Support user_data option in transfer cli (#2369)

* feat: add "user_data" arg in "transfer" cli

* doc: rebuild the CLI.md

* fix: update the "UserData::from_option_string" impl

* fix: correct the "UserData::from_option_string"

* doc: add more documentation to "user_data" option

* fix: handle the error case of parsing UserData from string

* Update linera-service/src/linera/main.rs

Co-authored-by: Andreas Fackler <afck@users.noreply.github.com>
Signed-off-by: duguorong009 <80258679+duguorong009@users.noreply.github.com>

---------

Signed-off-by: duguorong009 <80258679+duguorong009@users.noreply.github.com>
Co-authored-by: Andreas Fackler <afck@users.noreply.github.com>

CLI.md

@@ -140,7 +140,7 @@ A Byzantine-fault tolerant sidechain with low-latency finality and high throughp
 
 Transfer funds
 
-**Usage:** `linera transfer --from <SENDER> --to <RECIPIENT> <AMOUNT>`
+**Usage:** `linera transfer [OPTIONS] --from <SENDER> --to <RECIPIENT> <AMOUNT>`
 
 ###### **Arguments:**
 
@@ -150,6 +150,7 @@ Transfer funds
 
 * `--from <SENDER>` — Sending chain ID (must be one of our chains)
 * `--to <RECIPIENT>` — Recipient account
+* `--data <USER_DATA>` — User Data (should be a string whose bytes are at most 32 in length)
 
 
 

linera-client/src/client_options.rs

@@ -258,6 +258,10 @@ pub enum ClientCommand {
 
         /// Amount to transfer
         amount: Amount,
+
+        /// User Data (should be a string whose bytes are at most 32 in length)
+        #[arg(long = "data")]
+        user_data: Option<String>,
     },
 
     /// Open (i.e. activate) a new chain deriving the UID from an existing one.

linera-execution/src/system.rs

@@ -355,6 +355,34 @@ impl Recipient {
 #[derive(Eq, PartialEq, Ord, PartialOrd, Clone, Hash, Default, Debug, Serialize, Deserialize)]
 pub struct UserData(pub Option<[u8; 32]>);
 
+impl UserData {
+    pub fn from_option_string(opt_str: Option<String>) -> Result<Self, usize> {
+        // Convert the Option<String> to Option<[u8; 32]>
+        let option_array = match opt_str {
+            Some(s) => {
+                // Convert the String to a Vec<u8>
+                let vec = s.into_bytes();
+                if vec.len() <= 32 {
+                    // Create an array from the Vec<u8>
+                    let mut array = [b' '; 32];
+
+                    // Copy bytes from the vector into the array
+                    let len = vec.len().min(32);
+                    array[..len].copy_from_slice(&vec[..len]);
+
+                    Some(array)
+                } else {
+                    return Err(vec.len());
+                }
+            }
+            None => None,
+        };
+
+        // Return the UserData with the converted Option<[u8; 32]>
+        Ok(UserData(option_array))
+    }
+}
+
 #[derive(Error, Debug)]
 pub enum SystemExecutionError {
     #[error(transparent)]

linera-service/src/linera/main.rs

@@ -115,7 +115,15 @@ impl Runnable for Job {
                 sender,
                 recipient,
                 amount,
+                user_data,
             } => {
+                let data = match UserData::from_option_string(user_data) {
+                    Ok(data) => data,
+                    Err(bytes_len) => bail!(
+                        "Failed to parse user data ({} bytes) exceeding max length (32 bytes)",
+                        bytes_len
+                    ),
+                };
                 let chain_client = context.make_chain_client(sender.chain_id);
                 info!(
                     "Starting transfer of {} native tokens from {} to {}",
@@ -125,10 +133,10 @@ impl Runnable for Job {
                 let certificate = context
                     .apply_client_command(&chain_client, |chain_client| {
                         let chain_client = chain_client.clone();
+                        let user_data = data.clone();
                         async move {
-                            let data = UserData::default();
                             chain_client
-                                .transfer_to_account(sender.owner, amount, recipient, data)
+                                .transfer_to_account(sender.owner, amount, recipient, user_data)
                                 .await
                         }
                     })