fix(model-loading): keep track of open GRPC Clients (#3377)

Due to a previous refactor we moved the client constructor tight to the
model address, however that was just a string which we would use to
build the client each time.

With this change we make the loader to return a *Model which carries a
constructor for the client and stores the client on the first
connection.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

pkg/model/model.go

@@ -0,0 +1,29 @@
+package model
+
+import grpc "github.com/mudler/LocalAI/pkg/grpc"
+
+type Model struct {
+	address string
+	client  grpc.Backend
+}
+
+func NewModel(address string) *Model {
+	return &Model{
+		address: address,
+	}
+}
+
+func (m *Model) GRPC(parallel bool, wd *WatchDog) grpc.Backend {
+	if m.client != nil {
+		return m.client
+	}
+
+	enableWD := false
+	if wd != nil {
+		enableWD = true
+	}
+
+	client := grpc.NewClient(m.address, parallel, wd, enableWD)
+	m.client = client
+	return client
+}