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 // The base class of an output stream that logs to the logging framework. 34 template <class streamClass> 35 class LogStreamBase : public outputStream { 36 streamClass _current_line; 37 LogTargetHandle _log_handle; 38 39 public: 40 // Constructor to support creation from a LogTarget instance. 41 // 42 // LogTarget(Debug, gc) log; 43 // LogStreamBase(log) stream; 44 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag> 45 LogStreamBase(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>& type_carrier) : 46 _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {} 47 48 // Constructor to support creation from typed (likely NULL) pointer. Mostly used by the logging framework. 49 // 50 // LogStreamBase stream(log.debug()); 51 // or 52 // LogStreamBase stream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL); 53 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag> 54 LogStreamBase(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>* type_carrier) : 55 _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {} 56 57 // Constructor to support creation from a LogTargetHandle. 58 // 59 // LogTarget(Debug, gc) log; 60 // LogTargetHandle(log) handle; 61 // LogStreamBase stream(handle); 62 LogStreamBase(LogTargetHandle handle) : _log_handle(handle) {} 63 64 // Constructor to support creation from a log level and tagset. 65 // 66 // LogStreamBase(level, tageset); 67 LogStreamBase(LogLevelType level, LogTagSet* tagset) : _log_handle(level, tagset) {} 68 69 ~LogStreamBase() { 70 guarantee(_current_line.size() == 0, "Buffer not flushed. Missing call to print_cr()?"); 71 } 72 73 public: 74 void write(const char* s, size_t len); 75 }; 76 77 // A stringStream with an embedded ResourceMark. 78 class stringStreamWithResourceMark : outputStream { 79 private: 80 // The stringStream Resource allocate in the constructor, 81 // so the order of the fields is important. 82 ResourceMark _embedded_resource_mark; 83 stringStream _stream; 84 85 public: 86 stringStreamWithResourceMark(size_t initial_bufsize = 256) : 87 _embedded_resource_mark(), 88 _stream(initial_bufsize) {} 89 90 virtual void write(const char* c, size_t len) { _stream.write(c, len); } 91 size_t size() { return _stream.size(); } 92 const char* base() { return _stream.base(); } 93 void reset() { _stream.reset(); } 94 char* as_string() { return _stream.as_string(); } 95 }; 96 97 // An output stream that logs to the logging framework. 98 // 99 // The backing buffer is allocated in Resource memory. 100 // The caller is required to have a ResourceMark on the stack. 101 typedef LogStreamBase<stringStream> LogStreamNoResourceMark; 102 103 // An output stream that logs to the logging framework. 104 // 105 // The backing buffer is allocated in CHeap memory. 106 typedef LogStreamBase<bufferedStream> LogStreamCHeap; 107 108 // An output stream that logs to the logging framework, and embeds a ResourceMark. 109 // 110 // The backing buffer is allocated in Resource memory. 111 // The class is intended to be stack allocated. 112 // The class provides its own ResourceMark, 113 // so care needs to be taken when nested ResourceMarks are used. 114 typedef LogStreamBase<stringStreamWithResourceMark> LogStream; 115 116 // Support creation of a LogStream without having to provide a LogTarget pointer. 117 #define LogStreamHandle(level, ...) LogStreamTemplate<LogLevel::level, LOG_TAGS(__VA_ARGS__)> 118 119 template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag> 120 class LogStreamTemplate : public LogStream { 121 public: 122 LogStreamTemplate() : LogStream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL) {} 123 }; 124 125 #endif // SHARE_VM_LOGGING_LOGSTREAM_HPP