From 81563821e7ddb5ff9d26bd1abbdf8c93c26560f3 Mon Sep 17 00:00:00 2001
From: Alan Norbauer <altano@gmail.com>
Date: Mon, 5 Sep 2022 03:28:15 -0700
Subject: [PATCH] Parallelize @astrojs/image transforms

---
 .changeset/rich-dolphins-teach.md            |  5 ++++
 packages/integrations/image/package.json     |  1 +
 packages/integrations/image/src/build/ssg.ts | 26 ++++++++++++++------
 pnpm-lock.yaml                               |  6 +++++
 4 files changed, 31 insertions(+), 7 deletions(-)
 create mode 100644 .changeset/rich-dolphins-teach.md

diff --git a/.changeset/rich-dolphins-teach.md b/.changeset/rich-dolphins-teach.md
new file mode 100644
index 000000000000..a9bbf7de9bb1
--- /dev/null
+++ b/.changeset/rich-dolphins-teach.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/image': patch
+---
+
+Parallelize image transforms
diff --git a/packages/integrations/image/package.json b/packages/integrations/image/package.json
index 045569767cb6..fb1aaa67be18 100644
--- a/packages/integrations/image/package.json
+++ b/packages/integrations/image/package.json
@@ -40,6 +40,7 @@
     "test": "mocha --exit --timeout 20000 test"
   },
   "dependencies": {
+    "@altano/tiny-async-pool": "^1.0.2",
     "image-size": "^1.0.2",
     "magic-string": "^0.25.9",
     "mime": "^3.0.0",
diff --git a/packages/integrations/image/src/build/ssg.ts b/packages/integrations/image/src/build/ssg.ts
index 4602ef9356e1..6ee167ce6695 100644
--- a/packages/integrations/image/src/build/ssg.ts
+++ b/packages/integrations/image/src/build/ssg.ts
@@ -7,6 +7,8 @@ import type { SSRImageService, TransformOptions } from '../loaders/index.js';
 import { loadLocalImage, loadRemoteImage } from '../utils/images.js';
 import { debug, info, LoggerLevel, warn } from '../utils/logger.js';
 import { isRemoteImage } from '../utils/paths.js';
+import OS from 'node:os';
+import { doWork } from '@altano/tiny-async-pool';
 
 function getTimeStat(timeStart: number, timeEnd: number) {
 	const buildTime = timeEnd - timeStart;
@@ -23,19 +25,26 @@ export interface SSGBuildParams {
 
 export async function ssgBuild({ loader, staticImages, config, outDir, logLevel }: SSGBuildParams) {
 	const timer = performance.now();
+	const cpuCount = OS.cpus().length;
 
 	info({
 		level: logLevel,
 		prefix: false,
 		message: `${bgGreen(
-			black(` optimizing ${staticImages.size} image${staticImages.size > 1 ? 's' : ''} `)
+			black(
+				` optimizing ${staticImages.size} image${
+					staticImages.size > 1 ? 's' : ''
+				} in batches of ${cpuCount} `
+			)
 		)}`,
 	});
 
 	const inputFiles = new Set<string>();
 
-	// process transforms one original image file at a time
-	for (let [src, transformsMap] of staticImages) {
+	async function processStaticImage([src, transformsMap]: [
+		string,
+		Map<string, TransformOptions>
+	]): Promise<void> {
 		let inputFile: string | undefined = undefined;
 		let inputBuffer: Buffer | undefined = undefined;
 
@@ -60,15 +69,15 @@ export async function ssgBuild({ loader, staticImages, config, outDir, logLevel
 		if (!inputBuffer) {
 			// eslint-disable-next-line no-console
 			warn({ level: logLevel, message: `"${src}" image could not be fetched` });
-			continue;
+			return;
 		}
 
 		const transforms = Array.from(transformsMap.entries());
 
-		debug({ level: logLevel, prefix: false, message: `${green('▶')} ${src}` });
+		debug({ level: logLevel, prefix: false, message: `${green('▶')} transforming ${src}` });
 		let timeStart = performance.now();
 
-		// process each transformed versiono of the
+		// process each transformed version
 		for (const [filename, transform] of transforms) {
 			timeStart = performance.now();
 			let outputFile: string;
@@ -92,11 +101,14 @@ export async function ssgBuild({ loader, staticImages, config, outDir, logLevel
 			debug({
 				level: logLevel,
 				prefix: false,
-				message: `  ${cyan('└─')} ${dim(pathRelative)} ${dim(timeIncrease)}`,
+				message: `  ${cyan('created')} ${dim(pathRelative)} ${dim(timeIncrease)}`,
 			});
 		}
 	}
 
+	// transform each original image file in batches
+	await doWork(cpuCount, staticImages, processStaticImage);
+
 	info({
 		level: logLevel,
 		prefix: false,
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 1ac4cf7679fd..d1c78c5d5018 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2214,6 +2214,7 @@ importers:
 
   packages/integrations/image:
     specifiers:
+      '@altano/tiny-async-pool': ^1.0.2
       '@types/sharp': ^0.30.5
       astro: workspace:*
       astro-scripts: workspace:*
@@ -2223,6 +2224,7 @@ importers:
       mime: ^3.0.0
       sharp: ^0.30.6
     dependencies:
+      '@altano/tiny-async-pool': 1.0.2
       image-size: 1.0.2
       magic-string: 0.25.9
       mime: 3.0.0
@@ -3155,6 +3157,10 @@ packages:
       '@algolia/requester-common': 4.14.2
     dev: false
 
+  /@altano/tiny-async-pool/1.0.2:
+    resolution: {integrity: sha512-qQzaI0TBUPdpjZ3qo5b2ziQY9MSNpbziH2ZrE5lvtUZL+kn9GwVuVJwoOubaoNkeDB+rqEefnpu1k+oMpOCYiw==}
+    dev: false
+
   /@ampproject/remapping/2.2.0:
     resolution: {integrity: sha512-qRmjj8nj9qmLTQXXmaR1cck3UXSRMPrbsLJAasZpF+t3riI71BXed5ebIOYwQntykeZuhjsdweEc9BxH5Jc26w==}
     engines: {node: '>=6.0.0'}