FileSystemCommPort.h

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//-*-c++-*-
#ifndef INCLUDED_FileSystemCommPort_h_
#define INCLUDED_FileSystemCommPort_h_

#include "local/CommPort.h"
#include "Shared/plist.h"
#include <Wireless/netstream.h>
#include <ios>

//! Provides CommPort interface to file system devices, such as serial ports
/*! Pass a path to use a file system device, or see NetworkCommPort for a network interface */
class FileSystemCommPort : public CommPort, public virtual plist::PrimitiveListener {
public:
  //! constructor (see also sub-class constructor in protected section)
  explicit FileSystemCommPort(const std::string& name)
    : CommPort(autoRegisterFileSystemCommPort,name),
    path(), mode(std::ios_base::in | std::ios_base::out | std::ios_base::trunc | std::ios_base::binary),
    rbuf(), wbuf(), curloc(), curmode(), openedCnt(0)
  {
    addEntry("Path",path,"Path of file system object being accessed");
    addEntry("Mode",mode,"Mode bitmask to pass to the open() call, defaults to 'w+b': in|out|trunc|binary (see std::ios_base::openmode)");
  }
  
  //! destructor, checks that the file descriptor has already been closed
  virtual ~FileSystemCommPort() {
    lock.lock();
    if(openedCnt>0)
      connectionError("File descriptor still open in FileSystemCommPort destructor",true,NULL,false);
  }
  
  virtual std::string getClassName() const { return autoRegisterFileSystemCommPort; }
  
  virtual basic_netbuf<std::ios::char_type>& getReadStreambuf() { return rbuf; }
  virtual basic_netbuf<std::ios::char_type>& getWriteStreambuf() { return wbuf; }
  virtual bool isReadable() { return rbuf.is_open(); }
  virtual bool isWriteable() { return wbuf.is_open(); }
  
  //! tries to have #rbuf and/or #wbuf open #path, subject to #mode 
  virtual bool open();
  
  //! closes #rbuf and #wbuf
  virtual bool close();
  
  //! watches #path, triggers a close() and re-open() if it changes
  virtual void plistValueChanged(const plist::PrimitiveBase& pl);
  
  plist::Primitive<std::string> path; //!< path of file system object being accessed
  plist::Primitive<int> mode; //!< mode bitmask to pass to the open() call (see std::ios_base::openmode)
  
protected:
  explicit FileSystemCommPort(const std::string& classname, const std::string& instancename)
    : CommPort(classname,instancename), 
    path(), mode(std::ios_base::in | std::ios_base::out | std::ios_base::trunc | std::ios_base::binary),
    rbuf(), wbuf(), curloc(), curmode(), openedCnt(0)
  {
    addEntry("Path",path,"Path of file system object being accessed");
    addEntry("Mode",mode,"Mode bitmask to pass to the open() call, defaults to 'w+b': in|out|trunc|binary (see std::ios_base::openmode)");
  }
  
  //! Displays message on stderr and if @a fatal is set, calls closeFD()
  /*! Need the useClassName parameter because we can't trust autoRegisterFileSystemCommPort to
   *  still be valid during static destruction, so that's false when called from destructor */
  virtual void connectionError(const std::string& msg, bool fatal, const char* sysmsg, bool useClassName=true) {
    if(useClassName && getClassName()!=instanceName)
      std::cerr << getClassName() << " \"" << instanceName << "\": ";
    else
      std::cerr << instanceName << ": ";
    std::cerr << msg;
    if(sysmsg!=NULL && sysmsg[0]!='\0')
      std::cerr << ": " << sysmsg;
    std::cerr << std::endl;
    if(fatal && (rbuf.is_open() || wbuf.is_open())) {
      openedCnt=1;
      close();
    }
  }
  
  basic_netbuf<std::ios::char_type> rbuf;
  basic_netbuf<std::ios::char_type> wbuf;
  std::string curloc;
  std::ios_base::openmode curmode;
  unsigned int openedCnt;
  
  //! holds the class name, set via registration with the CommPort registry
  static const std::string autoRegisterFileSystemCommPort;
};

/*! @file
 * @brief Describes FileDescriptorMotionHook, which provides a file descriptor interface for hardware "drivers"
 * @author Ethan Tira-Thompson (ejt) (Creator)
 */

#endif