1//
2// Copyright 2010 The Android Open Source Project
3//
4// Provides a shared memory transport for input events.
5//
6#define LOG_TAG "InputTransport"
7
8//#define LOG_NDEBUG 0
9
10// Log debug messages about channel messages (send message, receive message)
11#define DEBUG_CHANNEL_MESSAGES 0
12
13// Log debug messages whenever InputChannel objects are created/destroyed
14#define DEBUG_CHANNEL_LIFECYCLE 0
15
16// Log debug messages about transport actions
17#define DEBUG_TRANSPORT_ACTIONS 0
18
19// Log debug messages about touch event resampling
20#define DEBUG_RESAMPLING 0
21
22#include <errno.h>
23#include <fcntl.h>
24#include <inttypes.h>
25#include <math.h>
26#include <sys/socket.h>
27#include <sys/types.h>
28#include <unistd.h>
29
30#include <cutils/properties.h>
31#include <log/log.h>
32
33#include <input/InputTransport.h>
34
35namespace android {
36
37// Socket buffer size.  The default is typically about 128KB, which is much larger than
38// we really need.  So we make it smaller.  It just needs to be big enough to hold
39// a few dozen large multi-finger motion events in the case where an application gets
40// behind processing touches.
41static const size_t SOCKET_BUFFER_SIZE = 32 * 1024;
42
43// Nanoseconds per milliseconds.
44static const nsecs_t NANOS_PER_MS = 1000000;
45
46// Latency added during resampling.  A few milliseconds doesn't hurt much but
47// reduces the impact of mispredicted touch positions.
48static const nsecs_t RESAMPLE_LATENCY = 5 * NANOS_PER_MS;
49
50// Minimum time difference between consecutive samples before attempting to resample.
51static const nsecs_t RESAMPLE_MIN_DELTA = 2 * NANOS_PER_MS;
52
53// Maximum time difference between consecutive samples before attempting to resample
54// by extrapolation.
55static const nsecs_t RESAMPLE_MAX_DELTA = 20 * NANOS_PER_MS;
56
57// Maximum time to predict forward from the last known state, to avoid predicting too
58// far into the future.  This time is further bounded by 50% of the last time delta.
59static const nsecs_t RESAMPLE_MAX_PREDICTION = 8 * NANOS_PER_MS;
60
61template<typename T>
62inline static T min(const T& a, const T& b) {
63    return a < b ? a : b;
64}
65
66inline static float lerp(float a, float b, float alpha) {
67    return a + alpha * (b - a);
68}
69
70// --- InputMessage ---
71
72bool InputMessage::isValid(size_t actualSize) const {
73    if (size() == actualSize) {
74        switch (header.type) {
75        case TYPE_KEY:
76            return true;
77        case TYPE_MOTION:
78            return body.motion.pointerCount > 0
79                    && body.motion.pointerCount <= MAX_POINTERS;
80        case TYPE_FINISHED:
81            return true;
82        }
83    }
84    return false;
85}
86
87size_t InputMessage::size() const {
88    switch (header.type) {
89    case TYPE_KEY:
90        return sizeof(Header) + body.key.size();
91    case TYPE_MOTION:
92        return sizeof(Header) + body.motion.size();
93    case TYPE_FINISHED:
94        return sizeof(Header) + body.finished.size();
95    }
96    return sizeof(Header);
97}
98
99
100// --- InputChannel ---
101
102InputChannel::InputChannel(const std::string& name, int fd) :
103        mName(name), mFd(fd) {
104#if DEBUG_CHANNEL_LIFECYCLE
105    ALOGD("Input channel constructed: name='%s', fd=%d",
106            mName.c_str(), fd);
107#endif
108
109    int result = fcntl(mFd, F_SETFL, O_NONBLOCK);
110    LOG_ALWAYS_FATAL_IF(result != 0, "channel '%s' ~ Could not make socket "
111            "non-blocking.  errno=%d", mName.c_str(), errno);
112}
113
114InputChannel::~InputChannel() {
115#if DEBUG_CHANNEL_LIFECYCLE
116    ALOGD("Input channel destroyed: name='%s', fd=%d",
117            mName.c_str(), mFd);
118#endif
119
120    ::close(mFd);
121}
122
123status_t InputChannel::openInputChannelPair(const std::string& name,
124        sp<InputChannel>& outServerChannel, sp<InputChannel>& outClientChannel) {
125    int sockets[2];
126    if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets)) {
127        status_t result = -errno;
128        ALOGE("channel '%s' ~ Could not create socket pair.  errno=%d",
129                name.c_str(), errno);
130        outServerChannel.clear();
131        outClientChannel.clear();
132        return result;
133    }
134
135    int bufferSize = SOCKET_BUFFER_SIZE;
136    setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
137    setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
138    setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
139    setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
140
141    std::string serverChannelName = name;
142    serverChannelName += " (server)";
143    outServerChannel = new InputChannel(serverChannelName, sockets[0]);
