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 // Cap out at a reasonable max to prevent runaway leaks. 50 const size_t reasonable_max = 1 * M; 51 assert(_cap <= reasonable_max, "sanity"); 52 if (_cap == reasonable_max) { 53 return; 54 } 55 56 const size_t additional_expansion = 256; 57 size_t newcap = align_up(atleast + additional_expansion, additional_expansion); 58 if (newcap > reasonable_max) { 59 log_info(logging)("Suspiciously long log line: \"%.100s%s", 60 _buf, (_pos >= 100 ? "..." : "")); 61 newcap = reasonable_max; 62 } 63 64 char* const newbuf = (char*) os::malloc(newcap, mtLogging); 65 if (newbuf == NULL) { // OOM. Leave object unchanged. 66 return; 67 } 68 if (_pos > 0) { // preserve old content 69 memcpy(newbuf, _buf, _pos + 1); // ..including trailing zero 70 } 71 if (_buf != _smallbuf) { 72 os::free(_buf); 73 } 74 _buf = newbuf; 75 _cap = newcap; 76 } 77 assert(_cap >= atleast, "sanity"); 78 } 79 80 void LogStream::LineBuffer::append(const char* s, size_t len) { 81 assert(_buf[_pos] == '\0', "sanity"); 82 assert(_pos < _cap, "sanity"); 83 const size_t minimum_capacity_needed = _pos + len + 1; 84 try_ensure_cap(minimum_capacity_needed); 85 // try_ensure_cap may not have enlarged the capacity to the full requested 86 // extend or may have not worked at all. In that case, just gracefully work 87 // with what we have already; just truncate if necessary. 88 if (_cap < minimum_capacity_needed) { 89 len = _cap - _pos - 1; 90 if (len == 0) { 91 return; 92 } 93 } 94 memcpy(_buf + _pos, s, len); 95 _pos += len; 96 _buf[_pos] = '\0'; 97 } 98 99 void LogStream::LineBuffer::reset() { 100 _pos = 0; 101 _buf[_pos] = '\0'; 102 } 103 104 void LogStream::write(const char* s, size_t len) { 105 if (len > 0 && s[len - 1] == '\n') { 106 _current_line.append(s, len - 1); // omit the newline. 107 _log_handle.print("%s", _current_line.buffer()); 108 _current_line.reset(); 109 } else { 110 _current_line.append(s, len); 111 } 112 update_position(s, len); 113 } 114