qdbusmarshaller.cpp

QT 开发环境里面一个很重要的文件

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the tools applications of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
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**
** If you are unsure which license is appropriate for your use, please
** review the following information:
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** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qdbusargument_p.h"
#include "qdbusutil_p.h"

static void qIterAppend(DBusMessageIter *it, QByteArray *ba, int type, const void *arg)
{
    if (ba)
        *ba += char(type);
    else
        dbus_message_iter_append_basic(it, type, arg);
}

QDBusMarshaller::~QDBusMarshaller()
{
    close();
}

inline void QDBusMarshaller::append(uchar arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_BYTE, &arg);
}

inline void QDBusMarshaller::append(bool arg)
{
    dbus_bool_t cast = arg;
    qIterAppend(&iterator, ba, DBUS_TYPE_BOOLEAN, &cast);
}

inline void QDBusMarshaller::append(short arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_INT16, &arg);
}

inline void QDBusMarshaller::append(ushort arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_UINT16, &arg);
}

inline void QDBusMarshaller::append(int arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_INT32, &arg);
}

inline void QDBusMarshaller::append(uint arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_UINT32, &arg);
}

inline void QDBusMarshaller::append(qlonglong arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_INT64, &arg);
}

inline void QDBusMarshaller::append(qulonglong arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_UINT64, &arg);
}

inline void QDBusMarshaller::append(double arg)
{
    qIterAppend(&iterator, ba, DBUS_TYPE_DOUBLE, &arg);
}

inline void QDBusMarshaller::append(const QString &arg)
{
    QByteArray data = arg.toUtf8();
    const char *cdata = data.constData();
    qIterAppend(&iterator, ba, DBUS_TYPE_STRING, &cdata);
}

inline void QDBusMarshaller::append(const QDBusObjectPath &arg)
{
    QByteArray data = arg.path().toUtf8();
    const char *cdata = data.constData();
    qIterAppend(&iterator, ba, DBUS_TYPE_OBJECT_PATH, &cdata);
}

inline void QDBusMarshaller::append(const QDBusSignature &arg)
{
    QByteArray data = arg.signature().toUtf8();
    const char *cdata = data.constData();
    qIterAppend(&iterator, ba, DBUS_TYPE_SIGNATURE, &cdata);
}

inline void QDBusMarshaller::append(const QByteArray &arg)
{
    if (ba) {
        *ba += DBUS_TYPE_ARRAY_AS_STRING DBUS_TYPE_BYTE_AS_STRING;
        return;
    }

    const char* cdata = arg.constData();
    DBusMessageIter subiterator;
    dbus_message_iter_open_container(&iterator, DBUS_TYPE_ARRAY, DBUS_TYPE_BYTE_AS_STRING,
                                     &subiterator);
    dbus_message_iter_append_fixed_array(&subiterator, DBUS_TYPE_BYTE, &cdata, arg.length());
    dbus_message_iter_close_container(&iterator, &subiterator);
}

inline bool QDBusMarshaller::append(const QDBusVariant &arg)
{
    if (ba) {
        *ba += DBUS_TYPE_VARIANT_AS_STRING;
        return true;
    }

    const QVariant &value = arg.variant();
    QVariant::Type id = QVariant::Type(value.userType());
    if (id == QVariant::Invalid) {
        qWarning("QDBusMarshaller: cannot add a null QDBusVariant");
        error();
        return false;
    }

    const char *signature = QDBusMetaType::typeToSignature(id);
    if (!signature) {
        qWarning("QDBusMarshaller: type `%s' (%d) is not registered with D-BUS. "
                 "Use qDBusRegisterMetaType to register it",
                 QVariant::typeToName( id ), id);
        error();
        return false;
    }

    QDBusMarshaller sub;
    open(sub, DBUS_TYPE_VARIANT, signature);
    bool isOk = sub.appendVariantInternal(value);
    // don't call sub.close(): it auto-closes

    return isOk;
}

inline void QDBusMarshaller::append(const QStringList &arg)
{
    if (ba) {
        *ba += DBUS_TYPE_ARRAY_AS_STRING DBUS_TYPE_STRING_AS_STRING;
        return;
    }

    QDBusMarshaller sub;
    open(sub, DBUS_TYPE_ARRAY, DBUS_TYPE_STRING_AS_STRING);
    QStringList::ConstIterator it = arg.constBegin();
    QStringList::ConstIterator end = arg.constEnd();
    for ( ; it != end; ++it)
        sub.append(*it);
    // don't call sub.close(): it auto-closes
}

inline QDBusMarshaller *QDBusMarshaller::beginStructure()
{
    return beginCommon(DBUS_TYPE_STRUCT, 0);
}

inline QDBusMarshaller *QDBusMarshaller::beginArray(int id)
{
    const char *signature = QDBusMetaType::typeToSignature( QVariant::Type(id) );
    if (!signature) {
        qWarning("QDBusMarshaller: type `%s' (%d) is not registered with D-BUS. "
                 "Use qDBusRegisterMetaType to register it",
                 QVariant::typeToName( QVariant::Type(id) ), id);
        error();
        return this;
    }

