controls.h

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * Control handling
 */

#pragma once

#include <assert.h>
#include <optional>
#include <set>
#include <stdint.h>
#include <string>
#include <unordered_map>
#include <vector>

#include <libcamera/base/class.h>
#include <libcamera/base/span.h>

#include <libcamera/geometry.h>

namespace libcamera {

class ControlValidator;

enum ControlType {
    ControlTypeNone,
    ControlTypeBool,
    ControlTypeByte,
    ControlTypeInteger32,
    ControlTypeInteger64,
    ControlTypeFloat,
    ControlTypeString,
    ControlTypeRectangle,
    ControlTypeSize,
};

namespace details {

template<typename T>
struct control_type {
};

template<>
struct control_type<void> {
    static constexpr ControlType value = ControlTypeNone;
};

template<>
struct control_type<bool> {
    static constexpr ControlType value = ControlTypeBool;
};

template<>
struct control_type<uint8_t> {
    static constexpr ControlType value = ControlTypeByte;
};

template<>
struct control_type<int32_t> {
    static constexpr ControlType value = ControlTypeInteger32;
};

template<>
struct control_type<int64_t> {
    static constexpr ControlType value = ControlTypeInteger64;
};

template<>
struct control_type<float> {
    static constexpr ControlType value = ControlTypeFloat;
};

template<>
struct control_type<std::string> {
    static constexpr ControlType value = ControlTypeString;
};

template<>
struct control_type<Rectangle> {
    static constexpr ControlType value = ControlTypeRectangle;
};

template<>
struct control_type<Size> {
    static constexpr ControlType value = ControlTypeSize;
};

template<typename T, std::size_t N>
struct control_type<Span<T, N>> : public control_type<std::remove_cv_t<T>> {
};

} /* namespace details */

class ControlValue
{
public:
    ControlValue();

#ifndef __DOXYGEN__
    template<typename T, std::enable_if_t<!details::is_span<T>::value &&
                          details::control_type<T>::value &&
                          !std::is_same<std::string, std::remove_cv_t<T>>::value,
                          std::nullptr_t> = nullptr>
    ControlValue(const T &value)
        : type_(ControlTypeNone), numElements_(0)
    {
        set(details::control_type<std::remove_cv_t<T>>::value, false,
            &value, 1, sizeof(T));
    }

    template<typename T, std::enable_if_t<details::is_span<T>::value ||
                          std::is_same<std::string, std::remove_cv_t<T>>::value,
                          std::nullptr_t> = nullptr>
#else
    template<typename T>
#endif
    ControlValue(const T &value)
        : type_(ControlTypeNone), numElements_(0)
    {
        set(details::control_type<std::remove_cv_t<T>>::value, true,
            value.data(), value.size(), sizeof(typename T::value_type));
    }

    ~ControlValue();

    ControlValue(const ControlValue &other);
    ControlValue &operator=(const ControlValue &other);

    ControlType type() const { return type_; }
    bool isNone() const { return type_ == ControlTypeNone; }
    bool isArray() const { return isArray_; }
    std::size_t numElements() const { return numElements_; }
    Span<const uint8_t> data() const;
    Span<uint8_t> data();

    std::string toString() const;

    bool operator==(const ControlValue &other) const;
    bool operator!=(const ControlValue &other) const
    {
        return !(*this == other);
    }

#ifndef __DOXYGEN__
    template<typename T, std::enable_if_t<!details::is_span<T>::value &&
                          !std::is_same<std::string, std::remove_cv_t<T>>::value,
                          std::nullptr_t> = nullptr>
    T get() const
    {
        assert(type_ == details::control_type<std::remove_cv_t<T>>::value);
        assert(!isArray_);

        return *reinterpret_cast<const T *>(data().data());
    }

    template<typename T, std::enable_if_t<details::is_span<T>::value ||
                          std::is_same<std::string, std::remove_cv_t<T>>::value,
                          std::nullptr_t> = nullptr>
#else
    template<typename T>
#endif
    T get() const
    {
        assert(type_ == details::control_type<std::remove_cv_t<T>>::value);
        assert(isArray_);

        using V = typename T::value_type;
        const V *value = reinterpret_cast<const V *>(data().data());
        return T{ value, numElements_ };
    }

#ifndef __DOXYGEN__
    template<typename T, std::enable_if_t<!details::is_span<T>::value &&
                          !std::is_same<std::string, std::remove_cv_t<T>>::value,
                          std::nullptr_t> = nullptr>
    void set(const T &value)
    {
        set(details::control_type<std::remove_cv_t<T>>::value, false,
            reinterpret_cast<const void *>(&value), 1, sizeof(T));
    }

    template<typename T, std::enable_if_t<details::is_span<T>::value ||
                          std::is_same<std::string, std::remove_cv_t<T>>::value,
                          std::nullptr_t> = nullptr>
#else
    template<typename T>
#endif
    void set(const T &value)
    {
        set(details::control_type<std::remove_cv_t<T>>::value, true,
            value.data(), value.size(), sizeof(typename T::value_type));
    }

    void reserve(ControlType type, bool isArray = false,
             std::size_t numElements = 1);

private:
    ControlType type_ : 8;
    bool isArray_;
    std::size_t numElements_ : 32;
    union {
        uint64_t value_;
        void *storage_;
    };

    void release();
    void set(ControlType type, bool isArray, const void *data,
         std::size_t numElements, std::size_t elementSize);
};

class ControlId
{
public:
    ControlId(unsigned int id, const std::string &name, ControlType type)
        : id_(id), name_(name), type_(type)
    {
    }

    unsigned int id() const { return id_; }
    const std::string &name() const { return name_; }
    ControlType type() const { return type_; }

private:
    LIBCAMERA_DISABLE_COPY_AND_MOVE(ControlId)

    unsigned int id_;
    std::string name_;
    ControlType type_;
};

static inline bool operator==(unsigned int lhs, const ControlId &rhs)
{
    return lhs == rhs.id();
}

static inline bool operator!=(unsigned int lhs, const ControlId &rhs)
{
    return !(lhs == rhs);
}

static inline bool operator==(const ControlId &lhs, unsigned int rhs)
{
    return lhs.id() == rhs;
}

static inline bool operator!=(const ControlId &lhs, unsigned int rhs)
{
    return !(lhs == rhs);
}

template<typename T>
class Control : public ControlId
{
public:
    using type = T;

