From 18e8a77683c86e967484db117e7012d73a41b418 Mon Sep 17 00:00:00 2001
From: enitrat <msaug@protonmail.com>
Date: Thu, 5 Sep 2024 11:50:49 +0200
Subject: [PATCH] dev: optimize FromBytes

---
 .tool-versions                 |  2 +-
 crates/utils/Scarb.toml        |  6 ++++-
 crates/utils/src/helpers.cairo | 40 ++++++++++------------------------
 3 files changed, 18 insertions(+), 30 deletions(-)

diff --git a/.tool-versions b/.tool-versions
index f5e9048bd..30efda798 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
 scarb 2.7.1
-starknet-foundry 0.28.0
+starknet-foundry 0.30.0
diff --git a/crates/utils/Scarb.toml b/crates/utils/Scarb.toml
index ad856c94a..f637ecf2e 100644
--- a/crates/utils/Scarb.toml
+++ b/crates/utils/Scarb.toml
@@ -9,11 +9,15 @@ edition = "2023_10"
 evm = { path = "../evm" }
 alexandria_data_structures = { path = "../alexandria_data_structures" }
 
+# For profiling
+[cairo]
+unstable-add-statements-functions-debug-info = true
+
 [tool]
 fmt.workspace = true
 
 [dev-dependencies]
-snforge_std = { git = "https://github.com/foundry-rs/starknet-foundry.git", tag = "v0.28.0" }
+snforge_std = { git = "https://github.com/foundry-rs/starknet-foundry.git", tag = "v0.30.0" }
 
 [scripts]
 test = "snforge test --max-n-steps 4294967295"
diff --git a/crates/utils/src/helpers.cairo b/crates/utils/src/helpers.cairo
index d2ce39238..2a7e19005 100644
--- a/crates/utils/src/helpers.cairo
+++ b/crates/utils/src/helpers.cairo
@@ -575,7 +575,7 @@ pub impl FromBytesImpl<
     +ByteSize<T>,
     +BytesUsedTrait<T>,
     +Into<u8, T>,
-    +Into<u32, T>,
+    +Into<u16, T>,
     +TryInto<T, u8>,
     +Copy<T>,
     +Drop<T>,
@@ -585,47 +585,31 @@ pub impl FromBytesImpl<
     fn from_be_bytes(self: Span<u8>) -> Option<T> {
         let byte_size = ByteSize::<T>::byte_size();
 
-        let len = self.len();
-        if len == 0 {
-            return Option::Some(Zero::zero());
-        }
-        if len > byte_size {
+        if self.len() != byte_size {
             return Option::None;
         }
-        let offset: u32 = len - 1;
-        let mut result: T = Zero::zero();
-        let mut i: u32 = 0;
-        while i != len {
-            let byte: T = (*self.at(i)).into();
-            // Safe unwrap, since offset - i is inbound in case of u8 { offset - i = 0 }, and
-            // TryInto<u32, u32>, TryInto<u32, u64>, TryInto<u32, u128>, TryInto<u32, 256> are safe
-            result += byte.shl((8 * (offset - i)).into());
 
-            i += 1;
+        let mut result: T = Zero::zero();
+        for byte in self {
+            let tmp = result * 256_u16.into();
+            result = tmp + (*byte).into();
         };
         Option::Some(result)
     }
 
     fn from_le_bytes(self: Span<u8>) -> Option<T> {
         let byte_size = ByteSize::<T>::byte_size();
-        let len = self.len();
 
-        if len == 0 {
-            return Option::Some(Zero::zero());
-        }
-        if len > byte_size {
+        if self.len() != byte_size {
             return Option::None;
         }
 
         let mut result: T = Zero::zero();
-        let mut i: u32 = 0;
-        while i != len {
-            let byte: T = (*self.at(i)).into();
-            // safe unwrap, as i is inbound in case of u8 { max value can be 8 * 1 = 8 }, and
-            // TryInto<u32, u32>, TryInto<u32, u64>, TryInto<u32, u128>, TryInto<u32, 256> are safe
-            result += byte.shl((8 * i).into());
-
-            i += 1;
+        let mut i = self.len();
+        while i != 0 {
+            i -= 1;
+            let tmp = result * 256_u16.into();
+            result = tmp + (*self[i]).into();
         };
         Option::Some(result)
     }