kea/src/lib/log/logger_support.cc

// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE

/// \brief Temporary Logger Support
///
/// Performs run-time initialization of the logger system.  In particular, it
/// is passed information from the command line and:
///
/// a) Sets the severity of the messages being logged (and debug level if
/// appropriate).
/// b) Reads in the local message file is one has been supplied.
///
/// These functions will be replaced once the code has been written to obtain
/// the logging parameters from the configuration database.

#include <iostream>
#include <algorithm>
#include <iostream>
#include <string>

#include <log/logger.h>
#include <log/logger_manager.h>
#include <log/logger_support.h>

namespace isc {
namespace log {

using namespace std;

// Declare a logger for the logging subsystem.  This is a sub-logger of the
// root logger and is used in all functions in this file.
Logger logger("log");

/// Logger Run-Time Initialization

void
initLogger(const string& root, isc::log::Severity severity, int dbglevel,
    const char* file) {
    LoggerManager::init(root, file, severity, dbglevel);
}

/// Logger Run-Time Initialization via Environment Variables
void initLogger() {

    // Root logger name is defined by the environment variable B10_LOGGER_ROOT.
    // If not present, the name is "b10root".
    const char* DEFAULT_ROOT = "b10root";
    const char* root = getenv("B10_LOGGER_ROOT");
    if (! root) {
        root = DEFAULT_ROOT;
    }

    // Set the logging severity.  The environment variable is
    // B10_LOGGER_SEVERITY, and can be one of "DEBUG", "INFO", "WARN", "ERROR"
    // of "FATAL".  Note that the string must be in upper case with no leading
    // of trailing blanks.
    isc::log::Severity severity = isc::log::DEBUG;
    const char* sev_char = getenv("B10_LOGGER_SEVERITY");
    if (sev_char) {
        string sev_string(sev_char);
        if (sev_string == "DEBUG") {
            severity = isc::log::DEBUG;
        } else if (sev_string == "INFO") {
            severity = isc::log::INFO;
        } else if (sev_string == "WARN") {
            severity = isc::log::WARN;
        } else if (sev_string == "ERROR") {
            severity = isc::log::ERROR;
        } else if (sev_string == "FATAL") {
            severity = isc::log::FATAL;
        } else {
            std::cerr << "**ERROR** unrecognised logger severity of '"
                      << sev_string << "' - default severity will be used\n";
        }
    }

    // If the severity is debug, get the debug level (environment variable
    // B10_LOGGER_DBGLEVEL), which should be in the range 0 to 99.
    int dbglevel = 0;
    if (severity == isc::log::DEBUG) {
        const char* dbg_char = getenv("B10_LOGGER_DBGLEVEL");
        if (dbg_char) {
            int level = 0;
            try {
                level = boost::lexical_cast<int>(dbg_char);
                if (level < MIN_DEBUG_LEVEL) {
                    std::cerr << "**ERROR** debug level of " << level
                              << " is invalid - a value of " << MIN_DEBUG_LEVEL
                              << " will be used\n";
                    level = MIN_DEBUG_LEVEL;
                } else if (level > MAX_DEBUG_LEVEL) {
                    std::cerr << "**ERROR** debug level of " << level
                              << " is invalid - a value of " << MAX_DEBUG_LEVEL
                              << " will be used\n";
                    level = MAX_DEBUG_LEVEL;
                }
            } catch (...) {
                // Error, but not fatal to the test
                std::cerr << "**ERROR** Unable to translate "
                             "B10_LOGGER_DBGLEVEL - a value of 0 will be used\n";
            }
            dbglevel = level;
        }
    }

    /// Set the local message file
    const char* localfile = getenv("B10_LOGGER_LOCALMSG");

    // Initialize logging
    initLogger(root, severity, dbglevel, localfile);
}

} // namespace log
} // namespace isc