144
145    std::string clientChannelName = name;
146    clientChannelName += " (client)";
147    outClientChannel = new InputChannel(clientChannelName, sockets[1]);
148    return OK;
149}
150
151status_t InputChannel::sendMessage(const InputMessage* msg) {
152    size_t msgLength = msg->size();
153    ssize_t nWrite;
154    do {
155        nWrite = ::send(mFd, msg, msgLength, MSG_DONTWAIT | MSG_NOSIGNAL);
156    } while (nWrite == -1 && errno == EINTR);
157
158    if (nWrite < 0) {
159        int error = errno;
160#if DEBUG_CHANNEL_MESSAGES
161        ALOGD("channel '%s' ~ error sending message of type %d, errno=%d", mName.c_str(),
162                msg->header.type, error);
163#endif
164        if (error == EAGAIN || error == EWOULDBLOCK) {
165            return WOULD_BLOCK;
166        }
167        if (error == EPIPE || error == ENOTCONN || error == ECONNREFUSED || error == ECONNRESET) {
168            return DEAD_OBJECT;
169        }
170        return -error;
171    }
172
173    if (size_t(nWrite) != msgLength) {
174#if DEBUG_CHANNEL_MESSAGES
175        ALOGD("channel '%s' ~ error sending message type %d, send was incomplete",
176                mName.c_str(), msg->header.type);
177#endif
178        return DEAD_OBJECT;
179    }
180
181#if DEBUG_CHANNEL_MESSAGES
182    ALOGD("channel '%s' ~ sent message of type %d", mName.c_str(), msg->header.type);
183#endif
184    return OK;
185}
186
187status_t InputChannel::receiveMessage(InputMessage* msg) {
188    ssize_t nRead;
189    do {
190        nRead = ::recv(mFd, msg, sizeof(InputMessage), MSG_DONTWAIT);
191    } while (nRead == -1 && errno == EINTR);
192
193    if (nRead < 0) {
194        int error = errno;
195#if DEBUG_CHANNEL_MESSAGES
196        ALOGD("channel '%s' ~ receive message failed, errno=%d", mName.c_str(), errno);
197#endif
198        if (error == EAGAIN || error == EWOULDBLOCK) {
199            return WOULD_BLOCK;
200        }
201        if (error == EPIPE || error == ENOTCONN || error == ECONNREFUSED) {
202            return DEAD_OBJECT;
203        }
204        return -error;
205    }
206
207    if (nRead == 0) { // check for EOF
208#if DEBUG_CHANNEL_MESSAGES
209        ALOGD("channel '%s' ~ receive message failed because peer was closed", mName.c_str());
210#endif
211        return DEAD_OBJECT;
212    }
213
214    if (!msg->isValid(nRead)) {
215#if DEBUG_CHANNEL_MESSAGES
216        ALOGD("channel '%s' ~ received invalid message", mName.c_str());
217#endif
218        return BAD_VALUE;
219    }
220
221#if DEBUG_CHANNEL_MESSAGES
222    ALOGD("channel '%s' ~ received message of type %d", mName.c_str(), msg->header.type);
223#endif
224    return OK;
225}
226
227sp<InputChannel> InputChannel::dup() const {
228    int fd = ::dup(getFd());
229    return fd >= 0 ? new InputChannel(getName(), fd) : NULL;
230}
231
232
233// --- InputPublisher ---
234
235InputPublisher::InputPublisher(const sp<InputChannel>& channel) :
236        mChannel(channel) {
237}
238
239InputPublisher::~InputPublisher() {
240}
241
242status_t InputPublisher::publishKeyEvent(
243        uint32_t seq,
244        int32_t deviceId,
245        int32_t source,
246        int32_t action,
247        int32_t flags,
248        int32_t keyCode,
249        int32_t scanCode,
250        int32_t metaState,
251        int32_t repeatCount,
252        nsecs_t downTime,
253        nsecs_t eventTime) {
254#if DEBUG_TRANSPORT_ACTIONS
255    ALOGD("channel '%s' publisher ~ publishKeyEvent: seq=%u, deviceId=%d, source=0x%x, "
256            "action=0x%x, flags=0x%x, keyCode=%d, scanCode=%d, metaState=0x%x, repeatCount=%d,"
257            "downTime=%" PRId64 ", eventTime=%" PRId64,
258            mChannel->getName().c_str(), seq,
259            deviceId, source, action, flags, keyCode, scanCode, metaState, repeatCount,
260            downTime, eventTime);
261#endif
262
263    if (!seq) {
264        ALOGE("Attempted to publish a key event with sequence number 0.");
265        return BAD_VALUE;
266    }
267
268    InputMessage msg;
269    msg.header.type = InputMessage::TYPE_KEY;
270    msg.body.key.seq = seq;
271    msg.body.key.deviceId = deviceId;
272    msg.body.key.source = source;
273    msg.body.key.action = action;
274    msg.body.key.flags = flags;
275    msg.body.key.keyCode = keyCode;
276    msg.body.key.scanCode = scanCode;
277    msg.body.key.metaState = metaState;
278    msg.body.key.repeatCount = repeatCount;
279    msg.body.key.downTime = downTime;
280    msg.body.key.eventTime = eventTime;
281    return mChannel->sendMessage(&msg);
282}
283
284status_t InputPublisher::publishMotionEvent(
285        uint32_t seq,
286        int32_t deviceId,
287        int32_t source,
288        int32_t displayId,
