summaryrefslogtreecommitdiff
path: root/include/logger.h
blob: 6bf64801f36f23952685aa27c6298bb465eb4ba0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
 *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
 *
 * This file is part of InspIRCd.  InspIRCd is free software: you can
 * redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation, version 2.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


#pragma once

/** Levels at which messages can be logged. */
enum LogLevel
{
	LOG_RAWIO   = 5,
	LOG_DEBUG   = 10,
	LOG_VERBOSE = 20,
	LOG_DEFAULT = 30,
	LOG_SPARSE  = 40,
	LOG_NONE    = 50
};

/** Simple wrapper providing periodic flushing to a disk-backed file.
 */
class CoreExport FileWriter
{
 protected:
	/** The log file (fd is inside this somewhere,
	 * we get it out with fileno())
	 */
	FILE* log;

	/** Number of write operations that have occured
	 */
	int writeops;

 public:
	/** The constructor takes an already opened logfile.
	 */
	FileWriter(FILE* logfile);

	/** Write one or more preformatted log lines.
	 * If the data cannot be written immediately,
	 * this class will insert itself into the
	 * SocketEngine, and register a write event,
	 * and when the write event occurs it will
	 * attempt again to write the data.
	 */
	void WriteLogLine(const std::string &line);

	/** Close the log file and cancel any events.
	 */
	virtual ~FileWriter();
};



/*
 * New world logging!
 * The brief summary:
 *  Logging used to be a simple affair, a FILE * handled by a nonblocking logging class inheriting from EventHandler, that was inserted
 *  into the socket engine, and wrote lines. If nofork was on, it was printf()'d.
 *
 *  We decided to horribly overcomplicate matters, and create vastly customisable logging. LogManager and LogStream form the visible basis
 *  of the new interface. Basically, a LogStream can be inherited to do different things with logging output. We inherit from it once in core
 *  to create a FileLogStream, that writes to a file, for example. Different LogStreams can hook different types of log messages, and different
 *  levels of output too, for extreme customisation. Multiple LogStreams can hook the same message/levels of output, meaning that e.g. output
 *  can go to a channel as well as a file.
 *
 *  HOW THIS WORKS
 *   LogManager handles all instances of LogStreams, classes derived from LogStream are instantiated and passed to it.
 */

/** LogStream base class. Modules (and other stuff) inherit from this to decide what logging they are interested in, and what to do with it.
 */
class CoreExport LogStream : public classbase
{
 protected:
	int loglvl;
 public:
	static const char LogHeader[];

	LogStream(int loglevel) : loglvl(loglevel)
	{
	}

	/* A LogStream's destructor should do whatever it needs to close any resources it was using (or indicate that it is no longer using a resource
	 * in the event that the resource is shared, see for example FileLogStream).
	 */
	virtual ~LogStream() { }

	/** Changes the loglevel for this LogStream on-the-fly.
	 * This is needed for -nofork. But other LogStreams could use it to change loglevels.
	 */
	void ChangeLevel(int lvl) { this->loglvl = lvl; }

	/** Called when there is stuff to log for this particular logstream. The derived class may take no action with it, or do what it
	 * wants with the output, basically. loglevel and type are primarily for informational purposes (the level and type of the event triggered)
	 * and msg is, of course, the actual message to log.
	 */
	virtual void OnLog(int loglevel, const std::string &type, const std::string &msg) = 0;
};

typedef std::map<FileWriter*, int> FileLogMap;

class CoreExport LogManager
{
 private:
	/** Lock variable, set to true when a log is in progress, which prevents further loggging from happening and creating a loop.
	 */
	bool Logging;

	/** Map of active log types and what LogStreams will receive them.
	 */
	std::map<std::string, std::vector<LogStream *> > LogStreams;

	/** Refcount map of all LogStreams managed by LogManager.
	 * If a logstream is not listed here, it won't be automatically closed by LogManager, even if it's loaded in one of the other lists.
	 */
	std::map<LogStream *, int> AllLogStreams;

