servicehost.cpp

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// Program Name: servicehost.cpp
// Created     : Jan. 19, 2010
//
// Purpose     : Service Host Abstract Class
//
// Copyright (c) 2010 David Blain <dblain@mythtv.org>
//
// Licensed under the GPL v2 or later, see LICENSE for details
//
#include "servicehost.h"
 
#include "libmythbase/mythlogging.h"
 
#include "libmythupnp/upnp.h"
#include "wsdl.h"
#include "xsd.h"
 
static constexpr int MAX_PARAMS = 256;
 
//
 
QVariant MethodInfo::Invoke( Service *pService, const QStringMap &reqParams ) const
{
    HttpRedirectException exception;
    bool                  bExceptionThrown = false;
    QStringMap            lowerParams;
 
    if (!pService)
        throw QString("Invalid argument to MethodInfo::Invoke. pService in nullptr");
 
     // Change params to lower case for case-insensitive comparison
    for (auto it = reqParams.cbegin(); it != reqParams.cend(); ++it)
    {
        lowerParams[it.key().toLower()] = *it;
    }
 
    // --------------------------------------------------------------
    // Provide actual parameters received to method
    // --------------------------------------------------------------
 
    pService->m_parsedParams = lowerParams.keys();
 
 
    QList<QByteArray> paramNames = m_oMethod.parameterNames();
    QList<QByteArray> paramTypes = m_oMethod.parameterTypes();
 
    // ----------------------------------------------------------------------
    // Create Parameter array (Can't have more than MAX_PARAMS parameters)....
    // switched to static array for performance.
    // ----------------------------------------------------------------------
 
    std::array<void*,MAX_PARAMS> param {};
    std::array<int,MAX_PARAMS> types {};
 
    try
    {
        // --------------------------------------------------------------
        // Add a place for the Return value
        // --------------------------------------------------------------
 
#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
        int nRetIdx = QMetaType::type( m_oMethod.typeName() );
        QMetaType oRetType = QMetaType(nRetIdx);
#else
        int nRetIdx = m_oMethod.returnType();
        QMetaType oRetType = m_oMethod.returnMetaType();
#endif
 
        if (nRetIdx != QMetaType::UnknownType)
        {
            param[ 0 ] = oRetType.create();
            types[ 0 ] = nRetIdx;
        }
        else
        {
            param[ 0 ] = nullptr;
            types[ 0 ] = QMetaType::UnknownType;
        }
 
        // --------------------------------------------------------------
        // Fill in parameters from request values
        // --------------------------------------------------------------
 
        for( int nIdx = 0; nIdx < paramNames.length(); ++nIdx )
        {
            QString sValue     = lowerParams[ paramNames[ nIdx ].toLower() ];
            QString sParamType = paramTypes[ nIdx ];
 
#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
            int     nId        = QMetaType::type( paramTypes[ nIdx ] );
            void   *pParam     = nullptr;
 
            if (nId != QMetaType::UnknownType)
            {
                pParam = QMetaType::create( nId );
            }
#else
            QMetaType metaType = QMetaType::fromName( paramTypes[ nIdx ] );
            void *pParam = metaType.create();
            int nId = metaType.id();
#endif
            if (nId == QMetaType::UnknownType)
            {
                LOG(VB_GENERAL, LOG_ERR,
                    QString("MethodInfo::Invoke - Type unknown '%1'")
                        .arg(sParamType));
                throw QString("MethodInfo::Invoke - Type unknown '%1'")
                          .arg(sParamType);
            }
 
            types[nIdx+1] = nId;
            param[nIdx+1] = pService->ConvertToParameterPtr( nId, sParamType,
                                                             pParam, sValue );
        }
 
#if 0
        QThread *currentThread = QThread::currentThread();
        QThread *objectThread  = pService->thread();
 
        if (currentThread == objectThread)
            LOG(VB_HTTP, LOG_DEBUG, "*** Threads are same ***");
        else
            LOG(VB_HTTP, LOG_DEBUG, "*** Threads are Different!!! ***");
#endif
 
        if (pService->qt_metacall(QMetaObject::InvokeMetaMethod, m_nMethodIndex, param.data()) >= 0)
            LOG(VB_GENERAL, LOG_WARNING, "qt_metacall error");
 
