[trac493] Add message utility functions and fix some coding style

problems

src/lib/cache/message_cache.cc

@@ -32,7 +32,8 @@ using namespace std;
 using namespace MessageUtility;
 
 MessageCache::MessageCache(boost::shared_ptr<RRsetCache> rrset_cache,
-    uint32_t cache_size, uint16_t message_class, boost::shared_ptr<RRsetCache> negative_soa_cache):
+                           uint32_t cache_size, uint16_t message_class,
+                           boost::shared_ptr<RRsetCache> negative_soa_cache):
     message_class_(message_class),
     rrset_cache_(rrset_cache),
     negative_soa_cache_(negative_soa_cache),
@@ -62,12 +63,14 @@ bool
 MessageCache::update(const Message& msg) {
     // If the message is a negative response, but no SOA record is found in
     // the authority section, the message cannot be cached
-    if (isNegativeResponse(msg) && !hasTheRecordInAuthoritySection(msg, RRType::SOA())){
+    if (isNegativeResponse(msg) &&
+        !hasTheRecordInAuthoritySection(msg, RRType::SOA())){
         return (false);
     }
 
     QuestionIterator iter = msg.beginQuestion();
-    std::string entry_name = genCacheEntryName((*iter)->getName(), (*iter)->getType());
+    std::string entry_name = genCacheEntryName((*iter)->getName(),
+                                               (*iter)->getType());
     HashKey entry_key = HashKey(entry_name, RRClass(message_class_));
 
     // The simplest way to update is removing the old message entry directly.
@@ -80,7 +83,8 @@ MessageCache::update(const Message& msg) {
         message_lru_.remove(old_msg_entry);
     }
 
-    MessageEntryPtr msg_entry(new MessageEntry(msg, rrset_cache_, negative_soa_cache_));
+    MessageEntryPtr msg_entry(new MessageEntry(msg, rrset_cache_,
+                                               negative_soa_cache_));
     message_lru_.add(msg_entry);
     return (message_table_.add(msg_entry, entry_key, true));
 }

src/lib/cache/message_entry.cc

@@ -83,7 +83,8 @@ MessageEntry::addRRset(isc::dns::Message& message,
     }
 
     for (uint16_t index = start_index; index < end_index; ++index) {
-        message.addRRset(section, rrset_entry_vec[index]->getRRset(), dnssec_need);
+        message.addRRset(section, rrset_entry_vec[index]->getRRset(),
+                         dnssec_need);
     }
 }
 
@@ -214,7 +215,8 @@ MessageEntry::parseSection(const isc::dns::Message& msg,
         RRsetPtr rrset_ptr = *iter;
         RRsetTrustLevel level = getRRsetTrustLevel(msg, rrset_ptr, section);
         RRsetEntryPtr rrset_entry = rrset_cache_->update(*rrset_ptr, level);
-        rrsets_.push_back(RRsetRef(rrset_ptr->getName(), rrset_ptr->getType(), rrset_cache_));
+        rrsets_.push_back(RRsetRef(rrset_ptr->getName(), rrset_ptr->getType(),
+                          rrset_cache_));
 
         uint32_t rrset_ttl = rrset_entry->getTTL();
         if (smaller_ttl > rrset_ttl) {
@@ -232,7 +234,6 @@ MessageEntry::parseNegativeResponseAuthoritySection(const isc::dns::Message& msg
         uint32_t& min_ttl,
         uint16_t& rrset_count)
 {
-    // We found the SOA record, so we can cache the message and RRsets in the cache
     uint16_t count = 0;
     for (RRsetIterator iter = msg.beginSection(Message::SECTION_AUTHORITY);
             iter != msg.endSection(Message::SECTION_AUTHORITY);

src/lib/cache/message_utility.cc

@@ -0,0 +1,63 @@
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+// $Id$
+
+#include "message_utility.h"
+#include <dns/rcode.h>
+
+using namespace isc::dns;
+
+namespace isc {
+namespace cache {
+namespace MessageUtility{
+
+bool
+hasTheRecordInAuthoritySection(const isc::dns::Message& msg, const isc::dns::RRType& type)
+{
+    for (RRsetIterator iter = msg.beginSection(Message::SECTION_AUTHORITY);
+            iter != msg.endSection(Message::SECTION_AUTHORITY);
+            ++iter) {
+        RRsetPtr rrset_ptr = *iter;
+        if (rrset_ptr->getType() == type) {
+            return (true);
+        }
+    }
+    return (false);
+}
+
+bool
+isNegativeResponse(const isc::dns::Message& msg)
+{
+    if (msg.getRcode() == Rcode::NXDOMAIN()) {
+        return (true);
+    } else if (msg.getRcode() == Rcode::NOERROR()) {
+        // no data in the answer section
+        if (msg.getRRCount(Message::SECTION_ANSWER) == 0) {
+            // NODATA type 1/ type 2 (ref sec2.2 of RFC2308) 
+            if (hasTheRecordInAuthoritySection(msg, RRType::SOA())) {
+                return (true);
+            } else if (!hasTheRecordInAuthoritySection(msg, RRType::NS())) {
+                // NODATA type 3 (sec2.2 of RFC2308)
+                return (true);
+            }
+        }
+    }
+
+    return (false);
+}
+
+} // namespace MessageUtility
+} // namespace cache
+} // namespace isc

src/lib/cache/message_utility.h

@@ -0,0 +1,51 @@
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+// $Id$
+
+#ifndef __MESSAGE_UTILITY_H
+#define __MESSAGE_UTILITY_H
+
+#include <dns/message.h>
+
+namespace isc {
+namespace cache {
+
+/// \brief Some utility functions to extract info from message
+///
+/// We need to check the message before cache it, for example, if no SOA
+/// record is found in the Authority section of NXDOMAIN response, the 
+/// message cannot be cached
+namespace MessageUtility{
+
+/// \brief Check whether there is some type of record in
+///        Authority section
+///
+/// \param msg The response message to be checked
+/// \param type The RR type that need to check
+bool hasTheRecordInAuthoritySection(const isc::dns::Message& msg,
+                                    const isc::dns::RRType& type);
+
+/// \brief Check whetehr the message is a negative response
+///        (NXDOMAIN or NOERROR_NODATA)
+///
+/// \param msg The response message
+bool isNegativeResponse(const isc::dns::Message& msg);
+
+} // namespace MessageUtility
+} // namespace cache
+} // namespace isc
+
+
+#endif//__MESSAGE_UTILITY_H

src/lib/cache/resolver_cache.cc

@@ -40,7 +40,8 @@ ResolverClassCache::ResolverClassCache(const RRClass& cache_class) :
 
     messages_cache_ = MessageCachePtr(new MessageCache(rrsets_cache_,
                                       MESSAGE_CACHE_DEFAULT_SIZE,
-                                      cache_class_.getCode(), negative_soa_cache_));
+                                      cache_class_.getCode(),
+                                      negative_soa_cache_));
 }
 
 ResolverClassCache::ResolverClassCache(CacheSizeInfo cache_info) :

src/lib/cache/resolver_cache.h

@@ -135,6 +135,11 @@ public:
     /// \note the function doesn't do any message validation check,
     ///       the user should make sure the message is valid, and of
     ///       the right class
+    /// TODO: Share the NXDOMAIN info between different type queries
+    ///       current implementation can only cache for the type that
+    ///       user quired, for example, if user query A record of 
+    ///       a.example. and the server replied with NXDOMAIN, this 
+    ///       should be cached for all the types queries of a.example.
     bool update(const isc::dns::Message& msg);
 
     /// \brief Update the rrset in the cache with the new one.