Add new SystemProperties.Handle interface (6e2cff7f) · Commits · e / os / android_frameworks_base

core/java/android/os/SystemProperties.java

+68 −1

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@ import android.util.MutableInt;

		import com.android.internal.annotations.GuardedBy;

		import dalvik.annotation.optimization.CriticalNative;
		import dalvik.annotation.optimization.FastNative;

		import libcore.util.HexEncoding;
		@@ -37,7 +38,6 @@ import java.util.ArrayList;
		import java.util.Arrays;
		import java.util.HashMap;


		/**
		* Gives access to the system properties store. The system properties
		* store contains a list of string key-value pairs.
		@@ -118,6 +118,17 @@ public class SystemProperties {
		@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
		private static native boolean native_get_boolean(String key, boolean def);

		@FastNative
		private static native long native_find(String name);
		@FastNative
		private static native String native_get(long handle);
		@CriticalNative
		private static native int native_get_int(long handle, int def);
		@CriticalNative
		private static native long native_get_long(long handle, long def);
		@CriticalNative
		private static native boolean native_get_boolean(long handle, boolean def);

		// _NOT_ FastNative: native_set performs IPC and can block
		@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
		private static native void native_set(String key, String def);
		@@ -303,4 +314,60 @@ public class SystemProperties {
		@UnsupportedAppUsage
		private SystemProperties() {
		}

		/**
		* Look up a property location by name.
		* @name name of the property
		* @return property handle or {@code null} if property isn't set
		* @hide
		*/
		@Nullable public static Handle find(@NonNull String name) {
		long nativeHandle = native_find(name);
		if (nativeHandle == 0) {
		return null;
		}
		return new Handle(nativeHandle);
		}

		/**
		* Handle to a pre-located property. Looking up a property handle in advance allows
		* for optimal repeated lookup of a single property.
		* @hide
		*/
		public static final class Handle {

		private final long mNativeHandle;

		/**
		* @return Value of the property
		*/
		@NonNull public String get() {
		return native_get(mNativeHandle);
		}
		/**
		* @param def default value
		* @return value or {@code def} on parse error
		*/
		public int getInt(int def) {
		return native_get_int(mNativeHandle, def);
		}
		/**
		* @param def default value
		* @return value or {@code def} on parse error
		*/
		public long getLong(long def) {
		return native_get_long(mNativeHandle, def);
		}
		/**
		* @param def default value
		* @return value or {@code def} on parse error
		*/
		public boolean getBoolean(boolean def) {
		return native_get_boolean(mNativeHandle, def);
		}

		private Handle(long nativeHandle) {
		mNativeHandle = nativeHandle;
		}
		}
		}

core/jni/android_os_SystemProperties.cpp

+71 −8

Original line number	Diff line number	Diff line
		@@ -41,6 +41,8 @@ struct prop_info;
		namespace android {
		namespace {

		using android::base::ParseBoolResult;

		template<typename Functor>
		void ReadProperty(const prop_info* prop, Functor&& functor)
		{
		@@ -102,14 +104,7 @@ T SystemProperties_get_integral(JNIEnv *env, jclass, jstring keyJ,
		return ret;
		}

		jboolean SystemProperties_get_boolean(JNIEnv *env, jclass, jstring keyJ,
		jboolean defJ)
		{
		using android::base::ParseBoolResult;
		ParseBoolResult parseResult;
		ReadProperty(env, keyJ, [&](const char* value) {
		parseResult = android::base::ParseBool(value);
		});
		static jboolean jbooleanFromParseBoolResult(ParseBoolResult parseResult, jboolean defJ) {
		jboolean ret;
		switch (parseResult) {
		case ParseBoolResult::kError:
		@@ -125,6 +120,62 @@ jboolean SystemProperties_get_boolean(JNIEnv *env, jclass, jstring keyJ,
		return ret;
		}

		jboolean SystemProperties_get_boolean(JNIEnv *env, jclass, jstring keyJ,
		jboolean defJ)
		{
		ParseBoolResult parseResult;
		ReadProperty(env, keyJ, [&](const char* value) {
		parseResult = android::base::ParseBool(value);
		});
		return jbooleanFromParseBoolResult(parseResult, defJ);
		}

