source: pacpusframework/trunk/3rd/apache-log4cxx/include/log4cxx/writerappender.h@ 76

Last change on this file since 76 was 2, checked in by sgosseli, 12 years ago

Add 3rd party libraries (log4cxx).
File size: 8.1 KB
Line 
1/*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18#ifndef _LOG4CXX_WRITER_APPENDER_H
19#define _LOG4CXX_WRITER_APPENDER_H
20
21#if defined(_MSC_VER)
22#pragma warning ( push )
23#pragma warning ( disable: 4231 4251 4275 4786 )
24#endif
25
26#include <log4cxx/appenderskeleton.h>
27#include <log4cxx/helpers/outputstreamwriter.h>
28
29namespace log4cxx
30{
31
32 namespace helpers {
33 class Transcoder;
34 }
35
36 /**
37 WriterAppender appends log events to a standard output stream
38 */
39 class LOG4CXX_EXPORT WriterAppender : public AppenderSkeleton
40 {
41 private:
42 /**
43 Immediate flush means that the underlying writer or output stream
44 will be flushed at the end of each append operation. Immediate
45 flush is slower but ensures that each append request is actually
46 written. If <code>immediateFlush</code> is set to
47 <code>false</code>, then there is a good chance that the last few
48 logs events are not actually written to persistent media if and
49 when the application crashes.
50
51 <p>The <code>immediateFlush</code> variable is set to
52 <code>true</code> by default.
53
54 */
55 bool immediateFlush;
56
57 /**
58 The encoding to use when opening an input stream.
59 <p>The <code>encoding</code> variable is set to <code>""</code> by
60 default which results in the utilization of the system's default
61 encoding. */
62 LogString encoding;
63
64 /**
65 * This is the {@link Writer Writer} where we will write to.
66 */
67 log4cxx::helpers::WriterPtr writer;
68
69
70 public:
71 DECLARE_ABSTRACT_LOG4CXX_OBJECT(WriterAppender)
72 BEGIN_LOG4CXX_CAST_MAP()
73 LOG4CXX_CAST_ENTRY(WriterAppender)
74 LOG4CXX_CAST_ENTRY_CHAIN(AppenderSkeleton)
75 END_LOG4CXX_CAST_MAP()
76
77 /**
78 This default constructor does nothing.*/
79 WriterAppender();
80 protected:
81 WriterAppender(const LayoutPtr& layout,
82 log4cxx::helpers::WriterPtr& writer);
83 WriterAppender(const LayoutPtr& layout);
84
85 public:
86 ~WriterAppender();
87
88 /**
89 Derived appenders should override this method if option structure
90 requires it.
91 */
92 virtual void activateOptions(log4cxx::helpers::Pool& pool);
93
94 /**
95 If the <b>ImmediateFlush</b> option is set to
96 <code>true</code>, the appender will flush at the end of each
97 write. This is the default behavior. If the option is set to
98 <code>false</code>, then the underlying stream can defer writing
99 to physical medium to a later time.
100
101 <p>Avoiding the flush operation at the end of each append results in
102 a performance gain of 10 to 20 percent. However, there is safety
103 tradeoff involved in skipping flushing. Indeed, when flushing is
104 skipped, then it is likely that the last few log events will not
105 be recorded on disk when the application exits. This is a high
106 price to pay even for a 20% performance gain.
107 */
108 void setImmediateFlush(bool value);
109 /**
110 Returns value of the <b>ImmediateFlush</b> option.
111 */
112 bool getImmediateFlush() const { return immediateFlush; }
113
114 /**
115 This method is called by the AppenderSkeleton#doAppend
116 method.
117
118 <p>If the output stream exists and is writable then write a log
119 statement to the output stream. Otherwise, write a single warning
120 message to <code>stderr</code>.
121
122 <p>The format of the output will depend on this appender's
123 layout.
124
125 */
126 virtual void append(const spi::LoggingEventPtr& event, log4cxx::helpers::Pool& p);
127
128
129 protected:
130 /**
131 This method determines if there is a sense in attempting to append.
132
133 <p>It checks whether there is a set output target and also if
134 there is a set layout. If these checks fail, then the boolean
135 value <code>false</code> is returned. */
136 virtual bool checkEntryConditions() const;
137
138
139 public:
140 /**
141 Close this appender instance. The underlying stream or writer is
142 also closed.
143
144 <p>Closed appenders cannot be reused.
145 */
146 virtual void close();
147
148 protected:
149 /**
150 * Close the underlying {@link log4cxx::helpers::Writer}.
151 * */
152 void closeWriter();
153
154 /**
155 Returns an OutputStreamWriter when passed an OutputStream. The
156 encoding used will depend on the value of the
157 <code>encoding</code> property. If the encoding value is
158 specified incorrectly the writer will be opened using the default
159 system encoding (an error message will be printed to the loglog. */
160 virtual log4cxx::helpers::WriterPtr createWriter(
161 log4cxx::helpers::OutputStreamPtr& os);
162
163 public:
164 LogString getEncoding() const;
165 void setEncoding(const LogString& value);
166 void setOption(const LogString& option,
167 const LogString& value);
168
169 /**
170 <p>Sets the Writer where the log output will go. The
171 specified Writer must be opened by the user and be
172 writable.
173
174 <p>The <code>java.io.Writer</code> will be closed when the
175 appender instance is closed.
176
177
178 <p><b>WARNING:</b> Logging to an unopened Writer will fail.
179 <p>
180 @param writer An already opened Writer. */
181 void setWriter(const log4cxx::helpers::WriterPtr& writer);
182
183 virtual bool requiresLayout() const;
184
185 protected:
186 /**
187 Actual writing occurs here.
188 */
189 virtual void subAppend(const spi::LoggingEventPtr& event, log4cxx::helpers::Pool& p);
190
191
192 /**
193 Write a footer as produced by the embedded layout's
194 Layout#appendFooter method. */
195 virtual void writeFooter(log4cxx::helpers::Pool& p);
196
197 /**
198 Write a header as produced by the embedded layout's
199 Layout#appendHeader method. */
200 virtual void writeHeader(log4cxx::helpers::Pool& p);
201
202 private:
203 //
204 // prevent copy and assignment
205 WriterAppender(const WriterAppender&);
206 WriterAppender& operator=(const WriterAppender&);
207 };
208
209 LOG4CXX_PTR_DEF(WriterAppender);
210
211} //namespace log4cxx
212
213#if defined(_MSC_VER)
214#pragma warning ( pop )
215#endif
216
217#endif //_LOG4CXX_WRITER_APPENDER_H
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