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 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_VM_LOGGING_LOGSTREAM_HPP 109