1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "logging/log.hpp"
  27 #include "logging/logStream.hpp"
  28 
  29 LogStream::LineBuffer::LineBuffer()
  30  : _buf(_smallbuf), _cap(sizeof(_smallbuf)), _pos(0)
  31 {
  32   _buf[0] = '\0';
  33 }
  34 
  35 LogStream::LineBuffer::~LineBuffer() {
  36   assert(_pos == 0, "still outstanding bytes in the line buffer");
  37   if (_buf != _smallbuf) {
  38     os::free(_buf);
  39   }
  40 }
  41 
  42 void LogStream::LineBuffer::ensure_cap(size_t atleast) {
  43   assert(_cap >= sizeof(_smallbuf), "sanity");
  44   if (_cap < atleast) { 
  45     const size_t newcap = MAX2(_cap * 2, atleast * 2);
  46     char* const newbuf = (char*) os::malloc(newcap, mtLogging);
  47     if (_pos > 0) { // preserve old content
  48       memcpy(newbuf, _buf, _pos + 1); // ..including trailing zero
  49     }
  50     if (_buf != _smallbuf) {
  51       os::free(_buf);
  52     }
  53     _buf = newbuf;
  54     _cap = newcap;
  55   }
  56   assert(_cap >= atleast, "sanity");
  57 }
  58 
  59 void LogStream::LineBuffer::append(const char* s, size_t len) {
  60   assert(_buf[_pos] == '\0', "sanity");
  61   const size_t remaining = _cap - _pos;
  62   ensure_cap(remaining + len + 1);
  63   memcpy(_buf + _pos, s, len);
  64   _pos += len;
  65   _buf[_pos] = '\0';
  66 }
  67     
  68 void LogStream::LineBuffer::reset() {
  69   _pos = 0;
  70   _buf[_pos] = '\0';
  71 }
  72 
  73 void LogStream::write(const char* s, size_t len) {
  74   if (len > 0 && s[len - 1] == '\n') {
  75     _current_line.append(s, len - 1); // omit the newline.
  76     _log_handle.print("%s", _current_line.ptr());
  77     _current_line.reset();
  78   } else {
  79     _current_line.append(s, len);
  80   }
  81   update_position(s, len);
  82 }
  83