msgpack: avoid copy during packing

Change-Id: I651cf8f4c8bc08367e90f98a2108cdabf6c53c25

src/ice_transport.cpp

@@ -1272,13 +1272,13 @@ IceTransport::packIceMsg(uint8_t version) const
     if (not isInitialized())
         return {};
 
-    std::stringstream ss;
+    msgpack::sbuffer buffer;
     if (version == 1) {
-        msgpack::pack(ss, version);
-        msgpack::pack(ss, std::make_pair(pimpl_->local_ufrag_, pimpl_->local_pwd_));
-        msgpack::pack(ss, static_cast<uint8_t>(pimpl_->component_count_));
+        msgpack::pack(buffer, version);
+        msgpack::pack(buffer, std::make_pair(pimpl_->local_ufrag_, pimpl_->local_pwd_));
+        msgpack::pack(buffer, static_cast<uint8_t>(pimpl_->component_count_));
         for (unsigned i = 0; i < pimpl_->component_count_; i++)
-            msgpack::pack(ss, getLocalCandidates(i));
+            msgpack::pack(buffer, getLocalCandidates(i));
     } else {
         SDP sdp;
         sdp.ufrag = pimpl_->local_ufrag_;
@@ -1288,10 +1288,9 @@ IceTransport::packIceMsg(uint8_t version) const
             sdp.candidates.reserve(sdp.candidates.size() + candidates.size());
             sdp.candidates.insert(sdp.candidates.end(), candidates.begin(), candidates.end());
         }
-        msgpack::pack(ss, sdp);
+        msgpack::pack(buffer, sdp);
     }
-    auto str(ss.str());
-    return std::vector<uint8_t>(str.begin(), str.end());
+    return std::vector<uint8_t>(buffer.data(), buffer.data() + buffer.size());
 }
 
 bool

src/jamidht/connectionmanager.cpp

@@ -488,9 +488,9 @@ ConnectionManager::Impl::sendChannelRequest(std::shared_ptr<MultiplexedSocket>&
     val.name = channelSock->name();
     val.state = ChannelRequestState::REQUEST;
     val.channel = channelSock->channel();
-    std::stringstream ss;
-    msgpack::pack(ss, val);
-    auto toSend = ss.str();
+    msgpack::sbuffer buffer(256);
+    msgpack::pack(buffer, val);
+
     sock->setOnChannelReady(channelSock->channel(), [channelSock, deviceId, vid, w = weak()]() {
         if (auto shared = w.lock()) {
             if (auto cb = shared->getPendingCallback({deviceId, vid}))
@@ -499,8 +499,8 @@ ConnectionManager::Impl::sendChannelRequest(std::shared_ptr<MultiplexedSocket>&
     });
     std::error_code ec;
     int res = sock->write(CONTROL_CHANNEL,
-                          reinterpret_cast<const uint8_t*>(&toSend[0]),
-                          toSend.size(),
+                          reinterpret_cast<const uint8_t*>(buffer.data()),
+                          buffer.size(),
                           ec);
     if (res < 0) {
         // TODO check if we should handle errors here