qgis_mapserver.cpp

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/***************************************************************************
                              qgs_mapserver.cpp
 
A QGIS development HTTP server for testing/development purposes.
The server listens to localhost:8000, the address and port can be changed with the
environment variable QGIS_SERVER_ADDRESS and QGIS_SERVER_PORT or passing <address>:<port>
on the command line.
 
All requests and application messages are printed to the standard output,
while QGIS server internal logging is printed to stderr.
 
                              -------------------
  begin                : Jan 17 2020
  copyright            : (C) 2020 by Alessandro Pasotti
  email                : elpaso at itopen dot it
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include <chrono>
#include <condition_variable>
#include <string>
#include <thread>
 
#include <QString>
 
using namespace Qt::StringLiterals;
 
//for CMAKE_INSTALL_PREFIX
#include "qgscommandlineutils.h"
#include "qgsconfig.h"
#include "qgsserver.h"
#include "qgssettings.h"
#include "qgssettingsentry.h"
#include "qgsbufferserverrequest.h"
#include "qgsbufferserverresponse.h"
#include "qgsapplication.h"
#include "qgsmessagelog.h"
 
#include <QFontDatabase>
#include <QString>
#include <QTcpServer>
#include <QTcpSocket>
#include <QNetworkInterface>
#include <QCommandLineParser>
#include <QObject>
#include <QQueue>
#include <QThread>
#include <QPointer>
 
#ifndef Q_OS_WIN
#include <csignal>
#endif

 
// For the signal exit handler
QAtomicInt IS_RUNNING = 1;
 
QString ipAddress;
QString serverPort;
 
std::condition_variable REQUEST_WAIT_CONDITION;
std::mutex REQUEST_QUEUE_MUTEX;
std::mutex SERVER_MUTEX;
 
struct RequestContext
{
    QPointer<QTcpSocket> clientConnection;
    QString httpHeader;
    std::chrono::steady_clock::time_point startTime;
    QgsBufferServerRequest request;
    QgsBufferServerResponse response;
};
 
 
QQueue<RequestContext *> REQUEST_QUEUE;
 
const QMap<int, QString> knownStatuses {
  { 200, u"OK"_s },
  { 201, u"Created"_s },
  { 202, u"Accepted"_s },
  { 204, u"No Content"_s },
  { 301, u"Moved Permanently"_s },
  { 302, u"Moved Temporarily"_s },
  { 304, u"Not Modified"_s },
  { 400, u"Bad Request"_s },
  { 401, u"Unauthorized"_s },
  { 403, u"Forbidden"_s },
  { 404, u"Not Found"_s },
  { 500, u"Internal Server Error"_s },
  { 501, u"Not Implemented"_s },
  { 502, u"Bad Gateway"_s },
  { 503, u"Service Unavailable"_s }
};

class HttpException : public std::exception
{
  public:
    HttpException( const QString &message )
      : mMessage( message )
    {}

    QString message() const { return mMessage; }
 
  private:
    QString mMessage;
};
 
 
class TcpServerWorker : public QObject
{
    Q_OBJECT
 
  public:
    TcpServerWorker( const QString &ipAddress, int port )
    {
      QHostAddress address { QHostAddress::AnyIPv4 };
      address.setAddress( ipAddress );
 
      if ( !mTcpServer.listen( address, port ) )
      {
        std::cerr << tr( "Unable to start the server: %1." ).arg( mTcpServer.errorString() ).toStdString() << std::endl;
      }
      else
      {
        const int port { mTcpServer.serverPort() };
 
        std::cout << tr( "QGIS Development Server listening on http://%1:%2" ).arg( ipAddress ).arg( port ).toStdString() << std::endl;
#ifndef Q_OS_WIN
        std::cout << tr( "CTRL+C to exit" ).toStdString() << std::endl;
#endif
 
        mIsListening = true;
 
        // Incoming connection handler
        QTcpServer::connect( &mTcpServer, &QTcpServer::newConnection, this, [this, ipAddress, port] {
          QTcpSocket *clientConnection = mTcpServer.nextPendingConnection();
 
          mConnectionCounter++;
 
          //qDebug() << "Active connections: " << mConnectionCounter;
 
          QString *incomingData = new QString();
 
          // Lambda disconnect context
          QObject *context { new QObject };
 
          // Deletes the connection later
          auto connectionDeleter = [this, clientConnection, incomingData]() {
            clientConnection->deleteLater();
            mConnectionCounter--;
            delete incomingData;
          };
 
          // This will delete the connection
          QObject::connect( clientConnection, &QAbstractSocket::disconnected, clientConnection, connectionDeleter, Qt::QueuedConnection );
 
