not resampled, delta time is %lld ns.", delta);
+#endif
+            return;
+        }
+        nsecs_t maxPredict = current->eventTime + min(delta / 2, RESAMPLE_MAX_PREDICTION);
+        if (sampleTime > maxPredict) {
+#if DEBUG_RESAMPLING
+            ALOGD("Sample time is too far in the future, adjusting prediction "
+                    "from %lld to %lld ns.",
+                    sampleTime - current->eventTime, maxPredict - current->eventTime);
+#endif
+            sampleTime = maxPredict;
+        }
+        alpha = float(current->eventTime - sampleTime) / delta;
+    } else {
+#if DEBUG_RESAMPLING
+        ALOGD("Not resampled, insufficient data.");
+#endif
+        return;
+    }
+
+    // Resample touch coordinates.
+    touchState.lastResample.eventTime = sampleTime;
+    touchState.lastResample.idBits.clear();
+    for (size_t i = 0; i < pointerCount; i++) {
+        uint32_t id = event->getPointerId(i);
+        touchState.lastResample.idToIndex[id] = i;
+        touchState.lastResample.idBits.markBit(id);
+        PointerCoords& resampledCoords = touchState.lastResample.pointers[i];
+        const PointerCoords& currentCoords = current->getPointerById(id);
+        if (other->idBits.hasBit(id)
+                && shouldResampleTool(event->getToolType(i))) {
+            const PointerCoords& otherCoords = other->getPointerById(id);
+            resampledCoords.copyFrom(currentCoords);
+            resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_X,
+                    lerp(currentCoords.getX(), otherCoords.getX(), alpha));
+            resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_Y,
+                    lerp(currentCoords.getY(), otherCoords.getY(), alpha));
+#if DEBUG_RESAMPLING
+            ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f), "
+                    "other (%0.3f, %0.3f), alpha %0.3f",
+                    id, resampledCoords.getX(), resampledCoords.getY(),
+                    currentCoords.getX(), currentCoords.getY(),
+                    otherCoords.getX(), otherCoords.getY(),
+                    alpha);
+#endif
+        } else {
+            resampledCoords.copyFrom(currentCoords);
+#if DEBUG_RESAMPLING
+            ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f)",
+                    id, resampledCoords.getX(), resampledCoords.getY(),
+                    currentCoords.getX(), currentCoords.getY());
+#endif
+        }
+    }
+
+    event->addSample(sampleTime, touchState.lastResample.pointers);
+}
+
+bool InputConsumer::shouldResampleTool(int32_t toolType) {
+    return toolType == AMOTION_EVENT_TOOL_TYPE_FINGER
+            || toolType == AMOTION_EVENT_TOOL_TYPE_UNKNOWN;
+}
+
+status_t InputConsumer::sendFinishedSignal(uint32_t seq, bool handled) {
+#if DEBUG_TRANSPORT_ACTIONS
+    ALOGD("channel '%s' consumer ~ sendFinishedSignal: seq=%u, handled=%s",
+            mChannel->getName().string(), seq, handled ? "true" : "false");
+#endif
+
+    if (!seq) {
+        ALOGE("Attempted to send a finished signal with sequence number 0.");
+        return BAD_VALUE;
+    }
+
+    // Send finished signals for the batch sequence chain first.
+    size_t seqChainCount = mSeqChains.size();
+    if (seqChainCount) {
+        uint32_t currentSeq = seq;
+        uint32_t chainSeqs[seqChainCount];
+        size_t chainIndex = 0;
+        for (size_t i = seqChainCount; i-- > 0; ) {
+             const SeqChain& seqChain = mSeqChains.itemAt(i);
+             if (seqChain.seq == currentSeq) {
+                 currentSeq = seqChain.chain;
+                 chainSeqs[chainIndex++] = currentSeq;
+                 mSeqChains.removeAt(i);
+             }
+        }
+        status_t status = OK;
+        while (!status && chainIndex-- > 0) {
+            status = sendUnchainedFinishedSignal(chainSeqs[chainIndex], handled);
+        }
+        if (status) {
+            // An error occurred so at least one signal was not sent, reconstruct the chain.
+            do {
+                SeqChain seqChain;
+                seqChain.seq = chainIndex != 0 ? chainSeqs[chainIndex - 1] : seq;
+                seqChain.chain = chainSeqs[chainIndex];
+                mSeqChains.push(seqChain);
+            } while (chainIndex-- > 0);
+            return status;
+        }
+    }
+
+    // Send finished signal for the last message in the batch.