        // --------------------------------------------------------------
        // Delete param array, skip return parameter since not dynamically
        // created.
        // --------------------------------------------------------------
 
        for (int nIdx=1; nIdx < paramNames.length()+1; ++nIdx)
        {
            if ((types[ nIdx ] != QMetaType::UnknownType) && (param[ nIdx ] != nullptr))
            {
                auto metaType = QMetaType( types[ nIdx ] );
                metaType.destroy(param[ nIdx ]);
            }
        }
    }
    catch (QString &sMsg)
    {
        LOG(VB_GENERAL, LOG_ERR,
            QString("MethodInfo::Invoke - An Exception Occurred: %1")
                 .arg(sMsg));
 
        if  ((types[ 0 ] != QMetaType::UnknownType) && (param[ 0 ] != nullptr ))
        {
            auto metaType = QMetaType( types[ 0 ] );
            metaType.destroy(param[ 0 ]);
        }
 
        throw;
    }
    catch (HttpRedirectException &ex)
    {
        bExceptionThrown = true;
        exception = ex;
    }
    catch (...)
    {
        LOG(VB_GENERAL, LOG_INFO,
            "MethodInfo::Invoke - An Exception Occurred" );
    }
 
    // --------------------------------------------------------------
    // return the result after converting to a QVariant
    // --------------------------------------------------------------
 
    QVariant vReturn;
 
    if ( param[ 0 ] != nullptr)
    {
        vReturn = pService->ConvertToVariant( types[ 0 ], param[ 0 ] );
 
        if (types[ 0 ] != QMetaType::UnknownType)
        {
            auto metaType = QMetaType( types[ 0 ] );
            metaType.destroy(param[ 0 ]);
        }
    }
 
    // --------------------------------------------------------------
    // Re-throw exception if needed.
    // --------------------------------------------------------------
 
    if (bExceptionThrown)
        throw HttpRedirectException(exception);
 
    return vReturn;
}
 
//
//
//
 
ServiceHost::ServiceHost(const QMetaObject &metaObject,
                         const QString     &sExtensionName,
                               QString      sBaseUrl,
                         const QString     &sSharePath )
            : HttpServerExtension ( sExtensionName,   sSharePath ),
              m_sBaseUrl(std::move(sBaseUrl)),
              m_oMetaObject(metaObject)
{
    // ----------------------------------------------------------------------
    // Create an instance of the service so custom types get registered.
    // ----------------------------------------------------------------------
 
    QObject *pService =  m_oMetaObject.newInstance();
 
    // ----------------------------------------------------------------------
    // Read in all callable methods and cache information about them
    // ----------------------------------------------------------------------
 
    for (int nIdx = 0; nIdx < m_oMetaObject.methodCount(); nIdx++)
    {
        QMetaMethod method = m_oMetaObject.method( nIdx );
 
        if ((method.methodType() == QMetaMethod::Slot   ) &&
            (method.access()     == QMetaMethod::Public ))
        {
            QString sName( method.methodSignature() );
 
            // --------------------------------------------------------------
            // Ignore the following methods...
            // --------------------------------------------------------------
 
            if (sName == "deleteLater()")
                continue;
 
            // --------------------------------------------------------------
 
            MethodInfo oInfo;
 
            oInfo.m_nMethodIndex = nIdx;
            oInfo.m_sName        = sName.section( '(', 0, 0 );
            oInfo.m_oMethod      = method;
            oInfo.m_eRequestType = (HttpRequestType)(RequestTypeGet |
                                                     RequestTypePost |
                                                     RequestTypeHead);
 
