system/usb/Context.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef META_OCEAN_SYSTEM_USB_CONTEXT_H
#define META_OCEAN_SYSTEM_USB_CONTEXT_H
 
#include "ocean/system/usb/USB.h"
 
#include "ocean/base/Lock.h"
 
namespace Ocean
{
 
namespace System
{
 
namespace USB
{
 
// Forward declaration.
class Context;
 
/**
 * Definition of a shared pointer holding a context.
 * @see Context
 * @ingroup systemusb
 */
using SharedContext = std::shared_ptr<Context>;
 
/**
 * This class wraps a libusb context.
 * @ingroup systemusb
 */
class OCEAN_SYSTEM_USB_EXPORT Context
{
    public:
 
        /** 
         * Move constructor.
         * @param context The context to be moved
         */
        inline Context(Context&& context) noexcept;
 
        /**
         * Creates a new custom context.
         * Commonly there is no need to create a custom context, instead use the Manager's context.
         * @param noDeviceDiscovery True, to disable device discovery (e.g., on Android platforms devices cannot be discovered but need to be provided explicitly from the Java side); False, to enable/allow device discovery
         * @param usbDk True, to use the USB-Dk driver on Windows platforms; False, otherwise
         * @see Manager::context().
         */
        explicit Context(const bool noDeviceDiscovery = false, const bool usbDk = false);
 
        /**
         * Destructs and releases the context.
         */
        ~Context();
 
        /**
         * Returns the actual libusb context.
         * @return The actual libusb context, may be nullptr which indicates the global default context
         */
        inline libusb_context* usbContext() const;
 
        /**
         * Explicitly releases the context.
         */
        void release();
 
        /**
         * Returns whether this object wraps a valid context (which is not nullptr).
         * @return True, if so
         */
        inline bool isValid() const;
 
        /**
         * Move operator.
         * @param context The context to be moved
         * @return Reference to this object
         */
        Context& operator=(Context&& context) noexcept;
 
    protected:
 
        /**
         * Disabled copy constructor.
         */
        Context(const Context&) = delete;
 
        /**
         * Disabled copy operator.
         * @return Reference to this object
         */
        Context& operator=(const Context&) = delete;
 
    protected:
 
        /// The actual libusb context.
        libusb_context* usbContext_ = nullptr;
 
        /// The context's lock.
        mutable Lock lock_;
};
 
inline Context::Context(Context&& context) noexcept
{
    *this = std::move(context);
}
 
inline libusb_context* Context::usbContext() const
{
    return usbContext_;
}
 
inline bool Context::isValid() const
{
    const ScopedLock scopedLock(lock_);
 
    return usbContext_ != nullptr;
}
 
}
 
}
 
}
 
#endif // META_OCEAN_SYSTEM_USB_CONTEXT_H