289        int32_t action,
290        int32_t actionButton,
291        int32_t flags,
292        int32_t edgeFlags,
293        int32_t metaState,
294        int32_t buttonState,
295        float xOffset,
296        float yOffset,
297        float xPrecision,
298        float yPrecision,
299        nsecs_t downTime,
300        nsecs_t eventTime,
301        uint32_t pointerCount,
302        const PointerProperties* pointerProperties,
303        const PointerCoords* pointerCoords) {
304#if DEBUG_TRANSPORT_ACTIONS
305    ALOGD("channel '%s' publisher ~ publishMotionEvent: seq=%u, deviceId=%d, source=0x%x, "
306            "action=0x%x, actionButton=0x%08x, flags=0x%x, edgeFlags=0x%x, "
307            "metaState=0x%x, buttonState=0x%x, xOffset=%f, yOffset=%f, "
308            "xPrecision=%f, yPrecision=%f, downTime=%" PRId64 ", eventTime=%" PRId64 ", "
309            "pointerCount=%" PRIu32,
310            mChannel->getName().c_str(), seq,
311            deviceId, source, action, actionButton, flags, edgeFlags, metaState, buttonState,
312            xOffset, yOffset, xPrecision, yPrecision, downTime, eventTime, pointerCount);
313#endif
314
315    if (!seq) {
316        ALOGE("Attempted to publish a motion event with sequence number 0.");
317        return BAD_VALUE;
318    }
319
320    if (pointerCount > MAX_POINTERS || pointerCount < 1) {
321        ALOGE("channel '%s' publisher ~ Invalid number of pointers provided: %" PRIu32 ".",
322                mChannel->getName().c_str(), pointerCount);
323        return BAD_VALUE;
324    }
325
326    InputMessage msg;
327    msg.header.type = InputMessage::TYPE_MOTION;
328    msg.body.motion.seq = seq;
329    msg.body.motion.deviceId = deviceId;
330    msg.body.motion.source = source;
331    msg.body.motion.displayId = displayId;
332    msg.body.motion.action = action;
333    msg.body.motion.actionButton = actionButton;
334    msg.body.motion.flags = flags;
335    msg.body.motion.edgeFlags = edgeFlags;
336    msg.body.motion.metaState = metaState;
337    msg.body.motion.buttonState = buttonState;
338    msg.body.motion.xOffset = xOffset;
339    msg.body.motion.yOffset = yOffset;
340    msg.body.motion.xPrecision = xPrecision;
341    msg.body.motion.yPrecision = yPrecision;
342    msg.body.motion.downTime = downTime;
343    msg.body.motion.eventTime = eventTime;
344    msg.body.motion.pointerCount = pointerCount;
345    for (uint32_t i = 0; i < pointerCount; i++) {
346        msg.body.motion.pointers[i].properties.copyFrom(pointerProperties[i]);
347        msg.body.motion.pointers[i].coords.copyFrom(pointerCoords[i]);
348    }
349    return mChannel->sendMessage(&msg);
350}
351
352status_t InputPublisher::receiveFinishedSignal(uint32_t* outSeq, bool* outHandled) {
353#if DEBUG_TRANSPORT_ACTIONS
354    ALOGD("channel '%s' publisher ~ receiveFinishedSignal",
355            mChannel->getName().c_str());
356#endif
357
358    InputMessage msg;
359    status_t result = mChannel->receiveMessage(&msg);
360    if (result) {
361        *outSeq = 0;
362        *outHandled = false;
363        return result;
364    }
365    if (msg.header.type != InputMessage::TYPE_FINISHED) {
366        ALOGE("channel '%s' publisher ~ Received unexpected message of type %d from consumer",
367                mChannel->getName().c_str(), msg.header.type);
368        return UNKNOWN_ERROR;
369    }
370    *outSeq = msg.body.finished.seq;
371    *outHandled = msg.body.finished.handled;
372    return OK;
373}
374
375// --- InputConsumer ---
376
377InputConsumer::InputConsumer(const sp<InputChannel>& channel) :
378        mResampleTouch(isTouchResamplingEnabled()),
379        mChannel(channel), mMsgDeferred(false) {
380}
381
382InputConsumer::~InputConsumer() {
383}
384
385bool InputConsumer::isTouchResamplingEnabled() {
386    char value[PROPERTY_VALUE_MAX];
387    int length = property_get("ro.input.noresample", value, NULL);
388    if (length > 0) {
389        if (!strcmp("1", value)) {
390            return false;
391        }
392        if (strcmp("0", value)) {
393            ALOGD("Unrecognized property value for 'ro.input.noresample'.  "
394                    "Use '1' or '0'.");
395        }
396    }
397    return true;
398}
399
400status_t InputConsumer::consume(InputEventFactoryInterface* factory,
401        bool consumeBatches, nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent,
402        int32_t* displayId) {
403#if DEBUG_TRANSPORT_ACTIONS
404    ALOGD("channel '%s' consumer ~ consume: consumeBatches=%s, frameTime=%" PRId64,
405            mChannel->getName().c_str(), consumeBatches ? "true" : "false", frameTime);
406#endif
407
408    *outSeq = 0;
409    *outEvent = NULL;
410    *displayId = -1;  // Invalid display.
