AccountSharedData.copy_into_owner_from_slice (#16755)

programs/bpf_loader/src/serialization.rs

@@ -1,8 +1,12 @@
 use byteorder::{ByteOrder, LittleEndian, WriteBytesExt};
 use solana_rbpf::{aligned_memory::AlignedMemory, ebpf::HOST_ALIGN};
 use solana_sdk::{
-    account::ReadableAccount, bpf_loader_deprecated, entrypoint::MAX_PERMITTED_DATA_INCREASE,
-    instruction::InstructionError, keyed_account::KeyedAccount, pubkey::Pubkey,
+    account::{ReadableAccount, WritableAccount},
+    bpf_loader_deprecated,
+    entrypoint::MAX_PERMITTED_DATA_INCREASE,
+    instruction::InstructionError,
+    keyed_account::KeyedAccount,
+    pubkey::Pubkey,
 };
 use std::{
     io::prelude::*,
@@ -263,10 +267,7 @@ pub fn deserialize_parameters_aligned(
                 + size_of::<u8>() // executable
                 + 4 // padding to 128-bit aligned
                 + size_of::<Pubkey>(); // key
-            account
-                .owner
-                .as_mut()
-                .copy_from_slice(&buffer[start..start + size_of::<Pubkey>()]);
+            account.copy_into_owner_from_slice(&buffer[start..start + size_of::<Pubkey>()]);
             start += size_of::<Pubkey>(); // owner
             account.lamports = LittleEndian::read_u64(&buffer[start..]);
             start += size_of::<u64>(); // lamports

sdk/src/account.rs

@@ -81,6 +81,7 @@ pub trait WritableAccount: ReadableAccount {
     fn set_lamports(&mut self, lamports: u64);
     fn data_as_mut_slice(&mut self) -> &mut [u8];
     fn set_owner(&mut self, owner: Pubkey);
+    fn copy_into_owner_from_slice(&mut self, source: &[u8]);
     fn set_executable(&mut self, executable: bool);
     fn set_rent_epoch(&mut self, epoch: Epoch);
     fn create(
@@ -128,6 +129,9 @@ impl WritableAccount for Account {
     fn set_owner(&mut self, owner: Pubkey) {
         self.owner = owner;
     }
+    fn copy_into_owner_from_slice(&mut self, source: &[u8]) {
+        self.owner.as_mut().copy_from_slice(source);
+    }
     fn set_executable(&mut self, executable: bool) {
         self.executable = executable;
     }
@@ -162,6 +166,9 @@ impl WritableAccount for AccountSharedData {
     fn set_owner(&mut self, owner: Pubkey) {
         self.owner = owner;
     }
+    fn copy_into_owner_from_slice(&mut self, source: &[u8]) {
+        self.owner.as_mut().copy_from_slice(source);
+    }
     fn set_executable(&mut self, executable: bool) {
         self.executable = executable;
     }
@@ -565,6 +572,17 @@ pub mod tests {
         (account1, account2)
     }
 
+    #[test]
+    fn test_account_data_copy_as_slice() {
+        let key = Pubkey::new_unique();
+        let key2 = Pubkey::new_unique();
+        let (mut account1, mut account2) = make_two_accounts(&key);
+        account1.copy_into_owner_from_slice(key2.as_ref());
+        account2.copy_into_owner_from_slice(key2.as_ref());
+        assert!(accounts_equal(&account1, &account2));
+        assert_eq!(account1.owner(), &key2);
+    }
+
     #[test]
     fn test_account_set_data_from_slice() {
         let key = Pubkey::new_unique();