UBERF-8899: Fix Reconnect performance (#7597)

Signed-off-by: Andrey Sobolev <haiodo@gmail.com>

server/middleware/src/model.ts

@@ -115,6 +115,7 @@ export class ModelMiddleware extends BaseMiddleware implements Middleware {
 
   private setLastHash (hash: string): void {
     this.lastHash = hash
+    this.context.lastHash = this.lastHash
     this.lastHashResponse = Promise.resolve({
       full: false,
       hash,

server/middleware/src/txPush.ts

@@ -16,12 +16,16 @@
 import core, {
   DOMAIN_TRANSIENT,
   DOMAIN_TX,
+  generateId,
   TxProcessor,
+  WorkspaceEvent,
   type Doc,
   type MeasureContext,
+  type SessionData,
   type Tx,
   type TxCUD,
-  type TxResult
+  type TxResult,
+  type TxWorkspaceEvent
 } from '@hcengineering/core'
 import { PlatformError, unknownError } from '@hcengineering/platform'
 import type { DBAdapterManager, Middleware, PipelineContext, TxMiddlewareResult } from '@hcengineering/server-core'
@@ -68,6 +72,22 @@ export class TxMiddleware extends BaseMiddleware implements Middleware {
           txes: Array.from(new Set(txToStore.map((it) => it._class)))
         }
       )
+      // We need to remember last Tx Id in context, so it will be used during reconnect to track a requirement for refresh.
+      this.context.lastTx = txToStore[txToStore.length - 1]._id
+      // We need to deliver information to all clients so far.
+      const evt: TxWorkspaceEvent = {
+        _class: core.class.TxWorkspaceEvent,
+        _id: generateId(),
+        event: WorkspaceEvent.LastTx,
+        modifiedBy: core.account.System,
+        modifiedOn: Date.now(),
+        objectSpace: core.space.DerivedTx,
+        space: core.space.DerivedTx,
+        params: {
+          lastTx: this.context.lastTx
+        }
+      }
+      ;(ctx.contextData as SessionData).broadcast.txes.push(evt)
     }
     if (txPromise !== undefined) {
       await txPromise