Remove backtest fb db initialisation from config (#322)

## 📝 Summary

Move the FlashbotsDB connection initialization from Config into the
RelayDB struct. This improves separation of concerns by making Config
unaware of any Postgres-specific details, while placing the connection
logic in the appropriate domain.

## 💡 Motivation and Context

<!--- (Optional) Why is this change required? What problem does it
solve? Remove this section if not applicable. -->

---

## ✅ I have completed the following steps:

* [ ] Run `make lint`
* [ ] Run `make test`
* [ ] Added tests (if applicable)

config-playground.toml

@@ -32,4 +32,4 @@ name = "custom"
 url = "http://0xac6e77dfe25ecd6110b8e780608cce0dab71fdd5ebea22a16c0205200f2f8e2e3ad3b71d3499c54ad14d6c21b41a37ae@localhost:5555"
 priority = 0
 use_ssz_for_submit = false
-use_gzip_for_submit = false
+use_gzip_for_submit = false

crates/rbuilder/src/backtest/fetch/flashbots_db.rs

@@ -30,6 +30,11 @@ impl RelayDB {
     pub fn new(pool: PgPool) -> Self {
         Self { pool }
     }
+
+    pub async fn from_url(url: String) -> eyre::Result<Self> {
+        let pool = PgPool::connect(&url).await?;
+        Ok(Self::new(pool))
+    }
 }
 
 impl RelayDB {

crates/rbuilder/src/backtest/fetch/mod.rs

@@ -18,7 +18,6 @@ use alloy_rpc_types::{Block, BlockId, BlockNumberOrTag, BlockTransactionsKind};
 use eyre::WrapErr;
 use flashbots_db::RelayDB;
 use futures::TryStreamExt;
-use sqlx::PgPool;
 use std::{
     collections::HashMap,
     path::PathBuf,
@@ -62,15 +61,13 @@ impl HistoricalDataFetcher {
     pub fn with_default_datasource(
         mut self,
         mempool_datadir: PathBuf,
-        flashbots_db: Option<PgPool>,
+        flashbots_db: Option<RelayDB>,
     ) -> eyre::Result<Self> {
         let mempool = Box::new(mempool::MempoolDumpsterDatasource::new(mempool_datadir)?);
         self.data_sources.push(mempool);
-
-        if let Some(db_pool) = flashbots_db {
-            let datasource = Box::new(RelayDB::new(db_pool));
-            self.data_sources.push(datasource);
-        }
+        if let Some(flashbots_db) = flashbots_db {
+            self.data_sources.push(Box::new(flashbots_db));
+        };
         Ok(self)
     }
 

crates/rbuilder/src/bin/backtest-fetch.rs

@@ -4,7 +4,7 @@
 use alloy_primitives::utils::format_ether;
 use clap::Parser;
 use rbuilder::{
-    backtest::{HistoricalDataFetcher, HistoricalDataStorage},
+    backtest::{fetch::flashbots_db::RelayDB, HistoricalDataFetcher, HistoricalDataStorage},
     live_builder::{base_config::load_config_toml_and_env, cli::LiveBuilderConfig, config::Config},
 };
 use std::{ffi::OsString, fs, path::PathBuf};
@@ -62,7 +62,12 @@ async fn main() -> eyre::Result<()> {
             let backtest_fetch_mempool_data_dir =
                 config.base_config().backtest_fetch_mempool_data_dir()?;
 
-            let db = config.base_config().flashbots_db().await?;
+            let db = if let Some(db) = config.base_config().flashbots_db.clone() {
+                Some(RelayDB::from_url(db.value()?).await?)
+            } else {
+                None
+            };
+
             let provider = config.base_config().eth_rpc_provider()?;
             let fetcher = HistoricalDataFetcher::new(
                 provider,

crates/rbuilder/src/live_builder/base_config.rs

@@ -23,7 +23,6 @@ use reth_provider::{
 };
 use serde::{Deserialize, Deserializer};
 use serde_with::{serde_as, DeserializeAs};
-use sqlx::PgPool;
 use std::{
     env::var,
     fs::read_to_string,
@@ -318,16 +317,6 @@ impl BaseConfig {
         Ok(HashSet::default())
     }
 
-    pub async fn flashbots_db(&self) -> eyre::Result<Option<PgPool>> {
-        if let Some(url) = &self.flashbots_db {
-            let url = url.value()?;
-            let pool = PgPool::connect(&url).await?;
-            Ok(Some(pool))
-        } else {
-            Ok(None)
-        }
-    }
-
     pub fn eth_rpc_provider(&self) -> eyre::Result<BoxedProvider> {
         Ok(http_provider(self.backtest_fetch_eth_rpc_url.parse()?))
     }