Change serializeToBuffer() interface to append rather than replace.

Signed-off-by: Miod Vallat <miod.vallat@powerdns.com>

diff --git a/ext/lmdb-safe/lmdb-typed.hh b/ext/lmdb-safe/lmdb-typed.hh
index 3a8180352ce37fb305f0ef90274f491ff27c7f1c..db408597ad4f289bc823a028059f4d20b71dd282 100644 (file)
--- a/ext/lmdb-safe/lmdb-typed.hh
+++ b/ext/lmdb-safe/lmdb-typed.hh
@@ -47,14 +47,12 @@ uint32_t MDBGetRandomID(MDBRWTransaction& txn, MDBDbi& dbi, uint32_t seed=0);
  * This is our serialization interface. It can be specialized for other types.
  */
 template <typename T>
-std::string serializeToBuffer(const T& value)
+void serializeToBuffer(std::string& buffer, const T& value)
 {
-  std::string buffer;
   boost::iostreams::back_insert_device<std::string> inserter(buffer);
   boost::iostreams::stream<boost::iostreams::back_insert_device<std::string>> inserterStream(inserter);
   boost::archive::binary_oarchive outputArchive(inserterStream, boost::archive::no_header | boost::archive::no_codecvt);
   outputArchive << value;
-  return buffer;
 }
 
 template <typename T>
@@ -775,7 +773,9 @@ public:
           // flags = MDB_APPEND;
         }
       }
-      (*d_txn)->put(d_parent->d_main, itemId, serializeToBuffer(value), flags);
+      std::string ser;
+      serializeToBuffer(ser, value);
+      (*d_txn)->put(d_parent->d_main, itemId, ser, flags);
 
       insert<0>(value, itemId);
       insert<1>(value, itemId);

diff --git a/modules/lmdbbackend/lmdbbackend.cc b/modules/lmdbbackend/lmdbbackend.cc
index 26683874c884ddd96e707a443ecf2bd9c9df19c4..1758fb96e9ec3d438606d6610a771a439c159284 100644 (file)
--- a/modules/lmdbbackend/lmdbbackend.cc
+++ b/modules/lmdbbackend/lmdbbackend.cc
@@ -1026,23 +1026,21 @@ constexpr size_t serialize_offset_disabled = serialize_offset_auth + sizeof(char
 constexpr size_t serialize_offset_ordername = serialize_offset_disabled + sizeof(char);
 
 template <>
-std::string serializeToBuffer(const LMDBBackend::LMDBResourceRecord& value)
+void serializeToBuffer(std::string& buffer, const LMDBBackend::LMDBResourceRecord& value)
 {
-  std::string buffer;
-
   // Data size of the resource record.
   uint16_t len = value.content.length();
 
   // Reserve space to store the size of the resource record + the content of the resource
   // record + a few other things.
-  buffer.reserve(sizeof(len) + len + sizeof(value.ttl) + sizeof(value.auth) + sizeof(value.disabled) + sizeof(value.hasOrderName));
+  buffer.reserve(buffer.size() + sizeof(len) + len + sizeof(value.ttl) + sizeof(value.auth) + sizeof(value.disabled) + sizeof(value.hasOrderName));
 
-  // Store the size of the resource record.
+  // Store the size of the resource record (in host order).
   // NOLINTNEXTLINE.
-  buffer.assign((const char*)&len, sizeof(len));
+  buffer.append((const char*)&len, sizeof(len));
 
   // Store the contents of the resource record.
-  buffer += value.content;
+  buffer.append(value.content);
 
   // The few other things.
   // NOLINTNEXTLINE.
@@ -1050,18 +1048,14 @@ std::string serializeToBuffer(const LMDBBackend::LMDBResourceRecord& value)
   buffer.append(1, (char)value.auth);
   buffer.append(1, (char)value.disabled);
   buffer.append(1, (char)value.hasOrderName);
-
-  return buffer;
 }
 
 template <>
-std::string serializeToBuffer(const vector<LMDBBackend::LMDBResourceRecord>& value)
+void serializeToBuffer(std::string& buffer, const vector<LMDBBackend::LMDBResourceRecord>& value)
 {
-  std::string ret;
   for (const auto& lrr : value) {
-    ret += serializeToBuffer(lrr);
+    serializeToBuffer(buffer, lrr);
   }
-  return ret;
 }
 
