From 241401e937954a2a7af0175f61224b7bc41814bf Mon Sep 17 00:00:00 2001
From: greged93 <82421016+greged93@users.noreply.github.com>
Date: Mon, 25 Mar 2024 19:35:39 +0100
Subject: [PATCH] opti: use `vec::with_capacity` when possible (#1535)

Co-authored-by: anondev1993 <kycbored@gmail.com>
---
 CHANGELOG.md                                | 1 +
 crates/primitives/snos-output/src/codec.rs  | 2 +-
 starknet-e2e-test/src/starknet_sovereign.rs | 3 ++-
 starknet-rpc-test/src/lib.rs                | 4 ++--
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 65c16f6027..d78174cf1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Next release
 
+- dev: change `Vec::new` to `Vec::with_capacity` where possible.
 - chore(rpc): clean trace api
 - feat(rpc): added state diff real value in trace api
 - chore: update cairo-vm commit and update gas per op
diff --git a/crates/primitives/snos-output/src/codec.rs b/crates/primitives/snos-output/src/codec.rs
index adc0b923ed..13229ccf9f 100644
--- a/crates/primitives/snos-output/src/codec.rs
+++ b/crates/primitives/snos-output/src/codec.rs
@@ -117,7 +117,7 @@ impl<T: SnosCodec> SnosCodec for Vec<T> {
 
     fn decode(input: &mut FeltReader) -> Result<Self, FeltReaderError> {
         let mut segment_reader = FeltReader::new(input.read_segment()?);
-        let mut elements: Vec<T> = Vec::new();
+        let mut elements: Vec<T> = Vec::with_capacity(segment_reader.remaining_len());
         while segment_reader.remaining_len() > 0 {
             elements.push(T::decode(&mut segment_reader)?);
         }
diff --git a/starknet-e2e-test/src/starknet_sovereign.rs b/starknet-e2e-test/src/starknet_sovereign.rs
index 6b868ac5b1..78bca30710 100644
--- a/starknet-e2e-test/src/starknet_sovereign.rs
+++ b/starknet-e2e-test/src/starknet_sovereign.rs
@@ -160,7 +160,8 @@ impl StarknetSovereign {
     }
 
     pub async fn message_to_l1_exists(&self, message: &MessageL2ToL1) -> bool {
-        let mut payload: Vec<u8> = Vec::new();
+        let message_felt_size = message.size_in_felts();
+        let mut payload: Vec<u8> = Vec::with_capacity(32 * message_felt_size);
         message.clone().into_encoded_vec().into_iter().for_each(|felt| payload.append(&mut felt.bytes().to_vec()));
 
         let msg_hash = keccak256(payload);
diff --git a/starknet-rpc-test/src/lib.rs b/starknet-rpc-test/src/lib.rs
index 450edee0f8..c369725b58 100644
--- a/starknet-rpc-test/src/lib.rs
+++ b/starknet-rpc-test/src/lib.rs
@@ -170,7 +170,7 @@ impl MadaraClient {
         &mut self,
         transactions: Vec<Transaction<'_>>,
     ) -> anyhow::Result<Vec<Result<TransactionResult, SendTransactionError>>> {
-        let mut results = Vec::new();
+        let mut results = Vec::with_capacity(transactions.len());
         for tx in transactions {
             let result = tx.send().await;
             results.push(result);
@@ -184,7 +184,7 @@ impl MadaraClient {
         &mut self,
         transactions: Vec<Transaction<'_>>,
     ) -> Vec<Result<TransactionResult, SendTransactionError>> {
-        let mut results = Vec::new();
+        let mut results = Vec::with_capacity(transactions.len());
         for tx in transactions {
             let result = tx.send().await;
             results.push(result);