13.0.3

README.md

@@ -85,6 +85,12 @@ document private.
 A module that contains a simple websocket backend and a websocket client that
 connects to that backend. The backend can be extended to persist updates in a
 leveldb database.
+  </dd>
+  <dt><a href="http://github.com/yjs/y-indexeddb">y-indexeddb</a></dt>
+  <dd>
+Efficiently persists document updates to the browsers indexeddb database.
+The document is immediately available and only diffs need to be synced through the
+network provider.
   </dd>
   <dt><a href="http://github.com/yjs/y-dat">y-dat</a></dt>
   <dd>

README.v12.md

@@ -1,305 +0,0 @@
-
-# ![Yjs](https://user-images.githubusercontent.com/5553757/48975307-61efb100-f06d-11e8-9177-ee895e5916e5.png)
-
-Yjs is a framework for offline-first p2p shared editing on structured data like
-text, richtext, json, or XML. It is fairly easy to get started, as Yjs hides
-most of the complexity of concurrent editing. For additional information, demos,
-and tutorials visit [y-js.org](http://y-js.org/).
-
-:warning: Checkout the [v13 docs](./README.md) for the upcoming release :warning:
-
-### Extensions
-Yjs only knows how to resolve conflicts on shared data. You have to choose a ..
-
-* *Connector* - a communication protocol that propagates changes to the clients
-* *Database* - a database to store your changes
-* one or more *Types* - that represent the shared data
-
-Connectors, Databases, and Types are available as modules that extend Yjs. Here
-is a list of the modules we know of:
-
-##### Connectors
-
-|Name            | Description               |
-|----------------|-----------------------------------|
-|[webrtc](https://github.com/y-js/y-webrtc) | Propagate updates Browser2Browser via WebRTC|
-|[websockets](https://github.com/y-js/y-websockets-client) | Set up [a central server](https://github.com/y-js/y-websockets-client), and connect to it via websockets |
-|[xmpp](https://github.com/y-js/y-xmpp) | Propagate updates in a XMPP multi-user-chat room ([XEP-0045](http://xmpp.org/extensions/xep-0045.html))|
-|[ipfs](https://github.com/ipfs-labs/y-ipfs-connector) | Connector for the [Interplanetary File System](https://ipfs.io/)!|
-|[test](https://github.com/y-js/y-test) | A Connector for testing purposes. It is designed to simulate delays that happen in worst case scenarios|
-
-##### Database adapters
-
-|Name            | Description               |
-|----------------|-----------------------------------|
-|[memory](https://github.com/y-js/y-memory) | In-memory storage. |
-|[indexeddb](https://github.com/y-js/y-indexeddb) | Offline storage for the browser |
-|[leveldb](https://github.com/y-js/y-leveldb) | Persistent storage for node apps |
-
-##### Types
-
-| Name     | Description       |
-|----------|-------------------|
-|[map](https://github.com/y-js/y-map) | A shared Map implementation. Maps from text to any stringify-able object |
-|[array](https://github.com/y-js/y-array) | A shared Array implementation |
-|[xml](https://github.com/y-js/y-xml) | An implementation of the DOM. You can create a two way binding to Browser DOM objects |
-|[text](https://github.com/y-js/y-text) | Collaborate on text. Supports two way binding to the [Ace Editor](https://ace.c9.io), [CodeMirror](https://codemirror.net/), [Monaco](https://github.com/Microsoft/monaco-editor), textareas, input elements, and HTML elements (e.g. <*h1*>, or <*p*>) |
-|[richtext](https://github.com/y-js/y-richtext) | Collaborate on rich text. Supports two way binding to the [Quill Rich Text Editor](http://quilljs.com/)|
-
-##### Other
-
-| Name      | Description       |
-|-----------|-------------------|
-|[y-element](http://y-js.org/y-element/) | Yjs Polymer Element |
-
-## Use it!
-Install Yjs, and its modules with [bower](http://bower.io/), or
-[npm](https://www.npmjs.org/package/yjs).
-
-### Bower
-
-```
-bower install --save yjs y-array % add all y-* modules you want to use
-```
-You only need to include the `y.js` file. Yjs is able to automatically require
-missing modules.  
-```
-<script src="./bower_components/yjs/y.js"></script>
-```
-
-### CDN
-
-```
-<script src="https://cdn.jsdelivr.net/npm/yjs@12/dist/y.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-array@10/dist/y-array.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-websockets-client@8/dist/y-websockets-client.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-memory@8/dist/y-memory.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-map@10/dist/y-map.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/y-text@9/dist/y-text.js"></script>
