table: Allow iteration over CS entries

Change-Id: I23bf0da9a853de70187c9e72a0f7a5cb98107fbd
Refs: #2340
diff --git a/daemon/table/cs-entry.cpp b/daemon/table/cs-entry.cpp
index 1262065..0bcdefc 100644
--- a/daemon/table/cs-entry.cpp
+++ b/daemon/table/cs-entry.cpp
@@ -35,12 +35,9 @@
 
 NFD_LOG_INIT("CsEntry");
 
-void
-Entry::release()
+Entry::Entry()
+  : m_isUnsolicited(false)
 {
-  BOOST_ASSERT(m_layerIterators.empty());
-
-  m_dataPacket.reset();
 }
 
 void
@@ -58,27 +55,18 @@
   m_staleAt = time::steady_clock::now() + m_dataPacket->getFreshnessPeriod();
 }
 
-void
-Entry::setIterator(int layer, const Entry::LayerIterators::mapped_type& layerIterator)
+bool
+Entry::isStale() const
 {
-  m_layerIterators[layer] = layerIterator;
+  return m_staleAt < time::steady_clock::now();
 }
 
 void
-Entry::removeIterator(int layer)
+Entry::reset()
 {
-  m_layerIterators.erase(layer);
-}
-
-void
-Entry::printIterators() const
-{
-  for (LayerIterators::const_iterator it = m_layerIterators.begin();
-       it != m_layerIterators.end();
-       ++it)
-    {
-      NFD_LOG_TRACE("[" << it->first << "]" << " " << &(*it->second));
-    }
+  m_staleAt = time::steady_clock::TimePoint();
+  m_dataPacket.reset();
+  m_isUnsolicited = false;
 }
 
 } // namespace cs