qdbusmetaobject.cpp

QT 开发环境里面一个很重要的文件

    QDBusIntrospection::Properties::ConstIterator prop_it = data->properties.constBegin();
    QDBusIntrospection::Properties::ConstIterator prop_end = data->properties.constEnd();
    for ( ; prop_it != prop_end; ++prop_it) {
        const QDBusIntrospection::Property &p = *prop_it;
        Property mp;
        Type type = findType(p.type.toLatin1(), p.annotations);
        if (type.id == QVariant::Invalid)
            continue;
        
        QByteArray name = p.name.toLatin1();
        mp.signature = p.type.toLatin1();
        mp.type = type.id;
        mp.typeName = type.name;

        // build the flags:
        mp.flags = StdCppSet | Scriptable | Stored | Designable;
        if (p.access != QDBusIntrospection::Property::Write)
            mp.flags |= Readable;
        if (p.access != QDBusIntrospection::Property::Read)
            mp.flags |= Writable;

        if (mp.typeName == "QDBusVariant")
            mp.flags |= 0xff << 24;
        else if (mp.type < 0xff)
            // encode the type in the flags
            mp.flags |= mp.type << 24;

        // add the property:
        properties.insert(name, mp);
    }
}

void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
{
    // this code here is mostly copied from qaxbase.cpp
    // with a few modifications to make it cleaner
    
    QString className = interface;
    className.replace(QLatin1Char('.'), QLatin1String("::"));
    if (className.isEmpty())
        className = QLatin1String("QDBusInterface");

    QVarLengthArray<int> idata;
    idata.resize(sizeof(QDBusMetaObjectPrivate) / sizeof(int));

    QDBusMetaObjectPrivate *header = reinterpret_cast<QDBusMetaObjectPrivate *>(idata.data());
    header->revision = 1;
    header->className = 0;
    header->classInfoCount = 0;
    header->classInfoData = 0;
    header->methodCount = methods.count();
    header->methodData = idata.size();
    header->propertyCount = properties.count();
    header->propertyData = header->methodData + header->methodCount * 5;
    header->enumeratorCount = 0;
    header->enumeratorData = 0;
    header->propertyDBusData = header->propertyData + header->propertyCount * 3;
    header->methodDBusData = header->propertyDBusData + header->propertyCount * intsPerProperty;

    int data_size = idata.size() +
                    (header->methodCount * (5+intsPerMethod)) +
                    (header->propertyCount * (3+intsPerProperty));
    foreach (const Method &mm, methods)
        data_size += 2 + mm.inputTypes.count() + mm.outputTypes.count();
    idata.resize(data_size + 1);

    char null('\0');
    QByteArray stringdata = className.toLatin1();
    stringdata += null;
    stringdata.reserve(8192);

    int offset = header->methodData;
    int signatureOffset = header->methodDBusData;
    int typeidOffset = header->methodDBusData + header->methodCount * intsPerMethod;
    idata[typeidOffset++] = 0;                           // eod

    // add each method:
    for (QMap<QByteArray, Method>::ConstIterator it = methods.constBegin();
         it != methods.constEnd(); ++it) {
        // form "prototype\0parameters\0typeName\0tag\0inputSignature\0outputSignature"
        const Method &mm = it.value();

        idata[offset++] = stringdata.length();
        stringdata += it.key();                 // prototype
        stringdata += null;
        idata[offset++] = stringdata.length();
        stringdata += mm.parameters;
        stringdata += null;
        idata[offset++] = stringdata.length();
        stringdata += mm.typeName;
        stringdata += null;
        idata[offset++] = stringdata.length();
        stringdata += mm.tag;
        stringdata += null;
        idata[offset++] = mm.flags;

        idata[signatureOffset++] = stringdata.length();
        stringdata += mm.inputSignature;
        stringdata += null;
        idata[signatureOffset++] = stringdata.length();
        stringdata += mm.outputSignature;
        stringdata += null;

        idata[signatureOffset++] = typeidOffset;
        idata[typeidOffset++] = mm.inputTypes.count();
        memcpy(idata.data() + typeidOffset, mm.inputTypes.data(), mm.inputTypes.count() * sizeof(int));
        typeidOffset += mm.inputTypes.count();

        idata[signatureOffset++] = typeidOffset;
        idata[typeidOffset++] = mm.outputTypes.count();
        memcpy(idata.data() + typeidOffset, mm.outputTypes.data(), mm.outputTypes.count() * sizeof(int));
        typeidOffset += mm.outputTypes.count();
    }

    Q_ASSERT(offset == header->propertyData);
    Q_ASSERT(signatureOffset == header->methodDBusData + header->methodCount * intsPerMethod);
    Q_ASSERT(typeidOffset == idata.size());

    // add each property
    signatureOffset = header->propertyDBusData;
    for (QMap<QByteArray, Property>::ConstIterator it = properties.constBegin();
         it != properties.constEnd(); ++it) {
        const Property &mp = it.value();

        // form is "name\0typeName\0signature\0"
        idata[offset++] = stringdata.length();
        stringdata += it.key();                 // name
        stringdata += null;
        idata[offset++] = stringdata.length();
        stringdata += mp.typeName;
        stringdata += null;
        idata[offset++] = mp.flags;

        idata[signatureOffset++] = stringdata.length();
        stringdata += mp.signature;
        stringdata += null;
        idata[signatureOffset++] = mp.type;
    }

