logHandle.hpp revision 10769:421b50008870 
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.
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24#ifndef SHARE_VM_LOGGING_LOGHANDLE_HPP
25#define SHARE_VM_LOGGING_LOGHANDLE_HPP
26
27#include "logging/log.hpp"
28
29// Wraps a Log instance and throws away the template information.
30//
31// This can be used to pass a Log instance as a parameter without
32// polluting the surrounding API with template functions.
33class LogHandle {
34private:
35  LogTagSet* _tagset;
36
37public:
38  template <LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
39  LogHandle(const LogImpl<T0, T1, T2, T3, T4, GuardTag>& type_carrier) :
40      _tagset(&LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}
41
42  bool is_level(LogLevelType level) {
43    return _tagset->is_level(level);
44  }
45
46#define LOG_LEVEL(level, name) ATTRIBUTE_PRINTF(2, 0)   \
47  LogHandle& v##name(const char* fmt, va_list args) { \
48    _tagset->vwrite(LogLevel::level, fmt, args); \
49    return *this; \
50  } \
51  LogHandle& name(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3) { \
52    va_list args; \
53    va_start(args, fmt); \
54    _tagset->vwrite(LogLevel::level, fmt, args); \
55    va_end(args); \
56    return *this; \
57  } \
58  bool is_##name() { \
59    return _tagset->is_level(LogLevel::level); \
60  }
61  LOG_LEVEL_LIST
62#undef LOG_LEVEL
63};
64
65// Wraps a LogTarget instance and throws away the template information.
66//
67// This can be used to pass a Log instance as a parameter without
68// polluting the surrounding API with template functions.
69class LogTargetHandle {
70  friend class LogStream;
71
72private:
73  const LogLevelType _level;
74  LogTagSet*         _tagset;
75
76public:
77  template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
78  LogTargetHandle(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>& type_carrier) :
79      _level(level),
80      _tagset(&LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}
81
82  template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
83  static LogTargetHandle create() {
84    return LogTargetHandle(LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>());
85  }
86
87  void print(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3) {
88    va_list args;
89    va_start(args, fmt);
90    _tagset->vwrite(_level, fmt, args);
91    va_end(args);
92  }
93
94  bool is_enabled() const {
95    return _tagset->is_level(_level);
96  }
97
98  // Creates a log stream from the information stored in this instance.
99  // Callers need a ResourceMark on the stack.
100  outputStream* stream() {
101    return create_log_stream(_level, _tagset);;
102  }
103};
104
105#endif // SHARE_VM_LOGGING_LOGHANDLE_HPP
106