From a03ddce60405aa8cb61b995ffc83493856e42e5c Mon Sep 17 00:00:00 2001
From: Nodari Chkuaselidze <nodar.chkuaselidze@gmail.com>
Date: Sun, 22 Sep 2024 16:23:51 +0400
Subject: [PATCH] wdb-migrations: add block time cache.

---
 lib/wallet/migrations.js | 14 ++++++++++++++
 test/util/migrations.js  |  2 +-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/wallet/migrations.js b/lib/wallet/migrations.js
index 8f810f2f5..01d367b79 100644
--- a/lib/wallet/migrations.js
+++ b/lib/wallet/migrations.js
@@ -11,6 +11,7 @@ const Logger = require('blgr');
 const bdb = require('bdb');
 const bio = require('bufio');
 const {BufferSet} = require('buffer-map');
+const LRU = require('blru');
 const HDPublicKey = require('../hd/public');
 const binary = require('../utils/binary');
 const {encoding} = bio;
@@ -808,6 +809,8 @@ class MigrateTXCountTimeIndex extends AbstractMigration {
     this.unconfirmedBatchSize = 1000;
 
     this.UNCONFIRMED_HEIGHT = 0xffffffff;
+
+    this.blockTimeCache = new LRU(50);
   }
 
   /**
@@ -1101,6 +1104,10 @@ class MigrateTXCountTimeIndex extends AbstractMigration {
       return null;
 
     const rawPath = await this.ldb.get(this.layout.wdb.P.encode(wid, hash));
+
+    if (!rawPath)
+      return null;
+
     const account = encoding.readU32(rawPath, 0);
     return account;
   }
@@ -1128,6 +1135,11 @@ class MigrateTXCountTimeIndex extends AbstractMigration {
 
   async getMedianTime(height) {
     const getBlockTime = async (height) => {
+      const cache = this.blockTimeCache.get(height);
+
+      if (cache != null)
+        return cache;
+
       const data = await this.ldb.get(this.layout.wdb.h.encode(height));
 
       if (!data)
@@ -1135,6 +1147,8 @@ class MigrateTXCountTimeIndex extends AbstractMigration {
 
       const time = encoding.readU64(data, 32);
 
+      this.blockTimeCache.set(height, time);
+
       return time;
     };
 
diff --git a/test/util/migrations.js b/test/util/migrations.js
index 02106d902..e3760ca54 100644
--- a/test/util/migrations.js
+++ b/test/util/migrations.js
@@ -235,7 +235,7 @@ exports.dumpChainDB = async (chaindb, prefixes) => {
  * @param {Boolean} options.throw - throw on error.
  * @param {Boolean} options.bail - bail on first error.
  * @param {Boolean} options.logErrors - log errors.
- * @returns {Promise<[]String>} - errors.
+ * @returns {Promise<String[]>} - errors.
  */
 
 exports.checkEntries = async (ldb, options) => {