	/** LogStreams with type * (which means everything), and a list a logtypes they are excluded from (eg for "* -USERINPUT -USEROUTPUT").
	 */
	std::map<LogStream *, std::vector<std::string> > GlobalLogStreams;

	/** Refcounted map of all FileWriters in use by FileLogStreams, for file stream sharing.
	 */
	FileLogMap FileLogs;

 public:
	LogManager();
	~LogManager();

	/** Adds a FileWriter instance to LogManager, or increments the reference count of an existing instance.
	 * Used for file-stream sharing for FileLogStreams.
	 */
	void AddLoggerRef(FileWriter* fw)
	{
		FileLogMap::iterator i = FileLogs.find(fw);
		if (i == FileLogs.end())
		{
			FileLogs.insert(std::make_pair(fw, 1));
		}
		else
		{
			++i->second;
		}
	}

	/** Indicates that a FileWriter reference has been removed. Reference count is decreased, and if zeroed, the FileWriter is closed.
	 */
	void DelLoggerRef(FileWriter* fw)
	{
		FileLogMap::iterator i = FileLogs.find(fw);
		if (i == FileLogs.end()) return; /* Maybe should log this? */
		if (--i->second < 1)
		{
			delete i->first;
			FileLogs.erase(i);
		}
	}

	/** Opens all logfiles defined in the configuration file using \<log method="file">.
	 */
	void OpenFileLogs();

	/** Removes all LogStreams, meaning they have to be readded for logging to continue.
	 * Only LogStreams that were listed in AllLogStreams are actually closed.
	 */
	void CloseLogs();

	/** Adds a single LogStream to multiple logtypes.
	 * This automatically handles things like "* -USERINPUT -USEROUTPUT" to mean all but USERINPUT and USEROUTPUT types.
	 * It is not a good idea to mix values of autoclose for the same LogStream.
	 * @param type The type string (from configuration, or whatever) to parse.
	 * @param l The LogStream to add.
	 * @param autoclose True to have the LogStream automatically closed when all references to it are removed from LogManager. False to leave it open.
	 */
	void AddLogTypes(const std::string &type, LogStream *l, bool autoclose);

	/** Registers a new logstream into the logging core, so it can be called for future events
	 * It is not a good idea to mix values of autoclose for the same LogStream.
	 * @param type The type to add this LogStream to.
	 * @param l The LogStream to add.
	 * @param autoclose True to have the LogStream automatically closed when all references to it are removed from LogManager. False to leave it open.
	 * @return True if the LogStream was added successfully, False otherwise.
	 */
	bool AddLogType(const std::string &type, LogStream *l, bool autoclose);

	/** Removes a logstream from the core. After removal, it will not recieve further events.
	 * If the LogStream was ever added with autoclose, it will be closed after this call (this means the pointer won't be valid anymore).
	 */
	void DelLogStream(LogStream* l);

	/** Removes a LogStream from a single type. If the LogStream has been registered for "*" it will still receive the type unless you remove it from "*" specifically.
	 * If the LogStream was added with autoclose set to true, then when the last occurrence of the stream is removed it will automatically be closed (freed).
	 */
	bool DelLogType(const std::string &type, LogStream *l);

	/** Logs an event, sending it to all LogStreams registered for the type.
	 * @param type Log message type (ex: "USERINPUT", "MODULE", ...)
	 * @param loglevel Log message level (LOG_DEBUG, LOG_VERBOSE, LOG_DEFAULT, LOG_SPARSE, LOG_NONE)
	 * @param msg The message to be logged (literal).
	 */
	void Log(const std::string &type, int loglevel, const std::string &msg);

	/** Logs an event, sending it to all LogStreams registered for the type.
	 * @param type Log message type (ex: "USERINPUT", "MODULE", ...)
	 * @param loglevel Log message level (LOG_DEBUG, LOG_VERBOSE, LOG_DEFAULT, LOG_SPARSE, LOG_NONE)
	 * @param fmt The format of the message to be logged. See your C manual on printf() for details.
	 */
	void Log(const std::string &type, int loglevel, const char *fmt, ...) CUSTOM_PRINTF(4, 5);
};