1/*
2 * Copyright (c) 2016, 2019, 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#ifndef SHARE_LOGGING_LOGMESSAGE_HPP
25#define SHARE_LOGGING_LOGMESSAGE_HPP
26
27#include "logging/log.hpp"
28#include "logging/logMessageBuffer.hpp"
29#include "logging/logPrefix.hpp"
30#include "logging/logTag.hpp"
31
32// The LogMessage class represents a multi-part/multi-line message
33// that is guaranteed to be sent and written to the log outputs
34// in a way that prevents interleaving by other log messages.
35//
36// The interface of LogMessage is very similar to the Log class,
37// with printf functions for each level (trace(), debug(), etc).
38// The difference is that these functions will append/write to the
39// LogMessage, which only buffers the message-parts until the whole
40// message is sent to a log (using Log::write). Internal buffers
41// are C heap allocated lazily on first write. LogMessages are
42// automatically written when they go out of scope.
43//
44// Example usage:
45//
46// {
47// LogMessage(logging) msg;
48// if (msg.is_debug()) {
49// msg.debug("debug message");
50// msg.trace("additional trace information");
51// }
52// }
53//
54// Log outputs on trace level will see both of the messages above,
55// and the trace line will immediately follow the debug line.
56// They will have identical decorations (apart from level).
57// Log outputs on debug level will see the debug message,
58// but not the trace message.
59//
60#define LogMessage(...) LogMessageImpl<LOG_TAGS(__VA_ARGS__)>
61template <LogTagType T0, LogTagType T1 = LogTag::__NO_TAG, LogTagType T2 = LogTag::__NO_TAG,
62 LogTagType T3 = LogTag::__NO_TAG, LogTagType T4 = LogTag::__NO_TAG, LogTagType GuardTag = LogTag::__NO_TAG>
63class LogMessageImpl : public LogMessageBuffer {
64 private:
65 LogImpl<T0, T1, T2, T3, T4, GuardTag> _log;
66 bool _has_content;
67
68 public:
69 LogMessageImpl() : _has_content(false) {
70 }
71
72 ~LogMessageImpl() {
73 if (_has_content) {
74 flush();
75 }
76 }
77
78 void flush() {
79 _log.write(*this);
80 reset();
81 }
82
83 void reset() {
84 _has_content = false;
85 LogMessageBuffer::reset();
86 }
87
88 ATTRIBUTE_PRINTF(3, 0)
89 void vwrite(LogLevelType level, const char* fmt, va_list args) {
90 if (!_has_content) {
91 _has_content = true;
92 set_prefix(LogPrefix<T0, T1, T2, T3, T4>::prefix);
93 }
94 LogMessageBuffer::vwrite(level, fmt, args);
95 }
96
97#define LOG_LEVEL(level, name) \
98 bool is_##name() const { \
99 return _log.is_level(LogLevel::level); \
100 }
101 LOG_LEVEL_LIST
102#undef LOG_LEVEL
103};
104
105#endif // SHARE_LOGGING_LOGMESSAGE_HPP
106