cross-process-lock

Cross-process file locking solution with lock-queue

Usage

const { lock } = require('cross-process-lock');
const { writeFileSync } = require('fs');
// create a lock for the given file
const unlock = await lock('file.txt')
// do smth with the file here
writeFileSync('file.txt', 'some content', 'utf8');
// unlock file with the received function
return unlock();

API

Lock

lock(file[, options]) - creates a lock for the given file for the actual process

Arguments:

• {string} file - the path of the file needs to be locked
• {lockOptions} options - the options to use to lock file, e.g timeouts

Returns: Promise<Function> - resolved with unlock function in case of successful lock; rejected in case of file couldn't be lock in the given timeout

Unlock

unlock(file) - deletes the lock for the given file for the actual process

Arguments:

• {string} file - the path of the file needs to be unlocked

Returns: Promise - resolved in case of successful unlock or rejected in case of any error

WithLock

withLock(file[, options], callback) - executes the callback with locking before and unlocking after the execution

Arguments:

• {string} file - path of the file needs to be locked
• {lockOptions} options - the options to use to lock file, e.g timeouts
• {() => Promise<T>} callback - the function to be executed

Returns: Promise<T> - resolved/rejected with the result of the callback

lockOptions

Option	Description	Default
lockTimeout {number}	timeout (ms) when locks automatically released	20 minutes
waitTimeout {number}	timeout (ms) until lock waits to lock a file	10 seconds

Debug

The package uses the debug NPM package with cross-process-lock:PID name, where PID is the process ID of the current process.

To enable debug logging, use for example the DEBUG=cross-process-lock:* environment variable, but for more information, check the documentation of the debug package.