    Control(unsigned int id, const char *name)
        : ControlId(id, name, details::control_type<std::remove_cv_t<T>>::value)
    {
    }

private:
    LIBCAMERA_DISABLE_COPY_AND_MOVE(Control)
};

class ControlInfo
{
public:
    explicit ControlInfo(const ControlValue &min = {},
                 const ControlValue &max = {},
                 const ControlValue &def = {});
    explicit ControlInfo(Span<const ControlValue> values,
                 const ControlValue &def = {});
    explicit ControlInfo(std::set<bool> values, bool def);
    explicit ControlInfo(bool value);

    const ControlValue &min() const { return min_; }
    const ControlValue &max() const { return max_; }
    const ControlValue &def() const { return def_; }
    const std::vector<ControlValue> &values() const { return values_; }

    std::string toString() const;

    bool operator==(const ControlInfo &other) const
    {
        return min_ == other.min_ && max_ == other.max_;
    }

    bool operator!=(const ControlInfo &other) const
    {
        return !(*this == other);
    }

private:
    ControlValue min_;
    ControlValue max_;
    ControlValue def_;
    std::vector<ControlValue> values_;
};

using ControlIdMap = std::unordered_map<unsigned int, const ControlId *>;

class ControlInfoMap : private std::unordered_map<const ControlId *, ControlInfo>
{
public:
    using Map = std::unordered_map<const ControlId *, ControlInfo>;

    ControlInfoMap() = default;
    ControlInfoMap(const ControlInfoMap &other) = default;
    ControlInfoMap(std::initializer_list<Map::value_type> init,
               const ControlIdMap &idmap);
    ControlInfoMap(Map &&info, const ControlIdMap &idmap);

    ControlInfoMap &operator=(const ControlInfoMap &other) = default;

    using Map::key_type;
    using Map::mapped_type;
    using Map::value_type;
    using Map::size_type;
    using Map::iterator;
    using Map::const_iterator;

    using Map::begin;
    using Map::cbegin;
    using Map::end;
    using Map::cend;
    using Map::at;
    using Map::empty;
    using Map::size;
    using Map::count;
    using Map::find;

    mapped_type &at(unsigned int key);
    const mapped_type &at(unsigned int key) const;
    size_type count(unsigned int key) const;
    iterator find(unsigned int key);
    const_iterator find(unsigned int key) const;

    const ControlIdMap &idmap() const { return *idmap_; }

private:
    bool validate();

    const ControlIdMap *idmap_ = nullptr;
};

class ControlList
{
private:
    using ControlListMap = std::unordered_map<unsigned int, ControlValue>;

public:
    enum class MergePolicy {
        KeepExisting = 0,
        OverwriteExisting,
    };

    ControlList();
    ControlList(const ControlIdMap &idmap, const ControlValidator *validator = nullptr);
    ControlList(const ControlInfoMap &infoMap, const ControlValidator *validator = nullptr);

    using iterator = ControlListMap::iterator;
    using const_iterator = ControlListMap::const_iterator;

    iterator begin() { return controls_.begin(); }
    iterator end() { return controls_.end(); }
    const_iterator begin() const { return controls_.begin(); }
    const_iterator end() const { return controls_.end(); }

    bool empty() const { return controls_.empty(); }
    std::size_t size() const { return controls_.size(); }

    void clear() { controls_.clear(); }
    void merge(const ControlList &source, MergePolicy policy = MergePolicy::KeepExisting);

    bool contains(unsigned int id) const;

    template<typename T>
    std::optional<T> get(const Control<T> &ctrl) const
    {
        const auto entry = controls_.find(ctrl.id());
        if (entry == controls_.end())
            return std::nullopt;

        const ControlValue &val = entry->second;
        return val.get<T>();
    }

    template<typename T, typename V>
    void set(const Control<T> &ctrl, const V &value)
    {
        ControlValue *val = find(ctrl.id());
        if (!val)
            return;

        val->set<T>(value);
    }

    template<typename T, typename V, size_t Size>
    void set(const Control<Span<T, Size>> &ctrl, const std::initializer_list<V> &value)
    {
        ControlValue *val = find(ctrl.id());
        if (!val)
            return;

        val->set(Span<const typename std::remove_cv_t<V>, Size>{ value.begin(), value.size() });
    }

    const ControlValue &get(unsigned int id) const;
    void set(unsigned int id, const ControlValue &value);

    const ControlInfoMap *infoMap() const { return infoMap_; }
    const ControlIdMap *idMap() const { return idmap_; }

private:
    const ControlValue *find(unsigned int id) const;
    ControlValue *find(unsigned int id);

    const ControlValidator *validator_;
    const ControlIdMap *idmap_;
    const ControlInfoMap *infoMap_;

    ControlListMap controls_;
};

} /* namespace libcamera */