#if 0 // Debugging output
          clientConnection->connect( clientConnection, &QAbstractSocket::errorOccurred, clientConnection, []( QAbstractSocket::SocketError socketError )
          {
            qDebug() << "Socket error #" << socketError;
          }, Qt::QueuedConnection );
#endif
 
          // Incoming connection parser
          QObject::connect( clientConnection, &QIODevice::readyRead, context, [clientConnection, incomingData, context, ipAddress, port] {
            // Read all incoming data
            while ( clientConnection->bytesAvailable() > 0 )
            {
              incomingData->append( clientConnection->readAll() );
            }
 
            try
            {
              // Parse protocol and URL GET /path HTTP/1.1
              const auto firstLinePos { incomingData->indexOf( "\r\n" ) };
              if ( firstLinePos == -1 )
              {
                throw HttpException( u"HTTP error finding protocol header"_s );
              }
 
              const QString firstLine { incomingData->left( firstLinePos ) };
              const QStringList firstLinePieces { firstLine.split( ' ' ) };
              if ( firstLinePieces.size() != 3 )
              {
                throw HttpException( u"HTTP error splitting protocol header"_s );
              }
 
              const QString methodString { firstLinePieces.at( 0 ) };
 
              QgsServerRequest::Method method;
              if ( methodString == "GET" )
              {
                method = QgsServerRequest::Method::GetMethod;
              }
              else if ( methodString == "POST" )
              {
                method = QgsServerRequest::Method::PostMethod;
              }
              else if ( methodString == "HEAD" )
              {
                method = QgsServerRequest::Method::HeadMethod;
              }
              else if ( methodString == "PUT" )
              {
                method = QgsServerRequest::Method::PutMethod;
              }
              else if ( methodString == "PATCH" )
              {
                method = QgsServerRequest::Method::PatchMethod;
              }
              else if ( methodString == "DELETE" )
              {
                method = QgsServerRequest::Method::DeleteMethod;
              }
              else if ( methodString == "OPTIONS" )
              {
                method = QgsServerRequest::Method::OptionsMethod;
              }
              else
              {
                throw HttpException( u"HTTP error unsupported method: %1"_s.arg( methodString ) );
              }
 
              // cppcheck-suppress containerOutOfBounds
              const QString protocol { firstLinePieces.at( 2 ) };
              if ( protocol != "HTTP/1.0"_L1 && protocol != "HTTP/1.1"_L1 )
              {
                throw HttpException( u"HTTP error unsupported protocol: %1"_s.arg( protocol ) );
              }
 
              // Headers
              QgsBufferServerRequest::Headers headers;
              const auto endHeadersPos { incomingData->indexOf( "\r\n\r\n" ) };
 
              if ( endHeadersPos == -1 )
              {
                throw HttpException( u"HTTP error finding headers"_s );
              }
 
              const QStringList httpHeaders { incomingData->mid( firstLinePos + 2, endHeadersPos - firstLinePos ).split( "\r\n" ) };
 
              for ( const auto &headerLine : httpHeaders )
              {
                const auto headerColonPos { headerLine.indexOf( ':' ) };
                if ( headerColonPos > 0 )
                {
                  headers.insert( headerLine.left( headerColonPos ), headerLine.mid( headerColonPos + 2 ) );
                }
              }
 
              const auto headersSize { endHeadersPos + 4 };
 
              // Check for content length and if we have got all data
              if ( headers.contains( u"Content-Length"_s ) )
              {
                bool ok;
                const int contentLength { headers.value( u"Content-Length"_s ).toInt( &ok ) };
                if ( ok && contentLength > incomingData->length() - headersSize )
                {
                  return;
                }
              }
 
              // At this point we should have read all data:
              // disconnect the lambdas
              delete context;
 
              // Build URL from env ...
              QString url { qgetenv( "REQUEST_URI" ) };
              // ... or from server ip/port and request path
              if ( url.isEmpty() )
              {
                // cppcheck-suppress containerOutOfBounds
                const QString path { firstLinePieces.at( 1 ) };
                // Take Host header if defined
                if ( headers.contains( u"Host"_s ) )
                {
                  url = u"http://%1%2"_s.arg( headers.value( u"Host"_s ), path );
                }
                else
                {
                  url = u"http://%1:%2%3"_s.arg( ipAddress ).arg( port ).arg( path );
                }
              }
 
