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InetTransport.cc

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/**************************************************************************
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#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <string>

#include <mps/mps.h>
#include <mps/transport_inet.h>

#include <FileDescriptor.h>
#include <SocketDescriptor.h>

namespace MPS {

InetTransport *InetTransport::instance = 0;

///////////////////////////////////////////////////////////////////////////

static string toString(int x) {
  char buf[20];
  sprintf(buf, "%d", x);
  return buf;
}

///////////////////////////////////////////////////////////////////////////

class InetTransport::InetIOStream: public MPS::InputStream, public MPS::OutputStream {
private:
  ref<FileDescriptor> fd;

protected:
  virtual string referenceTransport() const;

public:
  InetIOStream(ref<FileDescriptor> const &_fd)
    : fd(_fd)
  {}

  virtual int read() {
    int ch;
    try {
      while (!fd->read(ch))
        fd->block(true, false);
    } catch (FileDescriptor::Exception &fe) {
      throw MPS::MPSConnectionClosedException(fe.what());
    }
    return ch;
  }

  virtual void flush() {
    try {
      fd->write(getBody(), getLength(), true);
    } catch (FileDescriptor::Exception &fe) {
      throw MPS::MPSConnectionClosedException(fe.what());
    }
    MPS::OutputStream::flush();
  }
};

string InetTransport::InetIOStream::referenceTransport() const {
  return "inet";
}

///////////////////////////////////////////////////////////////////////////

class InetTransport::InetConnection: public MPS::Connection {
private:
  int oid;
  ref<FileDescriptor> fd;

  void ensureConnection() {
    if (!fd.valid() || !fd->isOpen()) {
      throw MPS::MPSConnectionClosedException("InetConnection has no active fd");
    }
  }

public:
  InetConnection(int _oid, MPS::Address const &a)
    : MPS::Connection(a),
           oid(_oid),
           fd(0)
  {}

  virtual MPS::OutputStream *getOutputStream() {
    ensureConnection();

    MPS::OutputStream *stream = new InetIOStream(fd);
    stream->writeint(oid);
    return stream;
  }

  virtual MPS::InputStream *getInputStream() {
    ensureConnection();

    MPS::InputStream *stream = new InetIOStream(fd);
    int inputOid = stream->readint();

    if (inputOid != oid) {
      throw MPS::MPSException("OID mismatch in InetTransport::InetConnection, got " +
                              toString(inputOid) + " expected " + toString(oid));
    }

    return stream;
  }

  virtual void releaseOutputStream(MPS::OutputStream *stream) { delete stream; }
  virtual void releaseInputStream(MPS::InputStream *stream) { delete stream; }

  void setActiveFd(ref<FileDescriptor> const &_fd) {
    fd = _fd;
  }
};

///////////////////////////////////////////////////////////////////////////

class InetTransport::InetDemux: public FileDescriptor::Callback {
public:
  typedef map< int, ref<InetConnection> > connectionMap_t;      ///< Map of OID -> Connection

private:
  connectionMap_t connectionMap;
  string canonicalAddress;
  ref<ClientSocketDescriptor> clientSock;

  void processEvent(ref<FileDescriptor> const &desc) {
    MPS::InputStream *input = 0;

    try {

      try {

        while (desc->inputReady()) {
          input = new InetIOStream(desc);

          int targetOid = input->readint();

          connectionMap_t::iterator i = connectionMap.find(targetOid);
          if (i == connectionMap.end()) {
            throw MPS::MPSException("Invalid OID in processRequest: " + toString(targetOid));
          } else {
            ref<InetConnection> &conn((*i).second);

            conn->setActiveFd(desc);
            conn->fireCallback(*input);
          }

          delete input;
          input = 0;
        }

      } catch (FileDescriptor::Exception &fe) {
        //      fprintf(stderr, "InetDemux::processEvent: %s (%d: %s)\n",
        //              fe.what(), fe.getErrno(), strerror(fe.getErrno()));
        throw;
      } catch (MPS::MPSException &mpse) {
        //      fprintf(stderr, "InetDemux::processEvent: %s\n", mpse.getMessage().c_str());
        throw;
      }

    } catch (...) {
      if (input)
        delete input;

      desc->close();
    }
  }

  void acceptConnection(ref<FileDescriptor> const &desc) {
    try {
      ref<ServerSocketDescriptor> server = desc.downcast<ServerSocketDescriptor>();
      registerFd(server->accept());
    } catch (InvalidDowncastException &ide) {
      throw MPS::MPSException("WARNING: InetDemux::acceptConnection was given "
                              "a non-server socket");
    }
  }

  void registerFd(ref<FileDescriptor> const &fd) {
    fd->setNonBlocking(true);
    fd->setReadCallback(this,
                        (FileDescriptor::Callback::Method) &InetDemux::processEvent);
  }

public:
  /// Client demux
  InetDemux(ref<ClientSocketDescriptor> const &_clientSock)
    : connectionMap(),
      canonicalAddress(),
      clientSock(_clientSock)
  {
//      fprintf(stderr, "New client connection: %s:%d ==> %s:%d\n",
//          clientSock->getLocalHostname().c_str(), clientSock->getLocalPort(),
//          clientSock->getRemoteHostname().c_str(), clientSock->getRemotePort());
    registerFd(clientSock);
  }

