feat: Replace FeltRng trait object in ClientBuilder and Client with generic

CHANGELOG.md

@@ -10,6 +10,7 @@
 * [BREAKING] Merged `concurrent` feature with `std` (#974).
 * [BREAKING] Changed `TransactionRequest` to use expected output recipients instead of output notes (#976).
 * [BREAKING] Removed `TransactionExecutor` from `Client` and `NoteScreener` (#998).
+* [BREAKING] Replace `FeltRng` trait object in `ClientBuilder` and `Client` with generic and remove `ClientRng` (#1015).
 
 ### Features
 

bin/miden-cli/src/commands/new_account.rs

@@ -20,7 +20,6 @@ use miden_lib::account::{auth::RpoFalcon512, wallets::BasicWallet};
 use miden_objects::account::{
     AccountComponent, AccountComponentTemplate, InitStorageData, StorageValueName,
 };
-use rand::RngCore;
 
 use crate::{
     CLIENT_BINARY_NAME, CliKeyStore, commands::account::maybe_set_default_account,

bin/miden-cli/tests/cli.rs

@@ -762,7 +762,7 @@ async fn create_rust_client_with_store_path(store_path: &Path) -> (TestClient, C
     let mut rng = rand::rng();
     let coin_seed: [u64; 4] = rng.random();
 
-    let rng = Box::new(RpoRandomCoin::new(coin_seed.map(Felt::new)));
+    let rng = RpoRandomCoin::new(coin_seed.map(Felt::new));
 
     let keystore = CliKeyStore::new(temp_dir()).unwrap();
 

crates/rust-client/src/builder.rs

@@ -2,7 +2,6 @@ use alloc::{
     string::{String, ToString},
     sync::Arc,
 };
-use std::boxed::Box;
 
 use miden_objects::{
     Felt, MAX_TX_EXECUTION_CYCLES, MIN_TX_EXECUTION_CYCLES,
@@ -46,13 +45,13 @@ enum AuthenticatorConfig {
 /// This builder allows you to configure the various components required by the client, such as the
 /// RPC endpoint, store, RNG, and keystore. It is generic over the keystore type. By default, it
 /// uses `FilesystemKeyStore<rand::rngs::StdRng>`.
-pub struct ClientBuilder {
+pub struct ClientBuilder<R: FeltRng = RpoRandomCoin> {
     /// An optional custom RPC client. If provided, this takes precedence over `rpc_endpoint`.
     rpc_api: Option<Arc<dyn NodeRpcClient + Send>>,
     /// An optional store provided by the user.
     store: Option<Arc<dyn Store>>,
-    /// An optional RNG provided by the user.
-    rng: Option<Box<dyn FeltRng>>,
+    /// RNG provided by the user.
+    rng: R,
     /// The store path to use when no store is directly provided via `with_store()`.
     #[cfg(feature = "sqlite")]
     store_path: String,
@@ -70,10 +69,16 @@ pub struct ClientBuilder {
 
 impl Default for ClientBuilder {
     fn default() -> Self {
+        let rng = {
+            let mut seed_rng = rand::rng();
+            let coin_seed: [u64; 4] = seed_rng.random();
+            RpoRandomCoin::new(coin_seed.map(Felt::new))
+        };
+
         Self {
             rpc_api: None,
             store: None,
-            rng: None,
+            rng,
             #[cfg(feature = "sqlite")]
             store_path: "store.sqlite3".to_string(),
             keystore: None,
@@ -90,7 +95,9 @@ impl ClientBuilder {
     pub fn new() -> Self {
         Self::default()
     }
+}
 
+impl<R: FeltRng> ClientBuilder<R> {
     /// Enable or disable debug mode.
     #[must_use]
     pub fn in_debug_mode(mut self, debug: bool) -> Self {
@@ -128,10 +135,10 @@ impl ClientBuilder {
         self
     }
 
