util: logging facility
refs #3562
Change-Id: I61d934c5306e1a73b41c81aeb3524d6bf581af3c
diff --git a/src/util/logging.cpp b/src/util/logging.cpp
new file mode 100644
index 0000000..dd10c4d
--- /dev/null
+++ b/src/util/logging.cpp
@@ -0,0 +1,209 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library 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 Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "logging.hpp"
+#include "logger.hpp"
+
+#include <boost/log/expressions.hpp>
+#include <cstdlib>
+#include <fstream>
+
+namespace ndn {
+namespace util {
+
+static const LogLevel INITIAL_DEFAULT_LEVEL = LogLevel::NONE;
+
+Logging&
+Logging::get()
+{
+ // Initialization of block-scope variables with static storage duration is thread-safe.
+ // See ISO C++ standard [stmt.dcl]/4
+ static Logging instance;
+ return instance;
+}
+
+Logging::Logging()
+{
+ this->setDestinationImpl(shared_ptr<std::ostream>(&std::clog, bind([]{})));
+
+ const char* environ = std::getenv("NDN_CXX_LOG");
+ if (environ != nullptr) {
+ this->setLevelImpl(environ);
+ }
+}
+
+void
+Logging::addLoggerImpl(Logger& logger)
+{
+ std::lock_guard<std::mutex> lock(m_mutex);
+
+ const std::string& moduleName = logger.getModuleName();
+ m_loggers.insert({moduleName, &logger});
+
+ auto levelIt = m_enabledLevel.find(moduleName);
+ if (levelIt == m_enabledLevel.end()) {
+ levelIt = m_enabledLevel.find("*");
+ }
+ LogLevel level = levelIt == m_enabledLevel.end() ? INITIAL_DEFAULT_LEVEL : levelIt->second;
+ logger.setLevel(level);
+}
+
+#ifdef NDN_CXX_HAVE_TESTS
+bool
+Logging::removeLogger(Logger& logger)
+{
+ const std::string& moduleName = logger.getModuleName();
+ auto range = m_loggers.equal_range(moduleName);
+ for (auto i = range.first; i != range.second; ++i) {
+ if (i->second == &logger) {
+ m_loggers.erase(i);
+ return true;
+ }
+ }
+ return false;
+}
+#endif // NDN_CXX_HAVE_TESTS
+
+void
+Logging::setLevelImpl(const std::string& moduleName, LogLevel level)
+{
+ std::lock_guard<std::mutex> lock(m_mutex);
+
+ if (moduleName == "*") {
+ this->setDefaultLevel(level);
+ return;
+ }
+
+ m_enabledLevel[moduleName] = level;
+ auto range = m_loggers.equal_range(moduleName);
+ for (auto i = range.first; i != range.second; ++i) {
+ i->second->setLevel(level);
+ }
+}
+
+void
+Logging::setDefaultLevel(LogLevel level)
+{
+ m_enabledLevel.clear();
+ m_enabledLevel["*"] = level;
+
+ for (auto i = m_loggers.begin(); i != m_loggers.end(); ++i) {
+ i->second->setLevel(level);
+ }
+}
+
+void
+Logging::setLevelImpl(const std::string& config)
+{
+ std::stringstream ss(config);
+ std::string configModule;
+ while (std::getline(ss, configModule, ':')) {
+ size_t ind = configModule.find('=');
+ if (ind == std::string::npos) {
+ BOOST_THROW_EXCEPTION(std::invalid_argument("malformed logging config: '=' is missing"));
+ }
+
+ std::string moduleName = configModule.substr(0, ind);
+ LogLevel level = parseLogLevel(configModule.substr(ind+1));
+
+ this->setLevelImpl(moduleName, level);
+ }
+}
+
+#ifdef NDN_CXX_HAVE_TESTS
+std::string
+Logging::getLevels() const
+{
+ std::ostringstream os;
+
+ auto defaultLevelIt = m_enabledLevel.find("*");
+ if (defaultLevelIt != m_enabledLevel.end()) {
+ os << "*=" << defaultLevelIt->second << ':';
+ }
+
+ for (auto it = m_enabledLevel.begin(); it != m_enabledLevel.end(); ++it) {
+ if (it->first == "*") {
+ continue;
+ }
+ os << it->first << '=' << it->second << ':';
+ }
+
+ std::string s = os.str();
+ if (!s.empty()) {
+ s.pop_back(); // delete last ':'
+ }
+ return s;
+}
+#endif // NDN_CXX_HAVE_TESTS
+
+#ifdef NDN_CXX_HAVE_TESTS
+void
+Logging::resetLevels()
+{
+ this->setDefaultLevel(INITIAL_DEFAULT_LEVEL);
+ m_enabledLevel.clear();
+}
+#endif // NDN_CXX_HAVE_TESTS
+
+void
+Logging::setDestination(std::ostream& os)
+{
+ setDestination(shared_ptr<std::ostream>(&os, bind([]{})));
+}
+
+void
+Logging::setDestinationImpl(shared_ptr<std::ostream> os)
+{
+ std::lock_guard<std::mutex> lock(m_mutex);
+
+ m_destination = os;
+
+ auto backend = boost::make_shared<boost::log::sinks::text_ostream_backend>();
+ backend->auto_flush(true);
+ backend->add_stream(boost::shared_ptr<std::ostream>(os.get(), bind([]{})));
+
+ if (m_sink != nullptr) {
+ boost::log::core::get()->remove_sink(m_sink);
+ m_sink->flush();
+ m_sink.reset();
+ }
+
+ m_sink = boost::make_shared<Sink>(backend);
+ m_sink->set_formatter(boost::log::expressions::stream << boost::log::expressions::message);
+ boost::log::core::get()->add_sink(m_sink);
+}
+
+#ifdef NDN_CXX_HAVE_TESTS
+shared_ptr<std::ostream>
+Logging::getDestination()
+{
+ return m_destination;
+}
+#endif // NDN_CXX_HAVE_TESTS
+
+void
+Logging::flushImpl()
+{
+ m_sink->flush();
+}
+
+} // namespace util
+} // namespace ndn