wip

README.md

@@ -346,6 +346,47 @@ In the pod client:
 nil
 ```
 
+#### Deferred namespace loading
+
+When your pod exposes multiple namespaces that can be used independently from
+each other, consider implementing the `load-ns` op which allows the pod client
+to load the namespace and process the client side code when it is loaded using
+`require`. This will speed up the initial setup of the pod using `load-pod`.
+
+In `describe` the pod will mark the namespaces as deferred:
+
+``` clojure
+{"name" "pod.lispyclouds.deferred-ns"
+ "defer" "true"}
+```
+
+When the user requires the namespace with `(require
+'[pod.lispyclouds.deferred-ns])` the pod client will then send a message:
+
+``` clojure
+{"op" "load-ns"
+ "ns" "pod.lispyclouds.deferred-ns"
+ "id  "..."}
+```
+
+upon which the pod will reply with the namespace data:
+
+``` clojure
+{"name" "pod.lispyclouds.deferred-ns"
+ "vars" [{"name" "myfunc" "code" "(defn my-func [])"}]}
+```
+
+If a deferred namespace depends on another deferred namespace, provide explicit
+`require`s in `code` segments:
+
+``` clojure
+{"name" "pod.lispyclouds.another-deferred-ns"
+ "vars"
+ [{"name" "myfunc"
+   "code" "(require '[pod.lispyclouds.deferred-ns :as dns])
+           (defn my-func [] (dns/x))"}]}
+```
+
 #### Async
 
 Asynchronous functions can be implemented using callbacks.

src/babashka/pods/impl.clj

@@ -189,8 +189,8 @@
         name-sym (symbol name-str)
         vars (get namespace "vars")
         vars (bencode->vars pod name-str vars)
-        lazy? (some-> namespace (get-maybe-string "lazy") (= "true"))]
+        defer? (some-> namespace (get-maybe-string "defer") (= "true"))]
-    [name-sym vars lazy?]))
+    [name-sym vars defer?]))
 
 (defn load-pod
   ([pod-spec] (load-pod pod-spec nil))

src/babashka/pods/jvm.clj

@@ -42,16 +42,14 @@
                               (intern
                                (create-ns (symbol (namespace sym)))
                                (symbol (name sym)))))})
-         namespaces (:namespaces pod)
+         namespaces (:namespaces pod)]
-         load? (contains? (:ops pod) :load-ns)]
+     (swap! namespaces-to-load
-     (when load?
+            merge
-       (swap! namespaces-to-load
+            (into {}
-              merge
+                  (keep (fn [[ns-name _ defer?]]
-              (into {}
+                          (when defer?
-                    (keep (fn [[ns-name _ lazy?]]
+                            [ns-name pod]))
-                            (when lazy?
+                        namespaces)))
-                              [ns-name pod]))
-                          namespaces))))
      (doseq [[ns-sym vars lazy?] namespaces
              :when (not lazy?)]
        (process-namespace {:name ns-sym :vars vars}))

src/babashka/pods/sci.clj

@@ -40,12 +40,10 @@
                                       v)
                                v))))}))
              namespaces (:namespaces pod)
-             load? (contains? (:ops pod) :load-ns)
+             namespaces-to-load (set (keep (fn [[ns-name _ defer?]]
-             namespaces-to-load (when load?
+                                             (when defer?
-                                  (set (keep (fn [[ns-name _ lazy?]]
+                                               ns-name))
-                                               (when lazy?
+                                           namespaces))]
-                                                 ns-name))
-                                               namespaces)))]
          (when (seq namespaces-to-load)
            (let [load-fn (fn load-fn [{:keys [:namespace]}]
                            (when (contains? namespaces-to-load namespace)

test-pod/pod/test_pod.clj

@@ -82,11 +82,10 @@
                                              "code" "(defn read-other-tag [x] [x x])"}]
                                            dependents)}
                              {"name" "pod.test-pod.loaded"
-                              "lazy" "true"}
+                              "defer" "true"}
                              {"name" "pod.test-pod.loaded2"
-                              "lazy" "true"}]
+                              "defer" "true"}]
-                            "ops" {"shutdown" {}
+                            "ops" {"shutdown" {}}})
-                                   "load-ns" {}}})
                     (recur))
                 :invoke (let [var (-> (get message "var")
                                       read-string