⚡ Send objects-map pages to the worker without a second encode (#12811)

* ⚡ Send objects-map pages to the worker without a second encode

When switching between pages on a large file e.g Material Design Icons, there's
some UI freeze from :index/initialize encoding object map shapes to send to the
worker. An objects map already stores the encoded JSON for each shape, and
`encode-str` was wrapping those strings in a second layer of JSON on the main
thread.

We can just transmit the already encoded JSON in a js/Map alongisde the
payload, similar to :blob, so structured clone just copies the strings verbaitm
without re-encoding. To do this this PR adds two functions to ObjectsMap that
converts to and from a js/Map.

The "Main components" page of the Material Design Icons has ~30k objects, so
this reduces the freeze when switching pages from 306ms -> 189ms (1.63x) on a
release build.

AI-assisted-by: claude-sonnet-5-5

* Split property tests out into new deftest

---------

Signed-off-by: Luke Lau <luke_lau@icloud.com>
Co-authored-by: Andrey Antukh <niwi@niwi.nz>

common/src/app/common/types/objects_map.cljc

@@ -504,6 +504,23 @@
          (into (create))
          (compact))))
 
+#?(:cljs
+   (defn ->js-map
+     "Builds a `js/Map` from the entries of an `ObjectsMap`."
+     [objects]
+     (reduce-kv (fn [^js result id shape]
+                  (.set result (str id) shape))
+                (js/Map.)
+                (get-data objects))))
+
+#?(:cljs
+   (defn from-js-map
+     "Builds an `ObjectsMap` from a `js/Map`."
+     [^js entries]
+     (from-data (into {}
+                      (map (fn [[id shape]] [(uuid id) shape]))
+                      (js/Array.from entries)))))
+
 #?(:clj
    (fres/add-handlers!
     {:name "penpot/objects-map/v2"

common/test/common_tests/types/objects_map_test.cljc

@@ -131,3 +131,40 @@
             (omap/objects-map? (:objects data))
             (omap/objects-map? (:objects res)))))
    {:num 100}))
+
+#?(:cljs
+   (t/deftest js-map-round-trip
+     (smt/check!
+      (smt/for [data (->> (sg/map-of (sg/uuid) (sg/generator cts/schema:shape))
+                          (sg/not-empty)
+                          (sg/fmap omap/wrap))]
+        (let [res (-> data omap/->js-map js/structuredClone omap/from-js-map)]
+          (and (omap/objects-map? res)
+               (= data res))))
+      {:num 100})))
+
+#?(:cljs
+   (t/deftest js-map-conversion
+     (t/testing "entries stay encoded strings"
+       (let [id           (uuid/custom 0 1)
+             ^js entries (omap/->js-map (omap/wrap {id {:foo 1}}))]
+         (t/is (= 1 (.-size entries)))
+         (t/is (string? (.get entries (str id))))))
+
+     (t/testing "added and removed shapes"
+       (let [id1 (uuid/custom 0 1)
+             id2 (uuid/custom 0 2)
+             id3 (uuid/custom 0 3)
+             obj (-> (omap/wrap {id1 {:foo 1} id2 {:bar 2}})
+                     (assoc id3 {:baz 3})
+                     (dissoc id1))
+             res (-> obj omap/->js-map omap/from-js-map)]
+         (t/is (= 2 (count res)))
+         (t/is (not (contains? res id1)))
+         (t/is (= {:bar 2} (get res id2)))
+         (t/is (= {:baz 3} (get res id3)))))
+
+     (t/testing "empty map"
+       (let [res (-> (omap/create) omap/->js-map omap/from-js-map)]
+         (t/is (omap/objects-map? res))
+         (t/is (zero? (count res)))))))

frontend/src/app/worker/messages.cljs

@@ -9,6 +9,7 @@
   (:require
    [app.common.data :as d]
    [app.common.transit :as t]
+   [app.common.types.objects-map :as omap]
    [app.util.object :as obj]))
 
