Name the protocol version types

This makes the code clearer, and will help us replace them with proper
structs and get rid of the macros later.

src/libstore/daemon.cc

@@ -45,9 +45,9 @@ struct TunnelLogger : public Logger
 
     Sync<State> state_;
 
-    unsigned int clientVersion;
+    WorkerProto::Version clientVersion;
 
-    TunnelLogger(FdSink & to, unsigned int clientVersion)
+    TunnelLogger(FdSink & to, WorkerProto::Version clientVersion)
         : to(to), clientVersion(clientVersion) { }
 
     void enqueueMsg(const std::string & s)
@@ -261,7 +261,7 @@ struct ClientSettings
     }
 };
 
-static std::vector<DerivedPath> readDerivedPaths(Store & store, unsigned int clientVersion, WorkerProto::ReadConn conn)
+static std::vector<DerivedPath> readDerivedPaths(Store & store, WorkerProto::Version clientVersion, WorkerProto::ReadConn conn)
 {
     std::vector<DerivedPath> reqs;
     if (GET_PROTOCOL_MINOR(clientVersion) >= 30) {
@@ -274,7 +274,7 @@ static std::vector<DerivedPath> readDerivedPaths(Store & store, unsigned int cli
 }
 
 static void performOp(TunnelLogger * logger, ref<Store> store,
-    TrustedFlag trusted, RecursiveFlag recursive, unsigned int clientVersion,
+    TrustedFlag trusted, RecursiveFlag recursive, WorkerProto::Version clientVersion,
     Source & from, BufferedSink & to, WorkerProto::Op op)
 {
     WorkerProto::ReadConn rconn { .from = from };
@@ -1017,7 +1017,7 @@ void processConnection(
     if (magic != WORKER_MAGIC_1) throw Error("protocol mismatch");
     to << WORKER_MAGIC_2 << PROTOCOL_VERSION;
     to.flush();
-    unsigned int clientVersion = readInt(from);
+    WorkerProto::Version clientVersion = readInt(from);
 
     if (clientVersion < 0x10a)
         throw Error("the Nix client version is too old");

src/libstore/legacy-ssh-store.cc

@@ -45,7 +45,7 @@ struct LegacySSHStore : public virtual LegacySSHStoreConfig, public virtual Stor
         std::unique_ptr<SSHMaster::Connection> sshConn;
         FdSink to;
         FdSource from;
-        int remoteVersion;
+        ServeProto::Version remoteVersion;
         bool good = true;
 
         /**

src/libstore/remote-store-connection.hh

@@ -30,7 +30,7 @@ struct RemoteStore::Connection
      * sides support. (If the maximum doesn't exist, we would fail to
      * establish a connection and produce a value of this type.)
      */
-    unsigned int daemonVersion;
+    WorkerProto::Version daemonVersion;
 
     /**
      * Whether the remote side trusts us or not.

src/libstore/serve-protocol.hh

@@ -30,6 +30,13 @@ struct ServeProto
      */
     enum struct Command : uint64_t;
 
+    /**
+     * Version type for the protocol.
+     *
+     * @todo Convert to struct with separate major vs minor fields.
+     */
+    using Version = unsigned int;
+
     /**
      * A unidirectional read connection, to be used by the read half of the
      * canonical serializers below.

src/libstore/worker-protocol.hh

@@ -47,6 +47,13 @@ struct WorkerProto
      */
     enum struct Op : uint64_t;
 
+    /**
+     * Version type for the protocol.
+     *
+     * @todo Convert to struct with separate major vs minor fields.
+     */
+    using Version = unsigned int;
+
     /**
      * A unidirectional read connection, to be used by the read half of the
      * canonical serializers below.

src/nix-store/nix-store.cc

@@ -818,7 +818,7 @@ static void opServe(Strings opFlags, Strings opArgs)
     if (magic != SERVE_MAGIC_1) throw Error("protocol mismatch");
     out << SERVE_MAGIC_2 << SERVE_PROTOCOL_VERSION;
     out.flush();
-    unsigned int clientVersion = readInt(in);
+    ServeProto::Version clientVersion = readInt(in);
 
     ServeProto::ReadConn rconn { .from = in };
     ServeProto::WriteConn wconn { .to = out };