Add event ID generator. am: bd25f1cad8 am: 2cb0a6eb69 am: d0ba60b9d2 (b8278d9b) · Commits · e / os / android_frameworks_native

include/input/Input.h

+32 −0

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	@@ -265,6 +265,38 @@ enum class MotionClassification : uint8_t {
	*/		*/
	const char* motionClassificationToString(MotionClassification classification);		const char* motionClassificationToString(MotionClassification classification);

			/**
			* Generator of unique numbers used to identify input events.
			*
			* Layout of ID:
			* \|--------------------------\|---------------------------\|
			* \| 2 bits for source \| 30 bits for random number \|
			* \|--------------------------\|---------------------------\|
			*/
			class IdGenerator {
			private:
			static constexpr uint32_t SOURCE_SHIFT = 30;

			public:
			// Used to divide integer space to ensure no conflict among these sources./
			enum class Source : int32_t {
			INPUT_READER = 0x0 << SOURCE_SHIFT,
			INPUT_DISPATCHER = 0x1 << SOURCE_SHIFT,
			OTHER = 0x3 << SOURCE_SHIFT, // E.g. app injected events
			};
			IdGenerator(Source source);

			int32_t nextId() const;

			// Extract source from given id.
			static inline Source getSource(int32_t id) { return static_cast<Source>(SOURCE_MASK & id); }

			private:
			const Source mSource;

			static constexpr int32_t SOURCE_MASK = 0x3 << SOURCE_SHIFT;
			};

	/**		/**
	* Invalid value for cursor position. Used for non-mouse events, tests and injected events. Don't		* Invalid value for cursor position. Used for non-mouse events, tests and injected events. Don't
	* use it for direct comparison with any other value, because NaN isn't equal to itself according to		* use it for direct comparison with any other value, because NaN isn't equal to itself according to

libs/input/Input.cpp

+29 −0

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	@@ -17,7 +17,9 @@
	#define LOG_TAG "Input"		#define LOG_TAG "Input"
	//#define LOG_NDEBUG 0		//#define LOG_NDEBUG 0

			#include <cutils/compiler.h>
	#include <limits.h>		#include <limits.h>
			#include <string.h>

	#include <input/Input.h>		#include <input/Input.h>
	#include <input/InputDevice.h>		#include <input/InputDevice.h>
	@@ -25,6 +27,7 @@

	#ifdef __ANDROID__		#ifdef __ANDROID__
	#include <binder/Parcel.h>		#include <binder/Parcel.h>
			#include <sys/random.h>
	#endif		#endif

	namespace android {		namespace android {
	@@ -40,6 +43,32 @@ const char* motionClassificationToString(MotionClassification classification) {
	}		}
	}		}

			// --- IdGenerator ---
			IdGenerator::IdGenerator(Source source) : mSource(source) {}

			int32_t IdGenerator::nextId() const {
			constexpr uint32_t SEQUENCE_NUMBER_MASK = ~SOURCE_MASK;
			int32_t id = 0;

			// Avoid building against syscall getrandom(2) on host, which will fail build on Mac. Host doesn't
			// use sequence number so just always return mSource.
			#ifdef __ANDROID__
			constexpr size_t BUF_LEN = sizeof(id);
			size_t totalBytes = 0;
			while (totalBytes < BUF_LEN) {
			ssize_t bytes = TEMP_FAILURE_RETRY(getrandom(&id, BUF_LEN, GRND_NONBLOCK));
			if (CC_UNLIKELY(bytes < 0)) {
			ALOGW("Failed to fill in random number for sequence number: %s.", strerror(errno));
			id = 0;
			break;
			}
			totalBytes += bytes;
			}
			#endif // __ANDROID__

			return (id & SEQUENCE_NUMBER_MASK) \| static_cast<int32_t>(mSource);
			}

	// --- InputEvent ---		// --- InputEvent ---

	const char* inputEventTypeToString(int32_t type) {		const char* inputEventTypeToString(int32_t type) {

libs/input/tests/Android.bp

+1 −0

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	@@ -2,6 +2,7 @@
	cc_test {		cc_test {
	name: "libinput_tests",		name: "libinput_tests",
	srcs: [		srcs: [
			"IdGenerator_test.cpp",
	"InputChannel_test.cpp",		"InputChannel_test.cpp",
	"InputDevice_test.cpp",		"InputDevice_test.cpp",
	"InputEvent_test.cpp",		"InputEvent_test.cpp",

libs/input/tests/IdGenerator_test.cpp

0 → 100644

+52 −0

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			/*
			* Copyright (C) 2020 The Android Open Source Project
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			#include <gtest/gtest.h>
			#include <input/Input.h>
			#include <ios>
			#include <memory>
			#include <unordered_set>

			namespace android::test {

			class IdGeneratorTest : public testing::TestWithParam<IdGenerator::Source> {
			protected:
			void SetUp() override { mGenerator.reset(new IdGenerator(GetParam())); }

			std::unique_ptr<IdGenerator> mGenerator;
			};

			TEST_P(IdGeneratorTest, GenerateRandomNumber) {
			for (int i = 0; i < 500; ++i) {
			mGenerator->nextId();
			}
			}

			TEST_P(IdGeneratorTest, GenerateRandomNumberWithProperFlag) {
			for (int i = 0; i < 500; ++i) {
			int32_t id = mGenerator->nextId();
			IdGenerator::Source source = IdGenerator::getSource(id);
			EXPECT_EQ(source, GetParam())
			<< std::hex << "Generator generated a value with wrong source. Value: 0x" << id
			<< " Source: 0x" << static_cast<int32_t>(source);
			}
			}

			INSTANTIATE_TEST_SUITE_P(SourceInstantiation, IdGeneratorTest,
			testing::Values(IdGenerator::Source::INPUT_READER,
			IdGenerator::Source::INPUT_DISPATCHER,
			IdGenerator::Source::OTHER));
			} // namespace android::test