411
412    // Fetch the next input message.
413    // Loop until an event can be returned or no additional events are received.
414    while (!*outEvent) {
415        if (mMsgDeferred) {
416            // mMsg contains a valid input message from the previous call to consume
417            // that has not yet been processed.
418            mMsgDeferred = false;
419        } else {
420            // Receive a fresh message.
421            status_t result = mChannel->receiveMessage(&mMsg);
422            if (result) {
423                // Consume the next batched event unless batches are being held for later.
424                if (consumeBatches || result != WOULD_BLOCK) {
425                    result = consumeBatch(factory, frameTime, outSeq, outEvent, displayId);
426                    if (*outEvent) {
427#if DEBUG_TRANSPORT_ACTIONS
428                        ALOGD("channel '%s' consumer ~ consumed batch event, seq=%u",
429                                mChannel->getName().c_str(), *outSeq);
430#endif
431                        break;
432                    }
433                }
434                return result;
435            }
436        }
437
438        switch (mMsg.header.type) {
439        case InputMessage::TYPE_KEY: {
440            KeyEvent* keyEvent = factory->createKeyEvent();
441            if (!keyEvent) return NO_MEMORY;
442
443            initializeKeyEvent(keyEvent, &mMsg);
444            *outSeq = mMsg.body.key.seq;
445            *outEvent = keyEvent;
446#if DEBUG_TRANSPORT_ACTIONS
447            ALOGD("channel '%s' consumer ~ consumed key event, seq=%u",
448                    mChannel->getName().c_str(), *outSeq);
449#endif
450            break;
451        }
452
453        case InputMessage::TYPE_MOTION: {
454            ssize_t batchIndex = findBatch(mMsg.body.motion.deviceId, mMsg.body.motion.source);
455            if (batchIndex >= 0) {
456                Batch& batch = mBatches.editItemAt(batchIndex);
457                if (canAddSample(batch, &mMsg)) {
458                    batch.samples.push(mMsg);
459#if DEBUG_TRANSPORT_ACTIONS
460                    ALOGD("channel '%s' consumer ~ appended to batch event",
461                            mChannel->getName().c_str());
462#endif
463                    break;
464                } else {
465                    // We cannot append to the batch in progress, so we need to consume
466                    // the previous batch right now and defer the new message until later.
467                    mMsgDeferred = true;
468                    status_t result = consumeSamples(factory,
469                            batch, batch.samples.size(), outSeq, outEvent, displayId);
470                    mBatches.removeAt(batchIndex);
471                    if (result) {
472                        return result;
473                    }
474#if DEBUG_TRANSPORT_ACTIONS
475                    ALOGD("channel '%s' consumer ~ consumed batch event and "
476                            "deferred current event, seq=%u",
477                            mChannel->getName().c_str(), *outSeq);
478#endif
479                    break;
480                }
481            }
482
483            // Start a new batch if needed.
