From 993831709d6bc47633172920e367180f83fb7d0e Mon Sep 17 00:00:00 2001
From: Matias Fontanini <matias.fontanini@gmail.com>
Date: Sat, 13 May 2017 19:44:57 -0700
Subject: [PATCH] Improve DNS class performance slightly

---
 include/tins/dns.h | 16 ++++++++++++++++
 src/dns.cpp        | 39 +++++++++++++++++++++++++++------------
 2 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/include/tins/dns.h b/include/tins/dns.h
index fa12cd4..ef93eaa 100644
--- a/include/tins/dns.h
+++ b/include/tins/dns.h
@@ -183,8 +183,13 @@ public:
          * \param tp The query type.
          * \param cl The query class.
          */
+        #if TINS_IS_CXX11
+        query(std::string nm, QueryType tp, QueryClass cl) 
+        : name_(std::move(nm)), type_(tp), qclass_(cl) {}
+        #else
         query(const std::string& nm, QueryType tp, QueryClass cl) 
         : name_(nm), type_(tp), qclass_(cl) {}
+        #endif
         
         /**
          * \brief Default constructs this Query.
@@ -448,6 +453,16 @@ public:
          * \param rclass The class of this record.
          * \param ttl The time-to-live of this record.
          */
+        #if TINS_IS_CXX11
+        resource(std::string dname, 
+                 std::string data, 
+                 uint16_t type,
+                 uint16_t rclass,
+                 uint32_t ttl,
+                 uint16_t preference = 0) 
+        : dname_(std::move(dname)), data_(std::move(data)), type_(type),
+          qclass_(rclass), ttl_(ttl), preference_(preference) {}
+        #else
         resource(const std::string& dname, 
                  const std::string& data, 
                  uint16_t type,
@@ -456,6 +471,7 @@ public:
                  uint16_t preference = 0) 
         : dname_(dname), data_(data), type_(type), qclass_(rclass), 
           ttl_(ttl), preference_(preference) {}
+        #endif 
         
         resource() : type_(), qclass_(), ttl_(), preference_() {}
         
diff --git a/src/dns.cpp b/src/dns.cpp
index 046fec1..d36c87a 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -105,7 +105,7 @@ void DNS::skip_to_section_end(InputMemoryStream& stream,
         skip_to_dname_end(stream);
         stream.skip(sizeof(uint16_t) * 2 + sizeof(uint32_t));
         uint16_t data_size = stream.read_be<uint16_t>();
-        if (!stream.can_read(data_size)) {
+        if (TINS_UNLIKELY(!stream.can_read(data_size))) {
             throw malformed_packet();
         }
         stream.skip(data_size);
@@ -339,7 +339,7 @@ uint32_t DNS::compose_name(const uint8_t* ptr, char* out_ptr) const {
     while (*ptr) {
         // It's an offset
         if ((*ptr & 0xc0)) {
-            if (ptr + sizeof(uint16_t) > end) {
+            if (TINS_UNLIKELY(ptr + sizeof(uint16_t) > end)) {
                 throw malformed_packet();
             }
             uint16_t index;
@@ -360,7 +360,7 @@ uint32_t DNS::compose_name(const uint8_t* ptr, char* out_ptr) const {
             // It's a label, grab its size.
             uint8_t size = *ptr;
             ptr++;
-            if (ptr + size > end || current_out_ptr - out_ptr + size + 1 > 255) {
+            if (TINS_UNLIKELY(ptr + size > end || current_out_ptr - out_ptr + size + 1 > 255)) {
                 throw malformed_packet();
             }
             // Append a dot if it's not the first one.
@@ -430,7 +430,7 @@ void DNS::convert_records(const uint8_t* ptr,
             preference = stream.read_be<uint16_t>();
             data_size -= sizeof(uint16_t);
         }
-        if (!stream.can_read(data_size)) {
+        if (TINS_UNLIKELY(!stream.can_read(data_size))) {
             throw malformed_packet();
         }
 
@@ -470,16 +470,27 @@ void DNS::convert_records(const uint8_t* ptr,
                 stream.skip(data_size);
                 break;
         }
-        res.push_back(
-            resource(
+        #if TINS_IS_CXX11
+            res.emplace_back(
                 dname, 
-                (used_small_buffer) ? small_addr_buf : data, 
+                (used_small_buffer) ? small_addr_buf : std::move(data), 
                 type, 
                 qclass, 
                 ttl,
                 preference
-            )
-        );
+            );
+        #else
+            res.push_back(
+                resource(
+                    dname, 
+                    (used_small_buffer) ? small_addr_buf : data, 
+                    type, 
+                    qclass, 
+                    ttl,
+                    preference
+                )
+            );
+        #endif
     }
 }
 
@@ -544,9 +555,13 @@ DNS::queries_type DNS::queries() const {
             stream.skip(compose_name(stream.pointer(), buffer));
             uint16_t query_type = stream.read_be<uint16_t>();
             uint16_t query_class = stream.read_be<uint16_t>();
-            output.push_back(
-                query(buffer, (QueryType)query_type, (QueryClass)query_class)
-            );
+            #if TINS_IS_CXX11
+                output.emplace_back(buffer, (QueryType)query_type, (QueryClass)query_class);
+            #else
+                output.push_back(
+                    query(buffer, (QueryType)query_type, (QueryClass)query_class)
+                );
+            #endif
         }
     }
     return output;