opfs.ts

export async function writeBlob(url: string, blob: Blob): Promise<void> {
	// only store models
	if (!url.match('https://huggingface.co')) return;
	try {
		const root = await navigator.storage.getDirectory();
		const dir = await root.getDirectoryHandle('piper', {
			create: true,
		});

		const path = url.split('/').at(-1)!;
		const file = await dir.getFileHandle(path, { create: true });
		if (file.createWritable) {
			const writable = await file.createWritable();
			await writable.write(blob);
			await writable.close();
		} else if (self.WorkerGlobalScope) {
			console.log(
				'createWritable not supported, trying syncronous API with createSyncAccessHandle as we are a worker',
			);
			// use the synchronous write API to write to the file. Only works in web workers
			const writer = await file.createSyncAccessHandle();
			writer.write(await blob.arrayBuffer());
			writer.close();
		} else {
			console.error(
				"Cannot write to OPFS file using createWritable and we are not a worker, so can't use createSyncAccessHandle",
			);
			// Remove the empty file
			await dir.removeEntry(path);
		}
	} catch (e) {
		console.error(e);
	}
}

export async function removeBlob(url: string) {
	try {
		const root = await navigator.storage.getDirectory();
		const dir = await root.getDirectoryHandle('piper');
		const path = url.split('/').at(-1)!;
		const file = await dir.getFileHandle(path); // @ts-ignore
		await file.remove();
	} catch (e) {
		console.error(e);
	}
}

export async function readBlob(url: string): Promise<Blob | undefined> {
	if (!url.match('https://huggingface.co')) return;
	try {
		const root = await navigator.storage.getDirectory();
		const dir = await root.getDirectoryHandle('piper', {
			create: true,
		});

		const path = url.split('/').at(-1)!;
		const file = await dir.getFileHandle(path);

		return await file.getFile();
	} catch (e) {
		return undefined;
	}
}