services/camera/libcameraservice/common/CameraProviderManager.h

/*
 * Copyright (C) 2016 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.
 */

#ifndef ANDROID_SERVERS_CAMERA_CAMERAPROVIDER_H
#define ANDROID_SERVERS_CAMERA_CAMERAPROVIDER_H

#include <vector>
#include <string>
#include <mutex>

#include <camera/CameraParameters2.h>
#include <camera/CameraMetadata.h>
#include <camera/CameraBase.h>
#include <utils/Errors.h>
#include <android/hardware/camera/common/1.0/types.h>
#include <android/hardware/camera/provider/2.4/ICameraProvider.h>
//#include <android/hardware/camera/provider/2.4/ICameraProviderCallbacks.h>
#include <android/hidl/manager/1.0/IServiceNotification.h>

namespace android {

/**
 * A manager for all camera providers available on an Android device.
 *
 * Responsible for enumerating providers and the individual camera devices
 * they export, both at startup and as providers and devices are added/removed.
 *
 * Provides methods for requesting information about individual devices and for
 * opening them for active use.
 *
 */
class CameraProviderManager : virtual public hidl::manager::V1_0::IServiceNotification {
public:

    ~CameraProviderManager();

    // Tiny proxy for the static methods in a HIDL interface that communicate with the hardware
    // service manager, to be replacable in unit tests with a fake.
    struct ServiceInteractionProxy {
        virtual bool registerForNotifications(
                const std::string &serviceName,
                const sp<hidl::manager::V1_0::IServiceNotification>
                &notification) = 0;
        virtual sp<hardware::camera::provider::V2_4::ICameraProvider> getService(
                const std::string &serviceName) = 0;
        virtual ~ServiceInteractionProxy() {}
    };

    // Standard use case - call into the normal generated static methods which invoke
    // the real hardware service manager
    struct HardwareServiceInteractionProxy : public ServiceInteractionProxy {
        virtual bool registerForNotifications(
                const std::string &serviceName,
                const sp<hidl::manager::V1_0::IServiceNotification>
                &notification) override {
            return hardware::camera::provider::V2_4::ICameraProvider::registerForNotifications(
                    serviceName, notification);
        }
        virtual sp<hardware::camera::provider::V2_4::ICameraProvider> getService(
                const std::string &serviceName) override {
            return hardware::camera::provider::V2_4::ICameraProvider::getService(serviceName);
        }
    };

    /**
     * Listener interface for device/torch status changes
     */
    struct StatusListener : virtual public RefBase {
        ~StatusListener() {}

        virtual void onDeviceStatusChanged(const String8 &cameraId,
                hardware::camera::common::V1_0::CameraDeviceStatus newStatus) = 0;
        virtual void onTorchStatusChanged(const String8 &cameraId,
                hardware::camera::common::V1_0::TorchModeStatus newStatus) = 0;
    };

    /**
     * Initialize the manager and give it a status listener; optionally accepts a service
     * interaction proxy.
     *
     * The default proxy communicates via the hardware service manager; alternate proxies can be
     * used for testing. The lifetime of the proxy must exceed the lifetime of the manager.
     */
    status_t initialize(wp<StatusListener> listener,
            ServiceInteractionProxy *proxy = &sHardwareServiceInteractionProxy);

    /**
     * Retrieve the total number of available cameras. This value may change dynamically as cameras
     * are added or removed.
     */
    int getCameraCount() const;

    /**
     * Retrieve the number of 'standard' cameras; these are internal and
     * backwards-compatible. This is the set of cameras that will be
     * accessible via the old camera API, with IDs in range of
     * [0, getStandardCameraCount()-1]. This value is not expected to change dynamically.
     */
    int getStandardCameraCount() const;

    std::vector<std::string> getCameraDeviceIds() const;

    /**
     * Return true if a device with a given ID and major version exists
     */
    bool isValidDevice(const std::string &id, uint16_t majorVersion) const;

    /**
     * Return true if a device with a given ID has a flash unit. Returns false
     * for devices that are unknown.
     */
    bool hasFlashUnit(const std::string &id) const;

    /**
     * Return the resource cost of this camera device
     */
    status_t getResourceCost(const std::string &id,
            hardware::camera::common::V1_0::CameraResourceCost* cost) const;

