chore: refactor fetcher to extend kona's fetcher instead of copying all of its logic

bin/client/justfile

@@ -73,10 +73,16 @@ run-client-native-against-devnet verbosity='' block_number='' rollup_config_path
 
   if [ -z "{{block_number}}" ]; then
     BLOCK_NUMBER=$(cast block finalized --json --rpc-url $L2_RPC | jq -r .number | cast 2d)
+    if [ $BLOCK_NUMBER -eq 0 ]; then
+      echo "No finalized blocks found on L2 chain. If devnet was just started, wait a bit and try again..."
+      echo "You can run the following command to check the latest finalized block."
+      echo "cast block finalized --json --rpc-url $L2_RPC | jq -r .number | cast 2d"
+      exit 1
+    fi
   else
     BLOCK_NUMBER={{block_number}}
   fi
-
+  set -x
   just run-client-native $BLOCK_NUMBER \
     $L1_RPC $L1_BEACON_RPC $L2_RPC $ROLLUP_NODE_RPC \
     $ROLLUP_CONFIG_PATH {{verbosity}}

bin/host/src/extended_fetcher/mod.rs

@@ -12,9 +12,13 @@ use std::sync::Arc;
 use tokio::sync::RwLock;
 use tracing::{error, info, trace, warn};
 
-/// The [Fetcher] struct is responsible for fetching preimages from a remote source.
+/// The [FetcherWithEigenDASupport] struct wraps and extends kona's [Fetcher] struct with the ability
+/// to fetch preimages from EigenDA.
+/// TODO: Kona is planning to change the fetcher interface to allow registering extra hints
+/// without needing a new type. We will probably want to switch when possible.
+/// See https://github.com/anton-rs/kona/issues/369
 #[derive(Debug)]
-pub struct ExtendedFetcher<KV>
+pub struct FetcherWithEigenDASupport<KV>
 where
     KV: KeyValueStore + ?Sized,
 {
@@ -25,10 +29,10 @@ where
     /// The eigenda provider
     eigenda_blob_provider: OnlineEigenDABlobProvider,
     /// The last hint that was received. [None] if no hint has been received yet.
-    last_hint: Option<String>,
+    last_eigenda_hint: Option<String>,
 }
 
-impl<KV> ExtendedFetcher<KV>
+impl<KV> FetcherWithEigenDASupport<KV>
 where
     KV: KeyValueStore + ?Sized,
 {
@@ -42,7 +46,7 @@ where
             fetcher,
             kv_store,
             eigenda_blob_provider,
-            last_hint: None,
+            last_eigenda_hint: None,
         }
     }
 
@@ -65,33 +69,41 @@ where
             fetcher,
             kv_store,
             eigenda_blob_provider,
-            last_hint: None,
+            last_eigenda_hint: None,
         }
     }
 
     /// Set the last hint to be received.
-    pub fn hint(&mut self, hint: &str) {
-        trace!(target: "fetcher", "Received hint: {hint}");
-        self.last_hint = Some(hint.to_string());
+    pub fn hint(&mut self, hint: &str) -> Result<()> {
+        trace!(target: "fetcher_with_eigenda_support", "Received hint: {hint}");
+        let (hint_type, _) = ExtendedHint::parse(hint)?.split();
+        // We route the hint to the right fetcher based on the hint type.
+        match hint_type {
+            ExtendedHintType::EigenDACommitment => {
+                self.last_eigenda_hint = Some(hint.to_string());
+            }
+            _ => {
+                self.fetcher.hint(hint);
+                // get_preimage will fetch from the underlying fetcher when last_eigenda_hint = None
+                self.last_eigenda_hint = None;
+            }
+        }
+        Ok(())
     }
 
-    /// Get the preimage for the given key.
-    /// TODO: there's probably a much nicer way to write this function.
-    /// Fetcher was not written with extensibility in mind, so we have to do this,
-    /// but there might be ways to change the Fetcher's API to make this easier (eg by making prefetch public).
+    /// Fetch the preimage for the given key. The requested is routed to the appropriate fetcher
+    /// based on the last hint that was received (see hint() above).
     /// ExtendedFetcher -> get_preimage_altda -> prefetch that only understands altda hints
     ///     \-> Fetcher -> get_preimage -> prefetch that understands all other hints
-    /// Both get_preimages just for loop until the preimage is found. Their hint coverage is mutually exclusive,
-    /// so only one of them will ever return, hence the tokio::select!.
     pub async fn get_preimage(&self, key: B256) -> Result<Vec<u8>> {
-        tokio::select! {
-            result = self.get_preimage_altda(key) => result,
-            result = self.fetcher.get_preimage(key) => result,
+        match self.last_eigenda_hint.as_ref() {
+            Some(hint) => self.get_preimage_altda(key, hint).await,
+            None => self.fetcher.get_preimage(key).await,
         }
     }
 
