logOutput.hpp revision 10870:5bc83f454d50 
1/*
2 * Copyright (c) 2015, 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.
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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_LOGOUTPUT_HPP
25#define SHARE_VM_LOGGING_LOGOUTPUT_HPP
26
27#include "logging/logDecorators.hpp"
28#include "logging/logLevel.hpp"
29#include "memory/allocation.hpp"
30#include "utilities/globalDefinitions.hpp"
31
32class LogDecorations;
33class LogTagSet;
34
35// The base class/interface for log outputs.
36// Keeps track of the latest configuration string,
37// and its selected decorators.
38class LogOutput : public CHeapObj<mtLogging> {
39  // Make LogConfiguration a friend to allow it to modify the configuration string.
40  friend class LogConfiguration;
41
42 private:
43  static const size_t InitialConfigBufferSize = 256;
44  char* _config_string;
45  size_t _config_string_buffer_size;
46
47 protected:
48  LogDecorators _decorators;
49
50  // Clears any previous config description in preparation of reconfiguration.
51  void clear_config_string();
52  // Adds the tagset on the given level to the config description (e.g. "tag1+tag2=level").
53  void add_to_config_string(const LogTagSet* ts, LogLevelType level);
54  // Replaces the current config description with the given string.
55  void set_config_string(const char* string);
56
57 public:
58  static LogOutput* const Stdout;
59  static LogOutput* const Stderr;
60
61  void set_decorators(const LogDecorators &decorators) {
62    _decorators = decorators;
63  }
64
65  const LogDecorators& decorators() const {
66    return _decorators;
67  }
68
69  const char* config_string() const {
70    return _config_string;
71  }
72
73  LogOutput() : _config_string(NULL), _config_string_buffer_size(0) {
74  }
75
76  virtual ~LogOutput();
77
78  // If the output can be rotated, trigger a forced rotation, otherwise do nothing.
79  // Log outputs with rotation capabilities should override this.
80  virtual void force_rotate() {
81    // Do nothing by default.
82  }
83
84  virtual const char* name() const = 0;
85  virtual bool initialize(const char* options, outputStream* errstream) = 0;
86  virtual int write(const LogDecorations &decorations, const char* msg) = 0;
87};
88
89#endif // SHARE_VM_LOGGING_LOGOUTPUT_HPP
90