feat: Waterfill - Slim Shady version

fynd-core/Cargo.toml

@@ -41,6 +41,10 @@ alloy = { workspace = true, features = ["sol-types", "signer-local"] }
 
 [features]
 test-utils = []
+# Per-pool simulation metering: counts and times every `get_amount_out` a solve makes, splits it
+# by protocol and by solve pass, and reports it. Off by default — measuring a swap costs two clock
+# reads on the hottest path in the solver. With it off, solving calls the panic guard directly.
+swap-metrics = []
 # Block-step-controller build path: lets a caller release buffered blocks one at
 # a time (deterministic stepping). Used by the hindsight monitor; the API is not
 # yet stable, so it is opt-in.

fynd-core/src/algorithm/bellman_ford.rs

@@ -43,7 +43,7 @@ use super::{
     split_primitives::MarketOverrides, Algorithm, AlgorithmConfig, AlgorithmError, NoPathReason,
 };
 use crate::{
-    algorithm::sim_guard::GuardedProtocolSim,
+    algorithm::{paths, sim_guard::GuardedProtocolSim},
     derived::{
         computation::ComputationRequirements,
         types::{SpotPrices, TokenGasPrices},
@@ -205,13 +205,7 @@ impl BellmanFordAlgorithm {
                 },
             )?;
 
-        let market_view = match label.as_ref() {
-            Some(l) => market
-                .read_labeled(l)
-                .await
-                .map_err(|e| AlgorithmError::Other(e.to_string()))?,
-            None => market.read().await,
-        };
+        let market_view = paths::read_market(&market, label).await?;
         let token_map: FxHashMap<NodeIndex, Arc<Token>> = token_nodes
             .iter()
             .filter_map(|&node| {

fynd-core/src/algorithm/mod.rs

@@ -23,11 +23,13 @@ pub mod most_liquid;
 pub mod path_frank_wolfe;
 pub(crate) mod paths;
 pub(crate) mod sim_guard;
+pub(crate) mod sim_meter;
 pub(crate) mod split_primitives;
 pub mod water_fill;
 
 #[cfg(test)]
 pub mod split_test_harness;
+mod swap_cache;
 #[cfg(test)]
 pub mod test_utils;