core: change logging from environment variable to configuration file-based

GlobalConfigurationFixture uses unit-tests.conf to determine default
and module specific logging levels. Logging will gracefully default to
INFO if unit-tests.conf is not found. See unit-tests.conf.sample for a
sample configuration file.

refs: #1375, #1267

Change-Id: Ib0c4eb4149748e6658f94ef1afa23ddd3072c0fa
diff --git a/daemon/core/logger-factory.cpp b/daemon/core/logger-factory.cpp
new file mode 100644
index 0000000..4a353f1
--- /dev/null
+++ b/daemon/core/logger-factory.cpp
@@ -0,0 +1,178 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (C) 2014 Named Data Networking Project
+ * See COPYING for copyright and distribution information.
+ */
+
+#include "logger-factory.hpp"
+
+namespace nfd {
+
+LoggerFactory&
+LoggerFactory::getInstance()
+{
+  static LoggerFactory globalLoggerFactory;
+
+  return globalLoggerFactory;
+}
+
+LoggerFactory::LoggerFactory()
+  : m_defaultLevel(LOG_INFO)
+{
+  m_levelNames["NONE"] = LOG_NONE;
+  m_levelNames["ERROR"] = LOG_ERROR;
+  m_levelNames["WARN"] = LOG_WARN;
+  m_levelNames["INFO"] = LOG_INFO;
+  m_levelNames["DEBUG"] = LOG_DEBUG;
+  m_levelNames["TRACE"] = LOG_TRACE;
+  m_levelNames["ALL"] = LOG_ALL;
+}
+
+void
+LoggerFactory::setConfigFile(ConfigFile& config)
+{
+  config.addSectionHandler("log", bind(&LoggerFactory::onConfig, this, _1, _2, _3));
+}
+
+LogLevel
+LoggerFactory::parseLevel(const std::string& level)
+{
+  std::string upperLevel = level;
+  boost::to_upper(upperLevel);
+
+  // std::cerr << "parsing level: " << upperLevel << std::endl;;
+  // std::cerr << "# levels: " << m_levelNames.size() << std::endl;
+  // std::cerr << m_levelNames.begin()->first << std::endl;
+
+  LevelMap::const_iterator levelIt = m_levelNames.find(upperLevel);
+  if (levelIt != m_levelNames.end())
+    {
+      return levelIt->second;
+    }
+  try
+    {
+      uint32_t levelNo = boost::lexical_cast<uint32_t>(level);
+
+      if ((LOG_NONE <= levelNo && levelNo <= LOG_TRACE) ||
+          levelNo == LOG_ALL)
+        {
+          return static_cast<LogLevel>(levelNo);
+        }
+    }
+  catch (const boost::bad_lexical_cast& error)
+    {
+    }
+  throw LoggerFactory::Error("Unsupported logging level \"" +
+                             level + "\"");
+}
+
+
+void
+LoggerFactory::onConfig(const ConfigSection& section,
+                        bool isDryRun,
+                        const std::string& filename)
+{
+// log
+// {
+//   ; default_level specifies the logging level for modules
+//   ; that are not explicitly named. All debugging levels
+//   ; listed above the selected value are enabled.
+//
+//   default_level INFO
+//
+//   ; You may also override the default for specific modules:
+//
+//   FibManager DEBUG
+//   Forwarder WARN
+// }
+
+  // std::cerr << "loading logging configuration" << std::endl;
+  for (ConfigSection::const_iterator item = section.begin();
+       item != section.end();
+       ++item)
+    {
+      std::string levelString;
+      try
+        {
+          levelString = item->second.get_value<std::string>();
+        }
+      catch (const boost::property_tree::ptree_error& error)
+        {
+        }
+
+      if (levelString.empty())
+        {
+          throw LoggerFactory::Error("No logging level found for option \"" + item->first + "\"");
+        }
+
+      LogLevel level = parseLevel(levelString);
+
+      if (item->first == "default_level")
+        {
+          if (!isDryRun)
+            {
+              setDefaultLevel(level);
+            }
+        }
+      else
+        {
+          LoggerMap::iterator loggerIt = m_loggers.find(item->first);
+          if (loggerIt == m_loggers.end())
+            {
+              throw LoggerFactory::Error("Invalid module name \"" +
+                                         item->first + "\" in configuration file");
+            }
+
+          if (!isDryRun)
+            {
+              // std::cerr << "changing level for module " << item->first << " to " << level << std::endl;
+              loggerIt->second.setLogLevel(level);
+            }
+        }
+    }
+}
+
+void
+LoggerFactory::setDefaultLevel(LogLevel level)
+{
+  // std::cerr << "changing to default_level " << level << std::endl;
+
+  m_defaultLevel = level;
+  for (LoggerMap::iterator i = m_loggers.begin(); i != m_loggers.end(); ++i)
+    {
+      // std::cerr << "changing " << i->first << " to default " << m_defaultLevel << std::endl;
+      i->second.setLogLevel(m_defaultLevel);
+    }
+}
+
+Logger&
+LoggerFactory::create(const std::string& moduleName)
+{
+  return LoggerFactory::getInstance().createLogger(moduleName);
+}
+
+Logger&
+LoggerFactory::createLogger(const std::string& moduleName)
+{
+  // std::cerr << "creating logger for " << moduleName
+  //           << " with level " << m_defaultLevel << std::endl;
+
+  std::pair<LoggerMap::iterator, bool> loggerIt =
+    m_loggers.insert(NameAndLogger(moduleName, Logger(moduleName, m_defaultLevel)));
+
+  return loggerIt.first->second;
+}
+
+std::list<std::string>
+LoggerFactory::getModules() const
+{
+  std::list<std::string> modules;
+  for (LoggerMap::const_iterator i = m_loggers.begin(); i != m_loggers.end(); ++i)
+    {
+      modules.push_back(i->first);
+    }
+
+  return modules;
+}
+
+} // namespace nfd