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