implement PermanentUserData storage prototype

2019-09-17 18:53:59 +02:00
parent 1d297601e8
commit d1f5ff0f59
16 changed files with 215 additions and 68 deletions
--- a/src/utils/PermanentUserData.js
+++ b/src/utils/PermanentUserData.js
@@ -0,0 +1,134 @@
+
+import {
+  YArray,
+  YMap,
+  readDeleteSet,
+  writeDeleteSet,
+  createDeleteSet,
+  ID, DeleteSet, YArrayEvent, Transaction, Doc // eslint-disable-line
+} from '../internals.js'
+
+import * as decoding from 'lib0/decoding.js'
+import * as encoding from 'lib0/encoding.js'
+import { mergeDeleteSets, isDeleted } from './DeleteSet.js'
+
+export class PermanentUserData {
+  /**
+   * @param {Doc} doc
+   * @param {string} key
+   */
+  constructor (doc, key = 'users') {
+    const users = doc.getMap(key)
+    /**
+     * @type {Map<string,DeleteSet>}
+     */
+    const dss = new Map()
+    this.yusers = users
+    this.doc = doc
+    /**
+     * Maps from clientid to userDescription
+     *
+     * @type {Map<number,string>}
+     */
+    this.clients = new Map()
+    this.dss = dss
+    /**
+     * @param {YMap<any>} user
+     * @param {string} userDescription
+     */
+    const initUser = (user, userDescription) => {
+      /**
+       * @type {YArray<Uint8Array>}
+       */
+      const ds = user.get('ds')
+      const ids = user.get('ids')
+      const addClientId = /** @param {number} clientid */ clientid => this.clients.set(clientid, userDescription)
+      ds.observe(/** @param {YArrayEvent<any>} event */ event => {
+        event.changes.added.forEach(item => {
+          item.content.getContent().forEach(encodedDs => {
+            if (encodedDs instanceof Uint8Array) {
+              this.dss.set(userDescription, mergeDeleteSets([this.dss.get(userDescription) || createDeleteSet(), readDeleteSet(decoding.createDecoder(encodedDs))]))
+            }
+          })
+        })
+      })
+      this.dss.set(userDescription, mergeDeleteSets(ds.map(encodedDs => readDeleteSet(decoding.createDecoder(encodedDs)))))
+      ids.observe(/** @param {YArrayEvent<any>} event */ event =>
+        event.changes.added.forEach(item => item.content.getContent().forEach(addClientId))
+      )
+      ids.forEach(addClientId)
+    }
+    // observe users
+    users.observe(event => {
+      event.keysChanged.forEach(userDescription =>
+        initUser(users.get(userDescription), userDescription)
+      )
+    })
+    // add intial data
+    users.forEach(initUser)
+  }
+  /**
+   * @param {Doc} doc
+   * @param {number} clientid
+   * @param {string} userDescription
+   */
+  setUserMapping (doc, clientid, userDescription) {
+    const users = this.yusers
+    let user = users.get(userDescription)
+    if (!user) {
+      user = new YMap()
+      user.set('ids', new YArray())
+      user.set('ds', new YArray())
+      users.set(userDescription, user)
+    }
+    user.get('ids').push([clientid])
+    users.observe(event => {
+      const userOverwrite = users.get(userDescription)
+      if (userOverwrite !== user) {
+        // user was overwritten, port all data over to the next user object
+        // @todo Experiment with Y.Sets here
+        user = userOverwrite
+        // @todo iterate over old type
+        this.clients.forEach((_userDescription, clientid) => {
+          if (userDescription === _userDescription) {
+            user.get('ids').push([clientid])
+          }
+        })
+        const encoder = encoding.createEncoder()
+        const ds = this.dss.get(userDescription)
+        if (ds) {
+          writeDeleteSet(encoder, ds)
+          user.get('ds').push([encoding.toUint8Array(encoder)])
+        }
+      }
+    })
+    doc.on('afterTransaction', /** @param {Transaction} transaction */ transaction => {
+      const yds = user.get('ds')
+      const ds = transaction.deleteSet
+      if (transaction.local && ds.clients.size > 0) {
+        const encoder = encoding.createEncoder()
+        writeDeleteSet(encoder, ds)
+        yds.push([encoding.toUint8Array(encoder)])
+      }
+    })
+  }
+  /**
+   * @param {number} clientid
+   * @return {any}
+   */
+  getUserByClientId (clientid) {
+    return this.clients.get(clientid) || null
+  }
+  /**
+   * @param {ID} id
+   * @return {string | null}
+   */
+  getUserByDeletedId (id) {
+    for (const [userDescription, ds] of this.dss) {
+      if (isDeleted(ds, id)) {
+        return userDescription
+      }
+    }
+    return null
+  }
+}