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Diffstat (limited to '')
| -rw-r--r-- | dolog.hh | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/dolog.hh b/dolog.hh new file mode 100644 index 0000000..a28777a --- /dev/null +++ b/dolog.hh @@ -0,0 +1,211 @@ +/* + * 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 <fstream> +#include <iostream> +#include <optional> +#include <sstream> +#include "config.h" +#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; +#ifdef DNSDIST +extern bool g_logtimestamps; +extern std::optional<std::ofstream> g_verboseStream; +#endif + +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(std::ostream& stream, int level, bool doSyslog, const char* s, Args... args) +{ + std::ostringstream str; + dolog(str, s, args...); + + auto output = str.str(); + + if (doSyslog) { + syslog(level, "%s", output.c_str()); + } + +#ifdef DNSDIST + if (g_logtimestamps) { + char buffer[50] = ""; + struct tm tm; + time_t t; + time(&t); + localtime_r(&t, &tm); + if (strftime(buffer, sizeof(buffer), "%b %d %H:%M:%S ", &tm) == 0) { + buffer[0] = '\0'; + } + stream<<buffer; + } +#endif + + stream<<output<<std::endl; +} + +template<typename... Args> +void verboselog(const char* s, Args... args) +{ +#ifdef DNSDIST + if (g_verboseStream) { + genlog(*g_verboseStream, LOG_DEBUG, false, s, args...); + } + else { +#endif /* DNSDIST */ + genlog(std::cout, LOG_DEBUG, g_syslog, s, args...); +#ifdef DNSDIST + } +#endif /* DNSDIST */ +} + +#define vinfolog if (g_verbose) verboselog + +template<typename... Args> +void infolog(const char* s, Args... args) +{ + genlog(std::cout, LOG_INFO, g_syslog, s, args...); +} + +template<typename... Args> +void warnlog(const char* s, Args... args) +{ + genlog(std::cout, LOG_WARNING, g_syslog, s, args...); +} + +template<typename... Args> +void errlog(const char* s, Args... args) +{ + genlog(std::cout, LOG_ERR, g_syslog, 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 |