484            if (mMsg.body.motion.action == AMOTION_EVENT_ACTION_MOVE
485                    || mMsg.body.motion.action == AMOTION_EVENT_ACTION_HOVER_MOVE) {
486                mBatches.push();
487                Batch& batch = mBatches.editTop();
488                batch.samples.push(mMsg);
489#if DEBUG_TRANSPORT_ACTIONS
490                ALOGD("channel '%s' consumer ~ started batch event",
491                        mChannel->getName().c_str());
492#endif
493                break;
494            }
495
496            MotionEvent* motionEvent = factory->createMotionEvent();
497            if (! motionEvent) return NO_MEMORY;
498
499            updateTouchState(mMsg);
500            initializeMotionEvent(motionEvent, &mMsg);
501            *outSeq = mMsg.body.motion.seq;
502            *outEvent = motionEvent;
503            *displayId = mMsg.body.motion.displayId;
504#if DEBUG_TRANSPORT_ACTIONS
505            ALOGD("channel '%s' consumer ~ consumed motion event, seq=%u",
506                    mChannel->getName().c_str(), *outSeq);
507#endif
508            break;
509        }
510
511        default:
512            ALOGE("channel '%s' consumer ~ Received unexpected message of type %d",
513                    mChannel->getName().c_str(), mMsg.header.type);
514            return UNKNOWN_ERROR;
515        }
516    }
517    return OK;
518}
519
520status_t InputConsumer::consumeBatch(InputEventFactoryInterface* factory,
521        nsecs_t frameTime, uint32_t* outSeq, InputEvent** outEvent, int32_t* displayId) {
522    status_t result;
523    for (size_t i = mBatches.size(); i > 0; ) {
524        i--;
525        Batch& batch = mBatches.editItemAt(i);
526        if (frameTime < 0) {
527            result = consumeSamples(factory, batch, batch.samples.size(),
528                    outSeq, outEvent, displayId);
529            mBatches.removeAt(i);
530            return result;
531        }
532
533        nsecs_t sampleTime = frameTime;
534        if (mResampleTouch) {
535            sampleTime -= RESAMPLE_LATENCY;
536        }
537        ssize_t split = findSampleNoLaterThan(batch, sampleTime);
538        if (split < 0) {
539            continue;
540        }
541
542        result = consumeSamples(factory, batch, split + 1, outSeq, outEvent, displayId);
543        const InputMessage* next;
544        if (batch.samples.isEmpty()) {
545            mBatches.removeAt(i);
546            next = NULL;
547        } else {
548            next = &batch.samples.itemAt(0);
549        }
550        if (!result && mResampleTouch) {
551            resampleTouchState(sampleTime, static_cast<MotionEvent*>(*outEvent), next);
552        }
553        return result;
554    }
555
556    return WOULD_BLOCK;
557}
558
559status_t InputConsumer::consumeSamples(InputEventFactoryInterface* factory,
560        Batch& batch, size_t count, uint32_t* outSeq, InputEvent** outEvent, int32_t* displayId) {
561    MotionEvent* motionEvent = factory->createMotionEvent();
562    if (! motionEvent) return NO_MEMORY;
563
564    uint32_t chain = 0;
565    for (size_t i = 0; i < count; i++) {
566        InputMessage& msg = batch.samples.editItemAt(i);
567        updateTouchState(msg);
568        if (i) {
569            SeqChain seqChain;
570            seqChain.seq = msg.body.motion.seq;
571            seqChain.chain = chain;
572            mSeqChains.push(seqChain);
573            addSample(motionEvent, &msg);
574        } else {
575            *displayId = msg.body.motion.displayId;
576            initializeMotionEvent(motionEvent, &msg);
577        }
578        chain = msg.body.motion.seq;
579    }
580    batch.samples.removeItemsAt(0, count);
581
582    *outSeq = chain;
583    *outEvent = motionEvent;
584    return OK;
585}
586
587void InputConsumer::updateTouchState(InputMessage& msg) {
588    if (!mResampleTouch ||
589            !(msg.body.motion.source & AINPUT_SOURCE_CLASS_POINTER)) {
590        return;
591    }
592
593    int32_t deviceId = msg.body.motion.deviceId;
594    int32_t source = msg.body.motion.source;
595
596    // Update the touch state history to incorporate the new input message.
597    // If the message is in the past relative to the most recently produced resampled
598    // touch, then use the resampled time and coordinates instead.
599    switch (msg.body.motion.action & AMOTION_EVENT_ACTION_MASK) {
600    case AMOTION_EVENT_ACTION_DOWN: {
601        ssize_t index = findTouchState(deviceId, source);
602        if (index < 0) {
603            mTouchStates.push();
604            index = mTouchStates.size() - 1;
605        }
606        TouchState& touchState = mTouchStates.editItemAt(index);
607        touchState.initialize(deviceId, source);
608        touchState.addHistory(msg);
609        break;
610    }
611
612    case AMOTION_EVENT_ACTION_MOVE: {
613        ssize_t index = findTouchState(deviceId, source);
614        if (index >= 0) {
615            TouchState& touchState = mTouchStates.editItemAt(index);
616            touchState.addHistory(msg);
617            rewriteMessage(touchState, msg);
618        }
619        break;
620    }
621
622    case AMOTION_EVENT_ACTION_POINTER_DOWN: {
623        ssize_t index = findTouchState(deviceId, source);
624        if (index >= 0) {
625            TouchState& touchState = mTouchStates.editItemAt(index);
626            touchState.lastResample.idBits.clearBit(msg.body.motion.getActionId());
627            rewriteMessage(touchState, msg);
628        }
629        break;
630    }
631
632    case AMOTION_EVENT_ACTION_POINTER_UP: {
633        ssize_t index = findTouchState(deviceId, source);
634        if (index >= 0) {
635            TouchState& touchState = mTouchStates.editItemAt(index);
636            rewriteMessage(touchState, msg);
637            touchState.lastResample.idBits.clearBit(msg.body.motion.getActionId());
638        }
639        break;
640    }
641
642    case AMOTION_EVENT_ACTION_SCROLL: {
643        ssize_t index = findTouchState(deviceId, source);
644        if (index >= 0) {
645            TouchState& touchState = mTouchStates.editItemAt(index);
646            rewriteMessage(touchState, msg);
647        }
648        break;
649    }
650
651    case AMOTION_EVENT_ACTION_UP:
652    case AMOTION_EVENT_ACTION_CANCEL: {
653        ssize_t index = findTouchState(deviceId, source);
654        if (index >= 0) {
655            TouchState& touchState = mTouchStates.editItemAt(index);
656            rewriteMessage(touchState, msg);
657            mTouchStates.removeAt(index);
658        }
659        break;
660    }
661    }
662}
663
664/**
665 * Replace the coordinates in msg with the coordinates in lastResample, if necessary.
