source: trunk/src/dbus/qdbusmessage.cpp@ 561

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the QtDBus module of the Qt Toolkit.
**
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** accordance with the Qt Commercial License Agreement provided with the
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** a written agreement between you and Nokia.
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
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** rights.  These rights are described in the Nokia Qt LGPL Exception
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
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#include "qdbusmessage.h"

#include <qdebug.h>
#include <qstringlist.h>

#include "qdbus_symbols_p.h"

#include "qdbusargument_p.h"
#include "qdbuserror.h"
#include "qdbusmessage_p.h"
#include "qdbusmetatype.h"
#include "qdbusconnection_p.h"
#include "qdbusutil_p.h"

QT_BEGIN_NAMESPACE

static inline const char *data(const QByteArray &arr)
{
    return arr.isEmpty() ? 0 : arr.constData();
}

QDBusMessagePrivate::QDBusMessagePrivate()
    : msg(0), reply(0), type(DBUS_MESSAGE_TYPE_INVALID),
      timeout(-1), localReply(0), ref(1), delayedReply(false), localMessage(false),
      parametersValidated(false)
{
}

QDBusMessagePrivate::~QDBusMessagePrivate()
{
    if (msg)
        q_dbus_message_unref(msg);
    if (reply)
        q_dbus_message_unref(reply);
    delete localReply;
}

/*!
    \since 4.3
     Returns the human-readable message associated with the error that was received.
*/
QString QDBusMessage::errorMessage() const
{
    if (d_ptr->type == ErrorMessage) {
        if (!d_ptr->message.isEmpty())
           return d_ptr->message;
        if (!d_ptr->arguments.isEmpty())
            return d_ptr->arguments.at(0).toString();
    }
    return QString();
}

/*!
    \internal
    Constructs a DBusMessage object from this object. The returned value must be de-referenced
    with q_dbus_message_unref.

    The \a error object is set to indicate the error if anything went wrong with the
    marshalling. Usually, this error message will be placed in the reply, as if the call failed.
    The \a error pointer must not be null.
*/
DBusMessage *QDBusMessagePrivate::toDBusMessage(const QDBusMessage &message, QDBusError *error)
{
    if (!qdbus_loadLibDBus()) {
        *error = QDBusError(QDBusError::Failed, QLatin1String("Could not open lidbus-1 library"));
        return 0;
    }

    DBusMessage *msg = 0;
    const QDBusMessagePrivate *d_ptr = message.d_ptr;

    switch (d_ptr->type) {
    case DBUS_MESSAGE_TYPE_INVALID:
        //qDebug() << "QDBusMessagePrivate::toDBusMessage" <<  "message is invalid";
        break;
    case DBUS_MESSAGE_TYPE_METHOD_CALL:
        // only service and interface can be empty -> path and name must not be empty
        if (!d_ptr->parametersValidated) {
            if (!QDBusUtil::checkBusName(d_ptr->service, QDBusUtil::EmptyAllowed, error))
                return 0;
            if (!QDBusUtil::checkObjectPath(d_ptr->path, QDBusUtil::EmptyNotAllowed, error))
                return 0;
            if (!QDBusUtil::checkInterfaceName(d_ptr->interface, QDBusUtil::EmptyAllowed, error))
                return 0;
            if (!QDBusUtil::checkMemberName(d_ptr->name, QDBusUtil::EmptyNotAllowed, error, "method"))
                return 0;
        }

        msg = q_dbus_message_new_method_call(data(d_ptr->service.toUtf8()), d_ptr->path.toUtf8(),
                                             data(d_ptr->interface.toUtf8()), d_ptr->name.toUtf8());
        break;
    case DBUS_MESSAGE_TYPE_METHOD_RETURN:
        msg = q_dbus_message_new(DBUS_MESSAGE_TYPE_METHOD_RETURN);
        if (!d_ptr->localMessage) {
            q_dbus_message_set_destination(msg, q_dbus_message_get_sender(d_ptr->reply));
            q_dbus_message_set_reply_serial(msg, q_dbus_message_get_serial(d_ptr->reply));
        }
        break;
    case DBUS_MESSAGE_TYPE_ERROR:
        // error name can't be empty
        if (!d_ptr->parametersValidated
            && !QDBusUtil::checkErrorName(d_ptr->name, QDBusUtil::EmptyNotAllowed, error))
            return 0;