  /// Server demux
  InetDemux(ref<ServerSocketDescriptor> const &serverSock)
    : connectionMap(),
      canonicalAddress(string("mps:inet:") + serverSock->getCanonicalAddress()),
      clientSock(0)
  {
//      fprintf(stderr, "New server connection: %s:%d ==> %s:%d\n",
//          serverSock->getLocalHostname().c_str(), serverSock->getLocalPort(),
//          serverSock->getRemoteHostname().c_str(), serverSock->getRemotePort());
    serverSock->setReadCallback(this,
                                (FileDescriptor::Callback::Method) &InetDemux::acceptConnection);
  }

  string const &getAddress() const { return canonicalAddress; }

  ref<InetConnection> connectionForOid(int oid, Address const &address) {
    ref<InetConnection> result;

    connectionMap_t::iterator i = connectionMap.find(oid);
    if (i == connectionMap.end()) {
      result = new InetConnection(oid, address);
      connectionMap[oid] = result;

      if (clientSock.valid())
        result->setActiveFd(clientSock);

    } else {
      result = (*i).second;
    }

    return result;
  }
};

///////////////////////////////////////////////////////////////////////////

class InetTransport::InetDispatcher: public Connection::Callback {
private:
  ref<InetConnection> connection;
  MPS::Server *server;

  void setupCallback() {
    connection->setCallback(this,
                            (Connection::Callback::Method) &InetDispatcher::dispatchRequest);
  }

public:
  InetDispatcher(ref<InetConnection> const &_connection,
                 MPS::Server *_server)
    : connection(_connection),
      server(_server)
  {
    setupCallback();
  }

  void dispatchRequest(MPS::InputStream &input) {
    setupCallback();

    MPS::OutputStream *output = connection->getOutputStream();
    int pos = output->getLength();
    server->dispatch(input, *output);
    if (output->getLength() > pos) {
      // Only flush if the dispatch ended up writing anything.
      // Otherwise we end up sending a header with no body :-)
      output->flush();
    }
    connection->releaseOutputStream(output);
  }
};

///////////////////////////////////////////////////////////////////////////

InetTransport::InetTransport(string const &hostName,
                             int portNumber)
  : Transport("inet"),
    fdMgr(new FileDescriptorManager()),
    clientMap(),
    serverMap(),
    defaultDemux(registerServerSocket(new ServerSocketDescriptor(fdMgr, portNumber, hostName))),
    nextOid(1)
{}

ref<InetTransport::InetDemux>
InetTransport::registerServerSocket(ref<ServerSocketDescriptor> const &serverSock)
{
  ref<InetDemux> demux = new InetDemux(serverSock);
  serverMap[serverSock->getCanonicalAddress()] = demux;
  return demux;
}

///////////////////////////////////////////////////////////////////////////

ref<Connection> InetTransport::connectTo(Address const &connectionSpec)
{
  if (connectionSpec.getParamCount() != 3)
    throw MPS::MPSException("Inet transport requires 3 Address parameters");

  string hostName = connectionSpec.getParam(0);
  int portNumber = atoi(connectionSpec.getParam(1).c_str());
  string address = hostName + ":" + connectionSpec.getParam(1);

  ref<InetDemux> demux;

  demuxMap_t::iterator i = clientMap.find(address);
  if (i == clientMap.end()) {
    try {
      demux = new InetDemux(new ClientSocketDescriptor(fdMgr, hostName, portNumber));
      clientMap[address] = demux;
    } catch (FileDescriptor::Exception &fe) {
      throw MPS::MPSException(fe.what());
    }
  } else {
    demux = (*i).second;
  }

  return demux->connectionForOid(atoi(connectionSpec.getParam(2).c_str()), connectionSpec);
}

string InetTransport::registerServer(Server *server, Address const &spec)
{
  ref<InetDemux> demux;

  if (spec.getParamCount() > 0) {
    string hostName = spec.getParam(0);
    int portNumber = atoi(spec.getParam(1).c_str());
    string address = hostName + ":" + spec.getParam(1);

    demuxMap_t::iterator i = serverMap.find(address);
    if (i == serverMap.end()) {
      demux = registerServerSocket(new ServerSocketDescriptor(fdMgr, portNumber, hostName));
    } else {
      demux = (*i).second;
    }
  } else {
    demux = defaultDemux;
    if (!demux.valid()) {
      demux = registerServerSocket(new ServerSocketDescriptor(fdMgr));
    }
  }

  if (!defaultDemux.valid()) {
    defaultDemux = demux;
  }

  int oid = nextOid++;

  Address newSpec(demux->getAddress());
  newSpec.setParam(2, toString(oid));

  ref<InetConnection> conn = demux->connectionForOid(oid, newSpec);
  conn->setCallback(new InetDispatcher(conn, server),
                    (Connection::Callback::Method) &InetDispatcher::dispatchRequest);

  return newSpec.getResolvedName();
}

string InetTransport::deregisterServer(Server *server, Address const &spec) {
  throw MPSException("InetTransport::deregisterServer not yet implemented"); // how embarrassing.
}

}

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