-// ..
-// do the same for all modules you want to use
-```
-
-### Npm
-
-```
-npm install --save yjs % add all y-* modules you want to use
-```
-
-If you don't include via script tag, you have to explicitly include all modules!
-(Same goes for other module systems)
-```
-var Y = require('yjs')
-require('y-array')(Y) // add the y-array type to Yjs
-require('y-websockets-client')(Y)
-require('y-memory')(Y)
-require('y-map')(Y)
-require('y-text')(Y)
-// ..
-// do the same for all modules you want to use
-```
-
-### ES6 Syntax
-
-```
-import Y from 'yjs'
-import yArray from 'y-array'
-import yWebsocketsClient from 'y-webrtc'
-import yMemory from 'y-memory'
-import yMap from 'y-map'
-import yText from 'y-text'
-// ..
-Y.extend(yArray, yWebsocketsClient, yMemory, yArray, yMap, yText /*, .. */)
-```
-
-# Text editing example
-
-Install dependencies
-```
-bower i yjs y-memory y-webrtc y-array y-text
-```
-
-Here is a simple example of a shared textarea
-```HTML
-  <!DOCTYPE html>
-  <html>
-    <body>
-      <script src="./bower_components/yjs/y.js"></script>
-      <!-- Yjs automatically includes all missing dependencies (browser only) -->
-      <script>
-        Y({
-          db: {
-            name: 'memory' // use memory database adapter.
-            // name: 'indexeddb' // use indexeddb database adapter instead for offline apps
-          },
-          connector: {
-            name: 'webrtc', // use webrtc connector
-            // name: 'websockets-client'
-            // name: 'xmpp'
-            room: 'my-room' // clients connecting to the same room share data
-          },
-          sourceDir: './bower_components', // location of the y-* modules (browser only)
-          share: {
-            textarea: 'Text' // y.share.textarea is of type y-text
-          }
-        }).then(function (y) {
-          // The Yjs instance `y` is available
-          // y.share.* contains the shared types
-
-          // Bind `y.share.textarea` to `<textarea/>`
-          y.share.textarea.bind(document.querySelector('textarea'))
-        })
-      </script>
-      <textarea></textarea>
-    </body>
-  </html>
-```
-
-## Get Help & Give Help
-There are some friendly people on [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/y-js/yjs?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge) who are eager to help, and answer questions. Please join!
-
-Report _any_ issues to the
-[Github issue page](https://github.com/y-js/yjs/issues)! I try to fix them very
-soon, if possible.
-
-# API
-
-### Y(options)
-* Y.extend(module1, module2, ..)
-  * Add extensions to Y
-  * `Y.extend(require('y-webrtc'))` has the same semantics as
-    `require('y-webrtc')(Y)`
-* options.db
-  * Will be forwarded to the database adapter. Specify the database adaper on
-    `options.db.name`.
-  * Have a look at the used database adapter repository to see all available
-    options.
-* options.connector
-  * Will be forwarded to the connector adapter. Specify the connector adaper on
-    `options.connector.name`.
-  * All our connectors implement a `room` property. Clients that specify the
-    same room share the same data.
-  * All of our connectors specify an `url` property that defines the connection
-    endpoint of the used connector.
-    * All of our connectors also have a default connection endpoint that you can
-      use for development.
-  * Set `options.connector.generateUserId = true` in order to genenerate a
-    userid, instead of receiving one from the server. This way the `Y(..)` is
-    immediately going to be resolved, without waiting for any confirmation from
-    the server. Use with caution.
-  * Have a look at the used connector repository to see all available options.
-  * *Only if you know what you are doing:* Set
-    `options.connector.preferUntransformed = true` in order receive the shared
-    data untransformed. This is very efficient as the database content is simply
-    copied to this client. This does only work if this client receives content
-    from only one client.
-* options.sourceDir (browser only)
-  * Path where all y-* modules are stored