        msg = q_dbus_message_new(DBUS_MESSAGE_TYPE_ERROR);
        q_dbus_message_set_error_name(msg, d_ptr->name.toUtf8());
        if (!d_ptr->localMessage) {
            q_dbus_message_set_destination(msg, q_dbus_message_get_sender(d_ptr->reply));
            q_dbus_message_set_reply_serial(msg, q_dbus_message_get_serial(d_ptr->reply));
        }
        break;
    case DBUS_MESSAGE_TYPE_SIGNAL:
        // nothing can be empty here
        if (!d_ptr->parametersValidated) {
            if (!QDBusUtil::checkObjectPath(d_ptr->path, QDBusUtil::EmptyNotAllowed, error))
                return 0;
            if (!QDBusUtil::checkInterfaceName(d_ptr->interface, QDBusUtil::EmptyAllowed, error))
                return 0;
            if (!QDBusUtil::checkMemberName(d_ptr->name, QDBusUtil::EmptyNotAllowed, error, "method"))
                return 0;
        }

        msg = q_dbus_message_new_signal(d_ptr->path.toUtf8(), d_ptr->interface.toUtf8(),
                                        d_ptr->name.toUtf8());
        break;
    default:
        Q_ASSERT(false);
        break;
    }

    // if we got here, the parameters validated
    // and since the message parameters cannot be changed once the message is created
    // we can record this fact
    d_ptr->parametersValidated = true;

    QDBusMarshaller marshaller;
    QVariantList::ConstIterator it =  d_ptr->arguments.constBegin();
    QVariantList::ConstIterator cend = d_ptr->arguments.constEnd();
    q_dbus_message_iter_init_append(msg, &marshaller.iterator);
    if (!d_ptr->message.isEmpty())
        // prepend the error message
        marshaller.append(d_ptr->message);
    for ( ; it != cend; ++it)
        marshaller.appendVariantInternal(*it);

    // check if everything is ok
    if (marshaller.ok)
        return msg;

    // not ok;
    q_dbus_message_unref(msg);
    *error = QDBusError(QDBusError::Failed, QLatin1String("Marshalling failed: ") + marshaller.errorString);
    return 0;
}

/*
struct DBusMessage
{
    DBusAtomic refcount;
    DBusHeader header;
    DBusString body;
    char byte_order;
    unsigned int locked : 1;
DBUS_DISABLE_CHECKS
    unsigned int in_cache : 1;
#endif
    DBusList *size_counters;
    long size_counter_delta;
    dbus_uint32_t changed_stamp : CHANGED_STAMP_BITS;
    DBusDataSlotList slot_list;
#ifndef DBUS_DISABLE_CHECKS
    int generation;
#endif
};
*/

/*!
    \internal
    Constructs a QDBusMessage by parsing the given DBusMessage object.
*/
QDBusMessage QDBusMessagePrivate::fromDBusMessage(DBusMessage *dmsg)
{
    QDBusMessage message;
    if (!dmsg)
        return message;

    message.d_ptr->type = q_dbus_message_get_type(dmsg);
    message.d_ptr->path = QString::fromUtf8(q_dbus_message_get_path(dmsg));
    message.d_ptr->interface = QString::fromUtf8(q_dbus_message_get_interface(dmsg));
    message.d_ptr->name = message.d_ptr->type == DBUS_MESSAGE_TYPE_ERROR ?
                      QString::fromUtf8(q_dbus_message_get_error_name(dmsg)) :
                      QString::fromUtf8(q_dbus_message_get_member(dmsg));
    message.d_ptr->service = QString::fromUtf8(q_dbus_message_get_sender(dmsg));
    message.d_ptr->signature = QString::fromUtf8(q_dbus_message_get_signature(dmsg));
    message.d_ptr->msg = q_dbus_message_ref(dmsg);

    QDBusDemarshaller demarshaller;
    demarshaller.message = q_dbus_message_ref(dmsg);
    if (q_dbus_message_iter_init(demarshaller.message, &demarshaller.iterator))
        while (!demarshaller.atEnd())
            message << demarshaller.toVariantInternal();
    return message;
}

bool QDBusMessagePrivate::isLocal(const QDBusMessage &message)
{
    return message.d_ptr->localMessage;
}

QDBusMessage QDBusMessagePrivate::makeLocal(const QDBusConnectionPrivate &conn,
                                            const QDBusMessage &asSent)
{
    // simulate the message being sent to the bus and then received back
    // the only field that the bus sets when delivering the message
    // (as opposed to the message as we send it), is the sender
    // so we simply set the sender to our unique name

    // determine if we are carrying any complex types
    QString computedSignature;
    QVariantList::ConstIterator it = asSent.d_ptr->arguments.constBegin();
    QVariantList::ConstIterator end = asSent.d_ptr->arguments.constEnd();
    for ( ; it != end; ++it) {
        int id = it->userType();
        const char *signature = QDBusMetaType::typeToSignature(id);
        if ((id != QVariant::StringList && id != QVariant::ByteArray &&
             qstrlen(signature) != 1) || id == qMetaTypeId<QDBusVariant>()) {
            // yes, we are
            // we must marshall and demarshall again so as to create QDBusArgument
            // entries for the complex types
            QDBusError error;
            DBusMessage *message = toDBusMessage(asSent, &error);
            if (!message) {
                // failed to marshall, so it's a call error
                return QDBusMessage::createError(error);
            }

            q_dbus_message_set_sender(message, conn.baseService.toUtf8());

