Remove risk parameters from solvers (#2598)

# Description
A follow up for #2585

Risk parameters are no longer used, and we have other means of tweaking
the gas cost estimation.

## How to test
Existing tests.

crates/e2e/src/setup/colocation.rs

@@ -12,18 +12,12 @@ weth = "{weth:?}"
 base-tokens = []
 max-hops = 1
 max-partial-attempts = 5
-risk-parameters = [0,0,0,0]
         "#,
     ));
 
     start_solver(config_file, "baseline".to_string()).await
 }
 
-pub async fn start_naive_solver() -> Url {
-    let config_file = config_tmp_file("risk-parameters = [0,0,0,0]");
-    start_solver(config_file, "naive".to_string()).await
-}
-
 pub async fn start_legacy_solver(solver_endpoint: Url, chain_id: Option<U256>) -> Url {
     let chain_id = chain_id.unwrap_or(U256::from(1));
     let config_file = config_tmp_file(format!(

crates/solvers/config/example.baseline.toml

@@ -4,5 +4,4 @@ chain-id = "1"
 base-tokens = []
 max-hops = 0
 max-partial-attempts = 5
-risk-parameters = [0,0,0,0]
 # solution-gas-offset = 106391 # rough estimate of the settlement overhead

crates/solvers/src/domain/mod.rs

@@ -5,8 +5,5 @@ pub mod eth;
 pub mod liquidity;
 pub mod notification;
 pub mod order;
-mod risk;
 pub mod solution;
 pub mod solver;
-
-pub use risk::Risk;

crates/solvers/src/domain/solver/baseline.rs

@@ -9,7 +9,6 @@ use {
     crate::{
         boundary,
         domain::{
-            self,
             auction,
             eth,
             liquidity,
@@ -32,7 +31,6 @@ pub struct Config {
     pub base_tokens: Vec<eth::TokenAddress>,
     pub max_hops: usize,
     pub max_partial_attempts: usize,
-    pub risk: domain::Risk,
     pub solution_gas_offset: eth::SignedGas,
 }
 
@@ -58,9 +56,6 @@ struct Inner {
     /// valid solution or exceed this count.
     max_partial_attempts: usize,
 
-    /// Parameters used to calculate the revert risk of a solution.
-    risk: domain::Risk,
-
     /// Units of gas that get added to the gas estimate for executing a
     /// computed trade route to arrive at a gas estimate for a whole settlement.
     solution_gas_offset: eth::SignedGas,
@@ -74,7 +69,6 @@ impl Baseline {
             base_tokens: config.base_tokens.into_iter().collect(),
             max_hops: config.max_hops,
             max_partial_attempts: config.max_partial_attempts,
-            risk: config.risk,
             solution_gas_offset: config.solution_gas_offset,
         }))
     }

crates/solvers/src/domain/solver/naive.rs

@@ -8,26 +8,14 @@
 use {
     crate::{
         boundary,
-        domain::{self, auction, eth, liquidity, order, solution},
+        domain::{auction, eth, liquidity, order, solution},
     },
     std::collections::HashMap,
 };
 
-pub struct Config {
-    pub risk: domain::Risk,
-}
-
-pub struct Naive {
-    /// Parameters used to calculate the revert risk of a solution.
-    risk: domain::Risk,
-}
+pub struct Naive;
 
 impl Naive {
-    /// Creates a new naive solver for the specified configuration.
-    pub fn new(config: Config) -> Self {
-        Self { risk: config.risk }
-    }
-
     /// Solves the specified auction, returning a vector of all possible
     /// solutions.
     pub async fn solve(&self, auction: auction::Auction) -> Vec<solution::Solution> {

crates/solvers/src/infra/cli.rs

@@ -36,10 +36,7 @@ pub enum Command {
         config: PathBuf,
     },
     /// optimistically batch similar orders and get difference from AMMs
-    Naive {
-        #[clap(long, env)]
-        config: PathBuf,
-    },
+    Naive,
     /// forward auction to solver implementing the legacy HTTP interface
     Legacy {
         #[clap(long, env)]

crates/solvers/src/infra/config/baseline.rs

@@ -1,6 +1,6 @@
 use {
     crate::{
-        domain::{eth, solver::baseline, Risk},
+        domain::{eth, solver::baseline},
         infra::{config::unwrap_or_log, contracts},
         util::serialize,
     },
@@ -39,10 +39,6 @@ struct Config {
     /// when trying to solve it against baseline liquidity.
     max_partial_attempts: usize,
 
