feat: Initial clean release of CHM

packages/app-mobile/utils/fs-driver/tarExtract.ts

@@ -0,0 +1,96 @@
+import { extract as tarStreamExtract } from 'tar-stream';
+import { resolve, dirname } from 'path';
+import shim from '@joplin/lib/shim';
+import { chunkSize } from './constants';
+
+export interface TarExtractOptions {
+	cwd: string;
+	file: string;
+}
+
+const tarExtract = async (options: TarExtractOptions) => {
+	const cwd = options.cwd;
+
+	// resolve doesn't correctly handle file:// or content:// URLs. Thus, we don't resolve relative
+	// to cwd if the source is a URL.
+	const isSourceUrl = options.file.match(/$[a-z]+:\/\//);
+	const filePath = isSourceUrl ? options.file : resolve(cwd, options.file);
+
+	const fsDriver = shim.fsDriver();
+	if (!(await fsDriver.exists(filePath))) {
+		throw new Error('tarExtract: Source file does not exist');
+	}
+
+	const extract = tarStreamExtract({ defaultEncoding: 'base64' });
+
+	extract.on('entry', async (header, stream, next) => {
+		const outPath = fsDriver.resolveRelativePathWithinDir(cwd, header.name);
+
+		if (await fsDriver.exists(outPath)) {
+			throw new Error(`Extracting ${outPath} would overwrite`);
+		}
+
+		// Allows moving to the next item after all data for this entry has been read
+		// **and** this data has been processed.
+		// See https://github.com/laurent22/joplin/issues/10285
+		const streamEndPromise = new Promise<void>((resolve) => {
+			stream.once('end', () => resolve());
+		});
+
+		if (header.type === 'directory') {
+			await fsDriver.mkdir(outPath);
+		} else if (header.type === 'file') {
+			const parentDir = dirname(outPath);
+			await fsDriver.mkdir(parentDir);
+
+			await fsDriver.appendBinaryReadableToFile(outPath, stream);
+		} else {
+			throw new Error(`Unsupported file system entity type: ${header.type}`);
+		}
+
+		// Drain the rest of the stream.
+		stream.resume();
+		await streamEndPromise;
+		next();
+	});
+
+	let finished = false;
+	const finishPromise = new Promise<void>((resolve, reject) => {
+		extract.once('finish', () => {
+			finished = true;
+			resolve();
+		});
+
+		extract.once('error', (error) => {
+			reject(error);
+		});
+	});
+
+	const fileHandle = await fsDriver.open(filePath, 'r');
+	const readChunk = async () => {
+		return await fsDriver.readFileChunkAsBuffer(fileHandle, chunkSize);
+	};
+
+	try {
+		let chunk = await readChunk();
+		let nextChunk = await readChunk();
+		do {
+			extract.write(chunk);
+
+			chunk = nextChunk;
+			nextChunk = await readChunk();
+		} while (nextChunk !== null && !finished);
+
+		if (chunk !== null) {
+			extract.end(chunk);
+		} else {
+			extract.end();
+		}
+	} finally {
+		await fsDriver.close(fileHandle);
+	}
+
+	await finishPromise;
+};
+
+export default tarExtract;