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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 
31 class LogMessageBuffer : public StackObj {
32   friend class LogMessageTest;
33  protected:
34   struct LogLine {
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.
operator =(const LogMessageBuffer & ref)57   void operator=(const LogMessageBuffer& ref) {}
LogMessageBuffer(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:
Iterator(const LogMessageBuffer & message,LogLevelType level,LogDecorations & decorations)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 
operator ++(int)79     void operator++(int) {
80       _current_line_index++;
81       skip_messages_with_finer_level();
82     }
83 
is_at_end()84     bool is_at_end() {
85       return _current_line_index == _message._line_count;
86     }
87 
message() const88     const char* message() const {
89       return _message._message_buffer + _message._lines[_current_line_index].message_offset;
90     }
91 
decorations()92     const LogDecorations& decorations() {
93       _decorations.set_level(_message._lines[_current_line_index].level);
94       return _decorations;
95     }
96   };
97 
98   void reset();
99 
least_detailed_level() const100   LogLevelType least_detailed_level() const {
101     return _least_detailed_level;
102   }
103 
iterator(LogLevelType level,LogDecorations & decorations) const104   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.
set_prefix(size_t (* prefix_fn)(char *,size_t))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