mgmt,main: configure tables with defaults when missing config section/values

refs: #1743

Change-Id: Id0c24bd2b2e86df763892d194f9c04777a369d0c
diff --git a/daemon/mgmt/tables-config-section.cpp b/daemon/mgmt/tables-config-section.cpp
index 0efa02d..124a2d3 100644
--- a/daemon/mgmt/tables-config-section.cpp
+++ b/daemon/mgmt/tables-config-section.cpp
@@ -33,6 +33,8 @@
 
 NFD_LOG_INIT("TablesConfigSection");
 
+const size_t TablesConfigSection::DEFAULT_CS_MAX_PACKETS = 65536;
+
 TablesConfigSection::TablesConfigSection(Cs& cs,
                                          Pit& pit,
                                          Fib& fib,
@@ -43,11 +45,32 @@
   // , m_fib(fib)
   // , m_strategyChoice(strategyChoice)
   // , m_measurements(measurements)
+  , m_areTablesConfigured(false)
 {
 
 }
 
 void
+TablesConfigSection::setConfigFile(ConfigFile& configFile)
+{
+  configFile.addSectionHandler("tables",
+                               bind(&TablesConfigSection::onConfig, this, _1, _2, _3));
+}
+
+
+void
+TablesConfigSection::ensureTablesAreConfigured()
+{
+  if (m_areTablesConfigured)
+    {
+      return;
+    }
+
+  NFD_LOG_INFO("Setting CS max packets to " << DEFAULT_CS_MAX_PACKETS);
+  m_cs.setLimit(DEFAULT_CS_MAX_PACKETS);
+}
+
+void
 TablesConfigSection::onConfig(const ConfigSection& configSection,
                               bool isDryRun,
                               const std::string& filename)
@@ -57,6 +80,8 @@
   //    cs_max_packets 65536
   // }
 
+  size_t nCsMaxPackets = DEFAULT_CS_MAX_PACKETS;
+
   boost::optional<const ConfigSection&> csMaxPacketsNode =
     configSection.get_child_optional("cs_max_packets");
 
@@ -70,18 +95,17 @@
           throw ConfigFile::Error("Invalid value for option \"cs_max_packets\""
                                   " in \"tables\" section");
         }
-      else if (!isDryRun)
-        {
-          m_cs.setLimit(*valCsMaxPackets);
-        }
-    }
-}
 
-void
-TablesConfigSection::setConfigFile(ConfigFile& configFile)
-{
-  configFile.addSectionHandler("tables",
-                               bind(&TablesConfigSection::onConfig, this, _1, _2, _3));
+      nCsMaxPackets = *valCsMaxPackets;
+    }
+
+  if (!isDryRun)
+    {
+      NFD_LOG_INFO("Setting CS max packets to " << nCsMaxPackets);
+
+      m_cs.setLimit(nCsMaxPackets);
+      m_areTablesConfigured = true;
+    }
 }
 
 } // namespace nfd
diff --git a/daemon/mgmt/tables-config-section.hpp b/daemon/mgmt/tables-config-section.hpp
index 482ceca..4571a59 100644
--- a/daemon/mgmt/tables-config-section.hpp
+++ b/daemon/mgmt/tables-config-section.hpp
@@ -39,7 +39,6 @@
 class TablesConfigSection
 {
 public:
-
   TablesConfigSection(Cs& cs,
                       Pit& pit,
                       Fib& fib,
@@ -50,6 +49,11 @@
   setConfigFile(ConfigFile& configFile);
 
   void
+  ensureTablesAreConfigured();
+
+private:
+
+  void
   onConfig(const ConfigSection& configSection,
            bool isDryRun,
            const std::string& filename);
@@ -60,6 +64,12 @@
   // Fib& m_fib;
   // StrategyChoice& m_strategyChoice;
   // Measurements& m_measurements;
+
+  bool m_areTablesConfigured;
+
+private:
+
+  static const size_t DEFAULT_CS_MAX_PACKETS;
 };
 
 } // namespace nfd