Merge pull request #4280 from naturalcrit/SaveDiffs

Diff Saving

client/homebrew/pages/editPage/editPage.jsx

@@ -3,6 +3,8 @@ require('./editPage.less');
 const React = require('react');
 const _ = require('lodash');
 const createClass = require('create-react-class');
+import {makePatches, applyPatches, stringifyPatches, parsePatches} from '@sanity/diff-match-patch';
+import { md5 } from 'hash-wasm';
 
 import request from '../../utils/request-middleware.js';
 const { Meta } = require('vitreum/headtags');
@@ -196,12 +198,19 @@ const EditPage = createClass({
 
 	trySave : function(immediate=false){
 		if(!this.debounceSave) this.debounceSave = _.debounce(this.save, SAVE_TIMEOUT);
-		if(this.hasChanges()){
+		if(this.state.isSaving)
+			return;
+
+		if(immediate) {
 			this.debounceSave();
-		} else {
-			this.debounceSave.cancel();
+			this.debounceSave.flush();
+			return;
 		}
-		if(immediate) this.debounceSave.flush();
+		
+		if(this.hasChanges())
+			this.debounceSave();
+		else
+			this.debounceSave.cancel();
 	},
 
 	handleGoogleClick : function(){
@@ -215,8 +224,7 @@ const EditPage = createClass({
 			confirmGoogleTransfer : !prevState.confirmGoogleTransfer
 		}));
 		this.setState({
-			error    : null,
-			isSaving : false
+			error    : null
 		});
 	},
 
@@ -232,9 +240,8 @@ const EditPage = createClass({
 	toggleGoogleStorage : function(){
 		this.setState((prevState)=>({
 			saveGoogle : !prevState.saveGoogle,
-			isSaving   : false,
 			error      : null
-		}), ()=>this.save());
+		}), ()=>this.trySave(true));
 	},
 
 	save : async function(){
@@ -249,11 +256,17 @@ const EditPage = createClass({
 		await updateHistory(this.state.brew).catch(console.error);
 		await versionHistoryGarbageCollection().catch(console.error);
 
-		const transfer = this.state.saveGoogle == _.isNil(this.state.brew.googleId);
+		const preSaveSnapshot = { ...this.state.brew }
 
-		const brew = this.state.brew;
+		//Prepare content to send to server
+		const brew     = { ...this.state.brew };
 		brew.pageCount = ((brew.renderer=='legacy' ? brew.text.match(/\\page/g) : brew.text.match(/^\\page$/gm)) || []).length + 1;
+		brew.patches   = makePatches(this.savedBrew.text, brew.text);
+		brew.hash      = await md5(this.savedBrew.text);
+		brew.text      = undefined;
+		brew.textBin   = undefined;
 
+		const transfer = this.state.saveGoogle == _.isNil(this.state.brew.googleId);
 		const params = `${transfer ? `?${this.state.saveGoogle ? 'saveToGoogle' : 'removeFromGoogle'}=true` : ''}`;
 		const res = await request
 			.put(`/api/update/${brew.editId}${params}`)
@@ -265,20 +278,28 @@ const EditPage = createClass({
 		if(!res) return;
 
 		this.savedBrew = {
-			...this.state.brew,
+			...preSaveSnapshot,
 			googleId : res.body.googleId ? res.body.googleId : null,
 			editId 	 : res.body.editId,
 			shareId  : res.body.shareId,
 			version  : res.body.version
 		};
-		history.replaceState(null, null, `/edit/${this.savedBrew.editId}`);
 
-		this.setState(()=>({
-			brew           : this.savedBrew,
-			unsavedChanges : false,
+		this.setState((prevState) => ({
+			brew: {
+				...prevState.brew,
+				googleId : res.body.googleId ? res.body.googleId : null,
+				editId 	 : res.body.editId,
+				shareId  : res.body.shareId,
+				version  : res.body.version
+			},
 			isSaving       : false,
 			unsavedTime    : new Date()
-		}));
+		}), ()=>{
+			this.setState({ unsavedChanges : this.hasChanges() });
+		});
+
+		history.replaceState(null, null, `/edit/${this.savedBrew.editId}`);
 	},
 
 	renderGoogleDriveIcon : function(){

package-lock.json

@@ -16,6 +16,7 @@
         "@babel/preset-react": "^7.27.1",
         "@babel/runtime": "^7.27.6",
         "@googleapis/drive": "^13.0.1",
+        "@sanity/diff-match-patch": "^3.2.0",
         "body-parser": "^2.2.0",
         "classnames": "^2.5.1",
         "codemirror": "^5.65.6",
@@ -29,6 +30,7 @@
         "express-async-handler": "^1.2.0",
         "express-static-gzip": "3.0.0",
         "fs-extra": "11.3.0",
+        "hash-wasm": "^4.12.0",
         "idb-keyval": "^6.2.2",
         "js-yaml": "^4.1.0",
         "jwt-simple": "^0.5.6",
@@ -2895,6 +2897,15 @@
         "url": "https://opencollective.com/pkgr"
       }
     },
+    "node_modules/@sanity/diff-match-patch": {
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/@sanity/diff-match-patch/-/diff-match-patch-3.2.0.tgz",
+      "integrity": "sha512-4hPADs0qUThFZkBK/crnfKKHg71qkRowfktBljH2UIxGHHTxIzt8g8fBiXItyCjxkuNy+zpYOdRMifQNv8+Yww==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=18.18"
+      }
+    },
     "node_modules/@sinclair/typebox": {
       "version": "0.34.37",
       "resolved": "https://registry.npmjs.org/@sinclair/typebox/-/typebox-0.34.37.tgz",
@@ -7440,6 +7451,11 @@
         "node": ">=4"
       }
     },
+    "node_modules/hash-wasm": {
+      "version": "4.12.0",
+      "resolved": "https://registry.npmjs.org/hash-wasm/-/hash-wasm-4.12.0.tgz",
+      "integrity": "sha512-+/2B2rYLb48I/evdOIhP+K/DD2ca2fgBjp6O+GBEnCDk2e4rpeXIK8GvIyRPjTezgmWn9gmKwkQjjx6BtqDHVQ=="
+    },
     "node_modules/hash.js": {
       "version": "1.1.7",
       "resolved": "https://registry.npmjs.org/hash.js/-/hash.js-1.1.7.tgz",

