pipeline_handler.h

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2018, Google Inc.
 *
 * Pipeline handler infrastructure
 */

#pragma once

#include <memory>
#include <queue>
#include <string>
#include <sys/types.h>
#include <vector>

#include <libcamera/base/object.h>

#include <libcamera/controls.h>
#include <libcamera/stream.h>

namespace libcamera {

class Camera;
class CameraConfiguration;
class CameraManager;
class DeviceEnumerator;
class DeviceMatch;
class FrameBuffer;
class MediaDevice;
class PipelineHandler;
class Request;

class PipelineHandler : public std::enable_shared_from_this<PipelineHandler>,
            public Object
{
public:
    PipelineHandler(CameraManager *manager);
    virtual ~PipelineHandler();

    virtual bool match(DeviceEnumerator *enumerator) = 0;
    MediaDevice *acquireMediaDevice(DeviceEnumerator *enumerator,
                    const DeviceMatch &dm);

    bool acquire(Camera *camera);
    void release(Camera *camera);

    virtual std::unique_ptr<CameraConfiguration> generateConfiguration(Camera *camera,
                                       Span<const StreamRole> roles) = 0;
    virtual int configure(Camera *camera, CameraConfiguration *config) = 0;

    virtual int exportFrameBuffers(Camera *camera, Stream *stream,
                       std::vector<std::unique_ptr<FrameBuffer>> *buffers) = 0;

    virtual int start(Camera *camera, const ControlList *controls) = 0;
    void stop(Camera *camera);
    bool hasPendingRequests(const Camera *camera) const;

    void registerRequest(Request *request);
    void queueRequest(Request *request);

    bool completeBuffer(Request *request, FrameBuffer *buffer);
    void completeRequest(Request *request);
    void cancelRequest(Request *request);

    std::string configurationFile(const std::string &subdir,
                      const std::string &name) const;

    const char *name() const { return name_; }

    CameraManager *cameraManager() const { return manager_; }

protected:
    void registerCamera(std::shared_ptr<Camera> camera);
    void hotplugMediaDevice(MediaDevice *media);

    virtual int queueRequestDevice(Camera *camera, Request *request) = 0;
    virtual void stopDevice(Camera *camera) = 0;

    virtual bool acquireDevice(Camera *camera);
    virtual void releaseDevice(Camera *camera);

    CameraManager *manager_;

private:
    void unlockMediaDevices();

    void mediaDeviceDisconnected(MediaDevice *media);
    virtual void disconnect();

    void doQueueRequest(Request *request);
    void doQueueRequests();

    std::vector<std::shared_ptr<MediaDevice>> mediaDevices_;
    std::vector<std::weak_ptr<Camera>> cameras_;

    std::queue<Request *> waitingRequests_;

    const char *name_;
    unsigned int useCount_;

    friend class PipelineHandlerFactoryBase;
};

class PipelineHandlerFactoryBase
{
public:
    PipelineHandlerFactoryBase(const char *name);
    virtual ~PipelineHandlerFactoryBase() = default;

    std::shared_ptr<PipelineHandler> create(CameraManager *manager) const;

    const std::string &name() const { return name_; }

    static std::vector<PipelineHandlerFactoryBase *> &factories();
    static const PipelineHandlerFactoryBase *getFactoryByName(const std::string &name);

private:
    static void registerType(PipelineHandlerFactoryBase *factory);

    virtual std::unique_ptr<PipelineHandler>
    createInstance(CameraManager *manager) const = 0;

    std::string name_;
};

template<typename _PipelineHandler>
class PipelineHandlerFactory final : public PipelineHandlerFactoryBase
{
public:
    PipelineHandlerFactory(const char *name)
        : PipelineHandlerFactoryBase(name)
    {
    }

    std::unique_ptr<PipelineHandler>
    createInstance(CameraManager *manager) const override
    {
        return std::make_unique<_PipelineHandler>(manager);
    }
};

#define REGISTER_PIPELINE_HANDLER(handler, name) \
    static PipelineHandlerFactory<handler> global_##handler##Factory(name);

} /* namespace libcamera */