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Merge "Intern Sensor object string using java String.intern()" into oc-dev

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This commit is contained in:
Peng Xu
2017-04-20 02:01:28 +00:00
committed by Android (Google) Code Review
parent aca246565a 3e13204989
commit 37658383b4
1 changed files with 49 additions and 63 deletions
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112
core/jni/android_hardware_SensorManager.cpp
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@@ -75,6 +75,12 @@ struct ListOffsets {
jmethodID add;
} gListOffsets;
struct StringOffsets {
jclass clazz;
jmethodID intern;
jstring emptyString;
} gStringOffsets;
/*
* nativeClassInit is not inteneded to be thread-safe. It should be called before other native...
* functions (except nativeCreate).
@@ -84,75 +90,55 @@ nativeClassInit (JNIEnv *_env, jclass _this)
{
//android.hardware.Sensor
SensorOffsets& sensorOffsets = gSensorOffsets;
jclass sensorClass = (jclass) _env->NewGlobalRef(_env->FindClass("android/hardware/Sensor"));
sensorOffsets.clazz = sensorClass;
sensorOffsets.name = _env->GetFieldID(sensorClass, "mName", "Ljava/lang/String;");
sensorOffsets.vendor = _env->GetFieldID(sensorClass, "mVendor", "Ljava/lang/String;");
sensorOffsets.version = _env->GetFieldID(sensorClass, "mVersion", "I");
sensorOffsets.handle = _env->GetFieldID(sensorClass, "mHandle", "I");
sensorOffsets.range = _env->GetFieldID(sensorClass, "mMaxRange", "F");
sensorOffsets.resolution = _env->GetFieldID(sensorClass, "mResolution","F");
sensorOffsets.power = _env->GetFieldID(sensorClass, "mPower", "F");
sensorOffsets.minDelay = _env->GetFieldID(sensorClass, "mMinDelay", "I");
jclass sensorClass = (jclass)
MakeGlobalRefOrDie(_env, FindClassOrDie(_env, "android/hardware/Sensor"));
sensorOffsets.clazz = sensorClass;
sensorOffsets.name = GetFieldIDOrDie(_env, sensorClass, "mName", "Ljava/lang/String;");
sensorOffsets.vendor = GetFieldIDOrDie(_env, sensorClass, "mVendor", "Ljava/lang/String;");
sensorOffsets.version = GetFieldIDOrDie(_env, sensorClass, "mVersion", "I");
sensorOffsets.handle = GetFieldIDOrDie(_env, sensorClass, "mHandle", "I");
sensorOffsets.range = GetFieldIDOrDie(_env, sensorClass, "mMaxRange", "F");
sensorOffsets.resolution = GetFieldIDOrDie(_env, sensorClass, "mResolution","F");
sensorOffsets.power = GetFieldIDOrDie(_env, sensorClass, "mPower", "F");
sensorOffsets.minDelay = GetFieldIDOrDie(_env, sensorClass, "mMinDelay", "I");
sensorOffsets.fifoReservedEventCount =
_env->GetFieldID(sensorClass, "mFifoReservedEventCount", "I");
sensorOffsets.fifoMaxEventCount = _env->GetFieldID(sensorClass, "mFifoMaxEventCount", "I");
sensorOffsets.stringType = _env->GetFieldID(sensorClass, "mStringType", "Ljava/lang/String;");
sensorOffsets.requiredPermission = _env->GetFieldID(sensorClass, "mRequiredPermission",
"Ljava/lang/String;");
sensorOffsets.maxDelay = _env->GetFieldID(sensorClass, "mMaxDelay", "I");
sensorOffsets.flags = _env->GetFieldID(sensorClass, "mFlags", "I");
GetFieldIDOrDie(_env,sensorClass, "mFifoReservedEventCount", "I");
sensorOffsets.fifoMaxEventCount = GetFieldIDOrDie(_env,sensorClass, "mFifoMaxEventCount", "I");
sensorOffsets.stringType =
GetFieldIDOrDie(_env,sensorClass, "mStringType", "Ljava/lang/String;");