    return beginCommon(DBUS_TYPE_ARRAY, signature);
}

inline QDBusMarshaller *QDBusMarshaller::beginMap(int kid, int vid)
{
    const char *ksignature = QDBusMetaType::typeToSignature( QVariant::Type(kid) );
    if (!ksignature) {
        qWarning("QDBusMarshaller: type `%s' (%d) is not registered with D-BUS. "
                 "Use qDBusRegisterMetaType to register it",
                 QVariant::typeToName( QVariant::Type(kid) ), kid);
        error();
        return this;
    }
    if (ksignature[1] != 0 || !dbus_type_is_basic(*ksignature)) {
        qWarning("QDBusMarshaller: type '%s' (%d) cannot be used as the key type in a D-BUS map.",
                 QVariant::typeToName( QVariant::Type(kid) ), kid);
        error();
        return this;
    }

    const char *vsignature = QDBusMetaType::typeToSignature( QVariant::Type(vid) );
    if (!vsignature) {
        qWarning("QDBusMarshaller: type `%s' (%d) is not registered with D-BUS. "
                 "Use qDBusRegisterMetaType to register it",
                 QVariant::typeToName( QVariant::Type(vid) ), vid);
        error();
        return this;
    }

    QByteArray signature;
    signature = DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING;
    signature += ksignature;
    signature += vsignature;
    signature += DBUS_DICT_ENTRY_END_CHAR_AS_STRING;
    return beginCommon(DBUS_TYPE_ARRAY, signature);
}

inline QDBusMarshaller *QDBusMarshaller::beginMapEntry()
{
    return beginCommon(DBUS_TYPE_DICT_ENTRY, 0);
}

void QDBusMarshaller::open(QDBusMarshaller &sub, int code, const char *signature)
{
    sub.parent = this;
    sub.ba = ba;
    sub.ok = true;

    if (ba)
        switch (code) {
        case DBUS_TYPE_ARRAY:
            *ba += char(code);
            *ba += signature;
            // fall through

        case DBUS_TYPE_DICT_ENTRY:
            sub.closeCode = 0;
            break;

        case DBUS_TYPE_STRUCT:
            *ba += DBUS_STRUCT_BEGIN_CHAR;
            sub.closeCode = DBUS_STRUCT_END_CHAR;
            break;
        }
    else
        dbus_message_iter_open_container(&iterator, code, signature, &sub.iterator);
}

QDBusMarshaller *QDBusMarshaller::beginCommon(int code, const char *signature)
{
    QDBusMarshaller *d = new QDBusMarshaller;
    open(*d, code, signature);
    return d;
}

inline QDBusMarshaller *QDBusMarshaller::endStructure()
{ return endCommon(); }

inline QDBusMarshaller *QDBusMarshaller::endArray()
{ return endCommon(); }

inline QDBusMarshaller *QDBusMarshaller::endMap()
{ return endCommon(); }

inline QDBusMarshaller *QDBusMarshaller::endMapEntry()
{ return endCommon(); }

QDBusMarshaller *QDBusMarshaller::endCommon()
{
    QDBusMarshaller *retval = parent;
    delete this;
    return retval;
}

void QDBusMarshaller::close()
{
    if (ba) {
        if (closeCode)
            *ba += closeCode;
    } else if (parent) {
        dbus_message_iter_close_container(&parent->iterator, &iterator);
    }
}

void QDBusMarshaller::error()
{
    ok = false;
    if (parent)
        parent->error();
}

bool QDBusMarshaller::appendVariantInternal(const QVariant &arg)
{
    int id = arg.userType();
    if (id == QVariant::Invalid) {
        qWarning("QDBusMarshaller: cannot add an invalid QVariant");
        error();
        return false;
    }

    // intercept QDBusArgument parameters here
    if (id == qMetaTypeId<QDBusArgument>()) {
        QDBusArgument dbusargument = qvariant_cast<QDBusArgument>(arg);
        QDBusDemarshaller *demarshaller = QDBusArgumentPrivate::demarshaller(dbusargument);
        if (demarshaller)
            return appendCrossMarshalling(demarshaller);
        return false;
    }

    const char *signature = QDBusMetaType::typeToSignature( QVariant::Type(id) );
    if (!signature) {
        qWarning("QDBusMarshaller: type `%s' (%d) is not registered with D-BUS. "
                 "Use qDBusRegisterMetaType to register it",
                 QVariant::typeToName( QVariant::Type(id) ), id);
        error();
        return false;
    }

    switch (*signature) {
#ifdef __OPTIMIZE__
    case DBUS_TYPE_BYTE:
    case DBUS_TYPE_BOOLEAN:
    case DBUS_TYPE_INT16:
    case DBUS_TYPE_UINT16:
    case DBUS_TYPE_INT32:
    case DBUS_TYPE_UINT32:
    case DBUS_TYPE_INT64:
    case DBUS_TYPE_UINT64:
    case DBUS_TYPE_DOUBLE:
        qIterAppend(&iterator, ba, *signature, arg.constData());
        return true;

