Open Source Projects Europe

/* -*- Mode: c++; -*- */

/*  --------------------------------------------------------------------

 *  Filename:

 *    src/mime-inputsource.h

 *  

 *  Description:

 *    The base class of the MIME input source

 *  --------------------------------------------------------------------

 *  Copyright 2002-2004 Andreas Aardal Hanssen

 *

 *  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.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.

 *  --------------------------------------------------------------------

 */

#ifndef mime_inputsource_h_included

#define mime_inputsource_h_included

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <string.h>

#include <unistd.h>

namespace Binc {

  class MimeInputSource {

  public:

    inline MimeInputSource(int fd, unsigned int start = 0);

    virtual inline ~MimeInputSource(void);

    virtual inline bool fillInputBuffer(void);

    virtual inline void reset(void);

    inline void seek(unsigned int offset);

    inline bool getChar(char *c);

    inline void ungetChar(void);

    inline int getFileDescriptor(void) const;

    inline unsigned int getOffset(void) const;

  private:

    int fd;

    char data[16384];

    unsigned int offset;

    unsigned int tail;

    unsigned int head;

    unsigned int start;

    char lastChar;

  };

  inline MimeInputSource::MimeInputSource(int fd, unsigned int start)

  {

    this->fd = fd;

    this->start = start;

    offset = 0;

    tail = 0;

    head = 0;

    lastChar = '\0';

    memset(data, '\0', sizeof(data));

    seek(start);

  }

  inline MimeInputSource::~MimeInputSource(void)

  {

  }

  inline bool MimeInputSource::fillInputBuffer(void)

  {

    char raw[4096];

    ssize_t nbytes = read(fd, raw, sizeof(raw));

    if (nbytes <= 0) {

      // FIXME: If ferror(crlffile) we should log this.

      return false;

    }

    for (ssize_t i = 0; i < nbytes; ++i) {

      const char c = raw[i];

      if (c == '\r') {

  if (lastChar == '\r') {

    data[tail++ & (0x4000-1)] = '\r';

    data[tail++ & (0x4000-1)] = '\n';

  }

      } else if (c == '\n') {

  data[tail++ & (0x4000-1)] = '\r';

  data[tail++ & (0x4000-1)] = '\n';

      } else {

  if (lastChar == '\r') {

    data[tail++ & (0x4000-1)] = '\r';

    data[tail++ & (0x4000-1)] = '\n';

  }

  data[tail++ & (0x4000-1)] = c;

      }

      lastChar = c;

    }

    return true;

  }

  inline void MimeInputSource::reset(void)

  {

    offset = head = tail = 0;

    lastChar = '\0';

    if (fd != -1)

      lseek(fd, 0, SEEK_SET);

  }

  inline void MimeInputSource::seek(unsigned int seekToOffset)

  {

    if (offset > seekToOffset)

      reset();

    char c;

    int n = 0;

    while (seekToOffset > offset) {

      if (!getChar(&c))

  break;

      ++n;

    }

  }

  inline bool MimeInputSource::getChar(char *c)

  {

    if (head == tail && !fillInputBuffer())

      return false;

    *c = data[head++ & (0x4000-1)];

    ++offset;

    return true;

  }

  inline void MimeInputSource::ungetChar()

  {

    --head;

    --offset;

  }

  inline int MimeInputSource::getFileDescriptor(void) const

  {

    return fd;

  }

  inline unsigned int MimeInputSource::getOffset(void) const

  {

    return offset;

  }

}

extern Binc::MimeInputSource *mimeSource;

#endif