    /**
     * Return the old camera API camera info
     */
    status_t getCameraInfo(const std::string &id,
            hardware::CameraInfo* info) const;

    /**
     * Return API2 camera characteristics - returns NAME_NOT_FOUND if a device ID does
     * not have a v3 or newer HAL version.
     */
    status_t getCameraCharacteristics(const std::string &id,
            CameraMetadata* characteristics) const;

    /**
     * Return the highest supported device interface version for this ID
     */
    status_t getHighestSupportedVersion(const std::string &id,
            hardware::hidl_version *v);

    /**
     * Turn on or off the flashlight on a given camera device.
     * May fail if the device is in active use, or if the device doesn't exist, etc.
     */
    status_t setTorchMode(const std::string &id, bool enabled);

    /**
     * Open an active session to a camera device.
     *
     * This fully powers on the camera device hardware, and returns a handle to a
     * session to be used for hardware configuration and operation.
     */
    status_t openSession(const std::string &id,
            const sp<hardware::camera::device::V3_2::ICameraDeviceCallback>& callback,
            /*out*/
            sp<hardware::camera::device::V3_2::ICameraDeviceSession> *session);

    status_t openSession(const std::string &id,
            const sp<hardware::camera::device::V1_0::ICameraDeviceCallback>& callback,
            /*out*/
            sp<hardware::camera::device::V1_0::ICameraDevice> *session);

    /**
     * IServiceNotification::onRegistration
     * Invoked by the hardware service manager when a new camera provider is registered
     */
    virtual hardware::Return<void> onRegistration(const hardware::hidl_string& fqName,
            const hardware::hidl_string& name,
            bool preexisting) override;

    /**
     * Dump out information about available providers and devices
     */
    status_t dump(int fd, const Vector<String16>& args);

    /**
     * Conversion methods between HAL Status and status_t and strings
     */
    static status_t mapToStatusT(const hardware::camera::common::V1_0::Status& s);
    static const char* statusToString(const hardware::camera::common::V1_0::Status& s);

private:
    // All private members, unless otherwise noted, expect mInterfaceMutex to be locked before use
    mutable std::mutex mInterfaceMutex;

    // the status listener update callbacks will lock mStatusMutex
    mutable std::mutex mStatusListenerMutex;
    wp<StatusListener> mListener;
    ServiceInteractionProxy* mServiceProxy;

    static HardwareServiceInteractionProxy sHardwareServiceInteractionProxy;

    struct ProviderInfo : virtual public hardware::camera::provider::V2_4::ICameraProviderCallback {
        const std::string mProviderName;
        const sp<hardware::camera::provider::V2_4::ICameraProvider> mInterface;

        ProviderInfo(const std::string &providerName,
                sp<hardware::camera::provider::V2_4::ICameraProvider>& interface,
                CameraProviderManager *manager);
        ~ProviderInfo();

        status_t initialize();

        const std::string& getType() const;

        status_t addDevice(const std::string& name,
                hardware::camera::common::V1_0::CameraDeviceStatus initialStatus =
                hardware::camera::common::V1_0::CameraDeviceStatus::PRESENT,
                /*out*/ std::string *parsedId = nullptr);

        status_t dump(int fd, const Vector<String16>& args) const;

        // ICameraProviderCallbacks interface - these lock the parent mInterfaceMutex
        virtual hardware::Return<void> cameraDeviceStatusChange(
                const hardware::hidl_string& cameraDeviceName,
                hardware::camera::common::V1_0::CameraDeviceStatus newStatus) override;
        virtual hardware::Return<void> torchModeStatusChange(
                const hardware::hidl_string& cameraDeviceName,
                hardware::camera::common::V1_0::TorchModeStatus newStatus) override;

        // Basic device information, common to all camera devices
        struct DeviceInfo {
            const std::string mName;  // Full instance name
            const std::string mId;    // ID section of full name
            const hardware::hidl_version mVersion;

            const hardware::camera::common::V1_0::CameraResourceCost mResourceCost;

            hardware::camera::common::V1_0::CameraDeviceStatus mStatus;

            bool hasFlashUnit() const { return mHasFlashUnit; }
            virtual status_t setTorchMode(bool enabled) = 0;
            virtual status_t getCameraInfo(hardware::CameraInfo *info) const = 0;
            virtual status_t getCameraCharacteristics(CameraMetadata *characteristics) const {
                (void) characteristics;
                return INVALID_OPERATION;
            }