-  * Defaults to `/bower_components`
-  * Not required when running on `nodejs` / `iojs`
-  * When using nodejs you need to manually extend Yjs:
-```
-var Y = require('yjs')
-// you have to require a db, connector, and *all* types you use!
-require('y-memory')(Y)
-require('y-webrtc')(Y)
-require('y-map')(Y)
-// ..
-```
-* options.share
-  * Specify on `options.share[arbitraryName]` types that are shared among all
-    users.
-  * E.g. Specify `options.share[arbitraryName] = 'Array'` to require y-array and
-    create an y-array type on `y.share[arbitraryName]`.
-  * If userA doesn't specify `options.share[arbitraryName]`, it won't be
-    available for userA.
-  * If userB specifies `options.share[arbitraryName]`, it still won't be
-    available for userA. But all the updates are send from userB to userA.
-  * In contrast to y-map, types on `y.share.*` cannot be overwritten or deleted.
-    Instead, they are merged among all users. This feature is only available on
-    `y.share.*`
-  * Weird behavior: It is supported that two users specify different types with
-    the same property name.
-     E.g. userA specifies `options.share.x = 'Array'`, and userB specifies
-     `options.share.x = 'Text'`. But they only share data if they specified the
-     same type with the same property name
-* options.type (browser only)
-  * Array of modules that Yjs needs to require, before instantiating a shared
-    type.
-  * By default Yjs requires the specified database adapter, the specified
-    connector, and all modules that are used in `options.share.*`
-  * Put all types here that you intend to use, but are not used in y.share.*
-
-### Instantiated Y object (y)
-`Y(options)` returns a promise that is fulfilled when..
-
-* All modules are loaded
-  * The specified database adapter is loaded
-  * The specified connector is loaded
-  * All types are included
-* The connector is initialized, and a unique user id is set (received from the
-  server)
-  * Note: When using y-indexeddb, a retrieved user id is stored on `localStorage`
-
-The promise returns an instance of Y. We denote it with a lower case `y`.
-
-* y.share.*
-  * Instances of the types you specified on options.share.*
-  * y.share.* can only be defined once when you instantiate Y!
-* y.connector is an instance of Y.AbstractConnector
-* y.connector.onUserEvent(function (event) {..})
-  * Observe user events (event.action is either 'userLeft' or 'userJoined')
-* y.connector.whenSynced(listener)
-  * `listener` is executed when y synced with at least one user.
-  * `listener` is not called when no other user is in the same room.
-  * y-websockets-client aways waits to sync with the server
-* y.connector.disconnect()
-  * Force to disconnect this instance from the other instances
-* y.connector.connect()
-  * Try to reconnect to the other instances (needs to be supported by the
-    connector)
-  * Not supported by y-xmpp
-* y.close()
-  * Destroy this object.
-  * Destroys all types (they will throw weird errors if you still use them)
-  * Disconnects from the other instances (via connector)
-  * Returns a promise
-* y.destroy()
-  * calls y.close()
-  * Removes all data from the database
-  * Returns a promise
-* y.db.stopGarbageCollector()
-  * Stop the garbage collector. Call y.db.garbageCollect() to continue garbage
-    collection
-* y.db.gc :: Boolean
-  * Whether gc is turned on
-* y.db.gcTimeout :: Number (defaults to 50000 ms)
-  * Time interval between two garbage collect cycles
-  * It is required that all instances exchanged all messages after two garbage
-    collect cycles (after 100000 ms per default)
-* y.db.userId :: String
-  * The used user id for this client. **Never overwrite this**
-
-### Logging
-Yjs uses [debug](https://github.com/visionmedia/debug) for logging. The flag
-`y*` enables logging for all y-* components. You can selectively remove
-components you are not interested in: E.g. The flag `y*,-y:connector-message`
-will not log the long `y:connector-message` messages.
-
-##### Enable logging in Node.js
-```sh
-DEBUG=y* node app.js
-```
-
-Remove the colors in order to log to a file:
-```sh
-DEBUG_COLORS=0 DEBUG=y* node app.js > log
-```
-
-##### Enable logging in the browser
-```js
-localStorage.debug = 'y*'
-```
-
-## License
-Yjs is licensed under the [MIT License](./LICENSE).

