From c5e2bb24321b3304ea54cf163856a0160fbfa7c8 Mon Sep 17 00:00:00 2001
From: Jori Lallo <jtlallo@gmail.com>
Date: Sat, 9 Dec 2017 15:04:55 -0800
Subject: [PATCH] Lock collection navigation tree changes

---
 server/models/Collection.js | 18 ++++++++++++++++++
 server/redis.js             |  5 ++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/server/models/Collection.js b/server/models/Collection.js
index 8cfd45ee..73069c9a 100644
--- a/server/models/Collection.js
+++ b/server/models/Collection.js
@@ -2,6 +2,7 @@
 import slug from 'slug';
 import randomstring from 'randomstring';
 import { DataTypes, sequelize } from '../sequelize';
+import { asyncLock } from '../redis';
 import Document from './Document';
 import Event from './Event';
 import _ from 'lodash';
@@ -111,6 +112,9 @@ Collection.prototype.addDocumentToStructure = async function(
     index,
   };
 
+  // documentStructure can only be updated by one request at the time
+  const unlock = await asyncLock(`collection-${this.id}`);
+
   // If moving existing document with children, use existing structure to
   // keep everything in shape and not loose documents
   const documentJson = {
@@ -158,6 +162,8 @@ Collection.prototype.addDocumentToStructure = async function(
     teamId: this.teamId,
   });
 
+  unlock();
+
   return this;
 };
 
@@ -166,6 +172,10 @@ Collection.prototype.addDocumentToStructure = async function(
  */
 Collection.prototype.updateDocument = async function(updatedDocument) {
   if (!this.documentStructure) return;
+
+  // documentStructure can only be updated by one request at the time
+  const unlock = await asyncLock(`collection-${this.id}`);
+
   const { id } = updatedDocument;
 
   const updateChildren = documents => {
@@ -184,6 +194,7 @@ Collection.prototype.updateDocument = async function(updatedDocument) {
 
   this.documentStructure = updateChildren(this.documentStructure);
   await this.save();
+  unlock();
   return this;
 };
 
@@ -216,7 +227,12 @@ Collection.prototype.removeDocument = async function(
   options: DeleteDocumentOptions = { deleteDocument: true }
 ) {
   if (!this.documentStructure) return;
+
   let returnValue;
+
+  // documentStructure can only be updated by one request at the time
+  const unlock = await asyncLock('testLock');
+
   const existingData = {
     old: this.documentStructure,
     documentId: document,
@@ -280,6 +296,8 @@ Collection.prototype.removeDocument = async function(
     teamId: this.teamId,
   });
 
+  await unlock();
+
   return returnValue;
 };
 
diff --git a/server/redis.js b/server/redis.js
index 11309366..182dedbf 100644
--- a/server/redis.js
+++ b/server/redis.js
@@ -5,4 +5,7 @@ import redisLock from 'redis-lock';
 const client = redis.createClient(process.env.REDIS_URL);
 const lock = redisLock(client);
 
-export { client, lock };
+const asyncLock = (lockName: string) =>
+  new Promise(resolve => lock(lockName, unlock => resolve(unlock)));
+
+export { client, asyncLock };