    case DBUS_TYPE_STRING:
    case DBUS_TYPE_OBJECT_PATH:
    case DBUS_TYPE_SIGNATURE: {
        const QByteArray data =
            reinterpret_cast<const QString *>(arg.constData())->toUtf8();
        const char *rawData = data.constData();
        qIterAppend(&iterator, ba, *signature, &rawData);
        return true;
    }
#else
    case DBUS_TYPE_BYTE:
        append( qvariant_cast<uchar>(arg) );
        return true;
    case DBUS_TYPE_BOOLEAN:
        append( arg.toBool() );
        return true;
    case DBUS_TYPE_INT16:
        append( qvariant_cast<short>(arg) );
        return true;
    case DBUS_TYPE_UINT16:
        append( qvariant_cast<ushort>(arg) );
        return true;
    case DBUS_TYPE_INT32:
        append( static_cast<dbus_int32_t>(arg.toInt()) );
        return true;
    case DBUS_TYPE_UINT32:
        append( static_cast<dbus_uint32_t>(arg.toUInt()) );
        return true;
    case DBUS_TYPE_INT64:
        append( arg.toLongLong() );
        return true;
    case DBUS_TYPE_UINT64:
        append( arg.toULongLong() );
        return true;
    case DBUS_TYPE_DOUBLE:
        append( arg.toDouble() );
        return true;
    case DBUS_TYPE_STRING:
        append( arg.toString() );
        return true;
    case DBUS_TYPE_OBJECT_PATH:
        append( qvariant_cast<QDBusObjectPath>(arg) );
        return true;
    case DBUS_TYPE_SIGNATURE:
        append( qvariant_cast<QDBusSignature>(arg) );
        return true;
#endif

    // compound types:
    case DBUS_TYPE_VARIANT:
        // nested QVariant
        return append( qvariant_cast<QDBusVariant>(arg) );

    case DBUS_TYPE_ARRAY:
        // could be many things
        // find out what kind of array it is
        switch (arg.type()) {
        case QVariant::StringList:
            append( arg.toStringList() );
            return true;

        case QVariant::ByteArray:
            append( arg.toByteArray() );
            return true;

        default:
            ;                   // fall through
        }
        // fall through

    case DBUS_TYPE_STRUCT:
    case DBUS_STRUCT_BEGIN_CHAR:
        return appendRegisteredType( arg );

    case DBUS_TYPE_DICT_ENTRY:
    case DBUS_DICT_ENTRY_BEGIN_CHAR:
        qFatal("QDBusMarshaller::appendVariantInternal got a DICT_ENTRY!");
        return false;

    default:
        qWarning("QDBusMarshaller::appendVariantInternal: Found unknown D-BUS type '%s'",
                 signature);
        return false;
    }

    return true;
}

bool QDBusMarshaller::appendRegisteredType(const QVariant &arg)
{
    ref.ref();                  // reference up
    QDBusArgument self(QDBusArgumentPrivate::create(this));
    return QDBusMetaType::marshall(self, arg.userType(), arg.constData());
}

bool QDBusMarshaller::appendCrossMarshalling(QDBusDemarshaller *demarshaller)
{
    int code = dbus_message_iter_get_arg_type(&demarshaller->iterator);
    if (dbus_type_is_basic(code)) {
        // easy: just append
        // do exactly like the D-BUS docs suggest
        // (see apidocs for dbus_message_iter_get_basic)

        qlonglong value;
        dbus_message_iter_get_basic(&demarshaller->iterator, &value);
        dbus_message_iter_next(&demarshaller->iterator);
        dbus_message_iter_append_basic(&iterator, code, &value);
        return true;
    }

    if (code == DBUS_TYPE_ARRAY) {
        int element = dbus_message_iter_get_element_type(&demarshaller->iterator);
        if (dbus_type_is_fixed(element)) {
            // another optimisation: fixed size arrays
            // code is exactly like QDBusDemarshaller::toByteArray
            DBusMessageIter sub;
            dbus_message_iter_recurse(&demarshaller->iterator, &sub);
            dbus_message_iter_next(&demarshaller->iterator);
            int len = dbus_message_iter_get_array_len(&sub);
            void* data;
            dbus_message_iter_get_fixed_array(&sub,&data,&len);

            char signature[2] = { element, 0 };
            dbus_message_iter_open_container(&iterator, DBUS_TYPE_ARRAY, signature, &sub);
            dbus_message_iter_append_fixed_array(&sub, element, &data, len);
            dbus_message_iter_close_container(&iterator, &sub);

            return true;
        }
    }

    // We have to recurse
    QDBusDemarshaller *drecursed = demarshaller->beginCommon();

    QDBusMarshaller mrecursed;  // create on the stack makes it autoclose
    open(mrecursed, code, drecursed->currentSignature().toLatin1());

    while (!drecursed->atEnd()) {
        if (!mrecursed.appendCrossMarshalling(drecursed)) {
            delete drecursed;
            return false;
        }
    }

    delete drecursed;
    return true;
}