    Q_ASSERT(offset == header->propertyDBusData);
    Q_ASSERT(signatureOffset == header->methodDBusData);

    char *string_data = new char[stringdata.length()];
    memcpy(string_data, stringdata, stringdata.length());

    uint *uint_data = new uint[idata.size()];
    memcpy(uint_data, idata.data(), idata.size() * sizeof(int));

    // put the metaobject together
    obj->d.data = uint_data;
    obj->d.extradata = 0;
    obj->d.stringdata = string_data;
    obj->d.superdata = &QDBusAbstractInterface::staticMetaObject;
}

#if 0
void QDBusMetaObjectGenerator::writeWithoutXml(const QString &interface)
{
    // no XML definition
    QString tmp(interface);
    tmp.replace(QLatin1Char('.'), QLatin1String("::"));
    QByteArray name(tmp.toLatin1());

    QDBusMetaObjectPrivate *header = new QDBusMetaObjectPrivate;
    memset(header, 0, sizeof *header);
    header->revision = 1;
    // leave the rest with 0

    char *stringdata = new char[name.length() + 1];
    stringdata[name.length()] = '\0';
    
    d.data = reinterpret_cast<uint*>(header);
    d.extradata = 0;
    d.stringdata = stringdata;
    d.superdata = &QDBusAbstractInterface::staticMetaObject;
    cached = false;
}
#endif

/////////
// class QDBusMetaObject

QDBusMetaObject *QDBusMetaObject::createMetaObject(const QString &interface, const QString &xml,
                                                   QHash<QString, QDBusMetaObject *> &cache,
                                                   QDBusError &error)
{
    error = QDBusError();
    QDBusIntrospection::Interfaces parsed = QDBusIntrospection::parseInterfaces(xml);

    QDBusMetaObject *we = 0;
    QDBusIntrospection::Interfaces::ConstIterator it = parsed.constBegin();
    QDBusIntrospection::Interfaces::ConstIterator end = parsed.constEnd();
    for ( ; it != end; ++it) {
        // check if it's in the cache
        bool us = it.key() == interface;

        QDBusMetaObject *obj = cache.value(it.key(), 0);
        if ( !obj && ( us || !interface.startsWith( QLatin1String("local.") ) ) ) {
            // not in cache; create
            obj = new QDBusMetaObject;
            QDBusMetaObjectGenerator generator(it.key(), it.value().constData());
            generator.write(obj);

            if ( (obj->cached = !it.key().startsWith( QLatin1String("local.") )) )
                // cache it
                cache.insert(it.key(), obj);
            else if (!us)
                delete obj;

        }

        if (us)
            // it's us
            we = obj;
    }

    if (we)
        return we;
    // still nothing?
    
    if (parsed.isEmpty()) {
        // object didn't return introspection
        we = new QDBusMetaObject;
        QDBusMetaObjectGenerator generator(interface, 0);
        generator.write(we);
        we->cached = false;
        return we;
    } else if (interface.isEmpty()) {
        // merge all interfaces
        it = parsed.constBegin();
        QDBusIntrospection::Interface merged = *it.value().constData();
 
        for (++it; it != end; ++it) {
            merged.annotations.unite(it.value()->annotations);
            merged.methods.unite(it.value()->methods);
            merged.signals_.unite(it.value()->signals_);
            merged.properties.unite(it.value()->properties);
        }

        merged.name = QLatin1String("local.Merged");
        merged.introspection.clear();

        we = new QDBusMetaObject;
        QDBusMetaObjectGenerator generator(merged.name, &merged);
        generator.write(we);
        we->cached = false;
        return we;
    }

    // mark as an error
    error = QDBusError(QDBusError::UnknownInterface,
                       QString( QLatin1String("Interface '%1' was not found") )
                       .arg(interface));
    return 0;
}

QDBusMetaObject::QDBusMetaObject()
{
}

inline const QDBusMetaObjectPrivate *priv(const uint* data)
{
    return reinterpret_cast<const QDBusMetaObjectPrivate *>(data);
}

const char *QDBusMetaObject::dbusNameForMethod(int id) const
{
    //id -= methodOffset();
    if (id >= 0 && id < priv(d.data)->methodCount) {
        int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
        return d.stringdata + d.data[handle];
    }
    return 0;
}

const char *QDBusMetaObject::inputSignatureForMethod(int id) const
{
    //id -= methodOffset();
    if (id >= 0 && id < priv(d.data)->methodCount) {
        int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
        return d.stringdata + d.data[handle + 1];
    }
    return 0;
}

const char *QDBusMetaObject::outputSignatureForMethod(int id) const
{
    //id -= methodOffset();
    if (id >= 0 && id < priv(d.data)->methodCount) {
        int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
        return d.stringdata + d.data[handle + 2];
    }
    return 0;
}

const int *QDBusMetaObject::inputTypesForMethod(int id) const
{
    //id -= methodOffset();
    if (id >= 0 && id < priv(d.data)->methodCount) {
        int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
        return reinterpret_cast<const int*>(d.data + d.data[handle + 3]);
    }
    return 0;
}

const int *QDBusMetaObject::outputTypesForMethod(int id) const
{
    //id -= methodOffset();
    if (id >= 0 && id < priv(d.data)->methodCount) {
        int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
        return reinterpret_cast<const int*>(d.data + d.data[handle + 4]);
    }
    return 0;
}

int QDBusMetaObject::propertyMetaType(int id) const
{
    //id -= propertyOffset();
    if (id >= 0 && id < priv(d.data)->propertyCount) {
        int handle = priv(d.data)->propertyDBusData + id*intsPerProperty;
        return d.data[handle + 1];
    }
    return 0;
}