Lock file on save and read (#824)

Fix #794

package.json

@@ -45,6 +45,7 @@
   "dependencies": {
     "@adiwajshing/keyed-db": "^0.2.4",
     "@hapi/boom": "^9.1.3",
+    "async-lock": "^1.4.1",
     "audio-decode": "^2.1.3",
     "axios": "^1.3.3",
     "cache-manager": "4.0.1",
@@ -69,6 +70,7 @@
     "eslint": "^8.0.0",
     "jest": "^27.0.6",
     "jimp": "^0.16.1",
+    "json": "^11.0.0",
     "link-preview-js": "^3.0.0",
     "open": "^8.4.2",
     "qrcode-terminal": "^0.12.0",
@@ -77,8 +79,7 @@
     "ts-jest": "^27.0.3",
     "ts-node": "^10.8.1",
     "typedoc": "^0.24.7",
-    "typescript": "^4.6.4",
+    "typescript": "^4.6.4"
-    "json": "^11.0.0"
   },
   "peerDependencies": {
     "jimp": "^0.16.1",

src/Utils/use-multi-file-auth-state.ts

@@ -1,3 +1,4 @@
+import AsyncLock from 'async-lock'
 import { mkdir, readFile, stat, unlink, writeFile } from 'fs/promises'
 import { join } from 'path'
 import { proto } from '../../WAProto'
@@ -5,6 +6,13 @@ import { AuthenticationCreds, AuthenticationState, SignalDataTypeMap } from '../
 import { initAuthCreds } from './auth-utils'
 import { BufferJSON } from './generics'
 
+// We need to lock files due to the fact that we are using async functions to read and write files
+// https://github.com/WhiskeySockets/Baileys/issues/794
+// https://github.com/nodejs/node/issues/26338
+// Default pending is 1000, set it to infinity
+// https://github.com/rogierschouten/async-lock/issues/63
+const fileLock = new AsyncLock({ maxPending: Infinity })
+
 /**
  * stores the full authentication state in a single folder.
  * Far more efficient than singlefileauthstate
@@ -15,12 +23,20 @@ import { BufferJSON } from './generics'
 export const useMultiFileAuthState = async(folder: string): Promise<{ state: AuthenticationState, saveCreds: () => Promise<void> }> => {
 
 	const writeData = (data: any, file: string) => {
-		return writeFile(join(folder, fixFileName(file)!), JSON.stringify(data, BufferJSON.replacer))
+		const filePath = join(folder, fixFileName(file)!)
+		return fileLock.acquire(
+			filePath,
+			() => writeFile(join(filePath), JSON.stringify(data, BufferJSON.replacer))
+		)
 	}
 
 	const readData = async(file: string) => {
 		try {
-			const data = await readFile(join(folder, fixFileName(file)!), { encoding: 'utf-8' })
+			const filePath = join(folder, fixFileName(file)!)
+			const data = await fileLock.acquire(
+				filePath,
+				() => readFile(filePath, { encoding: 'utf-8' })
+			)
 			return JSON.parse(data, BufferJSON.reviver)
 		} catch(error) {
 			return null
@@ -29,7 +45,11 @@ export const useMultiFileAuthState = async(folder: string): Promise<{ state: Aut
 
 	const removeData = async(file: string) => {
 		try {
-			await unlink(join(folder, fixFileName(file)!))
+			const filePath = join(folder, fixFileName(file)!)
+			await fileLock.acquire(
+				filePath,
+				() => unlink(filePath)
+			)
 		} catch{
 
 		}

yarn.lock

@@ -1724,6 +1724,11 @@ ast-types@^0.13.4:
   dependencies:
     tslib "^2.0.1"
 
+async-lock@^1.4.1:
+  version "1.4.1"
+  resolved "https://registry.yarnpkg.com/async-lock/-/async-lock-1.4.1.tgz#56b8718915a9b68b10fce2f2a9a3dddf765ef53f"
+  integrity sha512-Az2ZTpuytrtqENulXwO3GGv1Bztugx6TT37NIo7imr/Qo0gsYiGtSdBa2B6fsXhTpVZDNfu1Qn3pk531e3q+nQ==
+
 async-retry@1.3.3:
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/async-retry/-/async-retry-1.3.3.tgz#0e7f36c04d8478e7a58bdbed80cedf977785f280"