syncguard/firestore/operations/is-locked.js

Functional TypeScript library for distributed locking across microservices. Prevents race conditions with Redis, Firestore, and custom backends. Features automatic lock management, timeout handling, and extensible architecture.

/* SPDX-FileCopyrightText: 2025-present Kriasoft */
/* SPDX-License-Identifier: MIT */
import { withRetries } from "../retry.js";
/**
 * Creates an isLocked operation for Firestore backend
 */
export function createIsLockedOperation(db, locksCollection, config) {
    return async (key) => {
        return withRetries(async () => {
            const docRef = locksCollection.doc(key);
            const doc = await docRef.get();
            if (!doc.exists) {
                return false;
            }
            const data = doc.data();
            const currentTime = Date.now();
            if (data.expiresAt <= currentTime) {
                // Use atomic transaction for cleanup to prevent race conditions
                try {
                    await db.runTransaction(async (trx) => {
                        const transactionDoc = await trx.get(docRef);
                        if (transactionDoc.exists) {
                            const transactionData = transactionDoc.data();
                            // Double-check expiration within transaction
                            if (transactionData.expiresAt <= currentTime) {
                                trx.delete(docRef);
                            }
                        }
                    });
                }
                catch {
                    // Ignore cleanup errors - lock will eventually be cleaned up by other operations
                }
                return false;
            }
            return true;
        }, config);
    };
}