		jlong SystemProperties_find(JNIEnv* env, jclass, jstring keyJ)
		{
		#if defined(__BIONIC__)
		ScopedUtfChars key(env, keyJ);
		if (!key.c_str()) {
		return 0;
		}
		const prop_info* prop = __system_property_find(key.c_str());
		return reinterpret_cast<jlong>(prop);
		#else
		LOG(FATAL) << "fast property access supported only on device";
		__builtin_unreachable(); // Silence warning
		#endif
		}

		jstring SystemProperties_getH(JNIEnv* env, jclass clazz, jlong propJ)
		{
		jstring ret;
		auto prop = reinterpret_cast<const prop_info*>(propJ);
		ReadProperty(prop, [&](const char* value) {
		ret = env->NewStringUTF(value);
		});
		return ret;
		}

		template <typename T>
		T SystemProperties_get_integralH(CRITICAL_JNI_PARAMS_COMMA jlong propJ, T defJ)
		{
		T ret = defJ;
		auto prop = reinterpret_cast<const prop_info*>(propJ);
		ReadProperty(prop, [&](const char* value) {
		android::base::ParseInt<T>(value, &ret);
		});
		return ret;
		}

		jboolean SystemProperties_get_booleanH(CRITICAL_JNI_PARAMS_COMMA jlong propJ, jboolean defJ)
		{
		ParseBoolResult parseResult;
		auto prop = reinterpret_cast<const prop_info*>(propJ);
		ReadProperty(prop, [&](const char* value) {
		parseResult = android::base::ParseBool(value);
		});
		return jbooleanFromParseBoolResult(parseResult, defJ);
		}

		void SystemProperties_set(JNIEnv *env, jobject clazz, jstring keyJ,
		jstring valJ)
		{
		@@ -204,6 +255,18 @@ int register_android_os_SystemProperties(JNIEnv *env)
		(void*) SystemProperties_get_integral<jlong> },
		{ "native_get_boolean", "(Ljava/lang/String;Z)Z",
		(void*) SystemProperties_get_boolean },
		{ "native_find",
		"(Ljava/lang/String;)J",
		(void*) SystemProperties_find },
		{ "native_get",
		"(J)Ljava/lang/String;",
		(void*) SystemProperties_getH },
		{ "native_get_int", "(JI)I",
		(void*) SystemProperties_get_integralH<jint> },
		{ "native_get_long", "(JJ)J",
		(void*) SystemProperties_get_integralH<jlong> },
		{ "native_get_boolean", "(JZ)Z",
		(void*) SystemProperties_get_booleanH },
		{ "native_set", "(Ljava/lang/String;Ljava/lang/String;)V",
		(void*) SystemProperties_set },
		{ "native_add_change_callback", "()V",

core/tests/systemproperties/src/android/os/SystemPropertiesTest.java

+21 −0

Original line number	Diff line number	Diff line
		@@ -92,6 +92,27 @@ public class SystemPropertiesTest extends TestCase {
		assertEquals(expected, value);
		}

		@SmallTest
		private static void testHandle() throws Exception {
		String value;
		SystemProperties.Handle handle = SystemProperties.find("doesnotexist_2341431");
		assertNull(handle);
		SystemProperties.set(KEY, "abc");
		handle = SystemProperties.find(KEY);
		assertNotNull(handle);
		value = handle.get();
		assertEquals("abc", value);
		SystemProperties.set(KEY, "blarg");
		value = handle.get();
		assertEquals("blarg", value);
		SystemProperties.set(KEY, "1");
		assertEquals(1, handle.getInt(-1));
		assertEquals(1, handle.getLong(-1));
		assertEquals(true, handle.getBoolean(false));
		SystemProperties.set(KEY, "");
		assertEquals(12345, handle.getInt(12345));
		}

		@SmallTest
		public void testIntegralProperties() throws Exception {
		testInt("", 123, 123);