From 5cd4ecd34a6a55f116c0e8d5983feb0684955fc1 Mon Sep 17 00:00:00 2001
From: Tom Moor <tom.moor@gmail.com>
Date: Sun, 1 May 2022 08:30:07 -0700
Subject: [PATCH] fix: CRDT creation touches document updated timestamp (#3482)

fix: Race condition in collaboration document persistence
---
 server/collaboration/PersistenceExtension.ts  |   1 +
 .../commands/documentCollaborativeUpdater.ts  | 101 ++++++++++--------
 2 files changed, 56 insertions(+), 46 deletions(-)

diff --git a/server/collaboration/PersistenceExtension.ts b/server/collaboration/PersistenceExtension.ts
index 34974f9b0..5cdc3f416 100644
--- a/server/collaboration/PersistenceExtension.ts
+++ b/server/collaboration/PersistenceExtension.ts
@@ -54,6 +54,7 @@ export default class PersistenceExtension implements Extension {
           state: Buffer.from(state),
         },
         {
+          silent: true,
           hooks: false,
           transaction,
         }
diff --git a/server/commands/documentCollaborativeUpdater.ts b/server/commands/documentCollaborativeUpdater.ts
index 66a889990..2a9a06a37 100644
--- a/server/commands/documentCollaborativeUpdater.ts
+++ b/server/commands/documentCollaborativeUpdater.ts
@@ -3,6 +3,7 @@ import invariant from "invariant";
 import { uniq } from "lodash";
 import { Node } from "prosemirror-model";
 import * as Y from "yjs";
+import { sequelize } from "@server/database/sequelize";
 import { schema, serializer } from "@server/editor";
 import { Document, Event } from "@server/models";
 
@@ -15,56 +16,64 @@ export default async function documentCollaborativeUpdater({
   ydoc: Y.Doc;
   userId?: string;
 }) {
-  const document = await Document.scope("withState").findByPk(documentId);
-  invariant(document, "document not found");
+  return sequelize.transaction(async (transaction) => {
+    const document = await Document.unscoped()
+      .scope("withState")
+      .findByPk(documentId, {
+        transaction,
+        lock: {
+          of: Document,
+          level: transaction.LOCK.UPDATE,
+        },
+        paranoid: false,
+      });
+    invariant(document, "document not found");
 
-  const state = Y.encodeStateAsUpdate(ydoc);
-  const node = Node.fromJSON(schema, yDocToProsemirrorJSON(ydoc, "default"));
-  const text = serializer.serialize(node, undefined);
-  const isUnchanged = document.text === text;
-  const hasMultiplayerState = !!document.state;
+    const state = Y.encodeStateAsUpdate(ydoc);
+    const node = Node.fromJSON(schema, yDocToProsemirrorJSON(ydoc, "default"));
+    const text = serializer.serialize(node, undefined);
+    const isUnchanged = document.text === text;
+    const hasMultiplayerState = !!document.state;
 
-  if (isUnchanged && hasMultiplayerState) {
-    return;
-  }
-
-  // extract collaborators from doc user data
-  const pud = new Y.PermanentUserData(ydoc);
-  const pudIds = Array.from(pud.clients.values());
-  const existingIds = document.collaboratorIds;
-  const collaboratorIds = uniq([...pudIds, ...existingIds]);
-
-  await Document.scope(["withDrafts", "withState"]).update(
-    {
-      text,
-      state: Buffer.from(state),
-      updatedAt: isUnchanged ? document.updatedAt : new Date(),
-      lastModifiedById:
-        isUnchanged || !userId ? document.lastModifiedById : userId,
-      collaboratorIds,
-    },
-    {
-      silent: true,
-      hooks: false,
-      where: {
-        id: documentId,
-      },
+    if (isUnchanged && hasMultiplayerState) {
+      return;
     }
-  );
 
-  if (isUnchanged) {
-    return;
-  }
+    // extract collaborators from doc user data
+    const pud = new Y.PermanentUserData(ydoc);
+    const pudIds = Array.from(pud.clients.values());
+    const existingIds = document.collaboratorIds;
+    const collaboratorIds = uniq([...pudIds, ...existingIds]);
 
-  await Event.schedule({
-    name: "documents.update",
-    documentId: document.id,
-    collectionId: document.collectionId,
-    teamId: document.teamId,
-    actorId: userId,
-    data: {
-      multiplayer: true,
-      title: document.title,
-    },
+    await document.update(
+      {
+        text,
+        state: Buffer.from(state),
+        lastModifiedById:
+          isUnchanged || !userId ? document.lastModifiedById : userId,
+        collaboratorIds,
+      },
+      {
+        transaction,
+        silent: isUnchanged,
+        hooks: false,
+      }
+    );
+
+    if (isUnchanged) {
+      return;
+    }
+
+    await Event.schedule({
+      name: "documents.update",
+      documentId: document.id,
+      collectionId: document.collectionId,
+      teamId: document.teamId,
+      actorId: userId,
+      data: {
+        multiplayer: true,
+        title: document.title,
+      },
+    });
   });
 }