666 *
667 * If lastResample is no longer valid for a specific pointer (i.e. the lastResample time
668 * is in the past relative to msg and the past two events do not contain identical coordinates),
669 * then invalidate the lastResample data for that pointer.
670 * If the two past events have identical coordinates, then lastResample data for that pointer will
671 * remain valid, and will be used to replace these coordinates. Thus, if a certain coordinate x0 is
672 * resampled to the new value x1, then x1 will always be used to replace x0 until some new value
673 * not equal to x0 is received.
674 */
675void InputConsumer::rewriteMessage(TouchState& state, InputMessage& msg) {
676    nsecs_t eventTime = msg.body.motion.eventTime;
677    for (uint32_t i = 0; i < msg.body.motion.pointerCount; i++) {
678        uint32_t id = msg.body.motion.pointers[i].properties.id;
679        if (state.lastResample.idBits.hasBit(id)) {
680            if (eventTime < state.lastResample.eventTime ||
681                    state.recentCoordinatesAreIdentical(id)) {
682                PointerCoords& msgCoords = msg.body.motion.pointers[i].coords;
683                const PointerCoords& resampleCoords = state.lastResample.getPointerById(id);
684#if DEBUG_RESAMPLING
685                ALOGD("[%d] - rewrite (%0.3f, %0.3f), old (%0.3f, %0.3f)", id,
686                        resampleCoords.getX(), resampleCoords.getY(),
687                        msgCoords.getX(), msgCoords.getY());
688#endif
689                msgCoords.setAxisValue(AMOTION_EVENT_AXIS_X, resampleCoords.getX());
690                msgCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, resampleCoords.getY());
691            } else {
692                state.lastResample.idBits.clearBit(id);
693            }
694        }
695    }
696}
697
698void InputConsumer::resampleTouchState(nsecs_t sampleTime, MotionEvent* event,
699    const InputMessage* next) {
700    if (!mResampleTouch
701            || !(event->getSource() & AINPUT_SOURCE_CLASS_POINTER)
702            || event->getAction() != AMOTION_EVENT_ACTION_MOVE) {
703        return;
704    }
705
706    ssize_t index = findTouchState(event->getDeviceId(), event->getSource());
707    if (index < 0) {
708#if DEBUG_RESAMPLING
709        ALOGD("Not resampled, no touch state for device.");
710#endif
711        return;
712    }
713
714    TouchState& touchState = mTouchStates.editItemAt(index);
715    if (touchState.historySize < 1) {
716#if DEBUG_RESAMPLING
717        ALOGD("Not resampled, no history for device.");
718#endif
719        return;
720    }
721
722    // Ensure that the current sample has all of the pointers that need to be reported.
723    const History* current = touchState.getHistory(0);
724    size_t pointerCount = event->getPointerCount();
725    for (size_t i = 0; i < pointerCount; i++) {
726        uint32_t id = event->getPointerId(i);
727        if (!current->idBits.hasBit(id)) {
728#if DEBUG_RESAMPLING
729            ALOGD("Not resampled, missing id %d", id);
730#endif
731            return;
732        }
733    }
734
735    // Find the data to use for resampling.
736    const History* other;
737    History future;
738    float alpha;
739    if (next) {
740        // Interpolate between current sample and future sample.
741        // So current->eventTime <= sampleTime <= future.eventTime.
742        future.initializeFrom(*next);
743        other = &future;
744        nsecs_t delta = future.eventTime - current->eventTime;
745        if (delta < RESAMPLE_MIN_DELTA) {
746#if DEBUG_RESAMPLING
747            ALOGD("Not resampled, delta time is too small: %" PRId64 " ns.", delta);
748#endif
749            return;
750        }
751        alpha = float(sampleTime - current->eventTime) / delta;
752    } else if (touchState.historySize >= 2) {
753        // Extrapolate future sample using current sample and past sample.
754        // So other->eventTime <= current->eventTime <= sampleTime.
