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
25 #ifndef SHARE_VM_LOGGING_LOGSTREAM_HPP
26 #define SHARE_VM_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
35
36 // The base class of an output stream that logs to the logging framework.
37 template <class streamClass>
38 class LogStreamBase : public outputStream {
39 streamClass _current_line;
40 LogTargetHandle _log_handle;
41
42 public:
43 // Constructor to support creation from a LogTarget instance.
44 //
45 // LogTarget(Debug, gc) log;
46 // LogStreamBase(log) stream;
47 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
48 LogStreamBase(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>& type_carrier) :
49 _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}
50
51 // Constructor to support creation from typed (likely NULL) pointer. Mostly used by the logging framework.
52 //
53 // LogStreamBase stream(log.debug());
54 // or
55 // LogStreamBase stream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL);
56 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
57 LogStreamBase(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>* type_carrier) :
58 _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}
59
60 // Constructor to support creation from a LogTargetHandle.
61 //
62 // LogTarget(Debug, gc) log;
63 // LogTargetHandle(log) handle;
64 // LogStreamBase stream(handle);
65 LogStreamBase(LogTargetHandle handle) : _log_handle(handle) {}
66
67 // Constructor to support creation from a log level and tagset.
68 //
69 // LogStreamBase(level, tageset);
70 LogStreamBase(LogLevelType level, LogTagSet* tagset) : _log_handle(level, tagset) {}
71
72 ~LogStreamBase() {
73 guarantee(_current_line.size() == 0, "Buffer not flushed. Missing call to print_cr()?");
74 }
75
76 public:
77 void write(const char* s, size_t len);
78 };
79
80 // A stringStream with an embedded ResourceMark.
81 class stringStreamWithResourceMark : outputStream {
82 private:
83 // The stringStream Resource allocate in the constructor,
84 // so the order of the fields is important.
85 ResourceMark _embedded_resource_mark;
86 stringStream _stream;
87
88 public:
89 stringStreamWithResourceMark(size_t initial_bufsize = 256) :
90 _embedded_resource_mark(),
91 _stream(initial_bufsize) {}
92
93 virtual void write(const char* c, size_t len) { _stream.write(c, len); }
94 size_t size() { return _stream.size(); }
95 const char* base() { return _stream.base(); }
96 void reset() { _stream.reset(); }
97 char* as_string() { return _stream.as_string(); }
98 };
99
100 // An output stream that logs to the logging framework.
101 //
102 // The backing buffer is allocated in Resource memory.
103 // The caller is required to have a ResourceMark on the stack.
104 typedef LogStreamBase<stringStream> LogStreamNoResourceMark;
105
106 // An output stream that logs to the logging framework.
107 //
108 // The backing buffer is allocated in CHeap memory.
109 typedef LogStreamBase<bufferedStream> LogStreamCHeap;
110
111 // An output stream that logs to the logging framework, and embeds a ResourceMark.
112 //
113 // The backing buffer is allocated in Resource memory.
114 // The class is intended to be stack allocated.
115 // The class provides its own ResourceMark,
116 // so care needs to be taken when nested ResourceMarks are used.
117 typedef LogStreamBase<stringStreamWithResourceMark> LogStream;
118
119 // Support creation of a LogStream without having to provide a LogTarget pointer.
120 #define LogStreamHandle(level, ...) LogStreamTemplate<LogLevel::level, LOG_TAGS(__VA_ARGS__)>
121
122 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>
123 class LogStreamTemplate : public LogStream {
124 public:
125 LogStreamTemplate() : LogStream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL) {}
126 };
127
128
129 #endif // SHARE_VM_LOGGING_LOGSTREAM_HPP