-    /// Parameters used to calculate the revert risk of a solution.
-    /// (gas_amount_factor, gas_price_factor, nmb_orders_factor, intercept)
-    risk_parameters: (f64, f64, f64, f64),
-
     /// Units of gas that get added to the gas estimate for executing a
     /// computed trade route to arrive at a gas estimate for a whole settlement.
     #[serde(default = "default_gas_offset")]
@@ -81,12 +77,6 @@ pub async fn load(path: &Path) -> baseline::Config {
             .collect(),
         max_hops: config.max_hops,
         max_partial_attempts: config.max_partial_attempts,
-        risk: Risk {
-            gas_amount_factor: config.risk_parameters.0,
-            gas_price_factor: config.risk_parameters.1,
-            nmb_orders_factor: config.risk_parameters.2,
-            intercept: config.risk_parameters.3,
-        },
         solution_gas_offset: config.solution_gas_offset.into(),
     }
 }

crates/solvers/src/infra/config/mod.rs

@@ -2,7 +2,6 @@ use std::fmt::Debug;
 
 pub mod baseline;
 pub mod legacy;
-pub mod naive;
 
 /// Unwraps result or logs a `TOML` parsing error.
 fn unwrap_or_log<T, E, P>(result: Result<T, E>, path: &P) -> T

crates/solvers/src/run.rs

@@ -33,10 +33,7 @@ async fn run_with(args: cli::Args, bind: Option<oneshot::Sender<SocketAddr>>) {
             let config = config::baseline::load(&config).await;
             Solver::Baseline(solver::Baseline::new(config))
         }
-        cli::Command::Naive { config } => {
-            let config = config::naive::load(&config).await;
-            Solver::Naive(solver::Naive::new(config))
-        }
+        cli::Command::Naive => Solver::Naive(solver::Naive),
         cli::Command::Legacy { config } => {
             let config = config::legacy::load(&config).await;
             Solver::Legacy(solver::Legacy::new(config))

crates/solvers/src/tests/baseline/bal_liquidity.rs

@@ -12,7 +12,6 @@ async fn weighted() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -134,7 +133,6 @@ async fn weighted_v3plus() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -249,7 +247,6 @@ async fn stable() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -417,7 +414,6 @@ async fn composable_stable_v4() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),

crates/solvers/src/tests/baseline/buy_order_rounding.rs

@@ -118,7 +118,6 @@ async fn balancer_weighted() {
                 base-tokens = ["0x9c58bacc331c9aa871afd802db6379a98e80cedb"]
                 max-hops = 1
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -285,7 +284,6 @@ async fn balancer_weighted_v3plus() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -400,7 +398,6 @@ async fn distant_convergence() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -515,7 +512,6 @@ async fn same_path() {
                 base-tokens = ["0x9c58bacc331c9aa871afd802db6379a98e80cedb"]
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),
@@ -666,7 +662,6 @@ async fn balancer_stable() {
                 base-tokens = []
                 max-hops = 0
                 max-partial-attempts = 1
-                risk-parameters = [0,0,0,0]
             "#
             .to_owned(),
         ),

crates/solvers/src/tests/naive/extract_deepest_pool.rs

@@ -13,11 +13,7 @@ use {crate::tests, serde_json::json};
 
 #[tokio::test]
 async fn test() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::File("config/example.naive.toml".into()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({

crates/solvers/src/tests/naive/filters_out_of_price_orders.rs

@@ -5,11 +5,7 @@ use {crate::tests, serde_json::json};
 
 #[tokio::test]
 async fn sell_orders_on_both_sides() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::String(r#"risk-parameters = [0,0,0,0]"#.to_owned()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({

crates/solvers/src/tests/naive/limit_order_price.rs

@@ -5,11 +5,7 @@ use {crate::tests, serde_json::json};
 
 #[tokio::test]
 async fn test() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::String(r#"risk-parameters = [0,0,0,0]"#.to_owned()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({

crates/solvers/src/tests/naive/matches_orders.rs

@@ -5,11 +5,7 @@ use {crate::tests, serde_json::json};
 
 #[tokio::test]
 async fn sell_orders_on_both_sides() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::String(r#"risk-parameters = [0,0,0,0]"#.to_owned()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({
@@ -112,11 +108,7 @@ async fn sell_orders_on_both_sides() {
 
 #[tokio::test]
 async fn sell_orders_on_one_side() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::String(r#"risk-parameters = [0,0,0,0]"#.to_owned()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({
@@ -219,11 +211,7 @@ async fn sell_orders_on_one_side() {
 
 #[tokio::test]
 async fn buy_orders_on_both_sides() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::String(r#"risk-parameters = [0,0,0,0]"#.to_owned()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({
@@ -326,11 +314,7 @@ async fn buy_orders_on_both_sides() {
 
 #[tokio::test]
 async fn buy_and_sell_orders() {
-    let engine = tests::SolverEngine::new(
-        "naive",
-        tests::Config::String(r#"risk-parameters = [0,0,0,0]"#.to_owned()),
-    )
-    .await;
+    let engine = tests::SolverEngine::new("naive", tests::Config::None).await;
 
     let solution = engine
         .solve(json!({