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "yjs",
-  "version": "13.0.0",
+  "version": "13.0.3",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -1332,9 +1332,9 @@
       "dev": true
     },
     "isomorphic.js": {
-      "version": "0.1.1",
+      "version": "0.1.3",
-      "resolved": "https://registry.npmjs.org/isomorphic.js/-/isomorphic.js-0.1.1.tgz",
+      "resolved": "https://registry.npmjs.org/isomorphic.js/-/isomorphic.js-0.1.3.tgz",
-      "integrity": "sha512-Q85LNm6e50saL4EPWa0mWEYNUuV51n623gzPVNC1QiLGLmjONEtfFT3pa04OoUIYB7rzGJBpzO2iNPhV1Ib4hg=="
+      "integrity": "sha512-pabBRLDwYefSsNS+qCazJ97o7P5xDTrNoxSYFTM09JlZTxPrOEPGKekwqUy3/Np4C4PHnVUXHYsZPOix0jELsA=="
     },
     "js-tokens": {
       "version": "4.0.0",
@@ -1439,9 +1439,9 @@
       }
     },
     "lib0": {
-      "version": "0.2.7",
+      "version": "0.2.12",
-      "resolved": "https://registry.npmjs.org/lib0/-/lib0-0.2.7.tgz",
+      "resolved": "https://registry.npmjs.org/lib0/-/lib0-0.2.12.tgz",
-      "integrity": "sha512-25ojhgEondpayWt2mgVTKels6R8viO27AetFgvdOk+WWGVah+q2pXouQ6dGj/gtxNwCDD2ih2B0LbDovNEtCrg==",
+      "integrity": "sha512-ileLyIMsWqcpyFLP6WMIgD6C7rkwrdYjH6CCFvAnqOhnGcyAl8LmLkiryVNmKW0sLRw/gLcB47LGXJDw0tDlkg==",
       "requires": {
         "isomorphic.js": "^0.1.1"
       }
@@ -2291,9 +2291,9 @@
       }
     },
     "rollup": {
-      "version": "1.29.1",
+      "version": "1.30.0",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.29.1.tgz",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.30.0.tgz",
-      "integrity": "sha512-dGQ+b9d1FOX/gluiggTAVnTvzQZUEkCi/TwZcax7ujugVRHs0nkYJlV9U4hsifGEMojnO+jvEML2CJQ6qXgbHA==",
+      "integrity": "sha512-ANcmfaSQwpcJtZUTA0ZMNBtFcQ1B4A5FldlNqEK0WdWm9sHSKu93ffa2KV1ux8HA/yKIV/ZARV28m7rNdXJgEw==",
       "dev": true,
       "requires": {
         "@types/estree": "*",

