Configurable solution interactions iternalization (#58)

src/domain/solver/dex/mod.rs

@@ -43,6 +43,10 @@ pub struct Dex {
     /// Amount of gas that gets added to each swap to tweak the cost coverage of
     /// the solver.
     gas_offset: eth::Gas,
+
+    /// Whether to internalize the solution interactions using the Settlement
+    /// contract buffer.
+    internalize_interactions: bool,
 }
 
 /// The amount of time we aim the solver to finish before the final deadline is
@@ -67,6 +71,7 @@ impl Dex {
             fills: Fills::new(config.smallest_partial_fill),
             rate_limiter,
             gas_offset: config.gas_offset,
+            internalize_interactions: config.internalize_interactions,
         }
     }
 
@@ -202,6 +207,10 @@ impl Dex {
         // Maybe some liquidity appeared that enables a bigger fill.
         self.fills.increase_next_try(order.uid);
 
-        Some(solution.with_buffers_internalizations(tokens))
+        if self.internalize_interactions {
+            Some(solution.with_buffers_internalizations(tokens))
+        } else {
+            Some(solution)
+        }
     }
 }

src/infra/config/dex/file.rs

@@ -71,6 +71,11 @@ struct Config {
     /// This is useful for caching requests on an egress proxy.
     #[serde(with = "humantime_serde", default)]
     current_block_poll_interval: Option<Duration>,
+
+    /// Whether to internalize the solution interactions using the Settlement
+    /// contract buffers.
+    #[serde(default = "default_internalize_interactions")]
+    internalize_interactions: bool,
 }
 
 fn default_relative_slippage() -> BigDecimal {
@@ -103,6 +108,10 @@ fn default_gas_offset() -> eth::U256 {
     106_391.into()
 }
 
+fn default_internalize_interactions() -> bool {
+    true
+}
+
 /// Loads the base solver configuration from a TOML file.
 ///
 /// # Panics
@@ -167,6 +176,7 @@ pub async fn load<T: DeserializeOwned>(path: &Path) -> (super::Config, T) {
         .unwrap(),
         gas_offset: eth::Gas(config.gas_offset),
         block_stream,
+        internalize_interactions: config.internalize_interactions,
     };
     (config, dex)
 }

src/infra/config/dex/mod.rs

@@ -26,4 +26,5 @@ pub struct Config {
     pub rate_limiting_strategy: rate_limit::Strategy,
     pub gas_offset: eth::Gas,
     pub block_stream: Option<CurrentBlockStream>,
+    pub internalize_interactions: bool,
 }