            DeviceInfo(const std::string& name, const std::string &id,
                    const hardware::hidl_version& version,
                    const hardware::camera::common::V1_0::CameraResourceCost& resourceCost) :
                    mName(name), mId(id), mVersion(version), mResourceCost(resourceCost),
                    mStatus(hardware::camera::common::V1_0::CameraDeviceStatus::PRESENT),
                    mHasFlashUnit(false) {}
            virtual ~DeviceInfo();
        protected:
            bool mHasFlashUnit;

            template<class InterfaceT>
            static status_t setTorchMode(InterfaceT& interface, bool enabled);
        };
        std::vector<std::unique_ptr<DeviceInfo>> mDevices;

        // HALv1-specific camera fields, including the actual device interface
        struct DeviceInfo1 : public DeviceInfo {
            typedef hardware::camera::device::V1_0::ICameraDevice InterfaceT;
            const sp<InterfaceT> mInterface;

            virtual status_t setTorchMode(bool enabled) override;
            virtual status_t getCameraInfo(hardware::CameraInfo *info) const override;

            DeviceInfo1(const std::string& name, const std::string &id,
                    uint16_t minorVersion,
                    const hardware::camera::common::V1_0::CameraResourceCost& resourceCost,
                    sp<InterfaceT> interface);
            virtual ~DeviceInfo1();
        private:
            CameraParameters2 mDefaultParameters;
        };

        // HALv3-specific camera fields, including the actual device interface
        struct DeviceInfo3 : public DeviceInfo {
            typedef hardware::camera::device::V3_2::ICameraDevice InterfaceT;
            const sp<InterfaceT> mInterface;

            virtual status_t setTorchMode(bool enabled) override;
            virtual status_t getCameraInfo(hardware::CameraInfo *info) const override;
            virtual status_t getCameraCharacteristics(
                    CameraMetadata *characteristics) const override;

            DeviceInfo3(const std::string& name, const std::string &id,
                    uint16_t minorVersion,
                    const hardware::camera::common::V1_0::CameraResourceCost& resourceCost,
                    sp<InterfaceT> interface);
            virtual ~DeviceInfo3();
        private:
            CameraMetadata mCameraCharacteristics;
        };

    private:
        std::string mType;
        uint32_t mId;

        CameraProviderManager *mManager;

        // Templated method to instantiate the right kind of DeviceInfo and call the
        // right CameraProvider getCameraDeviceInterface_* method.
        template<class DeviceInfoT>
        std::unique_ptr<DeviceInfo> initializeDeviceInfo(const std::string &name,
                const std::string &id, uint16_t minorVersion) const;

        // Helper for initializeDeviceInfo to use the right CameraProvider get method.
        template<class InterfaceT>
        sp<InterfaceT> getDeviceInterface(const std::string &name) const;

        // Parse provider instance name for type and id
        static status_t parseProviderName(const std::string& name,
                std::string *type, uint32_t *id);

        // Parse device instance name for device version, type, and id.
        static status_t parseDeviceName(const std::string& name,
                uint16_t *major, uint16_t *minor, std::string *type, std::string *id);
    };

    // Utility to find a DeviceInfo by ID; pointer is only valid while mInterfaceMutex is held
    // and the calling code doesn't mutate the list of providers or their lists of devices.
    // Finds the first device of the given ID that falls within the requested version range
    //   minVersion <= deviceVersion < maxVersion
    // No guarantees on the order of traversal
    ProviderInfo::DeviceInfo* findDeviceInfoLocked(const std::string& id,
            hardware::hidl_version minVersion = hardware::hidl_version{0,0},
            hardware::hidl_version maxVersion = hardware::hidl_version{1000,0}) const;

    status_t addProvider(const std::string& newProvider, bool expected = true);
    status_t removeProvider(const std::string& provider);

    bool isValidDeviceLocked(const std::string &id, uint16_t majorVersion) const;

    std::vector<sp<ProviderInfo>> mProviders;

    static const char* deviceStatusToString(
        const hardware::camera::common::V1_0::CameraDeviceStatus&);
    static const char* torchStatusToString(
        const hardware::camera::common::V1_0::TorchModeStatus&);

};

} // namespace android

#endif