package.json

@@ -1,21 +1,20 @@
 {
   "name": "yjs",
-  "version": "13.0.0",
+  "version": "13.0.3",
   "description": "Shared Editing Library",
   "main": "./dist/yjs.cjs",
-  "module": "./src/index.js",
+  "module": "./dist/yjs.mjs",
   "types": "./dist/src/index.d.ts",
   "sideEffects": false,
   "scripts": {
     "test": "npm run dist && node ./dist/tests.cjs --repitition-time 50",
-    "test-exhaustive": "npm run lint && npm run dist && node ./dist/tests.cjs --production --repitition-time 10000",
+    "test-extensive": "npm run lint && npm run dist && node ./dist/tests.cjs --production --repitition-time 10000",
     "dist": "rm -rf dist && rollup -c && tsc",
     "watch": "rollup -wc",
     "lint": "markdownlint README.md && standard && tsc",
     "docs": "rm -rf docs; jsdoc --configure ./.jsdoc.json --verbose --readme ./README.md --package ./package.json || true",
     "serve-docs": "npm run docs && http-server ./docs/",
     "preversion": "npm run lint && PRODUCTION=1 npm run dist && npm run docs && node ./dist/tests.cjs --repitition-time 1000",
-    "postversion": "git push && git push --tags",
     "debug": "concurrently 'http-server -o test.html' 'npm run watch'",
     "trace-deopt": "clear && rollup -c  && node --trace-deopt dist/test.cjs",
     "trace-opt": "clear && rollup -c  && node --trace-opt dist/test.cjs"
@@ -57,7 +56,7 @@
   },
   "homepage": "https://yjs.dev",
   "dependencies": {
-    "lib0": "^0.2.7"
+    "lib0": "^0.2.12"
   },
   "devDependencies": {
     "@rollup/plugin-commonjs": "^11.0.1",
@@ -66,7 +65,7 @@
     "http-server": "^0.12.1",
     "jsdoc": "^3.6.3",
     "markdownlint-cli": "^0.19.0",
-    "rollup": "^1.29.1",
+    "rollup": "^1.30.0",
     "rollup-cli": "^1.0.9",
     "standard": "^14.0.0",
     "tui-jsdoc-template": "^1.2.2",

rollup.config.js

@@ -51,6 +51,21 @@ export default [{
     }
   },
   external: id => /^lib0\//.test(id)
+}, {
+  input: './src/index.js',
+  output: {
+    name: 'Y',
+    file: 'dist/yjs.mjs',
+    format: 'esm',
+    sourcemap: true,
+    paths: path => {
+      if (/^lib0\//.test(path)) {
+        return `lib0/dist/${path.slice(5, -3)}.cjs`
+      }
+      return path
+    }
+  },
+  external: id => /^lib0\//.test(id)
 }, {
   input: './tests/index.js',
   output: {

src/index.js

@@ -55,5 +55,7 @@ export {
   isDeleted,
   isParentOf,
   equalSnapshots,
-  PermanentUserData // @TODO experimental
+  PermanentUserData, // @TODO experimental
+  tryGc,
+  transact
 } from './internals.js'

src/structs/Item.js

@@ -68,10 +68,11 @@ export const followRedone = (store, id) => {
  * sending it to other peers
  *
  * @param {Item|null} item
+ * @param {boolean} keep
  */
-export const keepItem = item => {
+export const keepItem = (item, keep) => {
-  while (item !== null && !item.keep) {
+  while (item !== null && item.keep !== keep) {
-    item.keep = true
+    item.keep = keep
     item = item.parent._item
   }
 }
@@ -220,7 +221,7 @@ export const redoItem = (transaction, item, redoitems) => {
     item.content.copy()
   )
   item.redone = redoneItem.id
-  keepItem(redoneItem)
+  keepItem(redoneItem, true)
   redoneItem.integrate(transaction)
   return redoneItem
 }

src/types/YText.js

@@ -617,6 +617,11 @@ export class YText extends AbstractType {
     this._pending = string !== undefined ? [() => this.insert(0, string)] : []
   }
 
+  /**
+   * Number of characters of this text type.
+   *
+   * @type {number}
+   */
   get length () {
     return this._length
   }

src/utils/Doc.js

@@ -25,10 +25,12 @@ export class Doc extends Observable {
   /**
    * @param {Object} conf configuration
    * @param {boolean} [conf.gc] Disable garbage collection (default: gc=true)
+   * @param {function(Item):boolean} [conf.gcFilter] Will be called before an Item is garbage collected. Return false to keep the Item.
    */
-  constructor ({ gc = true } = {}) {
+  constructor ({ gc = true, gcFilter = () => true } = {}) {
     super()
     this.gc = gc
+    this.gcFilter = gcFilter
     this.clientID = random.uint32()
     /**
      * @type {Map<string, AbstractType<YEvent>>}

