Merge "b/12068020 Add a way to add uniqueness to device descriptors" (8d9802d9) · Commits · e / os / android_frameworks_base

services/input/EventHub.cpp

+64 −30

Original line number	Diff line number	Diff line
		@@ -102,34 +102,6 @@ static void getLinuxRelease(int* major, int* minor) {
		}
		}

		static void setDescriptor(InputDeviceIdentifier& identifier) {
		// Compute a device descriptor that uniquely identifies the device.
		// The descriptor is assumed to be a stable identifier. Its value should not
		// change between reboots, reconnections, firmware updates or new releases of Android.
		// Ideally, we also want the descriptor to be short and relatively opaque.
		String8 rawDescriptor;
		rawDescriptor.appendFormat(":%04x:%04x:", identifier.vendor, identifier.product);
		if (!identifier.uniqueId.isEmpty()) {
		rawDescriptor.append("uniqueId:");
		rawDescriptor.append(identifier.uniqueId);
		} if (identifier.vendor == 0 && identifier.product == 0) {
		// If we don't know the vendor and product id, then the device is probably
		// built-in so we need to rely on other information to uniquely identify
		// the input device. Usually we try to avoid relying on the device name or
		// location but for built-in input device, they are unlikely to ever change.
		if (!identifier.name.isEmpty()) {
		rawDescriptor.append("name:");
		rawDescriptor.append(identifier.name);
		} else if (!identifier.location.isEmpty()) {
		rawDescriptor.append("location:");
		rawDescriptor.append(identifier.location);
		}
		}
		identifier.descriptor = sha1(rawDescriptor);
		ALOGV("Created descriptor: raw=%s, cooked=%s", rawDescriptor.string(),
		identifier.descriptor.string());
		}

		// --- Global Functions ---

		uint32_t getAbsAxisUsage(int32_t axis, uint32_t deviceClasses) {
		@@ -590,6 +562,57 @@ bool EventHub::setKeyboardLayoutOverlay(int32_t deviceId,
		return false;
		}

		static String8 generateDescriptor(InputDeviceIdentifier& identifier) {
		String8 rawDescriptor;
		rawDescriptor.appendFormat(":%04x:%04x:", identifier.vendor,
		identifier.product);
		// TODO add handling for USB devices to not uniqueify kbs that show up twice
		if (!identifier.uniqueId.isEmpty()) {
		rawDescriptor.append("uniqueId:");
		rawDescriptor.append(identifier.uniqueId);
		} else if (identifier.nonce != 0) {
		rawDescriptor.appendFormat("nonce:%04x", identifier.nonce);
		}

		if (identifier.vendor == 0 && identifier.product == 0) {
		// If we don't know the vendor and product id, then the device is probably
		// built-in so we need to rely on other information to uniquely identify
		// the input device. Usually we try to avoid relying on the device name or
		// location but for built-in input device, they are unlikely to ever change.
		if (!identifier.name.isEmpty()) {
		rawDescriptor.append("name:");
		rawDescriptor.append(identifier.name);
		} else if (!identifier.location.isEmpty()) {
		rawDescriptor.append("location:");
		rawDescriptor.append(identifier.location);
		}
		}
		identifier.descriptor = sha1(rawDescriptor);
		return rawDescriptor;
		}

		void EventHub::assignDescriptorLocked(InputDeviceIdentifier& identifier) {
		// Compute a device descriptor that uniquely identifies the device.
		// The descriptor is assumed to be a stable identifier. Its value should not
		// change between reboots, reconnections, firmware updates or new releases
		// of Android. In practice we sometimes get devices that cannot be uniquely
		// identified. In this case we enforce uniqueness between connected devices.
		// Ideally, we also want the descriptor to be short and relatively opaque.

		identifier.nonce = 0;
		String8 rawDescriptor = generateDescriptor(identifier);
		if (identifier.uniqueId.isEmpty()) {
		// If it didn't have a unique id check for conflicts and enforce
		// uniqueness if necessary.
		while(getDeviceByDescriptorLocked(identifier.descriptor) != NULL) {
		identifier.nonce++;
		rawDescriptor = generateDescriptor(identifier);
		}
		}
		ALOGV("Created descriptor: raw=%s, cooked=%s", rawDescriptor.string(),
		identifier.descriptor.string());
		}

		void EventHub::vibrate(int32_t deviceId, nsecs_t duration) {
		AutoMutex _l(mLock);
		Device* device = getDeviceLocked(deviceId);
		@@ -646,6 +669,17 @@ void EventHub::cancelVibrate(int32_t deviceId) {
		}
		}

		EventHub::Device* EventHub::getDeviceByDescriptorLocked(String8& descriptor) const {
		size_t size = mDevices.size();
		for (size_t i = 0; i < size; i++) {
		Device* device = mDevices.valueAt(i);
		if (descriptor.compare(device->identifier.descriptor) == 0) {
		return device;
		}
		}
		return NULL;
		}

		EventHub::Device* EventHub::getDeviceLocked(int32_t deviceId) const {
		if (deviceId == BUILT_IN_KEYBOARD_ID) {
		deviceId = mBuiltInKeyboardId;
		@@ -1085,7 +1119,7 @@ status_t EventHub::openDeviceLocked(const char *devicePath) {
		}

		// Fill in the descriptor.
		setDescriptor(identifier);
		assignDescriptorLocked(identifier);

		// Make file descriptor non-blocking for use with poll().
		if (fcntl(fd, F_SETFL, O_NONBLOCK)) {
		@@ -1325,7 +1359,7 @@ void EventHub::createVirtualKeyboardLocked() {
		InputDeviceIdentifier identifier;
		identifier.name = "Virtual";
		identifier.uniqueId = "<virtual>";
		setDescriptor(identifier);
		assignDescriptorLocked(identifier);

		Device* device = new Device(-1, VIRTUAL_KEYBOARD_ID, String8("<virtual>"), identifier);
		device->classes = INPUT_DEVICE_CLASS_KEYBOARD

services/input/EventHub.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -373,6 +373,7 @@ private:
		status_t openDeviceLocked(const char *devicePath);
		void createVirtualKeyboardLocked();
		void addDeviceLocked(Device* device);
		void assignDescriptorLocked(InputDeviceIdentifier& identifier);

		status_t closeDeviceByPathLocked(const char *devicePath);
		void closeDeviceLocked(Device* device);
		@@ -382,6 +383,7 @@ private:
		void scanDevicesLocked();
		status_t readNotifyLocked();

		Device* getDeviceByDescriptorLocked(String8& descriptor) const;
		Device* getDeviceLocked(int32_t deviceId) const;
		Device* getDeviceByPathLocked(const char* devicePath) const;