Add a lockfile to prevent corruption

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hypermerge",
-  "version": "2.0.0-beta.23",
+  "version": "2.0.0-beta.25",
   "description": "Node.js library for building p2p collaborative applications without server infrastructure",
   "main": "dist/index.js",
   "scripts": {
@@ -39,6 +39,7 @@
     "js-sha1": "^0.6.0",
     "mime-types": "^2.1.24",
     "noise-peer": "^1.1.0",
+    "proper-lockfile": "^4.1.1",
     "pump": "^3.0.0",
     "random-access-file": "^2.1.3",
     "random-access-memory": "^3.0.0",
@@ -52,6 +53,7 @@
     "@types/debug": "^0.0.31",
     "@types/mime-types": "^2.1.0",
     "@types/node": "^12.12.6",
+    "@types/proper-lockfile": "^4.1.1",
     "@types/pump": "^1.1.0",
     "@types/tape": "^4.2.32",
     "@types/uuid": "^3.4.5",

src/RepoBackend.ts

@@ -1,3 +1,4 @@
+import lockfile from 'proper-lockfile'
 import Queue from './Queue'
 import { Metadata, PublicMetadata } from './Metadata'
 import { Actor, ActorMsg } from './Actor'
@@ -79,6 +80,7 @@ export class RepoBackend {
   network: Network
   messages: MessageRouter<PeerMsg>
   replication: ReplicationManager
+  lockRelease?: () => void
   swarmKey: Buffer // TODO: Remove this once we no longer use discovery-swarm/discovery-cloud
   private db: SqlDatabase.Database
   private fileServer: FileServer
@@ -90,6 +92,8 @@ export class RepoBackend {
     // initialize storage
     if (!opts.memory) {
       ensureDirectoryExists(this.path)
+      // Attempt to acquite a lock on the repo to prevent concurrent corrupting access.
+      this.lockRelease = lockfile.lockSync(this.path)
     }
     this.storage = opts.memory ? ram : raf
     this.db = SqlDatabase.open(path.resolve(this.path, 'hypermerge.db'), opts.memory || false)
@@ -245,7 +249,9 @@ export class RepoBackend {
       this.replication.close(),
       this.network.close(),
       this.fileServer.close(),
-    ])
+    ]).then(() => {
+      this.lockRelease?.()
+    })
   }
 
   private async allReadyActors(docId: DocId): Promise<Actor[]> {

yarn.lock

@@ -101,13 +101,25 @@
   resolved "https://registry.yarnpkg.com/@types/normalize-package-data/-/normalize-package-data-2.4.0.tgz#e486d0d97396d79beedd0a6e33f4534ff6b4973e"
   integrity sha512-f5j5b/Gf71L+dbqxIpQ4Z2WlmI/mPJ0fOkGGmFgtb6sAu97EPczzbS3/tJKxmcYDj55OX6ssqwDAWOHIYDRDGA==
 
+"@types/proper-lockfile@^4.1.1":
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/@types/proper-lockfile/-/proper-lockfile-4.1.1.tgz#99f026cbfdbe6305bdd454ffd5fefc1bd064beb1"
+  integrity sha512-HAjVfDa73pFgivViHyDu8HHHcds+W4MgOuZZAdyFJrHS8ngtCXmhl4hc2YXqSOwO6Bsa+iF2Sgxb2+gv874VOQ==
+  dependencies:
+    "@types/retry" "*"
+
 "@types/pump@^1.1.0":
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/@types/pump/-/pump-1.1.0.tgz#ed5214af511da32b6ee85c8d33ad3d59bb79ad8f"
   integrity sha512-YGGbsqf5o7sF8gGANP8ZYxgaRGlFgEAImx5tCvA4YKRCfqbsDQZO48UmWynZzSjbhn0ZWSlsWOcb5NwvOx8KcQ==
   dependencies:
     "@types/node" "*"
 
+"@types/retry@*":
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/@types/retry/-/retry-0.12.0.tgz#2b35eccfcee7d38cd72ad99232fbd58bffb3c84d"
+  integrity sha512-wWKOClTTiizcZhXnPY4wikVAwmdYHp8q6DmC+EJUzAMsycb7HB32Kh9RN4+0gExjmPmZSAQjgURXIGATPegAvA==
+
 "@types/tape@^4.2.32":
   version "4.2.32"
   resolved "https://registry.yarnpkg.com/@types/tape/-/tape-4.2.32.tgz#1188330d22c4e822648c344faa070277737982d9"
@@ -636,6 +648,11 @@ glob@^7.0.5, glob@~7.1.4:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
+graceful-fs@^4.1.11:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.2.3.tgz#4a12ff1b60376ef09862c2093edd908328be8423"
+  integrity sha512-a30VEBm4PEdx1dRB7MFK7BejejvCvBronbLjht+sHuGYj8PHs7M/5Z+rt5lw551vZ7yfTCj4Vuyy3mSJytDWRQ==
+
 has-flag@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-2.0.0.tgz#e8207af1cc7b30d446cc70b734b5e8be18f88d51"
@@ -1258,6 +1275,15 @@ process-nextick-args@~2.0.0:
   resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-2.0.1.tgz#7820d9b16120cc55ca9ae7792680ae7dba6d7fe2"
   integrity sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag==
 
+proper-lockfile@^4.1.1:
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/proper-lockfile/-/proper-lockfile-4.1.1.tgz#284cf9db9e30a90e647afad69deb7cb06881262c"
+  integrity sha512-1w6rxXodisVpn7QYvLk706mzprPTAPCYAqxMvctmPN3ekuRk/kuGkGc82pangZiAt4R3lwSuUzheTTn0/Yb7Zg==
+  dependencies:
+    graceful-fs "^4.1.11"
+    retry "^0.12.0"
+    signal-exit "^3.0.2"
+
 protocol-buffers-encodings@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/protocol-buffers-encodings/-/protocol-buffers-encodings-1.1.0.tgz#f3905631106669b85381bad47a336add7d206873"
@@ -1401,6 +1427,11 @@ resumer@~0.0.0:
   dependencies:
     through "~2.3.4"
 
+retry@^0.12.0:
+  version "0.12.0"
+  resolved "https://registry.yarnpkg.com/retry/-/retry-0.12.0.tgz#1b42a6266a21f07421d1b0b54b7dc167b01c013b"
+  integrity sha1-G0KmJmoh8HQh0bC1S33BZ7AcATs=
+
 run-node@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/run-node/-/run-node-1.0.0.tgz#46b50b946a2aa2d4947ae1d886e9856fd9cabe5e"
@@ -1468,7 +1499,7 @@ shuffled-priority-queue@^2.1.0:
   dependencies:
     unordered-set "^2.0.1"
 
-signal-exit@^3.0.0:
+signal-exit@^3.0.0, signal-exit@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/signal-exit/-/signal-exit-3.0.2.tgz#b5fdc08f1287ea1178628e415e25132b73646c6d"
   integrity sha1-tf3AjxKH6hF4Yo5BXiUTK3NkbG0=