src/utils/Transaction.js

@@ -10,7 +10,7 @@ import {
   findIndexSS,
   callEventHandlerListeners,
   Item,
-  ID, AbstractType, AbstractStruct, YEvent, Doc // eslint-disable-line
+  StructStore, ID, AbstractType, AbstractStruct, YEvent, Doc // eslint-disable-line
 } from '../internals.js'
 
 import * as encoding from 'lib0/encoding.js'
@@ -145,6 +145,85 @@ export const addChangedTypeToTransaction = (transaction, type, parentSub) => {
   }
 }
 
+/**
+ * @param {Array<AbstractStruct>} structs
+ * @param {number} pos
+ */
+const tryToMergeWithLeft = (structs, pos) => {
+  const left = structs[pos - 1]
+  const right = structs[pos]
+  if (left.deleted === right.deleted && left.constructor === right.constructor) {
+    if (left.mergeWith(right)) {
+      structs.splice(pos, 1)
+      if (right instanceof Item && right.parentSub !== null && right.parent._map.get(right.parentSub) === right) {
+        right.parent._map.set(right.parentSub, /** @type {Item} */ (left))
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ * @param {function(Item):boolean} gcFilter
+ */
+const tryGcDeleteSet = (ds, store, gcFilter) => {
+  for (const [client, deleteItems] of ds.clients) {
+    const structs = /** @type {Array<AbstractStruct>} */ (store.clients.get(client))
+    for (let di = deleteItems.length - 1; di >= 0; di--) {
+      const deleteItem = deleteItems[di]
+      const endDeleteItemClock = deleteItem.clock + deleteItem.len
+      for (
+        let si = findIndexSS(structs, deleteItem.clock), struct = structs[si];
+        si < structs.length && struct.id.clock < endDeleteItemClock;
+        struct = structs[++si]
+      ) {
+        const struct = structs[si]
+        if (deleteItem.clock + deleteItem.len <= struct.id.clock) {
+          break
+        }
+        if (struct instanceof Item && struct.deleted && !struct.keep && gcFilter(struct)) {
+          struct.gc(store, false)
+        }
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ */
+const tryMergeDeleteSet = (ds, store) => {
+  // try to merge deleted / gc'd items
+  // merge from right to left for better efficiecy and so we don't miss any merge targets
+  for (const [client, deleteItems] of ds.clients) {
+    const structs = /** @type {Array<AbstractStruct>} */ (store.clients.get(client))
+    for (let di = deleteItems.length - 1; di >= 0; di--) {
+      const deleteItem = deleteItems[di]
+      // start with merging the item next to the last deleted item
+      const mostRightIndexToCheck = math.min(structs.length - 1, 1 + findIndexSS(structs, deleteItem.clock + deleteItem.len - 1))
+      for (
+        let si = mostRightIndexToCheck, struct = structs[si];
+        si > 0 && struct.id.clock >= deleteItem.clock;
+        struct = structs[--si]
+      ) {
+        tryToMergeWithLeft(structs, si)
+      }
+    }
+  }
+}
+
+/**
+ * @param {DeleteSet} ds
+ * @param {StructStore} store
+ * @param {function(Item):boolean} gcFilter
+ */
+export const tryGc = (ds, store, gcFilter) => {
+  tryGcDeleteSet(ds, store, gcFilter)
+  tryMergeDeleteSet(ds, store)
+}
+
 /**
  * @param {Array<Transaction>} transactionCleanups
  * @param {number} i
@@ -201,63 +280,12 @@ const cleanupTransactions = (transactionCleanups, i) => {
       })
       callAll(fs, [])
     } finally {
-      /**
-       * @param {Array<AbstractStruct>} structs
-       * @param {number} pos
-       */
-      const tryToMergeWithLeft = (structs, pos) => {
-        const left = structs[pos - 1]
-        const right = structs[pos]
-        if (left.deleted === right.deleted && left.constructor === right.constructor) {
-          if (left.mergeWith(right)) {
-            structs.splice(pos, 1)
-            if (right instanceof Item && right.parentSub !== null && right.parent._map.get(right.parentSub) === right) {
-              right.parent._map.set(right.parentSub, /** @type {Item} */ (left))
-            }
-          }
-        }
-      }
       // Replace deleted items with ItemDeleted / GC.
       // This is where content is actually remove from the Yjs Doc.
       if (doc.gc) {
-        for (const [client, deleteItems] of ds.clients) {
+        tryGcDeleteSet(ds, store, doc.gcFilter)
-          const structs = /** @type {Array<AbstractStruct>} */ (store.clients.get(client))
-          for (let di = deleteItems.length - 1; di >= 0; di--) {
-            const deleteItem = deleteItems[di]
-            const endDeleteItemClock = deleteItem.clock + deleteItem.len
-            for (
-              let si = findIndexSS(structs, deleteItem.clock), struct = structs[si];
-              si < structs.length && struct.id.clock < endDeleteItemClock;
-              struct = structs[++si]
-            ) {
-              const struct = structs[si]
-              if (deleteItem.clock + deleteItem.len <= struct.id.clock) {
-                break
-              }
-              if (struct instanceof Item && struct.deleted && !struct.keep) {
-                struct.gc(store, false)
-              }
-            }
-          }
-        }
-      }
-      // try to merge deleted / gc'd items
-      // merge from right to left for better efficiecy and so we don't miss any merge targets
-      for (const [client, deleteItems] of ds.clients) {
-        const structs = /** @type {Array<AbstractStruct>} */ (store.clients.get(client))
-        for (let di = deleteItems.length - 1; di >= 0; di--) {
-          const deleteItem = deleteItems[di]
-          // start with merging the item next to the last deleted item
-          const mostRightIndexToCheck = math.min(structs.length - 1, 1 + findIndexSS(structs, deleteItem.clock + deleteItem.len - 1))
-          for (
-            let si = mostRightIndexToCheck, struct = structs[si];
-            si > 0 && struct.id.clock >= deleteItem.clock;
-            struct = structs[--si]
-          ) {
-            tryToMergeWithLeft(structs, si)
-          }
-        }
       }
+      tryMergeDeleteSet(ds, store)
 
