---

NamedPipe.cpp

Go to the documentation of this file.

#include <string.h>
#include "OSDependent/NamedPipe.h"

#define NPIPE_PREFIX    "\\\\.\\pipe\\"
#define NPIPE_MAXSZ     256

NamedPipe::NamedPipe() :
_pipe(NULL)
{
}

NamedPipe::~NamedPipe() 
{
  if (_is_server)
    DisconnectNamedPipe(_pipe);
  CloseHandle(_pipe);
}

long 
NamedPipe::write(char*buffer, long size) 
{
  DWORD n = 0;
  BOOL ret = 0;

  if (!_is_server || ConnectNamedPipe(_pipe,NULL))
    ret = WriteFile(_pipe,buffer,size,&n,NULL);

  if (!ret)
     n = -1;

  return (short)n;
}

long 
NamedPipe::read(char*buffer, long size) 
{
  DWORD n = 0;
  BOOL ret = 0;
  if (!_is_server || ConnectNamedPipe(_pipe,NULL))
    ret = ReadFile(_pipe,buffer,size,&n,NULL);

  if (!ret)
    n = -1;
  return n;
}
   
void 
NamedPipe::flush() 
{
  FlushFileBuffers(_pipe);
}

int
NamedPipe::create(const char* name, int mode) 
{
  char pname[NPIPE_MAXSZ];
  sprintf(pname, "%s%s", NPIPE_PREFIX, name);

  _is_server = 1;
  DWORD access_mode = 0;
  if (mode & NPIPE_READ)
    access_mode |= PIPE_ACCESS_INBOUND;
  if (mode & NPIPE_WRITE)
    access_mode |= PIPE_ACCESS_OUTBOUND;

  if (timeout == -1)
    timeout = 10000; //in milliseconds

  _pipe = CreateNamedPipe(pname,
                          access_mode,
                          PIPE_TYPE_BYTE|PIPE_READMODE_BYTE|PIPE_WAIT,
                          1,
                          4000, 4000,
                          timeout,
                          NULL);

  if (_pipe == NULL || _pipe == INVALID_HANDLE_VALUE)
    return -1;

  return 0;
}

int
NamedPipe::connect(const char* name, int mode, long timeout) 
{
  char pname[NPIPE_MAXSZ];
  sprintf(pname, "%s%s", NPIPE_PREFIX, name);

  _is_server = 0;
  DWORD access_mode = 0;
  if (mode & NPIPE_READ)
    access_mode |= GENERIC_READ;
  if (mode & NPIPE_WRITE)
    access_mode |= GENERIC_WRITE;

  short tries = 0;
  do {
    _pipe = CreateFile(pname,access_mode,0,NULL,OPEN_EXISTING,0,NULL);
    tries ++;
  }
  while((_pipe==NULL || _pipe == INVALID_HANDLE_VALUE) &&
       (timeout != -1) && (Sleep(timeout/10), tries <= 10));

  if (_pipe == NULL || _pipe == INVALID_HANDLE_VALUE)
    return -1;

  return 0;
}

---