Log worker's uncompressed size on reload, warn over 1MiB, closes #23

Author: mrbbot

src/helpers.ts

@@ -7,3 +7,9 @@ export class MiniflareError extends Error {
     this.name = new.target.name;
   }
 }
+
+export function formatSize(bytes: number): string {
+  if (bytes >= 524_288) return `${(bytes / 1_048_576).toFixed(2)}MiB`;
+  if (bytes >= 512) return `${(bytes / 1_024).toFixed(2)}KiB`;
+  return `${bytes}B`;
+}

src/index.ts

@@ -13,7 +13,7 @@ import cron from "node-cron";
 import sourceMap, { UrlAndMap } from "source-map-support";
 import StandardWebSocket from "ws";
 import Youch from "youch";
-import { MiniflareError } from "./helpers";
+import { MiniflareError, formatSize } from "./helpers";
 import { Cache, KVStorageNamespace } from "./kv";
 import { ConsoleLog, Log, NoOpLog, logResponse } from "./log";
 import { ResponseWaitUntil } from "./modules";
@@ -146,6 +146,9 @@ export class Miniflare {
     // processedModulesRules are always set in this
     assert(this.#options?.scripts && this.#options.processedModulesRules);
 
+    // Keep track of the size in bytes of all scripts
+    let size = 0;
+
     // Build modules linker maintaining set of referenced paths for watching
     const linker = new ScriptLinker(this.#options.processedModulesRules);
     this.#extraSourceMaps = linker.extraSourceMaps;
@@ -170,6 +173,7 @@ export class Miniflare {
       this.log.debug(`Reloading ${path.relative("", script.fileName)}...`);
 
       // Parse script and build instance
+      size += Buffer.byteLength(script.code, "utf8");
       let instance: ScriptScriptInstance | ModuleScriptInstance<ModuleExports>;
       try {
         instance = this.#options.modules
@@ -240,7 +244,15 @@ export class Miniflare {
       ws.close(1012, "Service Restart");
     }
 
-    this.log.info("Worker reloaded!");
+    // Log total size of worker with warning if required
+    size += linker.referencedPathsTotalSize;
+    this.log.info(`Worker reloaded! (${formatSize(size)})`);
+    if (size > 1_048_576)
+      this.log.warn(
+        "Worker's uncompressed size exceeds 1MiB!" +
+          "Note that your worker will be compressed during upload " +
+          "so you may still be able to deploy it."
+      );
   }
 
   /** @deprecated Since 1.2.0, this is just an alias for reloadOptions() */

src/scripts.ts

@@ -78,13 +78,21 @@ const commonJsCompilerOptions: CompilerOptions = {
 
 export class ScriptLinker {
   readonly referencedPaths = new Set<string>();
+  private _referencedPathsSizes = new Map<string, number>();
   readonly extraSourceMaps = new Map<string, string>();
   readonly linker: ModuleLinker;
 
   constructor(private moduleRules: ProcessedModuleRule[]) {
     this.linker = this._linker.bind(this);
   }
 
+  get referencedPathsTotalSize(): number {
+    // Make sure we only include each module once, even if it's referenced
+    // from multiple scripts
+    const sizes = Array.from(this._referencedPathsSizes.values());
+    return sizes.reduce((total, size) => total + size, 0);
+  }
+
   private async _linker(
     specifier: string,
     referencingModule: vm.Module
@@ -118,6 +126,7 @@ export class ScriptLinker {
     // Load module based on rule type
     this.referencedPaths.add(modulePath);
     const data = await fs.readFile(modulePath);
+    this._referencedPathsSizes.set(modulePath, data.byteLength);
     const moduleOptions = {
       identifier: modulePath,
       context: referencingModule.context,

test/fixtures/limits/a.mjs

@@ -0,0 +1,2 @@
+import s from "./shared.mjs";
+export default s + "a";

test/fixtures/limits/b.mjs

@@ -0,0 +1,2 @@
+import s from "./shared.mjs";
+export default s + "bb";

test/fixtures/limits/entry.mjs

@@ -0,0 +1,5 @@
+export default {
+  fetch() {
+    return new Response();
+  },
+};

test/fixtures/limits/entrydiamond.mjs

@@ -0,0 +1,8 @@
+import a from "./a.mjs";
+import b from "./b.mjs";
+
+export default {
+  fetch() {
+    return new Response(a + b);
+  },
+};

test/fixtures/limits/entryreferenced.mjs

@@ -0,0 +1,7 @@
+import s from "./shared.mjs";
+
+export default {
+  fetch() {
+    return new Response(s);
+  },
+};

test/fixtures/limits/object.mjs

@@ -0,0 +1,5 @@
+export class TestObject {
+  async fetch() {
+    return new Response("test");
+  }
+}

test/fixtures/limits/shared.mjs

@@ -0,0 +1 @@
+export default "shared";