From 5172f032e709e4e6cf7afa7f6e50131dbae2d809 Mon Sep 17 00:00:00 2001
From: Mononaut <github@monospace.live>
Date: Fri, 3 May 2024 16:31:56 +0000
Subject: [PATCH] Add sequence number to track-mempool subscription messages

---
 backend/src/api/websocket-handler.ts | 20 ++++++++++++--------
 backend/src/mempool.interfaces.ts    |  2 ++
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/backend/src/api/websocket-handler.ts b/backend/src/api/websocket-handler.ts
index 9e8a4653a..fdda3df88 100644
--- a/backend/src/api/websocket-handler.ts
+++ b/backend/src/api/websocket-handler.ts
@@ -558,6 +558,10 @@ class WebsocketHandler {
 
     const latestTransactions = memPool.getLatestTransactions();
 
+    if (memPool.isInSync()) {
+      this.mempoolSequence++;
+    }
+
     const replacedTransactions: { replaced: string, by: TransactionExtended }[] = [];
     for (const tx of newTransactions) {
       if (rbfTransactions[tx.txid]) {
@@ -567,12 +571,14 @@ class WebsocketHandler {
       }
     }
     const mempoolDeltaTxids: MempoolDeltaTxids = {
+      sequence: this.mempoolSequence,
       added: newTransactions.map(tx => tx.txid),
       removed: deletedTransactions.map(tx => tx.txid),
       mined: [],
       replaced: replacedTransactions.map(replacement => ({ replaced: replacement.replaced, by: replacement.by.txid })),
     };
     const mempoolDelta: MempoolDelta = {
+      sequence: this.mempoolSequence,
       added: newTransactions,
       removed: deletedTransactions.map(tx => tx.txid),
       mined: [],
@@ -638,10 +644,6 @@ class WebsocketHandler {
     const addressCache = this.makeAddressCache(newTransactions);
     const removedAddressCache = this.makeAddressCache(deletedTransactions);
 
-    if (memPool.isInSync()) {
-      this.mempoolSequence++;
-    }
-
     // TODO - Fix indentation after PR is merged
     for (const server of this.webSocketServers) {
     server.clients.forEach(async (client) => {
@@ -1034,6 +1036,10 @@ class WebsocketHandler {
 
     const mBlocksWithTransactions = mempoolBlocks.getMempoolBlocksWithTransactions();
 
+    if (memPool.isInSync()) {
+      this.mempoolSequence++;
+    }
+
     const replacedTransactions: { replaced: string, by: TransactionExtended }[] = [];
     for (const txid of Object.keys(rbfTransactions)) {
       for (const replaced of rbfTransactions[txid].replaced) {
@@ -1041,12 +1047,14 @@ class WebsocketHandler {
       }
     }
     const mempoolDeltaTxids: MempoolDeltaTxids = {
+      sequence: this.mempoolSequence,
       added: [],
       removed: [],
       mined: transactions.map(tx => tx.txid),
       replaced: replacedTransactions.map(replacement => ({ replaced: replacement.replaced, by: replacement.by.txid })),
     };
     const mempoolDelta: MempoolDelta = {
+      sequence: this.mempoolSequence,
       added: [],
       removed: [],
       mined: transactions.map(tx => tx.txid),
@@ -1061,10 +1069,6 @@ class WebsocketHandler {
       return responseCache[key];
     }
 
-    if (memPool.isInSync()) {
-      this.mempoolSequence++;
-    }
-
     // TODO - Fix indentation after PR is merged
     for (const server of this.webSocketServers) {
     server.clients.forEach((client) => {
diff --git a/backend/src/mempool.interfaces.ts b/backend/src/mempool.interfaces.ts
index 516748e9c..0fcddc45a 100644
--- a/backend/src/mempool.interfaces.ts
+++ b/backend/src/mempool.interfaces.ts
@@ -72,6 +72,7 @@ export interface MempoolBlockDelta {
 }
 
 export interface MempoolDeltaTxids {
+  sequence: number,
   added: string[];
   removed: string[];
   mined: string[];
@@ -79,6 +80,7 @@ export interface MempoolDeltaTxids {
 }
 
 export interface MempoolDelta {
+  sequence: number,
   added: MempoolTransactionExtended[];
   removed: string[];
   mined: string[];