From: Alekos Filini <alekos.filini@gmail.com>
Date: Fri, 18 Jun 2021 11:13:45 +0000 (+0200)
Subject: [verify] Cache txs to avoid multiple db/network lookups
X-Git-Tag: v0.9.0~11
X-Git-Url: http://internal-gitweb-vhost/%22https:/parse/scripts/database/-script/-debug/struct.EncoderStringWriter.html?a=commitdiff_plain;h=a67aca32c051f2923a27f955ef8f0f96c70848e3;p=bdk

[verify] Cache txs to avoid multiple db/network lookups
---

diff --git a/src/wallet/verify.rs b/src/wallet/verify.rs
index 34110516..2d5c193c 100644
--- a/src/wallet/verify.rs
+++ b/src/wallet/verify.rs
@@ -9,6 +9,7 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
+use std::collections::HashMap;
 use std::fmt;
 
 use bitcoin::consensus::serialize;
@@ -34,9 +35,12 @@ pub fn verify_tx<D: Database, B: Blockchain>(
     log::debug!("Verifying {}", tx.txid());
 
     let serialized_tx = serialize(tx);
+    let mut tx_cache = HashMap::<_, Transaction>::new();
 
     for (index, input) in tx.input.iter().enumerate() {
-        let prev_tx = if let Some(prev_tx) = database.get_raw_tx(&input.previous_output.txid)? {
+        let prev_tx = if let Some(prev_tx) = tx_cache.get(&input.previous_output.txid) {
+            prev_tx.clone()
+        } else if let Some(prev_tx) = database.get_raw_tx(&input.previous_output.txid)? {
             prev_tx
         } else if let Some(prev_tx) = blockchain.get_tx(&input.previous_output.txid)? {
             prev_tx
@@ -55,6 +59,10 @@ pub fn verify_tx<D: Database, B: Blockchain>(
             &serialized_tx,
             index,
         )?;
+
+        // Since we have a local cache we might as well cache stuff from the db, as it will very
+        // likely decrease latency compared to reading from disk or performing an SQL query.
+        tx_cache.insert(prev_tx.txid(), prev_tx);
     }
 
     Ok(())