755        other = touchState.getHistory(1);
756        nsecs_t delta = current->eventTime - other->eventTime;
757        if (delta < RESAMPLE_MIN_DELTA) {
758#if DEBUG_RESAMPLING
759            ALOGD("Not resampled, delta time is too small: %" PRId64 " ns.", delta);
760#endif
761            return;
762        } else if (delta > RESAMPLE_MAX_DELTA) {
763#if DEBUG_RESAMPLING
764            ALOGD("Not resampled, delta time is too large: %" PRId64 " ns.", delta);
765#endif
766            return;
767        }
768        nsecs_t maxPredict = current->eventTime + min(delta / 2, RESAMPLE_MAX_PREDICTION);
769        if (sampleTime > maxPredict) {
770#if DEBUG_RESAMPLING
771            ALOGD("Sample time is too far in the future, adjusting prediction "
772                    "from %" PRId64 " to %" PRId64 " ns.",
773                    sampleTime - current->eventTime, maxPredict - current->eventTime);
774#endif
775            sampleTime = maxPredict;
776        }
777        alpha = float(current->eventTime - sampleTime) / delta;
778    } else {
779#if DEBUG_RESAMPLING
780        ALOGD("Not resampled, insufficient data.");
781#endif
782        return;
783    }
784
785    // Resample touch coordinates.
786    History oldLastResample;
787    oldLastResample.initializeFrom(touchState.lastResample);
788    touchState.lastResample.eventTime = sampleTime;
789    touchState.lastResample.idBits.clear();
790    for (size_t i = 0; i < pointerCount; i++) {
791        uint32_t id = event->getPointerId(i);
792        touchState.lastResample.idToIndex[id] = i;
793        touchState.lastResample.idBits.markBit(id);
794        if (oldLastResample.hasPointerId(id) && touchState.recentCoordinatesAreIdentical(id)) {
795            // We maintain the previously resampled value for this pointer (stored in
796            // oldLastResample) when the coordinates for this pointer haven't changed since then.
797            // This way we don't introduce artificial jitter when pointers haven't actually moved.
798
799            // We know here that the coordinates for the pointer haven't changed because we
800            // would've cleared the resampled bit in rewriteMessage if they had. We can't modify
801            // lastResample in place becasue the mapping from pointer ID to index may have changed.
802            touchState.lastResample.pointers[i].copyFrom(oldLastResample.getPointerById(id));
803            continue;
804        }
805
806        PointerCoords& resampledCoords = touchState.lastResample.pointers[i];
807        const PointerCoords& currentCoords = current->getPointerById(id);
808        resampledCoords.copyFrom(currentCoords);
809        if (other->idBits.hasBit(id)
810                && shouldResampleTool(event->getToolType(i))) {
811            const PointerCoords& otherCoords = other->getPointerById(id);
812            resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_X,
813                    lerp(currentCoords.getX(), otherCoords.getX(), alpha));
814            resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_Y,
815                    lerp(currentCoords.getY(), otherCoords.getY(), alpha));
816#if DEBUG_RESAMPLING
817            ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f), "
818                    "other (%0.3f, %0.3f), alpha %0.3f",
819                    id, resampledCoords.getX(), resampledCoords.getY(),
820                    currentCoords.getX(), currentCoords.getY(),
821                    otherCoords.getX(), otherCoords.getY(),
822                    alpha);
823#endif
824        } else {
825#if DEBUG_RESAMPLING
826            ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f)",
827                    id, resampledCoords.getX(), resampledCoords.getY(),
828                    currentCoords.getX(), currentCoords.getY());
829#endif
830        }
831    }
832
833    event->addSample(sampleTime, touchState.lastResample.pointers);
834}
835
836bool InputConsumer::shouldResampleTool(int32_t toolType) {
837    return toolType == AMOTION_EVENT_TOOL_TYPE_FINGER
838            || toolType == AMOTION_EVENT_TOOL_TYPE_UNKNOWN;
839}
840
841status_t InputConsumer::sendFinishedSignal(uint32_t seq, bool handled) {
842#if DEBUG_TRANSPORT_ACTIONS
843    ALOGD("channel '%s' consumer ~ sendFinishedSignal: seq=%u, handled=%s",
844            mChannel->getName().c_str(), seq, handled ? "true" : "false");
845#endif
846
847    if (!seq) {
848        ALOGE("Attempted to send a finished signal with sequence number 0.");
849        return BAD_VALUE;
850    }
851
852    // Send finished signals for the batch sequence chain first.
853    size_t seqChainCount = mSeqChains.size();
854    if (seqChainCount) {
855        uint32_t currentSeq = seq;
856        uint32_t chainSeqs[seqChainCount];
857        size_t chainIndex = 0;
858        for (size_t i = seqChainCount; i > 0; ) {
859             i--;
860             const SeqChain& seqChain = mSeqChains.itemAt(i);
861             if (seqChain.seq == currentSeq) {
862                 currentSeq = seqChain.chain;
863                 chainSeqs[chainIndex++] = currentSeq;
864                 mSeqChains.removeAt(i);
865             }
866        }
867        status_t status = OK;
868        while (!status && chainIndex > 0) {
869            chainIndex--;
870            status = sendUnchainedFinishedSignal(chainSeqs[chainIndex], handled);
871        }
872        if (status) {
873            // An error occurred so at least one signal was not sent, reconstruct the chain.