package.json

@@ -89,6 +89,7 @@
     "@babel/preset-react": "^7.27.1",
     "@babel/runtime": "^7.27.6",
     "@googleapis/drive": "^13.0.1",
+    "@sanity/diff-match-patch": "^3.2.0",
     "body-parser": "^2.2.0",
     "classnames": "^2.5.1",
     "codemirror": "^5.65.6",
@@ -102,6 +103,7 @@
     "express-async-handler": "^1.2.0",
     "express-static-gzip": "3.0.0",
     "fs-extra": "11.3.0",
+    "hash-wasm": "^4.12.0",
     "idb-keyval": "^6.2.2",
     "js-yaml": "^4.1.0",
     "jwt-simple": "^0.5.6",

scripts/project.json

@@ -27,6 +27,7 @@
 		"codemirror/addon/selection/active-line.js",
 		"codemirror/addon/hint/show-hint.js",
 		"moment",
-		"superagent"
+		"superagent",
+		"@sanity/diff-match-patch"
 	]
 }

server/homebrew.api.js

@@ -8,6 +8,8 @@ import Markdown                      from '../shared/naturalcrit/markdown.js';
 import yaml                          from 'js-yaml';
 import asyncHandler                  from 'express-async-handler';
 import { nanoid }                    from 'nanoid';
+import {makePatches, applyPatches, stringifyPatches, parsePatch} from '@sanity/diff-match-patch';
+import { md5 }                       from 'hash-wasm';
 import { splitTextStyleAndMetadata, 
 		 brewSnippetsToJSON }        from '../shared/helpers.js';
 import checkClientVersion            from './middleware/check-client-version.js';
@@ -337,21 +339,30 @@ const api = {
 		// Initialize brew from request and body, destructure query params, and set the initial value for the after-save method
 		const brewFromClient = api.excludePropsFromUpdate(req.body);
 		const brewFromServer = req.brew;
-		if(brewFromServer.version && brewFromClient.version && brewFromServer.version > brewFromClient.version) {
-			console.log(`Version mismatch on brew ${brewFromClient.editId}`);
-			res.setHeader('Content-Type', 'application/json');
-			return res.status(409).send(JSON.stringify({ message: `The brew has been changed on a different device. Please save your changes elsewhere, refresh, and try again.` }));
-		}
+		splitTextStyleAndMetadata(brewFromServer);
+
+		brewFromServer.hash  = await md5(brewFromServer.text);
+
+		if((brewFromServer?.version !== brewFromClient?.version) || (brewFromServer?.hash !== brewFromClient?.hash)) {
+			if(brewFromClient?.version !== brewFromClient?.version)
+				console.log(`Version mismatch on brew ${brewFromClient.editId}`);
+			if(brewFromServer?.hash    !== brewFromClient?.hash) {
+				console.log(`Hash mismatch on brew ${brewFromClient.editId}`);
+			}
+			res.setHeader('Content-Type', 'application/json');
+			return res.status(409).send(JSON.stringify({ message: `The server copy is out of sync with the saved brew. Please save your changes elsewhere, refresh, and try again.` }));
+		}
+		
+		let brew         = _.assign(brewFromServer, brewFromClient);
+		brew.title       = brew.title.trim();
+		brew.description = brew.description.trim() || '';
+		brew.text        = applyPatches(brewFromClient.patches, brewFromServer.text)[0];
+		brew.text        = api.mergeBrewText(brew);
 
-		let brew = _.assign(brewFromServer, brewFromClient);
 		const googleId = brew.googleId;
 		const { saveToGoogle, removeFromGoogle } = req.query;
 		let afterSave = async ()=>true;
 
-		brew.title = brew.title.trim();
-		brew.description = brew.description.trim() || '';
-		brew.text = api.mergeBrewText(brew);
-
 		if(brew.googleId && removeFromGoogle) {
 			// If the google id exists and we're removing it from google, set afterSave to delete the google brew and mark the brew's google id as undefined
 			afterSave = async ()=>{
@@ -484,8 +495,8 @@ const api = {
 };
 
 router.post('/api', checkClientVersion, asyncHandler(api.newBrew));
-router.put('/api/:id', checkClientVersion, asyncHandler(api.getBrew('edit', true)), asyncHandler(api.updateBrew));
-router.put('/api/update/:id', checkClientVersion, asyncHandler(api.getBrew('edit', true)), asyncHandler(api.updateBrew));
+router.put('/api/:id', checkClientVersion, asyncHandler(api.getBrew('edit', false)), asyncHandler(api.updateBrew));
+router.put('/api/update/:id', checkClientVersion, asyncHandler(api.getBrew('edit', false)), asyncHandler(api.updateBrew));
 router.delete('/api/:id', checkClientVersion, asyncHandler(api.deleteBrew));
 router.get('/api/remove/:id', checkClientVersion, asyncHandler(api.deleteBrew));
 router.get('/api/theme/:renderer/:id', asyncHandler(api.getThemeBundle));