              // Inefficient copy :(
              QByteArray data { incomingData->mid( headersSize ).toUtf8() };
 
              if ( !incomingData->isEmpty() && clientConnection->state() == QAbstractSocket::SocketState::ConnectedState )
              {
                auto requestContext = new RequestContext {
                  clientConnection,
                  firstLinePieces.join( ' ' ),
                  std::chrono::steady_clock::now(),
                  { url, method, headers, &data },
                  {},
                };
                REQUEST_QUEUE_MUTEX.lock();
                REQUEST_QUEUE.enqueue( requestContext );
                REQUEST_QUEUE_MUTEX.unlock();
                REQUEST_WAIT_CONDITION.notify_one();
              }
            }
            catch ( HttpException &ex )
            {
              if ( clientConnection->state() == QAbstractSocket::SocketState::ConnectedState )
              {
                // Output stream: send error
                clientConnection->write( u"HTTP/1.0 %1 %2\r\n"_s.arg( 500 ).arg( knownStatuses.value( 500 ) ).toUtf8() );
                clientConnection->write( u"Server: QGIS\r\n"_s.toUtf8() );
                clientConnection->write( "\r\n" );
                clientConnection->write( ex.message().toUtf8() );
 
                std::cout << u"\033[1;31m%1 [%2] \"%3\" - - 500\033[0m"_s.arg( clientConnection->peerAddress().toString(), QDateTime::currentDateTime().toString(), ex.message() ).toStdString() << std::endl;
 
                clientConnection->disconnectFromHost();
              }
            }
          } );
        } );
      }
    }
 
    ~TcpServerWorker() override { mTcpServer.close(); }
 
    bool isListening() const { return mIsListening; }
 
  public slots:
 
    // Outgoing connection handler
    void responseReady( RequestContext *requestContext ) //#spellok
    {
      std::unique_ptr<RequestContext> request { requestContext };
      const auto elapsedTime { std::chrono::steady_clock::now() - request->startTime };
 
      const auto &response { request->response };
      const auto &clientConnection { request->clientConnection };
 
      if ( !clientConnection || clientConnection->state() != QAbstractSocket::SocketState::ConnectedState )
      {
        std::cout << "Connection reset by peer" << std::endl;
        return;
      }
 
      // Output stream
      if ( -1 == clientConnection->write( u"HTTP/1.0 %1 %2\r\n"_s.arg( response.statusCode() ).arg( knownStatuses.value( response.statusCode(), u"Unknown response code"_s ) ).toUtf8() ) )
      {
        std::cout << "Cannot write to output socket" << std::endl;
        clientConnection->disconnectFromHost();
        return;
      }
 
      clientConnection->write( u"Server: QGIS\r\n"_s.toUtf8() );
      const auto responseHeaders { response.fullHeaders() };
      for ( auto it = responseHeaders.constBegin(); it != responseHeaders.constEnd(); ++it )
      {
        for ( const QString &headerValue : std::as_const( it.value() ) )
          clientConnection->write( u"%1: %2\r\n"_s.arg( it.key(), headerValue ).toUtf8() );
      }
      clientConnection->write( "\r\n" );
      const QByteArray body { response.body() };
      clientConnection->write( body );
 
      // 10.185.248.71 [09/Jan/2015:19:12:06 +0000] 808840 <time> "GET / HTTP/1.1" 500"
      std::cout
        << u"\033[1;92m%1 [%2] %3 %4ms \"%5\" %6\033[0m"_s
             .arg(
               clientConnection->peerAddress().toString(),
               QDateTime::currentDateTime().toString(),
               QString::number( body.size() ),
               QString::number( std::chrono::duration_cast<std::chrono::milliseconds>( elapsedTime ).count() ),
               request->httpHeader,
               QString::number( response.statusCode() )
             )
             .toStdString()
        << std::endl;
 
      // This will trigger delete later on the socket object
      clientConnection->disconnectFromHost();
    }
 
  private:
    QTcpServer mTcpServer;
    qlonglong mConnectionCounter = 0;
    bool mIsListening = false;
};
 
 
class TcpServerThread : public QThread
{
    Q_OBJECT
 
  public:
    TcpServerThread( const QString &ipAddress, const int port )
      : mIpAddress( ipAddress )
      , mPort( port )
    {}
 
    void emitResponseReady( RequestContext *requestContext ) //#spellok
    {
      if ( requestContext->clientConnection )
        emit responseReady( requestContext ); //#spellok
    }
 
    void run() override
    {
      const TcpServerWorker worker( mIpAddress, mPort );
      if ( !worker.isListening() )
      {
        emit serverError();
      }
      else
      {
        // Forward signal to worker
        connect( this, &TcpServerThread::responseReady, &worker, &TcpServerWorker::responseReady ); //#spellok
        QThread::run();
      }
    }
 
  signals:
 
