From 7091c789c99f2f19378a147a6e0c202b3006b8a8 Mon Sep 17 00:00:00 2001
From: Eitan Seri-Levi <eserilev@ucsc.edu>
Date: Wed, 16 Oct 2024 22:53:31 -0700
Subject: [PATCH] Optimization to Redb slasher (#6481)

* first() & last() optimizations

* Fmt
---
 Cargo.lock                        |  4 ++--
 slasher/Cargo.toml                |  2 +-
 slasher/src/database/redb_impl.rs | 12 ++----------
 3 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ecbfd0cb8d..b12df12265 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6798,9 +6798,9 @@ dependencies = [
 
 [[package]]
 name = "redb"
-version = "2.1.2"
+version = "2.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "58323dc32ea52a8ae105ff94bc0460c5d906307533ba3401aa63db3cbe491fe5"
+checksum = "074373f3e7e5d27d8741d19512232adb47be8622d3daef3a45bcae72050c3d2a"
 dependencies = [
  "libc",
 ]
diff --git a/slasher/Cargo.toml b/slasher/Cargo.toml
index d74b0ac062..034a1b71a3 100644
--- a/slasher/Cargo.toml
+++ b/slasher/Cargo.toml
@@ -37,7 +37,7 @@ mdbx = { package = "libmdbx", git = "https://github.com/sigp/libmdbx-rs", rev =
 lmdb-rkv = { git = "https://github.com/sigp/lmdb-rs", rev = "f33845c6469b94265319aac0ed5085597862c27e", optional = true }
 lmdb-rkv-sys = { git = "https://github.com/sigp/lmdb-rs", rev = "f33845c6469b94265319aac0ed5085597862c27e", optional = true }
 
-redb = { version = "2.1", optional = true }
+redb = { version = "2.1.4", optional = true }
 
 [dev-dependencies]
 maplit = { workspace = true }
diff --git a/slasher/src/database/redb_impl.rs b/slasher/src/database/redb_impl.rs
index 6c5b62a44f..12bef71148 100644
--- a/slasher/src/database/redb_impl.rs
+++ b/slasher/src/database/redb_impl.rs
@@ -164,13 +164,9 @@ impl<'env> Cursor<'env> {
         let table_definition: TableDefinition<'_, &[u8], &[u8]> =
             TableDefinition::new(&self.db.table_name);
         let table = self.txn.open_table(table_definition)?;
-        let first = table
-            .iter()?
-            .next()
-            .map(|x| x.map(|(key, _)| key.value().to_vec()));
+        let first = table.first()?.map(|(key, _)| key.value().to_vec());
 
         if let Some(owned_key) = first {
-            let owned_key = owned_key?;
             self.current_key = Some(Cow::from(owned_key));
             Ok(self.current_key.clone())
         } else {
@@ -182,13 +178,9 @@ impl<'env> Cursor<'env> {
         let table_definition: TableDefinition<'_, &[u8], &[u8]> =
             TableDefinition::new(&self.db.table_name);
         let table = self.txn.open_table(table_definition)?;
-        let last = table
-            .iter()?
-            .next_back()
-            .map(|x| x.map(|(key, _)| key.value().to_vec()));
+        let last = table.last()?.map(|(key, _)| key.value().to_vec());
 
         if let Some(owned_key) = last {
-            let owned_key = owned_key?;
             self.current_key = Some(Cow::from(owned_key));
             return Ok(self.current_key.clone());
         }