-    /// Optionally provide a custom RNG.
+    /// Provide a custom RNG.
     #[must_use]
-    pub fn with_rng(mut self, rng: Box<dyn FeltRng>) -> Self {
-        self.rng = Some(rng);
+    pub fn with_rng(mut self, rng: R) -> Self {
+        self.rng = rng;
         self
     }
 
@@ -177,7 +184,7 @@ impl ClientBuilder {
     /// - Returns an error if the store cannot be instantiated.
     /// - Returns an error if the keystore is not specified or fails to initialize.
     #[allow(clippy::unused_async, unused_mut)]
-    pub async fn build(mut self) -> Result<Client, ClientError> {
+    pub async fn build(mut self) -> Result<Client<R>, ClientError> {
         // Determine the RPC client to use.
         let rpc_api: Arc<dyn NodeRpcClient + Send> = if let Some(client) = self.rpc_api {
             client
@@ -206,15 +213,6 @@ impl ClientBuilder {
             ));
         };
 
-        // Use the provided RNG, or create a default one.
-        let rng = if let Some(user_rng) = self.rng {
-            user_rng
-        } else {
-            let mut seed_rng = rand::rng();
-            let coin_seed: [u64; 4] = seed_rng.random();
-            Box::new(RpoRandomCoin::new(coin_seed.map(Felt::new)))
-        };
-
         // Initialize the authenticator.
         let authenticator = match self.keystore {
             Some(AuthenticatorConfig::Instance(authenticator)) => authenticator,
@@ -233,7 +231,7 @@ impl ClientBuilder {
 
         Ok(Client::new(
             rpc_api,
-            rng,
+            self.rng,
             arc_store,
             authenticator,
             ExecutionOptions::new(

crates/rust-client/src/lib.rs

@@ -87,7 +87,7 @@
 //! let endpoint = Endpoint::new("https".into(), "localhost".into(), Some(57291));
 //! let client: Client = Client::new(
 //!     Arc::new(TonicRpcClient::new(&endpoint, 10_000)),
-//!     Box::new(rng),
+//!     rng,
 //!     store,
 //!     Arc::new(keystore),
 //!     ExecutionOptions::new(
@@ -112,7 +112,6 @@
 
 #[macro_use]
 extern crate alloc;
-use alloc::boxed::Box;
 
 #[cfg(feature = "std")]
 extern crate std;
@@ -206,9 +205,8 @@ pub mod testing {
 
 use alloc::sync::Arc;
 
-use miden_objects::crypto::rand::FeltRng;
+use miden_objects::crypto::rand::{FeltRng, RpoRandomCoin};
 use miden_tx::{LocalTransactionProver, auth::TransactionAuthenticator};
-use rand::RngCore;
 use rpc::NodeRpcClient;
 use store::Store;
 
@@ -222,12 +220,12 @@ use store::Store;
 ///   as notes and transactions.
 /// - Connects to a Miden node to periodically sync with the current state of the network.
 /// - Executes, proves, and submits transactions to the network as directed by the user.
-pub struct Client {
+pub struct Client<R: FeltRng = RpoRandomCoin> {
     /// The client's store, which provides a way to write and read entities to provide persistence.
     store: Arc<dyn Store>,
     /// An instance of [`FeltRng`] which provides randomness tools for generating new keys,
     /// serial numbers, etc.
-    rng: ClientRng,
+    rng: R,
     /// An instance of [`NodeRpcClient`] which provides a way for the client to connect to the
     /// Miden node.
     rpc_api: Arc<dyn NodeRpcClient + Send>,
@@ -247,7 +245,7 @@ pub struct Client {
 }
 
 /// Construction and access methods.
-impl Client {
+impl<R: FeltRng> Client<R> {
     // CONSTRUCTOR
     // --------------------------------------------------------------------------------------------
 
@@ -275,7 +273,7 @@ impl Client {
     /// Returns an error if the client couldn't be instantiated.
     pub fn new(
         rpc_api: Arc<dyn NodeRpcClient + Send>,
-        rng: Box<dyn FeltRng>,
+        rng: R,
         store: Arc<dyn Store>,
         authenticator: Arc<dyn TransactionAuthenticator>,
         exec_options: ExecutionOptions,
@@ -287,7 +285,7 @@ impl Client {
 