+    return sendUnchainedFinishedSignal(seq, handled);
+}
+
+status_t InputConsumer::sendUnchainedFinishedSignal(uint32_t seq, bool handled) {
+    InputMessage msg;
+    msg.header.type = InputMessage::TYPE_FINISHED;
+    msg.body.finished.seq = seq;
+    msg.body.finished.handled = handled;
+    return mChannel->sendMessage(&msg);
+}
+
+bool InputConsumer::hasDeferredEvent() const {
+    return mMsgDeferred;
+}
+
+bool InputConsumer::hasPendingBatch() const {
+    return !mBatches.isEmpty();
+}
+
+ssize_t InputConsumer::findBatch(int32_t deviceId, int32_t source) const {
+    for (size_t i = 0; i < mBatches.size(); i++) {
+        const Batch& batch = mBatches.itemAt(i);
+        const InputMessage& head = batch.samples.itemAt(0);
+        if (head.body.motion.deviceId == deviceId && head.body.motion.source == source) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+ssize_t InputConsumer::findTouchState(int32_t deviceId, int32_t source) const {
+    for (size_t i = 0; i < mTouchStates.size(); i++) {
+        const TouchState& touchState = mTouchStates.itemAt(i);
+        if (touchState.deviceId == deviceId && touchState.source == source) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+void InputConsumer::initializeKeyEvent(KeyEvent* event, const InputMessage* msg) {
+    event->initialize(
+            msg->body.key.deviceId,
+            msg->body.key.source,
+            msg->body.key.action,
+            msg->body.key.flags,
+            msg->body.key.keyCode,
+            msg->body.key.scanCode,
+            msg->body.key.metaState,
+            msg->body.key.repeatCount,
+            msg->body.key.downTime,
+            msg->body.key.eventTime);
+}
+
+void InputConsumer::initializeMotionEvent(MotionEvent* event, const InputMessage* msg) {
+    size_t pointerCount = msg->body.motion.pointerCount;
+    PointerProperties pointerProperties[pointerCount];
+    PointerCoords pointerCoords[pointerCount];
+    for (size_t i = 0; i < pointerCount; i++) {
+        pointerProperties[i].copyFrom(msg->body.motion.pointers[i].properties);
+        pointerCoords[i].copyFrom(msg->body.motion.pointers[i].coords);
+    }
+
+    event->initialize(
+            msg->body.motion.deviceId,
+            msg->body.motion.source,
+            msg->body.motion.action,
+            msg->body.motion.flags,
+            msg->body.motion.edgeFlags,
+            msg->body.motion.metaState,
+            msg->body.motion.buttonState,
+            msg->body.motion.xOffset,
+            msg->body.motion.yOffset,
+            msg->body.motion.xPrecision,
+            msg->body.motion.yPrecision,
+            msg->body.motion.downTime,
+            msg->body.motion.eventTime,
+            pointerCount,
+            pointerProperties,
+            pointerCoords);
+}
+
+void InputConsumer::addSample(MotionEvent* event, const InputMessage* msg) {
+    size_t pointerCount = msg->body.motion.pointerCount;
+    PointerCoords pointerCoords[pointerCount];
+    for (size_t i = 0; i < pointerCount; i++) {
+        pointerCoords[i].copyFrom(msg->body.motion.pointers[i].coords);
+    }
+
+    event->setMetaState(event->getMetaState() | msg->body.motion.metaState);
+    event->addSample(msg->body.motion.eventTime, pointerCoords);
+}
+
+bool InputConsumer::canAddSample(const Batch& batch, const InputMessage *msg) {
+    const InputMessage& head = batch.samples.itemAt(0);
+    size_t pointerCount = msg->body.motion.pointerCount;
+    if (head.body.motion.pointerCount != pointerCount
+            || head.body.motion.action != msg->body.motion.action) {
+        return false;
+    }
+    for (size_t i = 0; i < pointerCount; i++) {
+        if (head.body.motion.pointers[i].properties
+                != msg->body.motion.pointers[i].properties) {
+            return false;
+        }
+    }
+    return true;
+}
+
+ssize_t InputConsumer::findSampleNoLaterThan(const Batch& batch, nsecs_t time) {
+    size_t numSamples = batch.samples.size();
+    size_t index = 0;
+    while (index < numSamples
+            && batch.samples.itemAt(index).body.motion.eventTime <= time) {
+        index += 1;
+    }
+    return ssize_t(index) - 1;
+}
+
+} // namespace android