Function optimize

optimize.js:28–72

({ filePaths, config })

import { showTotal } from './lib/show-total.js';

export async function optimize({ filePaths, config }) {
	const { isLossless } = programOptions;

	const filePathsCount = filePaths.length;

	if (filePathsCount <= 0) {
		return;
	}

	log(`Optimizing ${filePathsCount} ${getPlural(filePathsCount, 'image', 'images')} (${isLossless ? 'lossless' : 'lossy'})...`);

	const progressBarContainer = createProgressBarContainer(filePathsCount);
	const progressBar = progressBarContainer.create(filePathsCount, 0);

	const totalSize = { before: 0, after: 0 };

	const cpuCount = os.cpus().length;
	const tasksSimultaneousLimit = pLimit(cpuCount);
	const guetzliTasksSimultaneousLimit = pLimit(1); // Guetzli uses a large amount of memory and a significant amount of CPU time. To reduce system load, we only allow one instance of guetzli to run at the same time.

	await Promise.all(
		filePaths.map((filePath) => {
			const extension = path.extname(filePath.input).toLowerCase();
			const isJpeg = extension === '.jpg' || extension === '.jpeg';

			const limit = isJpeg && isLossless
				? guetzliTasksSimultaneousLimit
				: tasksSimultaneousLimit;

			return limit(() => processFile({
				filePath,
				config,
				progressBarContainer,
				progressBar,
				totalSize,
				isLossless,
			}));
		}),
	);

	progressBarContainer.update(); // Prevent logs lost. See: https://github.com/npkgz/cli-progress/issues/145#issuecomment-1859594159
	progressBarContainer.stop();

	showTotal(totalSize.before, totalSize.after);
}

async function processFile({
	filePath,