sensorOffsets.requiredPermission =
GetFieldIDOrDie(_env,sensorClass, "mRequiredPermission", "Ljava/lang/String;");
sensorOffsets.maxDelay = GetFieldIDOrDie(_env,sensorClass, "mMaxDelay", "I");
sensorOffsets.flags = GetFieldIDOrDie(_env,sensorClass, "mFlags", "I");
sensorOffsets.setType = _env->GetMethodID(sensorClass, "setType", "(I)Z");
sensorOffsets.setUuid = _env->GetMethodID(sensorClass, "setUuid", "(JJ)V");
sensorOffsets.init = _env->GetMethodID(sensorClass, "<init>", "()V");
sensorOffsets.setType = GetMethodIDOrDie(_env,sensorClass, "setType", "(I)Z");
sensorOffsets.setUuid = GetMethodIDOrDie(_env,sensorClass, "setUuid", "(JJ)V");
sensorOffsets.init = GetMethodIDOrDie(_env,sensorClass, "<init>", "()V");
// java.util.List;
ListOffsets& listOffsets = gListOffsets;
jclass listClass = (jclass) _env->NewGlobalRef(_env->FindClass("java/util/List"));
jclass listClass = (jclass) MakeGlobalRefOrDie(_env, FindClassOrDie(_env, "java/util/List"));
listOffsets.clazz = listClass;
listOffsets.add = _env->GetMethodID(listClass, "add", "(Ljava/lang/Object;)Z");
listOffsets.add = GetMethodIDOrDie(_env,listClass, "add", "(Ljava/lang/Object;)Z");
// initialize java.lang.String and empty string intern
StringOffsets& stringOffsets = gStringOffsets;
stringOffsets.clazz = MakeGlobalRefOrDie(_env, FindClassOrDie(_env, "java/lang/String"));
stringOffsets.intern =
GetMethodIDOrDie(_env, stringOffsets.clazz, "intern", "()Ljava/lang/String;");
ScopedLocalRef<jstring> empty(_env, _env->NewStringUTF(""));
stringOffsets.emptyString = (jstring)
MakeGlobalRefOrDie(_env, _env->CallObjectMethod(empty.get(), stringOffsets.intern));
}
/**
* 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;
}
if (string2 == NULL) {
return false;
}
return string1->compare(*string2) < 0;
static jstring getJavaInternedString(JNIEnv *env, const String8 &string) {
if (string == "") {
return gStringOffsets.emptyString;
}
};
/**
* 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);
}
ScopedLocalRef<jstring> javaString(env, env->NewStringUTF(string.string()));
jstring internedString = (jstring)
env->CallObjectMethod(javaString.get(), gStringOffsets.intern);
return internedString;
}
@@ -174,10 +160,10 @@ translateNativeSensorToJavaSensor(JNIEnv *env, jobject sensor, const Sensor& nat
}
if (sensor != NULL) {
jstring name = env->NewStringUTF(nativeSensor.getName().string());
jstring vendor = env->NewStringUTF(nativeSensor.getVendor().string());
jstring name = getJavaInternedString(env, nativeSensor.getName());
jstring vendor = getJavaInternedString(env, nativeSensor.getVendor());
jstring requiredPermission =
env->NewStringUTF(nativeSensor.getRequiredPermission().string());
getJavaInternedString(env, nativeSensor.getRequiredPermission());
env->SetObjectField(sensor, sensorOffsets.name, name);
env->SetObjectField(sensor, sensorOffsets.vendor, vendor);
@@ -198,7 +184,7 @@ translateNativeSensorToJavaSensor(JNIEnv *env, jobject sensor, const Sensor& nat
if (env->CallBooleanMethod(sensor, sensorOffsets.setType, nativeSensor.getType())
== JNI_FALSE) {
jstring stringType = getInternedString(env, &nativeSensor.getStringType());
jstring stringType = getJavaInternedString(env, nativeSensor.getStringType());
env->SetObjectField(sensor, sensorOffsets.stringType, stringType);
}