summaryrefslogtreecommitdiffstats
path: root/dolog.hh
blob: 557c767aadeecb1933c978324e974c854efb469f (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
/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#pragma once
#include <iostream>
#include <sstream>
#if !defined(RECURSOR)
#include <syslog.h>
#else
#include "logger.hh"
#endif // RECURSOR


/* This file is intended not to be metronome specific, and is simple example of C++2011
   variadic templates in action.

   The goal is rapid easy to use logging to console & syslog. 

   Usage: 
          string address="localhost";
          vinfolog("Got TCP connection from %s", remote);
          infolog("Bound to %s port %d", address, port);
          warnlog("Query took %d milliseconds", 1232.4); // yes, %d
          errlog("Unable to bind to %s: %s", ca.toStringWithPort(), strerr(errno));

   Will log to stdout. Will syslog in any case with LOG_INFO,
   LOG_WARNING, LOG_ERR respectively. If g_verbose=false, vinfolog is a noop.
   More generically, dolog(someiostream, "Hello %s", stream) will log to someiostream

   This will happily print a string to %d! Doesn't do further format processing.
*/

#if !defined(RECURSOR)
inline void dolog(std::ostream& os, const char*s)
{
  os<<s;
}

template<typename T, typename... Args>
void dolog(std::ostream& os, const char* s, T value, Args... args)
{
  while (*s) {
    if (*s == '%') {
      if (*(s + 1) == '%') {
	++s;
      }
      else {
	os << value;
	s += 2;
	dolog(os, s, args...);
	return;
      }
    }
    os << *s++;
  }
}

extern bool g_verbose;
extern bool g_syslog;

inline void setSyslogFacility(int facility)
{
  /* we always call openlog() right away at startup */
  closelog();
  openlog("dnsdist", LOG_PID|LOG_NDELAY, facility);
}

template<typename... Args>
void genlog(int level, const char* s, Args... args)
{
  std::ostringstream str;
  dolog(str, s, args...);
  if(g_syslog)
    syslog(level, "%s", str.str().c_str());
  std::cout<<str.str()<<std::endl;
}


#define vinfolog if(g_verbose)infolog

template<typename... Args>
void infolog(const char* s, Args... args)
{
  genlog(LOG_INFO, s, args...);
}

template<typename... Args>
void warnlog(const char* s, Args... args)
{
  genlog(LOG_WARNING, s, args...);
}

template<typename... Args>
void errlog(const char* s, Args... args)
{
  genlog(LOG_ERR, s, args...);
}


#else // RECURSOR

#define g_verbose 0

inline void dolog(Logger::Urgency u, const char* s)
{
  g_log << u << s << std::endl;
}

inline void dolog(const char* s)
{
  g_log << s << std::endl;
}

template<typename T, typename... Args>
void dolog(Logger::Urgency u, const char* s, T value, Args... args)
{
  g_log << u;
  while (*s) {
    if (*s == '%') {
      if (*(s + 1) == '%') {
	++s;
      }
      else {
	g_log << value;
	s += 2;
	dolog(s, args...);
	return;
      }
    }
    g_log << *s++;
  }
}

#define vinfolog if(g_verbose)infolog

template<typename... Args>
void infolog(const char* s, Args... args)
{
  dolog(Logger::Info, s, args...);
}

template<typename... Args>
void warnlog(const char* s, Args... args)
{
  dolog(Logger::Warning, s, args...);
}

template<typename... Args>
void errlog(const char* s, Args... args)
{
  dolog(Logger::Error, s, args...);
}

#endif