            QString sMethodClassInfo = oInfo.m_sName + "_Method";
 
            int nClassIdx =
                m_oMetaObject.indexOfClassInfo(sMethodClassInfo.toLatin1());
 
            if (nClassIdx >=0)
            {
                QString sRequestType =
                    m_oMetaObject.classInfo(nClassIdx).value();
 
                if (sRequestType == "POST")
                    oInfo.m_eRequestType = RequestTypePost;
                else if (sRequestType == "GET" )
                    oInfo.m_eRequestType = (HttpRequestType)(RequestTypeGet |
                                                             RequestTypeHead);
            }
 
            m_methods.insert( oInfo.m_sName, oInfo );
        }
    }
 
    // ----------------------------------------------------------------------
 
    delete pService;
}
 
//
 
QStringList ServiceHost::GetBasePaths()
{
    return QStringList( m_sBaseUrl );
}
 
//
 
bool ServiceHost::ProcessRequest( HTTPRequest *pRequest )
{
    bool     bHandled = false;
    Service *pService = nullptr;
 
    try
    {
        if (pRequest)
        {
            if (pRequest->m_sBaseUrl != m_sBaseUrl)
                return false;
 
            LOG(VB_HTTP, LOG_INFO,
                QString("ServiceHost::ProcessRequest: %1 : %2")
                    .arg(pRequest->m_sMethod, pRequest->m_sRawRequest));
 
            // --------------------------------------------------------------
            // Check to see if they are requesting the WSDL service Definition
            // --------------------------------------------------------------
 
            if (( pRequest->m_eType   == RequestTypeGet ) &&
                ( pRequest->m_sMethod == "wsdl"         ))
            {
                pService =  qobject_cast<Service*>(m_oMetaObject.newInstance());
 
                Wsdl wsdl( this );
 
                wsdl.GetWSDL( pRequest );
 
                delete pService;
                return true;
            }
 
            // --------------------------------------------------------------
            // Check to see if they are requesting XSD - Type Definition
            // --------------------------------------------------------------
 
            if (( pRequest->m_eType   == RequestTypeGet ) &&
                ( pRequest->m_sMethod == "xsd"          ))
            {
                bool bHandled2 = false;
                if ( pRequest->m_mapParams.count() > 0)
                {
                    pService =  qobject_cast<Service*>(m_oMetaObject.newInstance());
 
                    Xsd xsd;
 
                    if (pRequest->m_mapParams.contains( "type" ))
                        bHandled2 = xsd.GetXSD( pRequest, pRequest->m_mapParams[ "type" ] );
                    else
                        bHandled2 = xsd.GetEnumXSD( pRequest, pRequest->m_mapParams[ "enum" ] );
                    delete pService;
                    pService = nullptr;
                }
 
                if (!bHandled2)
                    throw QString("Invalid arguments to xsd query: %1")
                        .arg(pRequest->m_sRequestUrl.section('?', 1));
 
                return true;
            }
 
            // --------------------------------------------------------------
 
            if (( pRequest->m_eType   == RequestTypeGet ) &&
                ( pRequest->m_sMethod == "version"         ))
            {
 
                int nClassIdx = m_oMetaObject.indexOfClassInfo( "version" );
 
                if (nClassIdx >=0)
                {
                    QString sVersion =
                        m_oMetaObject.classInfo(nClassIdx).value();
 
                    return FormatResponse( pRequest, QVariant( sVersion ));
                }
            }
 
            // --------------------------------------------------------------
            // Allow a more REST like calling convention.  If the Method
            // Name isn't found, search for one with the request method
            // appended to the name ( "Get" or "Put" for POST)
            // --------------------------------------------------------------
 