         Self {
             store,
-            rng: ClientRng::new(rng),
+            rng,
             rpc_api,
             tx_prover,
             authenticator,
@@ -304,7 +302,7 @@ impl Client {
 
     /// Returns a reference to the client's random number generator. This can be used to generate
     /// randomness for various purposes such as serial numbers, keys, etc.
-    pub fn rng(&mut self) -> &mut ClientRng {
+    pub fn rng(&mut self) -> &mut R {
         &mut self.rng
     }
 
@@ -321,44 +319,3 @@ impl Client {
         &mut self.store
     }
 }
-
-// CLIENT RNG
-// ================================================================================================
-
-/// A wrapper around a [`FeltRng`] that implements the [`RngCore`] trait.
-/// This allows the user to pass their own generic RNG so that it's used by the client.
-pub struct ClientRng(Box<dyn FeltRng>);
-
-impl ClientRng {
-    pub fn new(rng: Box<dyn FeltRng>) -> Self {
-        Self(rng)
-    }
-
-    pub fn inner_mut(&mut self) -> &mut Box<dyn FeltRng> {
-        &mut self.0
-    }
-}
-
-impl RngCore for ClientRng {
-    fn next_u32(&mut self) -> u32 {
-        self.0.next_u32()
-    }
-
-    fn next_u64(&mut self) -> u64 {
-        self.0.next_u64()
-    }
-
-    fn fill_bytes(&mut self, dest: &mut [u8]) {
-        self.0.fill_bytes(dest);
-    }
-}
-
-impl FeltRng for ClientRng {
-    fn draw_element(&mut self) -> Felt {
-        self.0.draw_element()
-    }
-
-    fn draw_word(&mut self) -> Word {
-        self.0.draw_word()
-    }
-}

crates/rust-client/src/test_utils/common.rs

@@ -1,5 +1,4 @@
 use std::{
-    boxed::Box,
     env::temp_dir,
     fs::OpenOptions,
     io::Write,
@@ -19,7 +18,7 @@ use miden_objects::{
     note::{NoteId, NoteType},
     transaction::{InputNote, OutputNote, TransactionId},
 };
-use rand::{Rng, RngCore, rngs::StdRng};
+use rand::{Rng, rngs::StdRng};
 use toml::Table;
 use uuid::Uuid;
 
@@ -83,7 +82,7 @@ pub async fn create_test_client_builder() -> (ClientBuilder, TestClientKeyStore)
 
     let builder = ClientBuilder::new()
         .with_rpc(Arc::new(TonicRpcClient::new(&rpc_endpoint, rpc_timeout)))
-        .with_rng(Box::new(rng))
+        .with_rng(rng)
         .with_store(store)
         .with_filesystem_keystore(auth_path.to_str().unwrap())
         .in_debug_mode(true)

crates/rust-client/src/tests.rs

@@ -1,5 +1,5 @@
 use alloc::vec::Vec;
-use std::{boxed::Box, collections::BTreeSet, env::temp_dir, println, sync::Arc};
+use std::{collections::BTreeSet, env::temp_dir, println, sync::Arc};
 
 // TESTS
 // ================================================================================================
@@ -39,7 +39,7 @@ use miden_tx::{
     TransactionExecutorError,
     utils::{Deserializable, Serializable},
 };
-use rand::{Rng, RngCore, rngs::StdRng};
+use rand::{Rng, rngs::StdRng};
 use uuid::Uuid;
 
 use crate::{
@@ -93,7 +93,7 @@ pub async fn create_test_client_builder() -> (ClientBuilder, MockRpcApi, Filesys
 
