1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17
18#include <binder/AppOpsManager.h>
19#include <binder/IServiceManager.h>
20#include <gui/Sensor.h>
21#include <hardware/sensors.h>
22#include <log/log.h>
23#include <utils/Errors.h>
24#include <utils/String8.h>
25#include <utils/Flattenable.h>
26
27#include <inttypes.h>
28#include <stdint.h>
29#include <sys/types.h>
30#include <sys/limits.h>
31
32// ----------------------------------------------------------------------------
33namespace android {
34// ----------------------------------------------------------------------------
35
36Sensor::Sensor(const char * name) :
37        mName(name), mHandle(0), mType(0),
38        mMinValue(0), mMaxValue(0), mResolution(0),
39        mPower(0), mMinDelay(0), mVersion(0), mFifoReservedEventCount(0),
40        mFifoMaxEventCount(0), mRequiredAppOp(0),
41        mMaxDelay(0), mFlags(0) {
42}
43
44Sensor::Sensor(struct sensor_t const* hwSensor, int halVersion) :
45        Sensor(*hwSensor, uuid_t(), halVersion) {
46}
47
48Sensor::Sensor(struct sensor_t const& hwSensor, const uuid_t& uuid, int halVersion) {
49    mName = hwSensor.name;
50    mVendor = hwSensor.vendor;
51    mVersion = hwSensor.version;
52    mHandle = hwSensor.handle;
53    mType = hwSensor.type;
54    mMinValue = 0;                      // FIXME: minValue
55    mMaxValue = hwSensor.maxRange;     // FIXME: maxValue
56    mResolution = hwSensor.resolution;
57    mPower = hwSensor.power;
58    mMinDelay = hwSensor.minDelay;
59    mFlags = 0;
60    mUuid = uuid;
61
62    // Set fifo event count zero for older devices which do not support batching. Fused
63    // sensors also have their fifo counts set to zero.
64    if (halVersion > SENSORS_DEVICE_API_VERSION_1_0) {
65        mFifoReservedEventCount = hwSensor.fifoReservedEventCount;
66        mFifoMaxEventCount = hwSensor.fifoMaxEventCount;
67    } else {
68        mFifoReservedEventCount = 0;
69        mFifoMaxEventCount = 0;
70    }
71
72    if (halVersion >= SENSORS_DEVICE_API_VERSION_1_3) {
73        if (hwSensor.maxDelay > INT_MAX) {
74            // Max delay is declared as a 64 bit integer for 64 bit architectures. But it should
75            // always fit in a 32 bit integer, log error and cap it to INT_MAX.
76            ALOGE("Sensor maxDelay overflow error %s %" PRId64, mName.string(),
77                  static_cast<int64_t>(hwSensor.maxDelay));
78            mMaxDelay = INT_MAX;
79        } else {
80            mMaxDelay = static_cast<int32_t>(hwSensor.maxDelay);
81        }
82    } else {
83        // For older hals set maxDelay to 0.
84        mMaxDelay = 0;
85    }
86
87    // Ensure existing sensors have correct string type, required permissions and reporting mode.
88    // Set reportingMode for all android defined sensor types, set wake-up flag only for proximity
89    // sensor, significant motion, tilt, pick_up gesture, wake gesture and glance gesture on older
90    // HALs. Newer HALs can define both wake-up and non wake-up proximity sensors.
91    // All the OEM defined defined sensors have flags set to whatever is provided by the HAL.
