Add cache library to doxygen files

Make RRsetCache copy constructor and assignment operator private to make it uncopyable
Add TODO for rrsig processing

doc/Doxyfile

@@ -568,7 +568,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories
 # with spaces.
 
-INPUT                  = ../src/lib/cc ../src/lib/config ../src/lib/dns ../src/lib/exceptions ../src/lib/datasrc ../src/bin/auth ../src/lib/bench ../src/lib/log ../src/lib/asiolink/ ../src/lib/nsas
+INPUT                  = ../src/lib/cc ../src/lib/config ../src/lib/dns ../src/lib/exceptions ../src/lib/datasrc ../src/bin/auth ../src/lib/bench ../src/lib/log ../src/lib/asiolink/ ../src/lib/nsas ../src/lib/cache
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is

src/lib/cache/rrset_cache.h

@@ -32,10 +32,21 @@ class RRsetEntry;
 /// The object of RRsetCache represented the cache for class-specific
 /// RRsets.
 class RRsetCache{
+    ///
+    /// \name Constructors and Destructor
+    ///
+    /// Note: The copy constructor and the assignment operator are intentionally
+    /// defined as private to make it uncopyable
+    //@{
+private:
+    RRsetCache(const RRsetCache&);
+    RRsetCache& operator=(const RRsetCache&);
 public:
     /// \param cache_size the size of rrset cache.
     /// \param rrset_class the class of rrset cache.
     RRsetCache(uint32_t cache_size, uint16_t rrset_class);
+    ~RRsetCache() {}
+    //@}
 
     /// \brief Look up rrset in cache.
     /// \return return the shared_ptr of rrset entry if it can

src/lib/cache/rrset_entry.h

@@ -87,6 +87,7 @@ public:
     isc::dns::RRsetPtr getRRset();
 
     /// \brief Get the expiration time of the RRset.
+    /// \todo RRsig expiration processing
     time_t getExpireTime() const;
 
     /// \brief Get the ttl of the RRset.