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 // try_ensure_cap tries to enlarge the capacity of the internal buffer 43 // to the given atleast value. May fail if either OOM happens or atleast 44 // is larger than a reasonable max of 1 M. Caller must not assume 45 // capacity without checking. 46 void LogStream::LineBuffer::try_ensure_cap(size_t atleast) { 47 assert(_cap >= sizeof(_smallbuf), "sanity"); 48 if (_cap < atleast) { 49 const size_t reasonable_max = 1 * M; 50 size_t newcap = align_size_up(atleast + 64, 64); 51 assert(_cap <= reasonable_max, "sanity"); 52 // Cap out at a reasonable max to prevent runaway leaks. 53 if (newcap > reasonable_max) { 54 newcap = reasonable_max; 55 } 56 57 char* const newbuf = (char*) os::malloc(newcap, mtLogging); 58 if (newbuf == NULL) { // OOM. Leave object unchanged. 59 return; 60 } 61 if (_pos > 0) { // preserve old content 62 memcpy(newbuf, _buf, _pos + 1); // ..including trailing zero 63 } 64 if (_buf != _smallbuf) { 65 os::free(_buf); 66 } 67 _buf = newbuf; 68 _cap = newcap; 69 } 70 assert(_cap >= atleast, "sanity"); 71 } 72 73 void LogStream::LineBuffer::append(const char* s, size_t len) { 74 assert(_buf[_pos] == '\0', "sanity"); 75 assert(_pos < _cap, "sanity"); 76 try_ensure_cap(_pos + len + 1); 77 // try_ensure_cap may not have enlarged the capacity to the full requested 78 // extend or may have not worked at all. In that case, just gracefully work 79 // with what we have already; just truncate if necessary. 80 if (_pos + len + 1 > _cap) { 81 len = _cap - _pos - 1; 82 if (len == 0) { 83 return; 84 } 85 } 86 memcpy(_buf + _pos, s, len); 87 _pos += len; 88 _buf[_pos] = '\0'; 89 } 90 91 void LogStream::LineBuffer::reset() { 92 _pos = 0; 93 _buf[_pos] = '\0'; 94 } 95 96 void LogStream::write(const char* s, size_t len) { 97 if (len > 0 && s[len - 1] == '\n') { 98 _current_line.append(s, len - 1); // omit the newline. 99 _log_handle.print("%s", _current_line.ptr()); 100 _current_line.reset(); 101 } else { 102 _current_line.append(s, len); 103 } 104 update_position(s, len); 105 } 106