92    switch (mType) {
93    case SENSOR_TYPE_ACCELEROMETER:
94        mStringType = SENSOR_STRING_TYPE_ACCELEROMETER;
95        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
96        break;
97    case SENSOR_TYPE_AMBIENT_TEMPERATURE:
98        mStringType = SENSOR_STRING_TYPE_AMBIENT_TEMPERATURE;
99        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
100        break;
101    case SENSOR_TYPE_GAME_ROTATION_VECTOR:
102        mStringType = SENSOR_STRING_TYPE_GAME_ROTATION_VECTOR;
103        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
104        break;
105    case SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR:
106        mStringType = SENSOR_STRING_TYPE_GEOMAGNETIC_ROTATION_VECTOR;
107        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
108        break;
109    case SENSOR_TYPE_GRAVITY:
110        mStringType = SENSOR_STRING_TYPE_GRAVITY;
111        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
112        break;
113    case SENSOR_TYPE_GYROSCOPE:
114        mStringType = SENSOR_STRING_TYPE_GYROSCOPE;
115        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
116        break;
117    case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
118        mStringType = SENSOR_STRING_TYPE_GYROSCOPE_UNCALIBRATED;
119        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
120        break;
121    case SENSOR_TYPE_HEART_RATE: {
122        mStringType = SENSOR_STRING_TYPE_HEART_RATE;
123        mRequiredPermission = SENSOR_PERMISSION_BODY_SENSORS;
124        AppOpsManager appOps;
125        mRequiredAppOp = appOps.permissionToOpCode(String16(SENSOR_PERMISSION_BODY_SENSORS));
126        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
127        } break;
128    case SENSOR_TYPE_LIGHT:
129        mStringType = SENSOR_STRING_TYPE_LIGHT;
130        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
131        break;
132    case SENSOR_TYPE_LINEAR_ACCELERATION:
133        mStringType = SENSOR_STRING_TYPE_LINEAR_ACCELERATION;
134        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
135        break;
136    case SENSOR_TYPE_MAGNETIC_FIELD:
137        mStringType = SENSOR_STRING_TYPE_MAGNETIC_FIELD;
138        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
139        break;
140    case SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED:
141        mStringType = SENSOR_STRING_TYPE_MAGNETIC_FIELD_UNCALIBRATED;
142        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
143        break;
144    case SENSOR_TYPE_ORIENTATION:
145        mStringType = SENSOR_STRING_TYPE_ORIENTATION;
146        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
147        break;
148    case SENSOR_TYPE_PRESSURE:
149        mStringType = SENSOR_STRING_TYPE_PRESSURE;
150        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
151        break;
152    case SENSOR_TYPE_PROXIMITY:
153        mStringType = SENSOR_STRING_TYPE_PROXIMITY;
154        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
155        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
156            mFlags |= SENSOR_FLAG_WAKE_UP;
157        }
158        break;
159    case SENSOR_TYPE_RELATIVE_HUMIDITY:
160        mStringType = SENSOR_STRING_TYPE_RELATIVE_HUMIDITY;
161        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
162        break;
163    case SENSOR_TYPE_ROTATION_VECTOR:
164        mStringType = SENSOR_STRING_TYPE_ROTATION_VECTOR;
165        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
166        break;
167    case SENSOR_TYPE_SIGNIFICANT_MOTION:
168        mStringType = SENSOR_STRING_TYPE_SIGNIFICANT_MOTION;
169        mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
170        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
171            mFlags |= SENSOR_FLAG_WAKE_UP;
172        }
173        break;
174    case SENSOR_TYPE_STEP_COUNTER:
175        mStringType = SENSOR_STRING_TYPE_STEP_COUNTER;
176        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
177        break;
178    case SENSOR_TYPE_STEP_DETECTOR:
179        mStringType = SENSOR_STRING_TYPE_STEP_DETECTOR;
180        mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE;
181        break;
182    case SENSOR_TYPE_TEMPERATURE:
183        mStringType = SENSOR_STRING_TYPE_TEMPERATURE;
184        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
185        break;
186    case SENSOR_TYPE_TILT_DETECTOR:
187        mStringType = SENSOR_STRING_TYPE_TILT_DETECTOR;
188        mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE;
189        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
190            mFlags |= SENSOR_FLAG_WAKE_UP;
191        }
192        break;
193    case SENSOR_TYPE_WAKE_GESTURE:
194        mStringType = SENSOR_STRING_TYPE_WAKE_GESTURE;
195        mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
196        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
197            mFlags |= SENSOR_FLAG_WAKE_UP;
198        }
199        break;
200    case SENSOR_TYPE_GLANCE_GESTURE:
201        mStringType = SENSOR_STRING_TYPE_GLANCE_GESTURE;
202        mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
203        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
204            mFlags |= SENSOR_FLAG_WAKE_UP;
205        }
206        break;
207    case SENSOR_TYPE_PICK_UP_GESTURE:
208        mStringType = SENSOR_STRING_TYPE_PICK_UP_GESTURE;
209        mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
210        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
211            mFlags |= SENSOR_FLAG_WAKE_UP;
212        }
213        break;
214    case SENSOR_TYPE_WRIST_TILT_GESTURE:
215        mStringType = SENSOR_STRING_TYPE_WRIST_TILT_GESTURE;
216        mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE;
217        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
218            mFlags |= SENSOR_FLAG_WAKE_UP;
219        }
220        break;
221    case SENSOR_TYPE_DYNAMIC_SENSOR_META:
222        mStringType = SENSOR_STRING_TYPE_DYNAMIC_SENSOR_META;
223        mFlags = SENSOR_FLAG_SPECIAL_REPORTING_MODE; // special trigger and non-wake up
224        break;
225    case SENSOR_TYPE_POSE_6DOF:
226        mStringType = SENSOR_STRING_TYPE_POSE_6DOF;
227        mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
228        break;
229    case SENSOR_TYPE_STATIONARY_DETECT:
230        mStringType = SENSOR_STRING_TYPE_STATIONARY_DETECT;
231        mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
232        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
233            mFlags |= SENSOR_FLAG_WAKE_UP;
234        }
235        break;
236    case SENSOR_TYPE_MOTION_DETECT:
237        mStringType = SENSOR_STRING_TYPE_MOTION_DETECT;
238        mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
239        if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
240            mFlags |= SENSOR_FLAG_WAKE_UP;
241        }
242        break;
243    case SENSOR_TYPE_HEART_BEAT:
244        mStringType = SENSOR_STRING_TYPE_HEART_BEAT;
245        mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE;
246        break;
247    default:
248        // Only pipe the stringType, requiredPermission and flags for custom sensors.
