/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "logging/log.hpp"

#include "logging/logStream.hpp"

LogStream::LineBuffer::LineBuffer()

 : _buf(_smallbuf), _cap(sizeof(_smallbuf)), _pos(0)

{

  _buf[0] = '\0';

}

LogStream::LineBuffer::~LineBuffer() {

  assert(_pos == 0, "still outstanding bytes in the line buffer");

  if (_buf != _smallbuf) {

    os::free(_buf);

  }

}

// try_ensure_cap tries to enlarge the capacity of the internal buffer

// to the given atleast value. May fail if either OOM happens or atleast

// is larger than a reasonable max of 1 M. Caller must not assume

// capacity without checking.

void LogStream::LineBuffer::try_ensure_cap(size_t atleast) {

  assert(_cap >= sizeof(_smallbuf), "sanity");

  if (_cap < atleast) {

    // Cap out at a reasonable max to prevent runaway leaks.

    const size_t reasonable_max = 1 * M;

    assert(_cap <= reasonable_max, "sanity");

    if (_cap == reasonable_max) {

      return;

    }

    const size_t additional_expansion = 256;

    size_t newcap = align_up(atleast + additional_expansion, additional_expansion);

    if (newcap > reasonable_max) {

      log_info(logging)("Suspiciously long log line: \"%.100s%s",

              _buf, (_pos >= 100 ? "..." : ""));

      newcap = reasonable_max;

    }

    char* const newbuf = (char*) os::malloc(newcap, mtLogging);

    if (newbuf == NULL) { // OOM. Leave object unchanged.

      return;

    }

    if (_pos > 0) { // preserve old content

      memcpy(newbuf, _buf, _pos + 1); // ..including trailing zero

    }

    if (_buf != _smallbuf) {

      os::free(_buf);

    }

    _buf = newbuf;

    _cap = newcap;

  }

  assert(_cap >= atleast, "sanity");

}

void LogStream::LineBuffer::append(const char* s, size_t len) {

  assert(_buf[_pos] == '\0', "sanity");

  assert(_pos < _cap, "sanity");

  const size_t minimum_capacity_needed = _pos + len + 1;

  try_ensure_cap(minimum_capacity_needed);

  // try_ensure_cap may not have enlarged the capacity to the full requested

  // extend or may have not worked at all. In that case, just gracefully work

  // with what we have already; just truncate if necessary.

  if (_cap < minimum_capacity_needed) {

    len = _cap - _pos - 1;

    if (len == 0) {

      return;

    }

  }

  memcpy(_buf + _pos, s, len);

  _pos += len;

  _buf[_pos] = '\0';

}

void LogStream::LineBuffer::reset() {

  _pos = 0;

  _buf[_pos] = '\0';

}

void LogStream::write(const char* s, size_t len) {

  if (len > 0 && s[len - 1] == '\n') {

    _current_line.append(s, len - 1); // omit the newline.

    _log_handle.print("%s", _current_line.buffer());

    _current_line.reset();

  } else {

    _current_line.append(s, len);

  }

  update_position(s, len);

}