pchannel.cxx

基于VXWORKS H323通信技术源代码

/*
 * pchannel.cxx
 *
 * Operating System utilities.
 *
 * Portable Windows Library
 *
 * Copyright (c) 1993-1998 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Portable Windows Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
 * All Rights Reserved.
 *
 * Contributor(s): ______________________________________.
 *
 * $Log: pchannel.cxx,v $
 * Revision 1.6  1999/07/06 08:55:05  robertj
 * Fixed bug in PFile::Copy, does not write last chunk of data to new file.
 *
 * Revision 1.5  1999/06/17 14:44:42  robertj
 * Fixed incorrect comparison of open write channel
 *
 * Revision 1.4  1999/06/17 13:38:11  robertj
 * Fixed race condition on indirect channel close, mutex needed in PIndirectChannel.
 *
 * Revision 1.3  1999/02/22 10:10:12  robertj
 * Changed channel output flush to remove double Write() call.
 *
 * Revision 1.2  1999/01/31 00:57:18  robertj
 * Fixed bug when opening an already open file, should close it!
 *
 * Revision 1.1  1998/11/30 12:46:19  robertj
 * Initial revision
 *
 */

#include <ptlib.h>

#include <ctype.h>


///////////////////////////////////////////////////////////////////////////////
// PChannel

PChannelStreamBuffer::PChannelStreamBuffer(PChannel * chan)
  : channel(PAssertNULL(chan))
{
}


int PChannelStreamBuffer::overflow(int c)
{
  if (pbase() == NULL) {
    if (eback() == 0)
      setp(buffer, &buffer[sizeof(buffer)]);
    else {
      char * halfway = &buffer[sizeof(buffer)/2];
      setp(buffer, halfway);
      setg(halfway, &buffer[sizeof(buffer)], &buffer[sizeof(buffer)]);
    }
  }

  int bufSize = pptr() - pbase();
  if (bufSize > 0) {
    setp(pbase(), epptr());
    if (!channel->Write(pbase(), bufSize))
      return EOF;
  }

  if (c != EOF) {
    *pptr() = (char)c;
    pbump(1);
  }

  return 0;
}


int PChannelStreamBuffer::underflow()
{
  if (eback() == NULL) {
    if (pbase() == 0)
      setg(buffer, &buffer[sizeof(buffer)], &buffer[sizeof(buffer)]);
    else {
      char * halfway = &buffer[sizeof(buffer)/2];
      setp(buffer, halfway);
      setg(halfway, &buffer[sizeof(buffer)], &buffer[sizeof(buffer)]);
    }
  }

  if (gptr() != egptr())
    return (BYTE)*gptr();

  if (!channel->Read(eback(), egptr() - eback()) ||
                                  channel->GetErrorCode() != PChannel::NoError)
    return EOF;

  PINDEX count = channel->GetLastReadCount();
  char * p = egptr() - count;
  memmove(p, eback(), count);
  setg(eback(), p, egptr());
  return (BYTE)*p;
}


int PChannelStreamBuffer::sync()
{
  int inAvail = egptr() - gptr();
  if (inAvail > 0) {
    setg(eback(), egptr(), egptr());
    if (channel->IsDescendant(PFile::Class()))
      ((PFile *)channel)->SetPosition(-inAvail, PFile::Current);
  }

  if (pptr() > pbase())
    return overflow();

  return 0;
}


streampos PChannelStreamBuffer::seekoff(streamoff off,
#ifdef __MWERKS__
                                        ios::seekdir dir, ios::openmode)
#else
                                        ios::seek_dir dir, int)
#endif
{
  sync();
  if (!channel->IsDescendant(PFile::Class()))
    return -1;
  ((PFile *)channel)->SetPosition(off, (PFile::FilePositionOrigin)dir);
  return ((PFile *)channel)->GetPosition();
}


PChannel::PChannel()
  : readTimeout(PMaxTimeInterval), writeTimeout(PMaxTimeInterval)
{
  os_handle = -1;
  osError = 0;
  lastError = NoError;
  lastReadCount = lastWriteCount = 0;
  init(new PChannelStreamBuffer(this));
  Construct();
}


PChannel::~PChannel()
{
  flush();
  Close();
  delete (PChannelStreamBuffer *)rdbuf();
  init(NULL);
}


BOOL PChannel::IsOpen() const
{
  return os_handle >= 0;
}


int PChannel::ReadChar()
{
  BYTE c;
  BOOL retVal = Read(&c, 1);
  return (retVal && lastReadCount == 1) ? c : -1;
}


int PChannel::ReadCharWithTimeout(PTimeInterval & timeout)
{
  SetReadTimeout(timeout);
  PTimeInterval startTick = PTimer::Tick();
  int c;
  if ((c = ReadChar()) < 0) // Timeout or aborted
    return -1;
  timeout -= PTimer::Tick() - startTick;
  return c;
}


BOOL PChannel::ReadBlock(void * buf, PINDEX len)
{
  char * ptr = (char *)buf;
  PINDEX numRead = 0;

  while (numRead < len && Read(ptr+numRead, len - numRead))
    numRead += lastReadCount;

  lastReadCount = numRead;

  return lastReadCount == len;
}


PString PChannel::ReadString(PINDEX len)
{
  PString str;
  ReadBlock(str.GetPointer(len+1), len);
  str.SetSize(lastReadCount+1);
  return str;
}


