quarto preview ipynb performance: record results from initial render; use mtime for cache check

Author: jjallaire

src/project/serve/render.ts

@@ -2,6 +2,7 @@ import { isAbsolute, join } from "path/mod.ts";
 
 import { RenderResult } from "../../command/render/types.ts";
 import { md5Hash } from "../../core/hash.ts";
+import { isJupyterNotebook } from "../../core/jupyter/jupyter.ts";
 import { PromiseQueue } from "../../core/promise.ts";
 import { projectOutputDir } from "../project-shared.ts";
 import { ProjectContext } from "../types.ts";
@@ -71,9 +72,18 @@ export class ServeRenderManager {
         return hash;
       }
     }, "");
-    return md5Hash(Deno.readTextFileSync(file)) +
-      md5Hash(Deno.readTextFileSync(inputFile)) +
-      resourceHash;
+    // very large jupyter notebooks can take a long time to hash
+    // (~ 2 seconds for every 10mb) so we use the slightly less
+    // robust file modification time in that case
+    if (isJupyterNotebook(inputFile)) {
+      return String(Deno.statSync(file).mtime) +
+        String(Deno.statSync(inputFile).mtime) +
+        resourceHash;
+    } else {
+      return md5Hash(Deno.readTextFileSync(file)) +
+        md5Hash(Deno.readTextFileSync(inputFile)) +
+        resourceHash;
+    }
   }
 
   private fileRenders_ = new Map<string, string>();

src/project/serve/serve.ts

@@ -220,7 +220,9 @@ export async function serveProject(
   ) as string[]);
 
   // render manager for tracking need to re-render outputs
+  // (record any files we just rendered)
   const renderManager = new ServeRenderManager();
+  renderManager.onRenderResult(renderResult, resourceFiles, project);
 
   // function that can return the current target pdf output file
   const pdfOutputFile = (finalOutput && pdfOutput)