       // on all affected store.clients props, try to merge
       for (const [client, clock] of transaction.afterState) {
@@ -310,7 +338,6 @@ const cleanupTransactions = (transactionCleanups, i) => {
  * @param {function(Transaction):void} f
  * @param {any} [origin=true]
  *
- * @private
  * @function
  */
 export const transact = (doc, f, origin = null, local = true) => {

src/utils/UndoManager.js

@@ -199,13 +199,32 @@ export class UndoManager extends Observable {
       // make sure that deleted structs are not gc'd
       iterateDeletedStructs(transaction, transaction.deleteSet, /** @param {Item|GC} item */ item => {
         if (item instanceof Item && this.scope.some(type => isParentOf(type, item))) {
-          keepItem(item)
+          keepItem(item, true)
         }
       })
       this.emit('stack-item-added', [{ stackItem: stack[stack.length - 1], origin: transaction.origin, type: undoing ? 'redo' : 'undo' }, this])
     })
   }
 
+  clear () {
+    this.doc.transact(transaction => {
+      /**
+       * @param {StackItem} stackItem
+       */
+      const clearItem = stackItem => {
+        iterateDeletedStructs(transaction, stackItem.ds, item => {
+          if (item instanceof Item && this.scope.some(type => isParentOf(type, item))) {
+            keepItem(item, false)
+          }
+        })
+      }
+      this.undoStack.forEach(clearItem)
+      this.redoStack.forEach(clearItem)
+    })
+    this.undoStack = []
+    this.redoStack = []
+  }
+
   /**
    * UndoManager merges Undo-StackItem if they are created within time-gap
    * smaller than `options.captureTimeout`. Call `um.stopCapturing()` so that the next