249        if (halVersion > SENSORS_DEVICE_API_VERSION_1_0 && hwSensor.stringType) {
250            mStringType = hwSensor.stringType;
251        }
252        if (halVersion > SENSORS_DEVICE_API_VERSION_1_0 && hwSensor.requiredPermission) {
253            mRequiredPermission = hwSensor.requiredPermission;
254            if (!strcmp(mRequiredPermission, SENSOR_PERMISSION_BODY_SENSORS)) {
255                AppOpsManager appOps;
256                mRequiredAppOp = appOps.permissionToOpCode(String16(SENSOR_PERMISSION_BODY_SENSORS));
257            }
258        }
259
260        if (halVersion >= SENSORS_DEVICE_API_VERSION_1_3) {
261            mFlags = static_cast<uint32_t>(hwSensor.flags);
262        } else {
263            // This is an OEM defined sensor on an older HAL. Use minDelay to determine the
264            // reporting mode of the sensor.
265            if (mMinDelay > 0) {
266                mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
267            } else if (mMinDelay == 0) {
268                mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
269            } else if (mMinDelay < 0) {
270                mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
271            }
272        }
273        break;
274    }
275
276    if (halVersion >= SENSORS_DEVICE_API_VERSION_1_3) {
277        // Wake-up flag of HAL 1.3 and above is set here
278        mFlags |= (hwSensor.flags & SENSOR_FLAG_WAKE_UP);
279
280        // Log error if the reporting mode is not as expected, but respect HAL setting.
281        int actualReportingMode = (hwSensor.flags & REPORTING_MODE_MASK) >> REPORTING_MODE_SHIFT;
282        int expectedReportingMode = (mFlags & REPORTING_MODE_MASK) >> REPORTING_MODE_SHIFT;
283        if (actualReportingMode != expectedReportingMode) {
284            ALOGE("Reporting Mode incorrect: sensor %s handle=%#010" PRIx32 " type=%" PRId32 " "
285                   "actual=%d expected=%d",
286                   mName.string(), mHandle, mType, actualReportingMode, expectedReportingMode);
287        }
288    }
289
290    // Feature flags
291    // Set DYNAMIC_SENSOR_MASK and ADDITIONAL_INFO_MASK flag here. Compatible with HAL 1_3.
292    if (halVersion >= SENSORS_DEVICE_API_VERSION_1_3) {
293        mFlags |= (hwSensor.flags & (DYNAMIC_SENSOR_MASK | ADDITIONAL_INFO_MASK));
294    }
295    // Set DATA_INJECTION flag here. Defined in HAL 1_4.
296    if (halVersion >= SENSORS_DEVICE_API_VERSION_1_4) {
297        mFlags |= (hwSensor.flags & DATA_INJECTION_MASK);
298    }
299
300    if (mRequiredPermission.length() > 0) {
301        // If the sensor is protected by a permission we need to know if it is
302        // a runtime one to determine whether we can use the permission cache.
