[1579] (suggested) cleanup, mainly moving isNSEC[3] to FindDNSSECContext

these are short, and only used in FindDNSSECContext, so it'd make more sense
to enclose them there.
Other cleanups:
- also made FindDNSSECContext::isNSEC/isNSEC3 private as they now don't need
  to be called outside the class
- removed isInited(); simpy doesn't see the need for it as a separate method
- simplified the code logic of getResultFlag()

src/lib/datasrc/database.cc

@@ -669,24 +669,35 @@ DatabaseClient::Finder::FindDNSSECContext::init() {
     if (!initialized_) {
         initialized_ = true;
         if (need_dnssec_) {
-            // If NSEC3PARAM rrset exists, the zone looks like signed with
-            // NSEC3
-            is_nsec3_ = finder_.isNSEC3();
-            // If no NSEC3PARAM and it is DNSSEC query, check whether NSEC
-            // exist in apex of zone
-            is_nsec_ = is_nsec3_ ? false : finder_.isNSEC();
+            // If an NSEC3PARAM RR exists at the zone apex, it's quite likely
+            // that the zone is signed with NSEC3.  (If not the zone is more
+            // or less broken, but it's caller's responsibility how to handle
+            // such cases).
+            const string origin = finder_.getOrigin().toText();
+            const FoundRRsets nsec3_found =
+                finder_.getRRsets(origin, NSEC3PARAM_TYPES(), false);
+            const FoundIterator nfi=
+                nsec3_found.second.find(RRType::NSEC3PARAM());
+            is_nsec3_ = (nfi != nsec3_found.second.end());
+
+            // Likewise for NSEC, depending on the apex has an NSEC RR.
+            // If we know the zone is NSEC3-signed, however, we don't bother
+            // to check that.  This is aligned with the transition guideline
+            // described in Section 10.4 of RFC 5155.
+            if (!is_nsec3_) {
+                const FoundRRsets nsec_found =
+                    finder_.getRRsets(origin, NSEC_TYPES(), false);
+                const FoundIterator nfi =
+                    nsec_found.second.find(RRType::NSEC());
+                is_nsec_ = (nfi != nsec_found.second.end());
+            }
         }
     }
 }
 
 bool
-DatabaseClient::Finder::FindDNSSECContext::isInited() {
-    return (initialized_);
-}
-
-bool
 DatabaseClient::Finder::FindDNSSECContext::isNSEC3() {
-    if (isInited()) {
+    if (initialized_) {
         return (is_nsec3_);
     } else {
         init();
@@ -696,7 +707,7 @@ DatabaseClient::Finder::FindDNSSECContext::isNSEC3() {
 
 bool
 DatabaseClient::Finder::FindDNSSECContext::isNSEC() {
-    if (isInited()) {
+    if (initialized_) {
         return (is_nsec_);
     } else {
         init();
@@ -754,19 +765,12 @@ DatabaseClient::Finder::FindDNSSECContext::getDNSSECRRset(const Name &name,
 
 ZoneFinder::FindResultFlags
 DatabaseClient::Finder::FindDNSSECContext::getResultFlags() {
-    // If it is not DNSSEC query, it should return RESULT_DEFAULT
-    if (!need_dnssec_) {
-        return (RESULT_DEFAULT);
-    }
-    // If it is a DNSSEC query and the zone is signed with NSEC3, it should
-    // return RESULT_NSEC3_SIGNED
     if (isNSEC3()) {
         return (RESULT_NSEC3_SIGNED);
-    } else {
-        // If it is a DNSSEC query and the zone is signed with NSEC, it should
-        // return RESULT_NSEC_SIGNED, otherwise, return RESULT_DEFAULT
-        return (isNSEC() ? RESULT_NSEC_SIGNED : RESULT_DEFAULT);
+    } else if (isNSEC()) {
+        return (RESULT_NSEC_SIGNED);
     }
+    return (RESULT_DEFAULT);
 }
 
 ZoneFinder::ResultContext
@@ -907,28 +911,6 @@ DatabaseClient::Finder::findNoNameResult(const Name& name, const RRType& type,
                           dnssec_ctx.getResultFlags()));
 }
 
-bool
-DatabaseClient::Finder::isNSEC3() {
-    // If an NSEC3PARAM RR exists at the zone apex, it's quite likely that
-    // the zone is signed with NSEC3.  (If not the zone is more or less broken,
-    // but it's caller's responsibility how to handle such cases).
-    const FoundRRsets nsec3_found = getRRsets(origin_.toText(),
-                                              NSEC3PARAM_TYPES(), false);
-    const FoundIterator nfi(nsec3_found.second.find(RRType::NSEC3PARAM()));
-    return (nfi != nsec3_found.second.end());
-}
-
-bool
-DatabaseClient::Finder::isNSEC() {
-    // If an NSEC RR exists at the zone apex, it's quite likely that
-    // the zone is signed with NSEC.  (If not the zone is more or less broken,
-    // but it's caller's responsibility how to handle such cases).
-    const FoundRRsets nsec_found = getRRsets(origin_.toText(),
-                                             NSEC_TYPES(), false);
-    const FoundIterator nfi(nsec_found.second.find(RRType::NSEC()));
-    return (nfi != nsec_found.second.end());
-}
-
 ZoneFinder::ResultContext
 DatabaseClient::Finder::findInternal(const Name& name, const RRType& type,
                                      std::vector<ConstRRsetPtr>* target,

src/lib/datasrc/database.h

@@ -780,18 +780,6 @@ public:
         }
 
     private:
-        /// \brief check whether zone is signed with nsec
-        ///
-        /// searches the NSEC3PARAM RRset in the zone apex, if it exists, the
-        /// zone looks signed with nsec
-        bool isNSEC();
-
-        /// \brief check whether zone is signed with nsec3
-        ///
-        /// searches the NSEC3PARAM RRset in the zone apex, if it exists, the
-        /// zone looks signed with nsec3
-        bool isNSEC3();
-
         boost::shared_ptr<DatabaseAccessor> accessor_;
         const int zone_id_;
         const isc::dns::Name origin_;
@@ -907,6 +895,7 @@ public:
             isc::dns::ConstRRsetPtr getDNSSECRRset(const FoundRRsets&
                                                    found_set);
 
+        private:
             /// \brief Check whether the zone file is signed with NSECi3.
             ///
             /// It checks whether the zone file is signed with NSEC3. If
@@ -923,7 +912,6 @@ public:
             /// \return True for NSEC, false otherwise.
             bool isNSEC();
 
-        private:
             /// \brief Init the attributes in this entity.
             ///
             /// It should init the attributes of this entity. Check whether
@@ -933,14 +921,6 @@ public:
             /// again.
             void init();
 
-            /// \brief Check whether the entity is initialized.
-            ///
-            /// It should return true if the entity is inited, else return
-            /// false.
-            ///
-            /// \return True for inited, else return false.
-            bool isInited();
-
             DatabaseClient::Finder& finder_;
             const bool need_dnssec_;