Merge "Intern strings used in Sensor information." (1ea57363) · Commits · e / os / android_frameworks_base

core/java/android/hardware/Sensor.java

+92 −0

Original line number	Diff line number	Diff line
		@@ -833,4 +833,96 @@ public final class Sensor {
		+ ", type=" + mType + ", maxRange=" + mMaxRange + ", resolution=" + mResolution
		+ ", power=" + mPower + ", minDelay=" + mMinDelay + "}";
		}

		/**
		* Sets the Type associated with the sensor.
		* NOTE: to be used only by native bindings in SensorManager.
		*
		* This allows interned static strings to be used across all representations of the Sensor. If
		* a sensor type is not referenced here, it will still be interned by the native SensorManager.
		*
		* @return {@code true} if the StringType was successfully set, {@code false} otherwise.
		*/
		private boolean setType(int value) {
		mType = value;
		switch (mType) {
		case TYPE_ACCELEROMETER:
		mStringType = STRING_TYPE_ACCELEROMETER;
		return true;
		case TYPE_AMBIENT_TEMPERATURE:
		mStringType = STRING_TYPE_AMBIENT_TEMPERATURE;
		return true;
		case TYPE_GAME_ROTATION_VECTOR:
		mStringType = STRING_TYPE_GAME_ROTATION_VECTOR;
		return true;
		case TYPE_GEOMAGNETIC_ROTATION_VECTOR:
		mStringType = STRING_TYPE_GEOMAGNETIC_ROTATION_VECTOR;
		return true;
		case TYPE_GLANCE_GESTURE:
		mStringType = STRING_TYPE_GLANCE_GESTURE;
		return true;
		case TYPE_GRAVITY:
		mStringType = STRING_TYPE_GRAVITY;
		return true;
		case TYPE_GYROSCOPE:
		mStringType = STRING_TYPE_GYROSCOPE;
		return true;
		case TYPE_GYROSCOPE_UNCALIBRATED:
		mStringType = STRING_TYPE_GYROSCOPE_UNCALIBRATED;
		return true;
		case TYPE_HEART_RATE:
		mStringType = STRING_TYPE_HEART_RATE;
		return true;
		case TYPE_LIGHT:
		mStringType = STRING_TYPE_LIGHT;
		return true;
		case TYPE_LINEAR_ACCELERATION:
		mStringType = STRING_TYPE_LINEAR_ACCELERATION;
		return true;
		case TYPE_MAGNETIC_FIELD:
		mStringType = STRING_TYPE_MAGNETIC_FIELD;
		return true;
		case TYPE_MAGNETIC_FIELD_UNCALIBRATED:
		mStringType = STRING_TYPE_MAGNETIC_FIELD_UNCALIBRATED;
		return true;
		case TYPE_PICK_UP_GESTURE:
		mStringType = STRING_TYPE_PICK_UP_GESTURE;
		return true;
		case TYPE_PRESSURE:
		mStringType = STRING_TYPE_PRESSURE;
		return true;
		case TYPE_PROXIMITY:
		mStringType = STRING_TYPE_PROXIMITY;
		return true;
		case TYPE_RELATIVE_HUMIDITY:
		mStringType = STRING_TYPE_RELATIVE_HUMIDITY;
		return true;
		case TYPE_ROTATION_VECTOR:
		mStringType = STRING_TYPE_ROTATION_VECTOR;
		return true;
		case TYPE_SIGNIFICANT_MOTION:
		mStringType = STRING_TYPE_SIGNIFICANT_MOTION;
		return true;
		case TYPE_STEP_COUNTER:
		mStringType = STRING_TYPE_STEP_COUNTER;
		return true;
		case TYPE_STEP_DETECTOR:
		mStringType = STRING_TYPE_STEP_DETECTOR;
		return true;
		case TYPE_TILT_DETECTOR:
		mStringType = SENSOR_STRING_TYPE_TILT_DETECTOR;
		return true;
		case TYPE_WAKE_GESTURE:
		mStringType = STRING_TYPE_WAKE_GESTURE;
		return true;
		case TYPE_ORIENTATION:
		mStringType = STRING_TYPE_ORIENTATION;
		return true;
		case TYPE_TEMPERATURE:
		mStringType = STRING_TYPE_TEMPERATURE;
		return true;
		default:
		return false;
		}
		}
		}

core/jni/android_hardware_SensorManager.cpp

+53 −9

Original line number	Diff line number	Diff line
		@@ -16,6 +16,8 @@

		#define LOG_TAG "SensorManager"

		#include <map>

		#include <utils/Log.h>
		#include <utils/Looper.h>

		@@ -44,7 +46,6 @@ struct SensorOffsets
		jfieldID vendor;
		jfieldID version;
		jfieldID handle;
		jfieldID type;
		jfieldID range;
		jfieldID resolution;
		jfieldID power;
		@@ -55,6 +56,7 @@ struct SensorOffsets
		jfieldID requiredPermission;
		jfieldID maxDelay;
		jfieldID flags;
		jmethodID setType;
		} gSensorOffsets;