 static inline size_t deserializeRRFromBuffer(const string_view& str, LMDBBackend::LMDBResourceRecord& lrr)
@@ -1306,13 +1300,15 @@ void LMDBBackend::writeNSEC3RecordPair(const std::shared_ptr<RecordsRWTransactio
   // Write ordername -> qname back chain record with ttl set to 0
   lrr.ttl = 0;
   lrr.content = qname.toDNSStringLC();
-  string ser = serializeToBuffer(lrr);
+  std::string ser;
+  serializeToBuffer(ser, lrr);
   txn->txn->put(txn->db->dbi, co(domain_id, ordername, QType::NSEC3), ser);
 
   // Write qname -> ordername forward chain record with ttl set to 1
   lrr.ttl = 1;
   lrr.content = ordername.toDNSString();
-  ser = serializeToBuffer(lrr);
+  ser.clear();
+  serializeToBuffer(ser, lrr);
   txn->txn->put(txn->db->dbi, co(domain_id, qname, QType::NSEC3), ser);
 }
 
@@ -1361,7 +1357,7 @@ bool LMDBBackend::feedRecord(const DNSResourceRecord& r, const DNSName& ordernam
   if (!d_rwtxn->txn->get(d_rwtxn->db->dbi, matchName, _rrs)) {
     rrs = _rrs.get<string>();
   }
-  rrs += serializeToBuffer(lrr);
+  serializeToBuffer(rrs, lrr);
 
   d_rwtxn->txn->put(d_rwtxn->db->dbi, matchName, rrs);
 
@@ -1381,7 +1377,8 @@ bool LMDBBackend::feedEnts(domainid_t domain_id, map<DNSName, bool>& nonterm)
     lrr.auth = nt.second;
     lrr.hasOrderName = false;
 
-    std::string ser = serializeToBuffer(lrr);
+    std::string ser;
+    serializeToBuffer(ser, lrr);
     d_rwtxn->txn->put(d_rwtxn->db->dbi, co(domain_id, lrr.qname, QType::ENT), ser);
   }
   return true;
@@ -1398,7 +1395,8 @@ bool LMDBBackend::feedEnts3(domainid_t domain_id, const DNSName& domain, map<DNS
     lrr.ttl = 0;
     lrr.auth = nt.second;
     lrr.hasOrderName = lrr.auth && !narrow;
-    ser = serializeToBuffer(lrr);
+    ser.clear();
+    serializeToBuffer(ser, lrr);
     d_rwtxn->txn->put(d_rwtxn->db->dbi, co(domain_id, lrr.qname, QType::ENT), ser);
 
     if (lrr.hasOrderName) {
@@ -1482,7 +1480,9 @@ bool LMDBBackend::replaceRRSet(domainid_t domain_id, const DNSName& qname, const
 
       adjustedRRSet.emplace_back(lrr);
     }
-    txn->txn->put(txn->db->dbi, match, serializeToBuffer(adjustedRRSet));
+    std::string ser;
+    serializeToBuffer(ser, adjustedRRSet);
+    txn->txn->put(txn->db->dbi, match, ser);
   }
 
   if (needCommit)
@@ -2905,7 +2905,9 @@ bool LMDBBackend::updateDNSSECOrderNameAndAuth(domainid_t domain_id, const DNSNa
       newRRs.push_back(std::move(lrr));
     }
     if (changed) {
-      cursor.put(key, serializeToBuffer(newRRs));
+      std::string ser;
+      serializeToBuffer(ser, newRRs);
+      cursor.put(key, ser);
     }
   } while (cursor.next(key, val) == 0);
 
@@ -3007,7 +3009,8 @@ bool LMDBBackend::updateEmptyNonTerminals(domainid_t domain_id, set<DNSName>& in
     lrr.qname = name.makeRelative(info.zone);
     lrr.ttl = 0;
     lrr.auth = true;
-    std::string ser = serializeToBuffer(lrr);
+    std::string ser;
+    serializeToBuffer(ser, lrr);
     txn->txn->put(txn->db->dbi, order(domain_id, lrr.qname, QType::ENT), ser);
     // cout <<" +"<<name<<endl;
   }