Allow feeder calls to set the gas limit

piecrust/CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Change `Session::feeder_call` and `Session::feeder_call_raw` to allow for the
+ caller to specify the gas limit [#344]
+
 ## [0.17.0] - 2024-02-28
 
 ### Added
@@ -379,6 +384,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- ISSUES -->
 
+[#344]: https://github.com/dusk-network/piecrust/issues/344
 [#336]: https://github.com/dusk-network/piecrust/issues/336
 [#325]: https://github.com/dusk-network/piecrust/issues/325
 [#324]: https://github.com/dusk-network/piecrust/issues/324

piecrust/src/session.rs

@@ -465,14 +465,14 @@ impl Session {
  /// Feeder calls are used to have the contract be able to report larger
  /// amounts of data to the host via the channel included in this call.
  ///
- /// These calls are always performed with the maximum amount of gas, since
- /// the contracts may spend quite a large amount in an effort to report
- /// data.
+ /// These calls should be performed with a large amount of gas, since the
+ /// contracts may spend quite a large amount in an effort to report data.
  pub fn feeder_call<A, R>(
  &mut self,
  contract: ContractId,
  fn_name: &str,
  fn_arg: &A,
+ gas_limit: u64,
  feeder: mpsc::Sender<Vec<u8>>,
  ) -> Result<CallReceipt<R>, Error>
  where
@@ -483,7 +483,7 @@ impl Session {
  + for<'b> CheckBytes<DefaultValidator<'b>>,
  {
  self.inner.feeder = Some(feeder);
- let r = self.call(contract, fn_name, fn_arg, u64::MAX);
+ let r = self.call(contract, fn_name, fn_arg, gas_limit);
  self.inner.feeder = None;
  r
  }
@@ -500,10 +500,11 @@ impl Session {
  contract: ContractId,
  fn_name: &str,
  fn_arg: V,
+ gas_limit: u64,
  feeder: mpsc::Sender<Vec<u8>>,
  ) -> Result<CallReceipt<Vec<u8>>, Error> {
  self.inner.feeder = Some(feeder);
- let r = self.call_raw(contract, fn_name, fn_arg, u64::MAX);
+ let r = self.call_raw(contract, fn_name, fn_arg, gas_limit);
  self.inner.feeder = None;
  r
  }

piecrust/tests/feeder.rs

@@ -24,10 +24,12 @@ fn feed() -> Result<(), Error> {
  )?;
 
  const FEED_NUM: u32 = 10;
+ const GAS_LIMIT: u64 = 1_000_000;
 
  let (sender, receiver) = mpsc::channel();
 
- session.feeder_call::<_, ()>(id, "feed_num", &FEED_NUM, sender)?;
+ session
+ .feeder_call::<_, ()>(id, "feed_num", &FEED_NUM, GAS_LIMIT, sender)?;
 
  let numbers = receiver
  .into_iter()
@@ -69,3 +71,29 @@ fn feed_errors_when_normal_call() -> Result<(), Error> {
 
  Ok(())
 }
+
+#[test]
+fn feed_out_of_gas() -> Result<(), Error> {
+ let vm = VM::ephemeral()?;
+
+ let mut session = vm.session(SessionData::builder())?;
+
+ let id = session.deploy(
+ contract_bytecode!("feeder"),
+ ContractData::builder().owner(OWNER),
+ LIMIT,
+ )?;
+
+ const FEED_NUM: u32 = 100;
+ const GAS_LIMIT: u64 = 1_000;
+
+ let (sender, _receiver) = mpsc::channel();
+
+ let err = session
+ .feeder_call::<_, ()>(id, "feed_num", &FEED_NUM, GAS_LIMIT, sender)
+ .expect_err("Call should error when out of gas");
+
+ assert!(matches!(err, Error::OutOfGas));
+
+ Ok(())
+}