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
29LogStream::LineBuffer::LineBuffer()
30 : _buf(_smallbuf), _cap(sizeof(_smallbuf)), _pos(0)
31{
32 _buf[0] = '\0';
33}
34
35LogStream::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.
46void 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
80void 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
99void LogStream::LineBuffer::reset() {
100 _pos = 0;
101 _buf[_pos] = '\0';
102}
103
104void 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
115// Destructor writes any unfinished output left in the line buffer.
116LogStream::~LogStream() {
117 if (_current_line.is_empty() == false) {
118 _log_handle.print("%s", _current_line.buffer());
119 _current_line.reset();
120 }
121}
122
123
124