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#ifndef SHARE_VM_LOGGING_LOGMESSAGEBUFFER_HPP
25#define SHARE_VM_LOGGING_LOGMESSAGEBUFFER_HPP
26
27#include "logging/logDecorations.hpp"
28#include "logging/logLevel.hpp"
29#include "memory/allocation.hpp"
30
31class LogMessageBuffer : public StackObj {
32  friend class LogMessageTest;
33 protected:
34  struct LogLine VALUE_OBJ_CLASS_SPEC {
35    LogLevelType level;
36    size_t message_offset;
37  };
38  static const size_t InitialLineCapacity = 10;
39  static const size_t InitialMessageBufferCapacity = 1024;
40
41  size_t _message_buffer_size;
42  size_t _message_buffer_capacity;
43  char* _message_buffer;
44
45  size_t _line_count;
46  size_t _line_capacity;
47  LogLine* _lines;
48
49  bool _allocated;
50  LogLevelType _least_detailed_level;
51  size_t (*_prefix_fn)(char*, size_t);
52
53  void initialize_buffers();
54
55 private:
56  // Forbid copy assignment and copy constructor.
57  void operator=(const LogMessageBuffer& ref) {}
58  LogMessageBuffer(const LogMessageBuffer& ref) {}
59
60 public:
61  LogMessageBuffer();
62  ~LogMessageBuffer();
63
64  class Iterator {
65   private:
66    const LogMessageBuffer& _message;
67    size_t _current_line_index;
68    LogLevelType _level;
69    LogDecorations &_decorations;
70
71    void skip_messages_with_finer_level();
72
73   public:
74    Iterator(const LogMessageBuffer& message, LogLevelType level, LogDecorations& decorations)
75        : _message(message), _level(level), _decorations(decorations), _current_line_index(0) {
76      skip_messages_with_finer_level();
77    }
78
79    void operator++(int) {
80      _current_line_index++;
81      skip_messages_with_finer_level();
82    }
83
84    bool is_at_end() {
85      return _current_line_index == _message._line_count;
86    }
87
88    const char* message() const {
89      return _message._message_buffer + _message._lines[_current_line_index].message_offset;
90    }
91
92    const LogDecorations& decorations() {
93      _decorations.set_level(_message._lines[_current_line_index].level);
94      return _decorations;
95    }
96  };
97
98  void reset();
99
100  LogLevelType least_detailed_level() const {
101    return _least_detailed_level;
102  }
103
104  Iterator iterator(LogLevelType level, LogDecorations& decorations) const {
105    return Iterator(*this, level, decorations);
106  }
107
108  // Lines in LogMessageBuffers are not automatically prefixed based on tags
109  // like regular simple messages (see LogPrefix.hpp for more about prefixes).
110  // It is, however, possible to specify a prefix per LogMessageBuffer,
111  // using set_prefix(). Lines added to the LogMessageBuffer after a prefix
112  // function has been set will be prefixed automatically.
113  // Setting this to NULL will disable prefixing.
114  void set_prefix(size_t (*prefix_fn)(char*, size_t)) {
115    _prefix_fn = prefix_fn;
116  }
117
118  ATTRIBUTE_PRINTF(3, 4)
119  void write(LogLevelType level, const char* fmt, ...);
120
121  ATTRIBUTE_PRINTF(3, 0)
122  virtual void vwrite(LogLevelType level, const char* fmt, va_list args);
123
124#define LOG_LEVEL(level, name) \
125  LogMessageBuffer& v##name(const char* fmt, va_list args) ATTRIBUTE_PRINTF(2, 0); \
126  LogMessageBuffer& name(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
127  LOG_LEVEL_LIST
128#undef LOG_LEVEL
129};
130
131#endif // SHARE_VM_LOGGING_LOGMESSAGEBUFFER_HPP
132