Stop using global file locks

frontend/sync-client/src/sync-operations/document-lock.ts

@@ -1,48 +0,0 @@
-import type { RelativePath } from "../persistence/database";
-
-const locked = new Set<RelativePath>();
-const waiters = new Map<RelativePath, (() => void)[]>();
-
-export function tryLockDocument(relativePath: RelativePath): boolean {
-	if (locked.has(relativePath)) {
-		return false;
-	}
-
-	locked.add(relativePath);
-	return true;
-}
-
-export async function waitForDocumentLock(
-	relativePath: RelativePath
-): Promise<void> {
-	if (tryLockDocument(relativePath)) {
-		return Promise.resolve();
-	}
-
-	return new Promise((resolve) => {
-		let waiting = waiters.get(relativePath);
-		if (!waiting) {
-			waiting = [];
-			waiters.set(relativePath, waiting);
-		}
-
-		waiting.push(resolve);
-	});
-}
-
-export function unlockDocument(relativePath: RelativePath): void {
-	if (!locked.has(relativePath)) {
-		throw new Error(
-			`Document ${relativePath} is not locked, cannot unlock`
-		);
-	}
-
-	// Remove the first element to ensure FIFO unblocking order
-	const nextWaiting = waiters.get(relativePath)?.shift();
-
-	if (nextWaiting) {
-		nextWaiting();
-	} else {
-		locked.delete(relativePath);
-	}
-}

frontend/sync-client/src/sync-operations/document-locks.test.ts

@@ -1,89 +1,90 @@
-import { RelativePath } from "../persistence/database";
+import type { RelativePath } from "../persistence/database";
-import {
+import { DocumentLocks } from "./document-locks";
-	tryLockDocument,
-	waitForDocumentLock,
-	unlockDocument
-} from "./document-lock";
 
-describe("Document Lock Operations", () => {
+describe("Document lock", () => {
 	const testPath: RelativePath = "test/document/path";
+	let locks = new DocumentLocks();
 
 	beforeEach(() => {
-		// Reset the state before each test
+		locks = new DocumentLocks();
-		(global as any).locked = new Set<RelativePath>();
-		(global as any).waiters = new Map<RelativePath, (() => void)[]>();
 	});
 
 	test("should lock a document successfully", () => {
-		const result = tryLockDocument(testPath);
+		const result = locks.tryLockDocument(testPath);
 		expect(result).toBe(true);
 	});
 
 	test("should not lock a document that is already locked", () => {
-		tryLockDocument(testPath);
+		locks.tryLockDocument(testPath);
-		const result = tryLockDocument(testPath);
+		const result = locks.tryLockDocument(testPath);
 		expect(result).toBe(false);
 	});
 
 	test("should unlock a locked document", () => {
-		tryLockDocument(testPath);
+		locks.tryLockDocument(testPath);
-		unlockDocument(testPath);
+		locks.unlockDocument(testPath);
-		const result = tryLockDocument(testPath);
+		const result = locks.tryLockDocument(testPath);
 		expect(result).toBe(true);
-		unlockDocument(testPath);
+		locks.unlockDocument(testPath);
 	});
 
 	test("should throw an error when unlocking a document that is not locked", () => {
 		expect(() => {
-			unlockDocument(testPath);
+			locks.unlockDocument(testPath);
 		}).toThrow(`Document ${testPath} is not locked, cannot unlock`);
 	});
 
 	test("should wait for a document lock and resolve when unlocked", async () => {
-		tryLockDocument(testPath);
+		locks.tryLockDocument(testPath);
 
 		let resolved = false;
-		const waitPromise = waitForDocumentLock(testPath).then(() => {
+		const waitPromise = locks.waitForDocumentLock(testPath).then(() => {
 			resolved = true;
 		});
 
-		unlockDocument(testPath);
+		locks.unlockDocument(testPath);
 		await waitPromise;
 
 		expect(resolved).toBe(true);
 	});
 
 	test("should resolve multiple waiters in FIFO order", async () => {
-		tryLockDocument(testPath);
+		locks.tryLockDocument(testPath);
 
 		let firstResolved = false;
 		let secondResolved = false;
 		let thirdResolved = false;
 
-		const firstWaitPromise = waitForDocumentLock(testPath).then(() => {
+		const firstWaitPromise = locks
+			.waitForDocumentLock(testPath)
+			.then(() => {
 				firstResolved = true;
 			});
 
-		const secondWaitPromise = waitForDocumentLock(testPath).then(() => {
+		const secondWaitPromise = locks
+			.waitForDocumentLock(testPath)
+			.then(() => {
 				secondResolved = true;
 			});
 
-		const thirdWaitPromise = waitForDocumentLock(testPath).then(() => {
+		const thirdWaitPromise = locks
+			.waitForDocumentLock(testPath)
+			.then(() => {
 				thirdResolved = true;
 			});
 
-		unlockDocument(testPath);
+		locks.unlockDocument(testPath);
 		await firstWaitPromise;
 		expect(firstResolved).toBe(true);
 		expect(secondResolved).toBe(false);
 		expect(thirdResolved).toBe(false);
 
-		unlockDocument(testPath);
+		locks.unlockDocument(testPath);
 		await secondWaitPromise;
 		expect(secondResolved).toBe(true);
 		expect(thirdResolved).toBe(false);
 
-		unlockDocument(testPath);
+		locks.unlockDocument(testPath);
 		await thirdWaitPromise;
 		expect(thirdResolved).toBe(true);
 	});

frontend/sync-client/src/sync-operations/document-locks.ts

@@ -0,0 +1,50 @@
+import type { RelativePath } from "../persistence/database";
+
+export class DocumentLocks {
+	private readonly locked = new Set<RelativePath>();
+	private readonly waiters = new Map<RelativePath, (() => void)[]>();
+
+	public tryLockDocument(relativePath: RelativePath): boolean {
+		if (this.locked.has(relativePath)) {
+			return false;
+		}
+
+		this.locked.add(relativePath);
+		return true;
+	}
+
+	public async waitForDocumentLock(
+		relativePath: RelativePath
+	): Promise<void> {
+		if (this.tryLockDocument(relativePath)) {
+			return Promise.resolve();
+		}
+
+		return new Promise((resolve) => {
+			let waiting = this.waiters.get(relativePath);
+			if (!waiting) {
+				waiting = [];
+				this.waiters.set(relativePath, waiting);
+			}
+
+			waiting.push(resolve);
+		});
+	}
+
+	public unlockDocument(relativePath: RelativePath): void {
+		if (!this.locked.has(relativePath)) {
+			throw new Error(
+				`Document ${relativePath} is not locked, cannot unlock`
+			);
+		}
+
+		// Remove the first element to ensure FIFO unblocking order
+		const nextWaiting = this.waiters.get(relativePath)?.shift();
+
+		if (nextWaiting) {
+			nextWaiting();
+		} else {
+			this.locked.delete(relativePath);
+		}
+	}
+}