    void responseReady( RequestContext *requestContext ); //#spellok
    void serverError();
 
  private:
    QString mIpAddress;
    int mPort;
};
 
 
class QueueMonitorThread : public QThread
{
    Q_OBJECT
 
  public:
    void run() override
    {
      while ( mIsRunning )
      {
        std::unique_lock<std::mutex> requestLocker( REQUEST_QUEUE_MUTEX );
        REQUEST_WAIT_CONDITION.wait( requestLocker, [this] { return !mIsRunning || !REQUEST_QUEUE.isEmpty(); } );
        if ( mIsRunning )
        {
          // Lock if server is running
          SERVER_MUTEX.lock();
          emit requestReady( REQUEST_QUEUE.dequeue() );
        }
      }
    }
 
  signals:
 
    void requestReady( RequestContext *requestContext );
 
  public slots:
 
    void stop() { mIsRunning = false; }
 
  private:
    bool mIsRunning = true;
};
 
int main( int argc, char *argv[] )
{
  // Test if the environ variable DISPLAY is defined
  // if it's not, the server is running in offscreen mode
  // Qt supports using various QPA (Qt Platform Abstraction) back ends
  // for rendering. You can specify the back end to use with the environment
  // variable QT_QPA_PLATFORM when invoking a Qt-based application.
  // Available platform plugins are: directfbegl, directfb, eglfs, linuxfb,
  // minimal, minimalegl, offscreen, wayland-egl, wayland, xcb.
  // https://www.ics.com/blog/qt-tips-and-tricks-part-1
  // http://doc.qt.io/qt-5/qpa.html
  const QString display { qgetenv( "DISPLAY" ) };
  bool withDisplay = true;
  if ( display.isEmpty() )
  {
    withDisplay = false;
    qputenv( "QT_QPA_PLATFORM", "offscreen" );
  }
 
  // since version 3.0 QgsServer now needs a qApp so initialize QgsApplication
  const QgsApplication app( argc, argv, withDisplay, QString(), u"QGIS Development Server"_s );
 
  if ( const char *globalSettingsFile = getenv( "QGIS_GLOBAL_SETTINGS_FILE" ) )
  {
    const QString path = QString::fromLocal8Bit( globalSettingsFile );
    QgsSettings::setGlobalSettingsPath( path );
    QgsSettingsEntryBase::setGlobalSettingsPath( path );
  }
 
  QCoreApplication::setOrganizationName( QgsApplication::QGIS_ORGANIZATION_NAME );
  QCoreApplication::setOrganizationDomain( QgsApplication::QGIS_ORGANIZATION_DOMAIN );
  QCoreApplication::setApplicationName( "QGIS Development Server" );
  QCoreApplication::setApplicationVersion( VERSION );
 
  if ( !withDisplay )
  {
    QgsMessageLog::logMessage(
      "DISPLAY environment variable is not set, running in offscreen mode, all printing capabilities will not be available.\n"
      "Consider installing an X server like 'xvfb' and export DISPLAY to the actual display value.",
      "Server",
      Qgis::MessageLevel::Warning
    );
  }
 
#ifdef Q_OS_WIN
  // Initialize font database before fcgi_accept.
  // When using FCGI with IIS, environment variables (QT_QPA_FONTDIR in this case) are lost after fcgi_accept().
  QFontDatabase fontDB;
#endif
 
  // The port to listen
  serverPort = qgetenv( "QGIS_SERVER_PORT" );
  // The address to listen
  ipAddress = qgetenv( "QGIS_SERVER_ADDRESS" );
 
  if ( serverPort.isEmpty() )
  {
    serverPort = u"8000"_s;
  }
 
  if ( ipAddress.isEmpty() )
  {
    ipAddress = u"127.0.0.1"_s;
  }
 
  QCommandLineParser parser;
  parser.setApplicationDescription( QObject::tr( "QGIS Development Server %1" ).arg( VERSION ) );
  parser.addHelpOption();
 
  const QCommandLineOption versionOption( QStringList() << "v" << "version", QObject::tr( "Version of QGIS and libraries" ) );
  parser.addOption( versionOption );
 
  parser.addPositionalArgument(
    u"addressAndPort"_s,
    QObject::tr(
      "Address and port (default: \"localhost:8000\")\n"
      "address and port can also be specified with the environment\n"
      "variables QGIS_SERVER_ADDRESS and QGIS_SERVER_PORT."
    ),
    u"[address:port]"_s
  );
  const QCommandLineOption logLevelOption(
    "l",
    QObject::tr(
      "Log level (default: 0)\n"
      "0: INFO\n"
      "1: WARNING\n"
      "2: CRITICAL"
    ),
    "logLevel",
    "0"
  );
  parser.addOption( logLevelOption );
 
