add code_size, comments, and slight optimization

Author: rachel-bousfield

stylus-sdk/src/evm.rs

@@ -14,7 +14,7 @@
 
 use crate::hostio::{self, wrap_hostio};
 use alloc::{vec, vec::Vec};
-use alloy_primitives::{Address, B256};
+use alloy_primitives::B256;
 use alloy_sol_types::{token::WordToken, SolEvent, TopicList};
 
 /// Emits an evm log from combined topics and data.
@@ -57,22 +57,6 @@ pub fn pay_for_memory_grow(pages: u16) {
     unsafe { hostio::pay_for_memory_grow(pages) }
 }
 
-/// Get the code associated with the given `address`.
-///
-/// Start at `offset` into the code and write at most `size` bytes.
-pub fn ext_code(address: &Address, offset: usize, size: Option<usize>) -> Vec<u8> {
-    let size = if let Some(sz) = size {
-        sz
-    } else {
-        unsafe { hostio::account_code_size(address.0.as_ptr()) }
-    };
-    let mut data = vec![0; size];
-    let size_written =
-        unsafe { hostio::account_code(address.0.as_ptr(), offset, size, data.as_mut_ptr()) };
-    data.truncate(size_written);
-    data
-}
-
 wrap_hostio!(
     /// Gets the amount of gas remaining. See [`Ink and Gas`] for more information on Stylus's compute pricing.
     ///

stylus-sdk/src/storage/map.rs

@@ -186,7 +186,7 @@ impl StorageKey for String {
 
 impl StorageKey for Address {
     fn to_slot(&self, root: B256) -> U256 {
-        let int: U160 = self.0.try_into().unwrap();
+        let int: U160 = self.0.into();
         int.to_slot(root)
     }
 }

stylus-sdk/src/types.rs

@@ -13,20 +13,29 @@
 //! let balance = account.balance();
 //! ```
 
-use alloc::vec;
-use alloc::vec::Vec;
-
 use crate::hostio;
+use alloc::vec::Vec;
 use alloy_primitives::{b256, Address, B256, U256};
 
 /// Trait that allows the [`Address`] type to inspect the corresponding account's balance and codehash.
 pub trait AddressVM {
     /// The balance in wei of the account.
     fn balance(&self) -> U256;
 
-    /// The code of the contract at the given address.
+    /// The account's code.
+    ///
+    /// Returns an empty [`vec`] for [`EOAs`].
+    ///
+    /// [`EOAs`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
     fn code(&self) -> Vec<u8>;
 
+    /// The length of the account's code in bytes.
+    ///
+    /// Returns `0` for [`EOAs`].
+    ///
+    /// [`EOAs`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
+    fn code_size(&self) -> usize;
+
     /// The codehash of the contract or [`EOA`] at the given address.
     ///
     /// [`EOA`]: https://ethereum.org/en/developers/docs/accounts/#types-of-account
@@ -43,22 +52,27 @@ pub trait AddressVM {
 impl AddressVM for Address {
     fn balance(&self) -> U256 {
         let mut data = [0; 32];
-        unsafe { hostio::account_balance(self.0.as_ptr(), data.as_mut_ptr()) };
+        unsafe { hostio::account_balance(self.as_ptr(), data.as_mut_ptr()) };
         U256::from_be_bytes(data)
     }
 
     fn code(&self) -> Vec<u8> {
-        let size = unsafe { hostio::account_code_size(self.0.as_ptr()) };
-        let mut data = vec![0; size];
+        let size = self.code_size();
+        let mut data = Vec::with_capacity(size);
         unsafe {
-            hostio::account_code(self.0.as_ptr(), 0, size, data.as_mut_ptr());
+            hostio::account_code(self.as_ptr(), 0, size, data.as_mut_ptr());
+            data.set_len(size);
         }
         data
     }
 
+    fn code_size(&self) -> usize {
+        unsafe { hostio::account_code_size(self.as_ptr()) }
+    }
+
     fn codehash(&self) -> B256 {
         let mut data = [0; 32];
-        unsafe { hostio::account_codehash(self.0.as_ptr(), data.as_mut_ptr()) };
+        unsafe { hostio::account_codehash(self.as_ptr(), data.as_mut_ptr()) };
         data.into()
     }