Squash Odysseus development history

static/js/editor/render-cancellation.js

@@ -0,0 +1,15 @@
+/** Cooperative render generations shared by synchronous and future async renderers. */
+export function createRenderGeneration() {
+  let generation = 0;
+  return {
+    begin() {
+      const id = ++generation;
+      return {
+        id,
+        isCurrent: () => id === generation,
+        cancel: () => { if (id === generation) generation += 1; },
+      };
+    },
+    invalidate() { generation += 1; },
+  };
+}