303        sp<IBinder> binder = defaultServiceManager()->getService(String16("permission"));
304        if (binder != 0) {
305            sp<IPermissionController> permCtrl = interface_cast<IPermissionController>(binder);
306            mRequiredPermissionRuntime = permCtrl->isRuntimePermission(
307                    String16(mRequiredPermission));
308        }
309    }
310}
311
312Sensor::~Sensor() {
313}
314
315const String8& Sensor::getName() const {
316    return mName;
317}
318
319const String8& Sensor::getVendor() const {
320    return mVendor;
321}
322
323int32_t Sensor::getHandle() const {
324    return mHandle;
325}
326
327int32_t Sensor::getType() const {
328    return mType;
329}
330
331float Sensor::getMinValue() const {
332    return mMinValue;
333}
334
335float Sensor::getMaxValue() const {
336    return mMaxValue;
337}
338
339float Sensor::getResolution() const {
340    return mResolution;
341}
342
343float Sensor::getPowerUsage() const {
344    return mPower;
345}
346
347int32_t Sensor::getMinDelay() const {
348    return mMinDelay;
349}
350
351nsecs_t Sensor::getMinDelayNs() const {
352    return getMinDelay() * 1000;
353}
354
355int32_t Sensor::getVersion() const {
356    return mVersion;
357}
358
359uint32_t Sensor::getFifoReservedEventCount() const {
360    return mFifoReservedEventCount;
361}
362
363uint32_t Sensor::getFifoMaxEventCount() const {
364    return mFifoMaxEventCount;
365}
366
367const String8& Sensor::getStringType() const {
368    return mStringType;
369}
370
371const String8& Sensor::getRequiredPermission() const {
372    return mRequiredPermission;
373}
374
375bool Sensor::isRequiredPermissionRuntime() const {
376    return mRequiredPermissionRuntime;
377}
378
379int32_t Sensor::getRequiredAppOp() const {
380    return mRequiredAppOp;
381}
382
383int32_t Sensor::getMaxDelay() const {
384    return mMaxDelay;
385}
386
387uint32_t Sensor::getFlags() const {
388    return mFlags;
389}
390
391bool Sensor::isWakeUpSensor() const {
392    return (mFlags & SENSOR_FLAG_WAKE_UP) != 0;
393}
394
395bool Sensor::isDynamicSensor() const {
396    return (mFlags & SENSOR_FLAG_DYNAMIC_SENSOR) != 0;
397}
398
399bool Sensor::hasAdditionalInfo() const {
400    return (mFlags & SENSOR_FLAG_ADDITIONAL_INFO) != 0;
401}
402
403int32_t Sensor::getReportingMode() const {
404    return ((mFlags & REPORTING_MODE_MASK) >> REPORTING_MODE_SHIFT);
405}
406
407const Sensor::uuid_t& Sensor::getUuid() const {
408    return mUuid;
409}
410
411void Sensor::setId(int32_t id) {
412    mUuid.i64[0] = id;
413    mUuid.i64[1] = 0;
414}
415
416int32_t Sensor::getId() const {
417    return int32_t(mUuid.i64[0]);
418}
419
420size_t Sensor::getFlattenedSize() const {
421    size_t fixedSize =
422            sizeof(mVersion) + sizeof(mHandle) + sizeof(mType) +
423            sizeof(mMinValue) + sizeof(mMaxValue) + sizeof(mResolution) +
424            sizeof(mPower) + sizeof(mMinDelay) + sizeof(mFifoMaxEventCount) +
425            sizeof(mFifoMaxEventCount) + sizeof(mRequiredPermissionRuntime) +
426            sizeof(mRequiredAppOp) + sizeof(mMaxDelay) + sizeof(mFlags) + sizeof(mUuid);
427
428    size_t variableSize =
429            sizeof(uint32_t) + FlattenableUtils::align<4>(mName.length()) +
430            sizeof(uint32_t) + FlattenableUtils::align<4>(mVendor.length()) +
431            sizeof(uint32_t) + FlattenableUtils::align<4>(mStringType.length()) +
432            sizeof(uint32_t) + FlattenableUtils::align<4>(mRequiredPermission.length());
433
434    return fixedSize + variableSize;
435}
436
437status_t Sensor::flatten(void* buffer, size_t size) const {
438    if (size < getFlattenedSize()) {
439        return NO_MEMORY;
440    }
441
442    flattenString8(buffer, size, mName);
443    flattenString8(buffer, size, mVendor);
444    FlattenableUtils::write(buffer, size, mVersion);
445    FlattenableUtils::write(buffer, size, mHandle);
446    FlattenableUtils::write(buffer, size, mType);
447    FlattenableUtils::write(buffer, size, mMinValue);
448    FlattenableUtils::write(buffer, size, mMaxValue);
449    FlattenableUtils::write(buffer, size, mResolution);
450    FlattenableUtils::write(buffer, size, mPower);
451    FlattenableUtils::write(buffer, size, mMinDelay);
452    FlattenableUtils::write(buffer, size, mFifoReservedEventCount);
453    FlattenableUtils::write(buffer, size, mFifoMaxEventCount);
454    flattenString8(buffer, size, mStringType);
455    flattenString8(buffer, size, mRequiredPermission);
456    FlattenableUtils::write(buffer, size, mRequiredPermissionRuntime);
457    FlattenableUtils::write(buffer, size, mRequiredAppOp);
458    FlattenableUtils::write(buffer, size, mMaxDelay);
459    FlattenableUtils::write(buffer, size, mFlags);
460    if (mUuid.i64[1] != 0) {
461        // We should never hit this case with our current API, but we
462        // could via a careless API change.  If that happens,
463        // this code will keep us from leaking our UUID (while probably
464        // breaking dynamic sensors).  See b/29547335.