874            for (;;) {
875                SeqChain seqChain;
876                seqChain.seq = chainIndex != 0 ? chainSeqs[chainIndex - 1] : seq;
877                seqChain.chain = chainSeqs[chainIndex];
878                mSeqChains.push(seqChain);
879                if (!chainIndex) break;
880                chainIndex--;
881            }
882            return status;
883        }
884    }
885
886    // Send finished signal for the last message in the batch.
887    return sendUnchainedFinishedSignal(seq, handled);
888}
889
890status_t InputConsumer::sendUnchainedFinishedSignal(uint32_t seq, bool handled) {
891    InputMessage msg;
892    msg.header.type = InputMessage::TYPE_FINISHED;
893    msg.body.finished.seq = seq;
894    msg.body.finished.handled = handled;
895    return mChannel->sendMessage(&msg);
896}
897
898bool InputConsumer::hasDeferredEvent() const {
899    return mMsgDeferred;
900}
901
902bool InputConsumer::hasPendingBatch() const {
903    return !mBatches.isEmpty();
904}
905
906ssize_t InputConsumer::findBatch(int32_t deviceId, int32_t source) const {
907    for (size_t i = 0; i < mBatches.size(); i++) {
908        const Batch& batch = mBatches.itemAt(i);
909        const InputMessage& head = batch.samples.itemAt(0);
910        if (head.body.motion.deviceId == deviceId && head.body.motion.source == source) {
911            return i;
912        }
913    }
914    return -1;
915}
916
917ssize_t InputConsumer::findTouchState(int32_t deviceId, int32_t source) const {
918    for (size_t i = 0; i < mTouchStates.size(); i++) {
919        const TouchState& touchState = mTouchStates.itemAt(i);
920        if (touchState.deviceId == deviceId && touchState.source == source) {
921            return i;
922        }
923    }
924    return -1;
925}
926
927void InputConsumer::initializeKeyEvent(KeyEvent* event, const InputMessage* msg) {
928    event->initialize(
929            msg->body.key.deviceId,
930            msg->body.key.source,
931            msg->body.key.action,
932            msg->body.key.flags,
933            msg->body.key.keyCode,
934            msg->body.key.scanCode,
935            msg->body.key.metaState,
936            msg->body.key.repeatCount,
937            msg->body.key.downTime,
938            msg->body.key.eventTime);
939}
940
941void InputConsumer::initializeMotionEvent(MotionEvent* event, const InputMessage* msg) {
942    uint32_t pointerCount = msg->body.motion.pointerCount;
943    PointerProperties pointerProperties[pointerCount];
944    PointerCoords pointerCoords[pointerCount];
945    for (uint32_t i = 0; i < pointerCount; i++) {
946        pointerProperties[i].copyFrom(msg->body.motion.pointers[i].properties);
947        pointerCoords[i].copyFrom(msg->body.motion.pointers[i].coords);
948    }
949
950    event->initialize(
951            msg->body.motion.deviceId,
952            msg->body.motion.source,
953            msg->body.motion.action,
954            msg->body.motion.actionButton,
955            msg->body.motion.flags,
956            msg->body.motion.edgeFlags,
957            msg->body.motion.metaState,
958            msg->body.motion.buttonState,
959            msg->body.motion.xOffset,
960            msg->body.motion.yOffset,
961            msg->body.motion.xPrecision,
962            msg->body.motion.yPrecision,
963            msg->body.motion.downTime,
964            msg->body.motion.eventTime,
965            pointerCount,
966            pointerProperties,
967            pointerCoords);
968}
969
970void InputConsumer::addSample(MotionEvent* event, const InputMessage* msg) {
971    uint32_t pointerCount = msg->body.motion.pointerCount;
972    PointerCoords pointerCoords[pointerCount];
973    for (uint32_t i = 0; i < pointerCount; i++) {
974        pointerCoords[i].copyFrom(msg->body.motion.pointers[i].coords);
975    }
976
977    event->setMetaState(event->getMetaState() | msg->body.motion.metaState);
978    event->addSample(msg->body.motion.eventTime, pointerCoords);
979}
980
981bool InputConsumer::canAddSample(const Batch& batch, const InputMessage *msg) {
982    const InputMessage& head = batch.samples.itemAt(0);
983    uint32_t pointerCount = msg->body.motion.pointerCount;
984    if (head.body.motion.pointerCount != pointerCount
985            || head.body.motion.action != msg->body.motion.action) {
986        return false;
987    }
988    for (size_t i = 0; i < pointerCount; i++) {
989        if (head.body.motion.pointers[i].properties
990                != msg->body.motion.pointers[i].properties) {
991            return false;
992        }
993    }
994    return true;
995}
996
997ssize_t InputConsumer::findSampleNoLaterThan(const Batch& batch, nsecs_t time) {
998    size_t numSamples = batch.samples.size();
999    size_t index = 0;
1000    while (index < numSamples
1001            && batch.samples.itemAt(index).body.motion.eventTime <= time) {
1002        index += 1;
1003    }
1004    return ssize_t(index) - 1;
1005}
1006
1007} // namespace android
1008