  const QCommandLineOption projectOption(
    "p",
    QObject::tr(
      "Path to a QGIS project file (*.qgs or *.qgz),\n"
      "if specified it will override the query string MAP argument\n"
      "and the QGIS_PROJECT_FILE environment variable."
    ),
    "projectPath",
    ""
  );
  parser.addOption( projectOption );
 
  parser.process( app );
 
  if ( parser.isSet( versionOption ) )
  {
    std::cout << QgsCommandLineUtils::allVersions().toStdString();
    return 0;
  }
 
  const QStringList args = parser.positionalArguments();
 
  if ( args.size() == 1 )
  {
    const QStringList addressAndPort { args.at( 0 ).split( ':' ) };
    if ( addressAndPort.size() == 2 )
    {
      ipAddress = addressAndPort.at( 0 );
      // cppcheck-suppress containerOutOfBounds
      serverPort = addressAndPort.at( 1 );
    }
  }
 
  const QString logLevel = parser.value( logLevelOption );
  qunsetenv( "QGIS_SERVER_LOG_FILE" );
  qputenv( "QGIS_SERVER_LOG_LEVEL", logLevel.toUtf8() );
  qputenv( "QGIS_SERVER_LOG_STDERR", "1" );
 
  QgsServer server;
 
  if ( !parser.value( projectOption ).isEmpty() )
  {
    // Check it!
    const QString projectFilePath { parser.value( projectOption ) };
    if ( !QgsProject::instance()
            ->read( projectFilePath, Qgis::ProjectReadFlag::DontResolveLayers | Qgis::ProjectReadFlag::DontLoadLayouts | Qgis::ProjectReadFlag::DontStoreOriginalStyles | Qgis::ProjectReadFlag::DontLoad3DViews | Qgis::ProjectReadFlag::DontUpgradeAnnotations ) )
    {
      std::cout << QObject::tr( "Project file not found, the option will be ignored." ).toStdString() << std::endl;
    }
    else
    {
      qputenv( "QGIS_PROJECT_FILE", projectFilePath.toUtf8() );
    }
  }
 
  // Disable parallel rendering because if its internal loop
  //qputenv( "QGIS_SERVER_PARALLEL_RENDERING", "0" );
 
 
#ifdef HAVE_SERVER_PYTHON_PLUGINS
  server.initPython();
#endif
 
  // TCP thread
  TcpServerThread tcpServerThread { ipAddress, serverPort.toInt() };
 
  bool isTcpError = false;
  TcpServerThread::connect(
    &tcpServerThread,
    &TcpServerThread::serverError,
    qApp,
    [&] {
      isTcpError = true;
      qApp->quit();
    },
    Qt::QueuedConnection
  );
 
  // Monitoring thread
  QueueMonitorThread queueMonitorThread;
  QueueMonitorThread::connect( &queueMonitorThread, &QueueMonitorThread::requestReady, qApp, [&]( RequestContext *requestContext ) {
    if ( requestContext->clientConnection && requestContext->clientConnection->isValid() )
    {
      server.handleRequest( requestContext->request, requestContext->response );
      SERVER_MUTEX.unlock();
    }
    else
    {
      delete requestContext;
      SERVER_MUTEX.unlock();
      return;
    }
    if ( requestContext->clientConnection && requestContext->clientConnection->isValid() )
      tcpServerThread.emitResponseReady( requestContext ); //#spellok
    else
      delete requestContext;
  } );
 
  // Exit handlers
#ifndef Q_OS_WIN
 
  auto exitHandler = []( int signal ) {
    std::cout << u"Signal %1 received: quitting"_s.arg( signal ).toStdString() << std::endl;
    IS_RUNNING = 0;
    qApp->quit();
  };
 
  signal( SIGTERM, exitHandler );
  signal( SIGABRT, exitHandler );
  signal( SIGINT, exitHandler );
  signal( SIGPIPE, []( int ) { std::cerr << u"Signal SIGPIPE received: ignoring"_s.toStdString() << std::endl; } );
 
#endif
 
  tcpServerThread.start();
  queueMonitorThread.start();
 
  QgsApplication::exec();
  // Wait for threads
  tcpServerThread.exit();
  tcpServerThread.wait();
  queueMonitorThread.stop();
  REQUEST_WAIT_CONDITION.notify_all();
  queueMonitorThread.wait();
  QgsApplication::exitQgis();
 
  return isTcpError ? 1 : 0;
}
 
#include "qgis_mapserver.moc"