     let builder = ClientBuilder::new()
         .with_rpc(arc_rpc_api)
-        .with_rng(Box::new(rng))
+        .with_rng(rng)
         .with_store(store)
         .with_filesystem_keystore(keystore_path.to_str().unwrap())
         .in_debug_mode(true)

crates/rust-client/src/transaction/request/builder.rs

@@ -7,7 +7,10 @@ use miden_objects::{
     account::AccountId,
     asset::{Asset, FungibleAsset},
     block::BlockNumber,
-    crypto::merkle::{InnerNodeInfo, MerkleStore},
+    crypto::{
+        merkle::{InnerNodeInfo, MerkleStore},
+        rand::FeltRng,
+    },
     note::{Note, NoteDetails, NoteId, NoteRecipient, NoteTag, NoteType, PartialNote},
     transaction::{OutputNote, TransactionScript},
     vm::AdviceMap,
@@ -17,7 +20,6 @@ use super::{
     ForeignAccount, NoteArgs, TransactionRequest, TransactionRequestError,
     TransactionScriptTemplate,
 };
-use crate::ClientRng;
 
 // TRANSACTION REQUEST BUILDER
 // ================================================================================================
@@ -250,12 +252,12 @@ impl TransactionRequestBuilder {
     ///   note.
     ///
     /// This function cannot be used with a previously set custom script.
-    pub fn build_mint_fungible_asset(
+    pub fn build_mint_fungible_asset<R: FeltRng>(
         self,
         asset: FungibleAsset,
         target_id: AccountId,
         note_type: NoteType,
-        rng: &mut ClientRng,
+        rng: &mut R,
     ) -> Result<TransactionRequest, TransactionRequestError> {
         let created_note = create_p2id_note(
             asset.faucet_id(),
@@ -281,12 +283,12 @@ impl TransactionRequestBuilder {
     ///   note.
     ///
     /// This function cannot be used with a previously set custom script.
-    pub fn build_pay_to_id(
+    pub fn build_pay_to_id<R: FeltRng>(
         self,
         payment_data: PaymentTransactionData,
         recall_height: Option<BlockNumber>,
         note_type: NoteType,
-        rng: &mut ClientRng,
+        rng: &mut R,
     ) -> Result<TransactionRequest, TransactionRequestError> {
         let PaymentTransactionData {
             assets,
@@ -336,11 +338,11 @@ impl TransactionRequestBuilder {
     ///   note.
     ///
     /// This function cannot be used with a previously set custom script.
-    pub fn build_swap(
+    pub fn build_swap<R: FeltRng>(
         self,
         swap_data: &SwapTransactionData,
         note_type: NoteType,
-        rng: &mut ClientRng,
+        rng: &mut R,
     ) -> Result<TransactionRequest, TransactionRequestError> {
         // The created note is the one that we need as the output of the tx, the other one is the
         // one that we expect to receive and consume eventually.

crates/web-client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@demox-labs/miden-sdk",
-  "version": "0.10.0-next.4",
+  "version": "0.10.0-next.5",
   "description": "Miden Wasm SDK",
   "collaborators": [
     "Miden",

crates/web-client/src/lib.rs

@@ -87,7 +87,7 @@ impl WebClient {
 
         self.inner = Some(Client::new(
             web_rpc_client,
-            Box::new(rng),
+            rng,
             web_store.clone(),
             Arc::new(keystore.clone()),
             ExecutionOptions::new(

crates/web-client/src/new_account.rs

@@ -6,7 +6,6 @@ use miden_client::{
 };
 use miden_lib::account::{auth::RpoFalcon512, faucets::BasicFungibleFaucet};
 use miden_objects::asset::TokenSymbol;
-use rand::RngCore;
 use wasm_bindgen::prelude::*;
 
 use super::models::{

tests/src/network_transaction_tests.rs

@@ -19,7 +19,6 @@ use miden_objects::{
     account::AccountComponent,
     assembly::{Assembler, DefaultSourceManager, Library, LibraryPath, Module, ModuleKind},
 };
-use rand::RngCore;
 
 // HELPERS
 // ================================================================================================