            QString sMethodName  = pRequest->m_sMethod;
            bool    bMethodFound = false;
 
            if (m_methods.contains(sMethodName))
                bMethodFound = true;
            else
            {
                switch( pRequest->m_eType )
                {
                    case RequestTypeHead:
                    case RequestTypeGet :
                        sMethodName = "Get" + sMethodName;
                        break;
                    case RequestTypePost:
                        sMethodName = "Put" + sMethodName;
                        break;
                    case RequestTypeUnknown:
                    case RequestTypeOptions:
                    case RequestTypeMSearch:
                    case RequestTypeSubscribe:
                    case RequestTypeUnsubscribe:
                    case RequestTypeNotify:
                    case RequestTypeResponse:
                        // silence compiler
                        break;
                }
 
                if (m_methods.contains(sMethodName))
                    bMethodFound = true;
            }
 
            if (bMethodFound)
            {
                MethodInfo oInfo = m_methods.value( sMethodName );
 
                if (( pRequest->m_eType & oInfo.m_eRequestType ) != 0)
                {
                    // ------------------------------------------------------
                    // Create new Instance of the Service Class so
                    // it's guaranteed to be on the same thread
                    // since we are making direct calls into it.
                    // ------------------------------------------------------
 
                    pService =
                        qobject_cast<Service*>(m_oMetaObject.newInstance());
 
                    QVariant vResult = oInfo.Invoke(pService,
                                                    pRequest->m_mapParams);
 
                    bHandled = FormatResponse( pRequest, vResult );
                }
            }
 
            if (!bHandled)
                UPnp::FormatErrorResponse( pRequest, UPnPResult_InvalidAction );
        }
    }
    catch (HttpRedirectException &ex)
    {
        UPnp::FormatRedirectResponse( pRequest, ex.m_hostName );
        bHandled = true;
    }
    catch (HttpException &ex)
    {
        LOG(VB_GENERAL, LOG_ERR, ex.m_msg);
        UPnp::FormatErrorResponse( pRequest, UPnPResult_ActionFailed, ex.m_msg );
 
        bHandled = true;
 
    }
    catch (QString &sMsg)
    {
        LOG(VB_GENERAL, LOG_ERR, sMsg);
        UPnp::FormatErrorResponse( pRequest, UPnPResult_ActionFailed, sMsg );
 
        bHandled = true;
    }
    catch ( ...)
    {
        QString sMsg( "ServiceHost::ProcessRequest - Unexpected Exception" );
 
        LOG(VB_GENERAL, LOG_ERR, sMsg);
        UPnp::FormatErrorResponse( pRequest, UPnPResult_ActionFailed, sMsg );
 
        bHandled = true;
    }
 
    delete pService;
    return bHandled;
}
 
//
 
bool ServiceHost::FormatResponse( HTTPRequest *pRequest, QObject *pResults )
{
    if (pResults != nullptr)
    {
        Serializer *pSer = pRequest->GetSerializer();
 
        pSer->Serialize( pResults );
 
        pRequest->FormatActionResponse( pSer );
 
        delete pResults;
 
        return true;
    }
    UPnp::FormatErrorResponse( pRequest, UPnPResult_ActionFailed, "Call to method failed" );
 
    return false;
}
 
//
 
bool ServiceHost::FormatResponse( HTTPRequest *pRequest, const QFileInfo& oInfo )
{
    if (oInfo.exists())
    {
        if (oInfo.isSymLink())
            pRequest->FormatFileResponse( oInfo.symLinkTarget() );
        else
            pRequest->FormatFileResponse( oInfo.absoluteFilePath() );
    }
    else
    {
        // force return as a 404...
        pRequest->FormatFileResponse( "" );
    }
 
    return true;
}
 
 
//
 
bool ServiceHost::FormatResponse( HTTPRequest *pRequest, const QVariant& vValue )
{
    if ( vValue.canConvert< QObject* >())
    {
        const QObject *pObject = vValue.value< QObject* >();
 
        return FormatResponse( pRequest, (QObject *)pObject );
    }
 
    if ( vValue.canConvert< QFileInfo >())
    {
        const auto oFileInfo = vValue.value< QFileInfo >();
 
        return FormatResponse( pRequest, oFileInfo );
    }
 
    // ----------------------------------------------------------------------
    // Simple Variant... serialize it.
    // ----------------------------------------------------------------------
 
    Serializer *pSer = pRequest->GetSerializer();
 
    pSer->Serialize( vValue, vValue.typeName() );
 
    pRequest->FormatActionResponse( pSer );
 
    return true;
}