		@@ -71,7 +73,6 @@ nativeClassInit (JNIEnv *_env, jclass _this)
		sensorOffsets.vendor = _env->GetFieldID(sensorClass, "mVendor", "Ljava/lang/String;");
		sensorOffsets.version = _env->GetFieldID(sensorClass, "mVersion", "I");
		sensorOffsets.handle = _env->GetFieldID(sensorClass, "mHandle", "I");
		sensorOffsets.type = _env->GetFieldID(sensorClass, "mType", "I");
		sensorOffsets.range = _env->GetFieldID(sensorClass, "mMaxRange", "F");
		sensorOffsets.resolution = _env->GetFieldID(sensorClass, "mResolution","F");
		sensorOffsets.power = _env->GetFieldID(sensorClass, "mPower", "F");
		@@ -84,6 +85,47 @@ nativeClassInit (JNIEnv *_env, jclass _this)
		"Ljava/lang/String;");
		sensorOffsets.maxDelay = _env->GetFieldID(sensorClass, "mMaxDelay", "I");
		sensorOffsets.flags = _env->GetFieldID(sensorClass, "mFlags", "I");
		sensorOffsets.setType = _env->GetMethodID(sensorClass, "setType", "(I)Z");
		}

		/**
		* A key comparator predicate.
		* It is used to intern strings associated with Sensor data.
		* It defines a 'Strict weak ordering' for the interned strings.
		*/
		class InternedStringCompare {
		public:
		bool operator()(const String8* string1, const String8* string2) const {
		if (string1 == NULL) {
		return string2 != NULL;
		}
		return string1->compare(*string2) < 0;
		}
		};

		/**
		* A localized interning mechanism for Sensor strings.
		* We implement our own interning to avoid the overhead of using java.lang.String#intern().
		* It is common that Vendor, StringType, and RequirePermission data is common between many of the
		* Sensors, by interning the memory usage to represent Sensors is optimized.
		*/
		static jstring
		getInternedString(JNIEnv env, const String8 string) {
		static std::map<const String8*, jstring, InternedStringCompare> internedStrings;

		jstring internedString;
		std::map<const String8*, jstring>::iterator iterator = internedStrings.find(string);
		if (iterator != internedStrings.end()) {
		internedString = iterator->second;
		} else {
		jstring localString = env->NewStringUTF(string->string());
		// we are implementing our own interning so expect these strings to be backed by global refs
		internedString = (jstring) env->NewGlobalRef(localString);
		internedStrings.insert(std::make_pair(string, internedString));
		env->DeleteLocalRef(localString);
		}

		return internedString;
		}

		static jint
		@@ -93,20 +135,19 @@ nativeGetNextSensor(JNIEnv *env, jclass clazz, jobject sensor, jint next)

		Sensor const* const* sensorList;
		size_t count = mgr.getSensorList(&sensorList);
		if (size_t(next) >= count)
		if (size_t(next) >= count) {
		return -1;
		}

		Sensor const* const list = sensorList[next];
		const SensorOffsets& sensorOffsets(gSensorOffsets);
		jstring name = env->NewStringUTF(list->getName().string());
		jstring vendor = env->NewStringUTF(list->getVendor().string());
		jstring stringType = env->NewStringUTF(list->getStringType().string());
		jstring requiredPermission = env->NewStringUTF(list->getRequiredPermission().string());
		jstring name = getInternedString(env, &list->getName());
		jstring vendor = getInternedString(env, &list->getVendor());
		jstring requiredPermission = getInternedString(env, &list->getRequiredPermission());
		env->SetObjectField(sensor, sensorOffsets.name, name);
		env->SetObjectField(sensor, sensorOffsets.vendor, vendor);
		env->SetIntField(sensor, sensorOffsets.version, list->getVersion());
		env->SetIntField(sensor, sensorOffsets.handle, list->getHandle());
		env->SetIntField(sensor, sensorOffsets.type, list->getType());
		env->SetFloatField(sensor, sensorOffsets.range, list->getMaxValue());
		env->SetFloatField(sensor, sensorOffsets.resolution, list->getResolution());
		env->SetFloatField(sensor, sensorOffsets.power, list->getPowerUsage());
		@@ -115,11 +156,14 @@ nativeGetNextSensor(JNIEnv *env, jclass clazz, jobject sensor, jint next)
		list->getFifoReservedEventCount());
		env->SetIntField(sensor, sensorOffsets.fifoMaxEventCount,
		list->getFifoMaxEventCount());
		env->SetObjectField(sensor, sensorOffsets.stringType, stringType);
		env->SetObjectField(sensor, sensorOffsets.requiredPermission,
		requiredPermission);
		env->SetIntField(sensor, sensorOffsets.maxDelay, list->getMaxDelay());
		env->SetIntField(sensor, sensorOffsets.flags, list->getFlags());
		if (env->CallBooleanMethod(sensor, sensorOffsets.setType, list->getType()) == JNI_FALSE) {
		jstring stringType = getInternedString(env, &list->getStringType());
		env->SetObjectField(sensor, sensorOffsets.stringType, stringType);
		}
		next++;
		return size_t(next) < count ? next : 0;
		}