BOOL PChannel::WriteString(const PString & str)
{
  const char * ptr = str;
  PINDEX len = 0, slen = str.GetLength();

  while (len < slen && Write(ptr+len, slen - len))
    len += lastWriteCount;

  return len == slen;
}


BOOL PChannel::ReadAsync(void * buf, PINDEX len)
{
  BOOL retVal = Read(buf, len);
  OnReadComplete(buf, lastReadCount);
  return retVal;
}


void PChannel::OnReadComplete(void *, PINDEX)
{
}


BOOL PChannel::WriteChar(int c)
{
  PAssert(c >= 0 && c < 256, PInvalidParameter);
  char buf = (char)c;
  return Write(&buf, 1);
}


BOOL PChannel::WriteAsync(const void * buf, PINDEX len)
{
  BOOL retVal = Write(buf, len);
  OnWriteComplete(buf, lastWriteCount);
  return retVal;
}


void PChannel::OnWriteComplete(const void *, PINDEX)
{
}


enum {
  NextCharEndOfString = -1,
  NextCharDelay = -2,
  NextCharSend = -3,
  NextCharWait = -4
};


static int HexDigit(char c)
{
  if (!isxdigit(c))
    return 0;

  int hex = c - '0';
  if (hex < 10)
    return hex;

  hex -= 'A' - '9' - 1;
  if (hex < 16)
    return hex;

  return hex - ('a' - 'A');
}


static int GetNextChar(const PString & command,
                                    PINDEX & pos, PTimeInterval * time = NULL)
{
  int temp;

  if (command[pos] == '\0')
    return NextCharEndOfString;

  if (command[pos] != '\\')
    return command[pos++];

  switch (command[++pos]) {
    case '\0' :
      return NextCharEndOfString;

    case 'a' : // alert (ascii value 7)
      pos++;
      return 7;

    case 'b' : // backspace (ascii value 8)
      pos++;
      return 8;

    case 'f' : // formfeed (ascii value 12)
      pos++;
      return 12;

    case 'n' : // newline (ascii value 10)
      pos++;
      return 10;

    case 'r' : // return (ascii value 13)
      pos++;
      return 13;

    case 't' : // horizontal tab (ascii value 9)
      pos++;
      return 9;

    case 'v' : // vertical tab (ascii value 11)
      pos++;
      return 11;

    case 'x' : // followed by hh  where nn is hex number (ascii value 0xhh)
      if (isxdigit(command[++pos])) {
        temp = HexDigit(command[pos++]);
        if (isxdigit(command[pos]))
          temp += HexDigit(command[pos++]);
        return temp;
      }
      return command[pos];

    case 's' :
      pos++;
      return NextCharSend;

    case 'd' : // ns  delay for n seconds/milliseconds
    case 'w' :
      temp = command[pos] == 'd' ? NextCharDelay : NextCharWait;
      long milliseconds = 0;
      while (isdigit(command[++pos]))
        milliseconds = milliseconds*10 + command[pos] - '0';
      if (milliseconds <= 0)
        milliseconds = 1;
      if (command[pos] == 'm')
        pos++;
      else {
        milliseconds *= 1000;
        if (command[pos] == 's')
          pos++;
      }
      if (time != NULL)
        *time = milliseconds;
      return temp;
  }

  if (command[pos] < '0' || command[pos] > '7')
    return command[pos++];

  // octal number
  temp = command[pos++] - '0';
  if (command[pos] < '0' || command[pos] > '7')
    return temp;

  temp += command[pos++] - '0';
  if (command[pos] < '0' || command[pos] > '7')
    return temp;

  temp += command[pos++] - '0';
  return temp;
}


BOOL PChannel::ReceiveCommandString(int nextChar,
                            const PString & reply, PINDEX & pos, PINDEX start)
{
  if (nextChar != GetNextChar(reply, pos)) {
    pos = start;
    return FALSE;
  }

  PINDEX dummyPos = pos;
  return GetNextChar(reply, dummyPos) < 0;
}


BOOL PChannel::SendCommandString(const PString & command)
{
  abortCommandString = FALSE;

  int nextChar;
  PINDEX sendPosition = 0;
  PTimeInterval timeout;
  SetWriteTimeout(10000);

  while (!abortCommandString) { // not aborted
    nextChar = GetNextChar(command, sendPosition, &timeout);
    switch (nextChar) {
      default :
        if (!WriteChar(nextChar))
          return FALSE;
        break;

      case NextCharEndOfString :
        return TRUE;  // Success!!

      case NextCharSend :
        break;

      case NextCharDelay : // Delay in send
        PThread::Current()->Sleep(timeout);
        break;

      case NextCharWait : // Wait for reply
        PINDEX receivePosition = sendPosition;
        if (GetNextChar(command, receivePosition) < 0) {
          SetReadTimeout(timeout);
          while (ReadChar() >= 0)
            if (abortCommandString) // aborted
              return FALSE;
        }
        else {
          receivePosition = sendPosition;
          do {
            if (abortCommandString) // aborted
              return FALSE;
            if ((nextChar = ReadCharWithTimeout(timeout)) < 0)