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24 
25 #ifndef SHARE_LOGGING_LOGSTREAM_HPP
26 #define SHARE_LOGGING_LOGSTREAM_HPP
27 
28 #include "logging/log.hpp"
29 #include "logging/logHandle.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "utilities/ostream.hpp"
32 
33 
34 class LogStream : public outputStream {
35   friend class LogStreamTest_TestLineBufferAllocation_test_vm_Test; // see test/native/logging/test_logStream.cpp
36   friend class LogStreamTest_TestLineBufferAllocationCap_test_vm_Test; // see test/native/logging/test_logStream.cpp
37 
38   // Helper class, maintains the line buffer. For small line lengths,
39   // we avoid malloc and use a fixed sized member char array. If LogStream
40   // is allocated on the stack, this means small lines are assembled
41   // directly on the stack.
42   class LineBuffer {
43     char _smallbuf[64];
44     char* _buf;
45     size_t _cap;
46     size_t _pos;
47     void try_ensure_cap(size_t cap);
48   public:
49     LineBuffer();
50     ~LineBuffer();
is_empty() const51     bool is_empty() const { return _pos == 0; }
buffer() const52     const char* buffer() const { return _buf; }
53     void append(const char* s, size_t len);
54     void reset();
55   };
56   LineBuffer  _current_line;
57   LogTargetHandle _log_handle;
58 
59   // Prevent operator new for LogStream.
60   static void* operator new (size_t);
61   static void* operator new[] (size_t);
62 
63 public:
64   // Constructor to support creation from a LogTarget instance.
65   //
66   // LogTarget(Debug, gc) log;
67   // LogStreamBase(log) stream;
68   template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
LogStream(const LogTargetImpl<level,T0,T1,T2,T3,T4,GuardTag> & type_carrier)69   LogStream(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>& type_carrier) :
70       _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}
71 
72   // Constructor to support creation from typed (likely NULL) pointer. Mostly used by the logging framework.
73   //
74   // LogStreamBase stream(log.debug());
75   //  or
76   // LogStreamBase stream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL);
77   template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
LogStream(const LogTargetImpl<level,T0,T1,T2,T3,T4,GuardTag> * type_carrier)78   LogStream(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>* type_carrier) :
79       _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}
80 
81   // Destructor writes any unfinished output left in the line buffer.
82   ~LogStream();
83 
84   // Constructor to support creation from a LogTargetHandle.
85   //
86   // LogTarget(Debug, gc) log;
87   // LogTargetHandle(log) handle;
88   // LogStreamBase stream(handle);
LogStream(LogTargetHandle handle)89   LogStream(LogTargetHandle handle) : _log_handle(handle) {}
90 
91   // Constructor to support creation from a log level and tagset.
92   //
93   // LogStreamBase(level, tageset);
LogStream(LogLevelType level,LogTagSet * tagset)94   LogStream(LogLevelType level, LogTagSet* tagset) : _log_handle(level, tagset) {}
95 
96   void write(const char* s, size_t len);
97 };
98 
99 // Support creation of a LogStream without having to provide a LogTarget pointer.
100 #define LogStreamHandle(level, ...) LogStreamTemplate<LogLevel::level, LOG_TAGS(__VA_ARGS__)>
101 
102 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
103 class LogStreamTemplate : public LogStream {
104 public:
LogStreamTemplate()105   LogStreamTemplate() : LogStream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL) {}
106 };
107 
108 #endif // SHARE_LOGGING_LOGSTREAM_HPP
109