            QDBusMessage retval = fromDBusMessage(message);
            retval.d_ptr->localMessage = true;
            q_dbus_message_unref(message);
            if (retval.d_ptr->service.isEmpty())
                retval.d_ptr->service = conn.baseService;
            return retval;
        } else {
            computedSignature += QLatin1String(signature);
        }
    }

    // no complex types seen
    // optimise by using the variant list itself
    QDBusMessage retval;
    QDBusMessagePrivate *d = retval.d_ptr;
    d->arguments = asSent.d_ptr->arguments;
    d->path = asSent.d_ptr->path;
    d->interface = asSent.d_ptr->interface;
    d->name = asSent.d_ptr->name;
    d->message = asSent.d_ptr->message;
    d->type = asSent.d_ptr->type;

    d->service = conn.baseService;
    d->signature = computedSignature;
    d->localMessage = true;
    return retval;
}

QDBusMessage QDBusMessagePrivate::makeLocalReply(const QDBusConnectionPrivate &conn,
                                                 const QDBusMessage &callMsg)
{
    // simulate the reply (return or error) message being sent to the bus and
    // then received back.
    if (callMsg.d_ptr->localReply)
        return makeLocal(conn, *callMsg.d_ptr->localReply);
    return QDBusMessage();      // failed
}

/*!
    \class QDBusMessage
    \inmodule QtDBus
    \since 4.2

    \brief The QDBusMessage class represents one message sent or
    received over the D-Bus bus.

    This object can represent any of the four different types of
    messages (MessageType) that can occur on the bus:

    \list
      \o Method calls
      \o Method return values
      \o Signal emissions
      \o Error codes
    \endlist

    Objects of this type are created with the static createError(),
    createMethodCall() and createSignal() functions. Use the
    QDBusConnection::send() function to send the messages.
*/

/*!
    \enum QDBusMessage::MessageType
    The possible message types:

    \value MethodCallMessage    a message representing an outgoing or incoming method call
    \value SignalMessage        a message representing an outgoing or incoming signal emission
    \value ReplyMessage         a message representing the return values of a method call
    \value ErrorMessage         a message representing an error condition in response to a method call
    \value InvalidMessage       an invalid message: this is never set on messages received from D-Bus
*/

/*!
    Constructs a new DBus message with the given \a path, \a interface
    and \a name, representing a signal emission.

    A DBus signal is emitted from one application and is received by
    all applications that are listening for that signal from that
    interface.

    The QDBusMessage object that is returned can be sent using the
    QDBusConnection::send() function.
*/
QDBusMessage QDBusMessage::createSignal(const QString &path, const QString &interface,
                                        const QString &name)
{
    QDBusMessage message;
    message.d_ptr->type = DBUS_MESSAGE_TYPE_SIGNAL;
    message.d_ptr->path = path;
    message.d_ptr->interface = interface;
    message.d_ptr->name = name;

    return message;
}

/*!
    Constructs a new DBus message representing a method call.
    A method call always informs its destination address
    (\a service, \a path, \a interface and \a method).

    The DBus bus allows calling a method on a given remote object without specifying the
    destination interface, if the method name is unique. However, if two interfaces on the
    remote object export the same method name, the result is undefined (one of the two may be
    called or an error may be returned).

    When using DBus in a peer-to-peer context (i.e., not on a bus), the \a service parameter is
    optional.

    The QDBusObject and QDBusInterface classes provide a simpler abstraction to synchronous
    method calling.

    This function returns a QDBusMessage object that can be sent with
    QDBusConnection::call().
*/
QDBusMessage QDBusMessage::createMethodCall(const QString &service, const QString &path,
                                            const QString &interface, const QString &method)
{
    QDBusMessage message;
    message.d_ptr->type = DBUS_MESSAGE_TYPE_METHOD_CALL;
    message.d_ptr->service = service;
    message.d_ptr->path = path;
    message.d_ptr->interface = interface;
    message.d_ptr->name = method;

    return message;
}

/*!
    Constructs a new DBus message representing an error,
    with the given \a name and \a msg.
*/
QDBusMessage QDBusMessage::createError(const QString &name, const QString &msg)
{
    QDBusMessage error;
    error.d_ptr->type = DBUS_MESSAGE_TYPE_ERROR;
    error.d_ptr->name = name;
    error.d_ptr->message = msg;

    return error;
}