From e69d61eaf47955a416321502145c25a4ec0729f6 Mon Sep 17 00:00:00 2001
From: Andrey Antukh <niwi@niwi.nz>
Date: Tue, 12 Aug 2025 11:27:13 +0200
Subject: [PATCH] :sparkles: Add facilities for work with dataview with common
 alases

---
 common/src/app/common/buffer.cljc             | 12 ++------
 frontend/src/app/render_wasm/api.cljs         | 30 ++++++++++---------
 frontend/src/app/render_wasm/mem.cljs         | 16 ++++++++++
 frontend/src/app/render_wasm/serializers.cljs |  1 -
 4 files changed, 35 insertions(+), 24 deletions(-)

diff --git a/common/src/app/common/buffer.cljc b/common/src/app/common/buffer.cljc
index 226e547b45..55ec4f83c8 100644
--- a/common/src/app/common/buffer.cljc
+++ b/common/src/app/common/buffer.cljc
@@ -129,15 +129,9 @@
 
 (defn wrap
   [data]
-  #?(:clj (let [buffer (ByteBuffer/wrap ^bytes data)]
-            (.order buffer ByteOrder/LITTLE_ENDIAN))
-     :cljs
-     (cond
-       (instance? js/Uint8Array data)
-       (new js/DataView (.-buffer ^js data))
-
-       :else
-       (throw (js/Error. "unexpected type")))))
+  #?(:clj  (let [buffer (ByteBuffer/wrap ^bytes data)]
+             (.order buffer ByteOrder/LITTLE_ENDIAN))
+     :cljs (new js/DataView (.-buffer ^js data))))
 
 (defn allocate
   [size]
diff --git a/frontend/src/app/render_wasm/api.cljs b/frontend/src/app/render_wasm/api.cljs
index 95e29e612f..4c4008bed7 100644
--- a/frontend/src/app/render_wasm/api.cljs
+++ b/frontend/src/app/render_wasm/api.cljs
@@ -8,7 +8,6 @@
   "A WASM based render API"
   (:require
    ["react-dom/server" :as rds]
-   [app.common.buffer :as buf]
    [app.common.data :as d :refer [not-empty?]]
    [app.common.data.macros :as dm]
    [app.common.types.fills :as types.fills]
@@ -455,8 +454,7 @@
   [entries]
   (let [size    (mem/get-alloc-size entries GRID-LAYOUT-ROW-U8-SIZE)
         offset  (mem/alloc size)
-        heapu8  (mem/get-heap-u8)
-        buffer  (buf/wrap heapu8)]
+        dview   (mem/get-data-view)]
 
     (reduce (fn [offset {:keys [type value]}]
               ;; NOTE: because of the nature of the grid row data
@@ -464,8 +462,8 @@
               ;; alligned writes, so for heteregeneus writes we use
               ;; the buffer abstraction (DataView) for perform
               ;; surgical writes.
-              (buf/write-byte buffer (+ offset 0) (sr/translate-grid-track-type type))
-              (buf/write-float buffer (+ offset 1) value)
+              (mem/write-u8 dview (+ offset 0) (sr/translate-grid-track-type type))
+              (mem/write-f32 dview (+ offset 1) value)
               (+ offset GRID-LAYOUT-ROW-U8-SIZE))
             offset
             entries)
@@ -476,16 +474,20 @@
   [entries]
   (let [size   (mem/get-alloc-size entries GRID-LAYOUT-COLUMN-U8-SIZE)
         offset (mem/alloc size)
-        heap   (-> (mem/get-heap-u8)
-                   (mem/view offset size))]
+        dview  (mem/get-data-view)]
+
+    (reduce (fn [offset {:keys [type value]}]
+              ;; NOTE: because of the nature of the grid column data
+              ;; structure memory layout we can't use fully 32 bits
+              ;; alligned writes, so for heteregeneus writes we use
+              ;; the buffer abstraction (DataView) for perform
+              ;; surgical writes.
+              (mem/write-u8 dview (+ offset 0) (sr/translate-grid-track-type type))
+              (mem/write-f32 dview (+ offset 1) value)
+              (+ offset GRID-LAYOUT-COLUMN-U8-SIZE))
+            offset
+            entries)
 
-    (loop [entries (seq entries)
-           current-offset  0]
-      (when-not (empty? entries)
-        (let [{:keys [type value]} (first entries)]
-          (.set heap (sr/u8 (sr/translate-grid-track-type type)) (+ current-offset 0))
-          (.set heap (sr/f32->u8 value) (+ current-offset 1))
-          (recur (rest entries) (+ current-offset GRID-LAYOUT-COLUMN-U8-SIZE)))))
     (h/call wasm/internal-module "_set_grid_columns")))
 
 (defn set-grid-layout-cells
diff --git a/frontend/src/app/render_wasm/mem.cljs b/frontend/src/app/render_wasm/mem.cljs
index e56ec4a01f..59562329c8 100644
--- a/frontend/src/app/render_wasm/mem.cljs
+++ b/frontend/src/app/render_wasm/mem.cljs
@@ -6,6 +6,7 @@
 
 (ns app.render-wasm.mem
   (:require
+   [app.common.buffer :as buf]
    [app.render-wasm.helpers :as h]
    [app.render-wasm.wasm :as wasm]))
 
@@ -71,3 +72,18 @@
   same element types as for this typed array."
   [heap offset size]
   (.subarray ^js heap offset (+ offset size)))
+
+(defn get-data-view
+  "Returns a heap wrapped in a DataView for surgical write operations"
+  []
+  (buf/wrap (get-heap-u8)))
+
+(defn write-u8
+  "Write unsigned int8. Expects a DataView instance"
+  [target offset value]
+  (buf/write-byte target offset value))
+
+(defn write-f32
+  "Write float32. Expects a DataView instance"
+  [target offset value]
+  (buf/write-float target offset value))
diff --git a/frontend/src/app/render_wasm/serializers.cljs b/frontend/src/app/render_wasm/serializers.cljs
index bf9dfb45cb..5efd965b6d 100644
--- a/frontend/src/app/render_wasm/serializers.cljs
+++ b/frontend/src/app/render_wasm/serializers.cljs
@@ -6,7 +6,6 @@
 
 (ns app.render-wasm.serializers
   (:require
-   [app.common.data.macros :as dm]
    [app.common.uuid :as uuid]
    [cuerdas.core :as str]))