 (defn encode
@@ -16,7 +17,12 @@
 
   Transit cannot carry `js/Blob`. If the payload map has `:blob`, or the
   message already has a top-level `:blob`, that value is sent as a
-  structured-clone field beside the Transit string — not inside it."
+  structured-clone field beside the Transit string — not inside it.
+
+  The same goes for the objects of a `:page` that are an `ObjectsMap`:
+  every shape in it is already a Transit string, so Transit would only
+  wrap those strings in a second layer of JSON. They travel as the
+  `pageObjects` field, a `js/Map` of id -> encoded shape."
   [{:keys [sender-id reply-to payload buffer? blob completed error]}]
   (let [;; Peel `:blob` out of map payloads before Transit (selection/snap
         ;; replies are vectors and other non-maps; leave them untouched).
@@ -25,6 +31,15 @@
         payload     (cond-> payload
                       (some? inline-blob)
                       (dissoc :blob))
+
+        page-objects (when (map? payload)
+                       (let [objects (get-in payload [:page :objects])]
+                         (when (omap/objects-map? objects)
+                           objects)))
+        payload      (cond-> payload
+                       (some? page-objects)
+                       (update :page dissoc :objects))
+
         obj #js {:cmd (d/name (:cmd payload))
                  :senderId (when sender-id (str sender-id))
                  :replyTo (when reply-to (str reply-to))
@@ -33,6 +48,8 @@
                  :completed (when completed true)}]
     (when (some? blob)
       (obj/set! obj "blob" blob))
+    (when (some? page-objects)
+      (obj/set! obj "pageObjects" (omap/->js-map page-objects)))
     (when (some? error)
       (obj/set! obj "error" (clj->js error)))
     obj))
@@ -51,6 +68,7 @@
         payload (obj/get data "payload")
         buffer (obj/get data "buffer")
         blob (obj/get data "blob")
+        page-objects (obj/get data "pageObjects")
         completed (obj/get data "completed")
         error (obj/get data "error")
         decoded
@@ -63,4 +81,7 @@
           :error (js->error-map error)})]
     (cond-> decoded
       (some? blob)
-      (update :payload assoc :blob blob))))
+      (update :payload assoc :blob blob)
+
+      (some? page-objects)
+      (assoc-in [:payload :page :objects] (omap/from-js-map page-objects)))))

frontend/test/frontend_tests/runner.cljs

@@ -185,6 +185,7 @@
    [frontend-tests.worker-snap-test]
    [frontend-tests.worker.exports-test]
    [frontend-tests.worker.index-test]
+   [frontend-tests.worker.messages-test]
    [frontend-tests.worker.trim-test]
    [goog.object :as gobj]))
 
@@ -226,6 +227,7 @@
    'frontend-tests.data.jobs-test
    'frontend-tests.worker.exports-test
    'frontend-tests.worker.index-test
+   'frontend-tests.worker.messages-test
    'frontend-tests.worker.trim-test
    'frontend-tests.data.svg-upload-test
    'frontend-tests.data.uploads-test

frontend/test/frontend_tests/worker/messages_test.cljs

@@ -0,0 +1,32 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS SUBSIDIARY SL
+
+(ns frontend-tests.worker.messages-test
+  (:require
+   [app.common.files.builder :as fb]
+   [app.common.types.objects-map :as omap]
+   [app.common.uuid :as uuid]
+   [app.util.object :as obj]
+   [app.worker.messages :as wm]
+   [cljs.test :as t :include-macros true]
+   [clojure.string :as str]))
+
+(defn- make-page
+  []
+  (-> (fb/create-state)
+      (fb/add-file {:name "Test"})
+      (fb/add-page {:name "Page 1"})
+      (fb/add-shape {:type :rect :name "unique-shape-name" :x 0 :y 0 :width 100 :height 100})
+      (fb/get-current-page)))
+
+(t/deftest objects-map-shapes-skip-transit
+  (let [page    (update (make-page) :objects omap/wrap)
+        encoded (wm/encode {:sender-id (uuid/next)
+                            :payload {:cmd :index/initialize :page page}})]
+    (t/is (not (str/includes? (obj/get encoded "payload") "unique-shape-name")))
+    (t/is (instance? js/Map (obj/get encoded "pageObjects")))
+    (t/is (= (count (:objects page))
+             (.-size (obj/get encoded "pageObjects"))))))