qpipewire_propertydict.cpp

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// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qpipewire_propertydict_p.h"
 
#include <pipewire/extensions/metadata.h>
 
#include <QtCore/qspan.h>
 
#include <cstdint>
 
QT_BEGIN_NAMESPACE
 
#ifndef PW_KEY_DEVICE_SYSFS_PATH
#  define PW_KEY_DEVICE_SYSFS_PATH "device.sysfs.path"
#endif
#ifndef PW_KEY_OBJECT_SERIAL
#  define PW_KEY_OBJECT_SERIAL "object.serial"
#endif
 
namespace QtPipeWire {
 
PwPropertiesHandle makeProperties(QSpan<const spa_dict_item> keyValuePairs)
{
    struct spa_dict info = SPA_DICT_INIT(keyValuePairs.data(), uint32_t(keyValuePairs.size()));
 
    return PwPropertiesHandle{
        pw_properties_new_dict(&info),
    };
}
 
PwPropertyDict toPropertyDict(const spa_dict &dict)
{
    QSpan<const spa_dict_item> items{ dict.items, dict.n_items };
 
    PwPropertyDict map;
    for (const spa_dict_item &item : items)
        map.emplace(item.key, item.value);
    return map;
}
 
namespace {
 
std::optional<std::string_view> resolveInDictionary(const PwPropertyDict &dict,
                                                    std::string_view key)
{
    if (auto it = dict.find(key); it != dict.end())
        return it->second;
    return std::nullopt;
}
 
template <typename Converter>
auto resolveInDictionaryHelper(const PwPropertyDict &dict, std::string_view key,
                               Converter &&convert)
{
    using ResultType = decltype(convert(std::declval<std::string_view>()));
 
    if (auto it = dict.find(key); it != dict.end())
        return convert(it->second);
    return ResultType{ std::nullopt };
}
 
template <typename T>
struct Converter
{
};
 
template <>
struct Converter<uint32_t>
{
    std::optional<uint32_t> operator()(std::string_view sv) const
    {
        bool ok{};
        uint32_t ret = QLatin1StringView(sv).toInt(&ok);
        if (ok)
            return ret;
 
        return std::nullopt;
    }
};
 
template <>
struct Converter<uint64_t>
{
    std::optional<uint64_t> operator()(std::string_view sv) const
    {
        static_assert(sizeof(qulonglong) == sizeof(uint64_t));
 
        bool ok{};
        uint64_t ret = QLatin1StringView(sv).toULongLong(&ok);
        if (ok)
            return ret;
 
        return std::nullopt;
    }
};
 
template <typename T>
std::optional<T> resolveInDictionary(const PwPropertyDict &dict, std::string_view key)
{
    return resolveInDictionaryHelper(dict, key, Converter<T>{});
}
 
} // namespace
 
std::optional<std::string_view> getMediaClass(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_MEDIA_CLASS);
}
 
std::optional<std::string_view> getNodeName(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_NODE_NAME);
}
 
std::optional<std::string_view> getNodeDescription(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_NODE_DESCRIPTION);
}
 
std::optional<ObjectId> getDeviceId(const PwPropertyDict &dict)
{
    auto resolvedUint32 = resolveInDictionary<uint32_t>(dict, PW_KEY_DEVICE_ID);
    if (resolvedUint32)
        return ObjectId{ *resolvedUint32 };
    return std::nullopt;
}
 
std::optional<std::string_view> getDeviceSysfsPath(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_DEVICE_SYSFS_PATH);
}
 
std::optional<std::string_view> getDeviceName(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_DEVICE_NAME);
}
 
std::optional<std::string_view> getDeviceDescription(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_DEVICE_DESCRIPTION);
}
 
std::optional<ObjectSerial> getObjectSerial(const PwPropertyDict &dict)
{
    auto resolvedUint64 = resolveInDictionary<uint64_t>(dict, PW_KEY_OBJECT_SERIAL);
    if (resolvedUint64)
        return ObjectSerial{ *resolvedUint64 };
    return std::nullopt;
}
 
std::optional<std::string_view> getMetadataName(const PwPropertyDict &dict)
{
    return resolveInDictionary(dict, PW_KEY_METADATA_NAME);
}
 
} // namespace QtPipeWire
 
QT_END_NAMESPACE