465        ALOGW("Sensor with UUID being flattened; sending 0.  Expect "
466              "bad dynamic sensor behavior");
467        uuid_t tmpUuid;  // default constructor makes this 0.
468        FlattenableUtils::write(buffer, size, tmpUuid);
469    } else {
470        FlattenableUtils::write(buffer, size, mUuid);
471    }
472    return NO_ERROR;
473}
474
475status_t Sensor::unflatten(void const* buffer, size_t size) {
476    if (!unflattenString8(buffer, size, mName)) {
477        return NO_MEMORY;
478    }
479    if (!unflattenString8(buffer, size, mVendor)) {
480        return NO_MEMORY;
481    }
482
483    size_t fixedSize1 =
484            sizeof(mVersion) + sizeof(mHandle) + sizeof(mType) + sizeof(mMinValue) +
485            sizeof(mMaxValue) + sizeof(mResolution) + sizeof(mPower) + sizeof(mMinDelay) +
486            sizeof(mFifoMaxEventCount) + sizeof(mFifoMaxEventCount);
487    if (size < fixedSize1) {
488        return NO_MEMORY;
489    }
490
491    FlattenableUtils::read(buffer, size, mVersion);
492    FlattenableUtils::read(buffer, size, mHandle);
493    FlattenableUtils::read(buffer, size, mType);
494    FlattenableUtils::read(buffer, size, mMinValue);
495    FlattenableUtils::read(buffer, size, mMaxValue);
496    FlattenableUtils::read(buffer, size, mResolution);
497    FlattenableUtils::read(buffer, size, mPower);
498    FlattenableUtils::read(buffer, size, mMinDelay);
499    FlattenableUtils::read(buffer, size, mFifoReservedEventCount);
500    FlattenableUtils::read(buffer, size, mFifoMaxEventCount);
501
502    if (!unflattenString8(buffer, size, mStringType)) {
503        return NO_MEMORY;
504    }
505    if (!unflattenString8(buffer, size, mRequiredPermission)) {
506        return NO_MEMORY;
507    }
508
509    size_t fixedSize2 =
510            sizeof(mRequiredPermissionRuntime) + sizeof(mRequiredAppOp) + sizeof(mMaxDelay) +
511            sizeof(mFlags) + sizeof(mUuid);
512    if (size < fixedSize2) {
513        return NO_MEMORY;
514    }
515
516    FlattenableUtils::read(buffer, size, mRequiredPermissionRuntime);
517    FlattenableUtils::read(buffer, size, mRequiredAppOp);
518    FlattenableUtils::read(buffer, size, mMaxDelay);
519    FlattenableUtils::read(buffer, size, mFlags);
520    FlattenableUtils::read(buffer, size, mUuid);
521    return NO_ERROR;
522}
523
524void Sensor::flattenString8(void*& buffer, size_t& size,
525        const String8& string8) {
526    uint32_t len = static_cast<uint32_t>(string8.length());
527    FlattenableUtils::write(buffer, size, len);
528    memcpy(static_cast<char*>(buffer), string8.string(), len);
529    FlattenableUtils::advance(buffer, size, FlattenableUtils::align<4>(len));
530}
531
532bool Sensor::unflattenString8(void const*& buffer, size_t& size, String8& outputString8) {
533    uint32_t len;
534    if (size < sizeof(len)) {
535        return false;
536    }
537    FlattenableUtils::read(buffer, size, len);
538    if (size < len) {
539        return false;
540    }
541    outputString8.setTo(static_cast<char const*>(buffer), len);
542    FlattenableUtils::advance(buffer, size, FlattenableUtils::align<4>(len));
543    return true;
544}
545
546// ----------------------------------------------------------------------------
547}; // namespace android
548