feat(nbstore): add doc sync state

packages/common/nbstore/src/storage/index.ts

@@ -1,12 +1,13 @@
 import EventEmitter2 from 'eventemitter2';
 
 import type { ConnectionStatus } from '../connection';
+import type { AwarenessStorage } from './awareness';
 import type { BlobStorage } from './blob';
 import type { DocStorage } from './doc';
 import type { Storage, StorageType } from './storage';
 import type { SyncStorage } from './sync';
 
-type Storages = DocStorage | BlobStorage | SyncStorage;
+type Storages = DocStorage | BlobStorage | SyncStorage | AwarenessStorage;
 
 export class SpaceStorage {
   protected readonly storages: Map<StorageType, Storage> = new Map();

packages/common/nbstore/src/sync/doc/index.ts

@@ -1,16 +1,55 @@
+import type { Observable } from 'rxjs';
+import { combineLatest, map } from 'rxjs';
+
 import type { DocStorage, SyncStorage } from '../../storage';
 import { DocSyncPeer } from './peer';
 
+export interface DocSyncState {
+  total: number;
+  syncing: number;
+  retrying: boolean;
+  errorMessage: string | null;
+}
+
+export interface DocSyncDocState {
+  syncing: boolean;
+  retrying: boolean;
+  errorMessage: string | null;
+}
+
 export class DocSync {
-  private readonly peers: DocSyncPeer[];
+  private readonly peers: DocSyncPeer[] = this.remotes.map(
+    remote => new DocSyncPeer(this.local, this.sync, remote)
+  );
   private abort: AbortController | null = null;
 
+  readonly state$: Observable<DocSyncState> = combineLatest(
+    this.peers.map(peer => peer.peerState$)
+  ).pipe(
+    map(allPeers => ({
+      total: allPeers.reduce((acc, peer) => acc + peer.total, 0),
+      syncing: allPeers.reduce((acc, peer) => acc + peer.syncing, 0),
+      retrying: allPeers.some(peer => peer.retrying),
+      errorMessage:
+        allPeers.find(peer => peer.errorMessage)?.errorMessage ?? null,
+    }))
+  );
+
   constructor(
     readonly local: DocStorage,
     readonly sync: SyncStorage,
     readonly remotes: DocStorage[]
-  ) {
-    this.peers = remotes.map(remote => new DocSyncPeer(local, sync, remote));
+  ) {}
+
+  docState$(docId: string): Observable<DocSyncDocState> {
+    return combineLatest(this.peers.map(peer => peer.docState$(docId))).pipe(
+      map(allPeers => ({
+        errorMessage:
+          allPeers.find(peer => peer.errorMessage)?.errorMessage ?? null,
+        retrying: allPeers.some(peer => peer.retrying),
+        syncing: allPeers.some(peer => peer.syncing),
+      }))
+    );
   }
 
   start() {

packages/common/nbstore/src/sync/doc/peer.ts

@@ -1,6 +1,6 @@
 import { remove } from 'lodash-es';
 import { nanoid } from 'nanoid';
-import { Subject } from 'rxjs';
+import { Observable, Subject } from 'rxjs';
 import { diffUpdate, encodeStateVectorFromUpdate, mergeUpdates } from 'yjs';
 
 import type { DocStorage, SyncStorage } from '../../storage';
@@ -46,6 +46,19 @@ interface Status {
   errorMessage: string | null;
 }
 
+interface PeerState {
+  total: number;
+  syncing: number;
+  retrying: boolean;
+  errorMessage: string | null;
+}
+
+interface PeerDocState {
+  syncing: boolean;
+  retrying: boolean;
+  errorMessage: string | null;
+}
+
 interface DocSyncPeerOptions {
   mergeUpdates?: (updates: Uint8Array[]) => Promise<Uint8Array> | Uint8Array;
 }
@@ -101,6 +114,50 @@ export class DocSyncPeer {
   };
   private readonly statusUpdatedSubject$ = new Subject<string | true>();
 
+  peerState$ = new Observable<PeerState>(subscribe => {
+    const next = () => {
+      if (!this.status.syncing) {
+        // if syncing = false, jobMap is empty
+        subscribe.next({
+          total: this.status.docs.size,
+          syncing: this.status.docs.size,
+          retrying: this.status.retrying,
+          errorMessage: this.status.errorMessage,
+        });
+      } else {
+        const syncing = this.status.jobMap.size;
+        subscribe.next({
+          total: this.status.docs.size,
+          syncing: syncing,
+          retrying: this.status.retrying,
+          errorMessage: this.status.errorMessage,
+        });
+      }
+    };
+    next();
+    return this.statusUpdatedSubject$.subscribe(() => {
+      next();
+    });
+  });
+
+  docState$(docId: string) {
+    return new Observable<PeerDocState>(subscribe => {
+      const next = () => {
+        subscribe.next({
+          syncing:
+            !this.status.connectedDocs.has(docId) ||
+            this.status.jobMap.has(docId),
+          retrying: this.status.retrying,
+          errorMessage: this.status.errorMessage,
+        });
+      };
+      next();
+      return this.statusUpdatedSubject$.subscribe(updatedId => {
+        if (updatedId === true || updatedId === docId) next();
+      });
+    });
+  }
+
   private readonly jobs = createJobErrorCatcher({
     connect: async (docId: string, signal?: AbortSignal) => {
       const pushedClock =

packages/common/nbstore/src/sync/index.ts

@@ -1,10 +1,21 @@
+import { combineLatest, map, type Observable, of } from 'rxjs';
+
 import type { BlobStorage, DocStorage, SpaceStorage } from '../storage';
+import type { AwarenessStorage } from '../storage/awareness';
+import { AwarenessSync } from './awareness';
 import { BlobSync } from './blob';
-import { DocSync } from './doc';
+import { DocSync, type DocSyncState } from './doc';
+
+export interface SyncState {
+  doc?: DocSyncState;
+}
 
 export class Sync {
-  private readonly doc: DocSync | null;
-  private readonly blob: BlobSync | null;
+  readonly doc: DocSync | null;
+  readonly blob: BlobSync | null;
+  readonly awareness: AwarenessSync | null;
+
+  readonly state$: Observable<SyncState>;
 
   constructor(
     readonly local: SpaceStorage,
@@ -13,6 +24,7 @@ export class Sync {
     const doc = local.tryGet('doc');
     const blob = local.tryGet('blob');
     const sync = local.tryGet('sync');
+    const awareness = local.tryGet('awareness');
 
     this.doc =
       doc && sync
@@ -32,6 +44,18 @@ export class Sync {
             .filter((v): v is BlobStorage => !!v)
         )
       : null;
+    this.awareness = awareness
+      ? new AwarenessSync(
+          awareness,
+          peers
+            .map(peer => peer.tryGet('awareness'))
+            .filter((v): v is AwarenessStorage => !!v)
+        )
+      : null;
+
+    this.state$ = combineLatest([this.doc?.state$ ?? of(undefined)]).pipe(
+      map(([doc]) => ({ doc }))
+    );
   }
 
   start() {