lineStreamBuf.cxx

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/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file lineStreamBuf.cxx
 * @author drose
 * @date 2000-02-26
 */

#include "lineStreamBuf.h"

using std::string;

/**
 *
 */
LineStreamBuf::
LineStreamBuf() {
  _has_newline = false;

  // The LineStreamBuf doesn't actually need a buffer--it's happy writing
  // characters one at a time, since they're just getting stuffed into a
  // string.  (Although the code is written portably enough to use a buffer
  // correctly, if we had one.)
  setg(nullptr, nullptr, nullptr);
  setp(nullptr, nullptr);
}

/**
 *
 */
LineStreamBuf::
~LineStreamBuf() {
  sync();
}

/**
 * Extracts the next line of text from the LineStreamBuf, and sets the
 * has_newline() flag according to whether this line had a trailing newline or
 * not.
 */
string LineStreamBuf::
get_line() {
  // Extract the data up to, but not including, the next newline character.
  size_t nl = _data.find('\n');
  if (nl == string::npos) {
    // No trailing newline; return the remainder of the string.
    _has_newline = false;
    string result = _data;
    _data = "";
    return result;
  }

  _has_newline = true;
  string result = _data.substr(0, nl);
  _data = _data.substr(nl + 1);
  return result;
}

/**
 * Called by the system ostream implementation when the buffer should be
 * flushed to output (for instance, on destruction).
 */
int LineStreamBuf::
sync() {
  std::streamsize n = pptr() - pbase();
  write_chars(pbase(), n);
  pbump(-(int)n);  // Reset pptr().
  return 0;  // EOF to indicate write full.
}

/**
 * Called by the system ostream implementation when its internal buffer is
 * filled, plus one character.
 */
int LineStreamBuf::
overflow(int ch) {
  std::streamsize n = pptr() - pbase();

  if (n != 0 && sync() != 0) {
    return EOF;
  }

  if (ch != EOF) {
    // Write one more character.
    char c = (char)ch;
    write_chars(&c, 1);
  }

  return 0;
}