Dedup more protocol code

Use NixOS/nix#10749

src/hydra-queue-runner/build-remote.cc

@@ -267,32 +267,6 @@ static BuildResult performBuild(
     return result;
 }
 
-static std::map<StorePath, UnkeyedValidPathInfo> queryPathInfos(
-    ::Machine::Connection & conn,
-    Store & localStore,
-    StorePathSet & outputs,
-    size_t & totalNarSize
-)
-{
-
-    /* Get info about each output path. */
-    std::map<StorePath, UnkeyedValidPathInfo> infos;
-    conn.to << ServeProto::Command::QueryPathInfos;
-    ServeProto::write(localStore, conn, outputs);
-    conn.to.flush();
-    while (true) {
-        auto storePathS = readString(conn.from);
-        if (storePathS == "") break;
-
-        auto storePath = localStore.parseStorePath(storePathS);
-        auto info = ServeProto::Serialise<UnkeyedValidPathInfo>::read(localStore, conn);
-        totalNarSize += info.narSize;
-        infos.insert_or_assign(std::move(storePath), std::move(info));
-    }
-
-    return infos;
-}
-
 static void copyPathFromRemote(
     ::Machine::Connection & conn,
     NarMemberDatas & narMembers,
@@ -552,8 +526,10 @@ void State::buildRemote(ref<Store> destStore,
 
             auto now1 = std::chrono::steady_clock::now();
 
+            auto infos = conn.queryPathInfos(*localStore, outputs);
+
             size_t totalNarSize = 0;
-            auto infos = build_remote::queryPathInfos(conn, *localStore, outputs, totalNarSize);
+            for (auto & [_, info] : infos) totalNarSize += info.narSize;
 
             if (totalNarSize > maxOutputSize) {
                 result.stepStatus = bsNarSizeLimitExceeded;