-    async fn get_preimage_altda(&self, key: B256) -> Result<Vec<u8>> {
-        trace!(target: "extended fetcher", "Pre-image requested. Key: {key}");
+    async fn get_preimage_altda(&self, key: B256, hint: &str) -> Result<Vec<u8>> {
+        trace!(target: "fetcher_with_eigenda_support", "Pre-image requested. Key: {key}");
 
         // Acquire a read lock on the key-value store.
         let kv_lock = self.kv_store.read().await;
@@ -101,12 +113,10 @@ where
         drop(kv_lock);
 
         // Use a loop to keep retrying the prefetch as long as the key is not found
-        while preimage.is_none() && self.last_hint.is_some() {
-            let hint = self.last_hint.as_ref().expect("Cannot be None");
-
+        while preimage.is_none() {
             if let Err(e) = self.prefetch(hint).await {
-                error!(target: "fetcher", "Failed to prefetch hint: {e}");
-                warn!(target: "fetcher", "Retrying hint fetch: {hint}");
+                error!(target: "fetcher_with_eigenda_support", "Failed to prefetch hint: {e}");
+                warn!(target: "fetcher_with_eigenda_support", "Retrying hint fetch: {hint}");
                 continue;
             }
 
@@ -119,22 +129,22 @@ where
 
     /// Fetch the preimage for the given hint and insert it into the key-value store.
     async fn prefetch(&self, hint: &str) -> Result<()> {
-        trace!(target: "fetcher", "prefetch: {hint}");
+        trace!(target: "fetcher_with_eigenda_support", "prefetch: {hint}");
         let hint = ExtendedHint::parse(hint)?;
         let (hint_type, hint_data) = hint.split();
-        trace!(target: "fetcher", "Fetching hint: {hint_type} {hint_data}");
+        trace!(target: "fetcher_with_eigenda_support", "Fetching hint: {hint_type} {hint_data}");
 
-        if hint_type == ExtendedHintType::AltDACommitment {
+        if hint_type == ExtendedHintType::EigenDACommitment {
             let cert = hint_data;
-            info!(target: "fetcher", "Fetching AltDACommitment cert: {:?}", cert);
+            info!(target: "fetcher_with_eigenda_support", "Fetching AltDACommitment cert: {:?}", cert);
             // Fetch the blob sidecar from the blob provider.
             let eigenda_blob = self
                 .eigenda_blob_provider
                 .fetch_eigenda_blob(&cert)
                 .await
                 .map_err(|e| anyhow!("Failed to fetch eigenda blob: {e}"))?;
 
-            info!(target: "fetcher", "eigenda_blob len {}", eigenda_blob.len());
+            info!(target: "fetcher_with_eigenda_support", "eigenda_blob len {}", eigenda_blob.len());
             // Acquire a lock on the key-value store and set the preimages.
             let mut kv_write_lock = self.kv_store.write().await;
 

bin/host/src/lib.rs

@@ -14,7 +14,7 @@ use kona_host::kv;
 
 use crate::eigenda_blobs::OnlineEigenDABlobProvider;
 use anyhow::{anyhow, Result};
-use extended_fetcher::ExtendedFetcher;
+use extended_fetcher::FetcherWithEigenDASupport;
 use kona_preimage::{
     BidirectionalChannel, HintReader, HintWriter, NativeChannel, OracleReader, OracleServer,
 };
@@ -46,7 +46,7 @@ pub async fn start_server_and_native_client(cfg: HostCli) -> Result<i32> {
         .await
         .map_err(|e| anyhow!("Failed to load eigenda blob provider configuration: {e}"))?;
 
-        Some(Arc::new(RwLock::new(ExtendedFetcher::new_from_parts(
+        Some(Arc::new(RwLock::new(FetcherWithEigenDASupport::new_from_parts(
             kv_store.clone(),
             l1_provider,
             blob_provider,
@@ -84,7 +84,7 @@ pub async fn start_server_and_native_client(cfg: HostCli) -> Result<i32> {
 
 pub async fn start_native_preimage_server<KV>(
     kv_store: Arc<RwLock<KV>>,
-    fetcher: Option<Arc<RwLock<ExtendedFetcher<KV>>>>,
+    fetcher: Option<Arc<RwLock<FetcherWithEigenDASupport<KV>>>>,
     hint_chan: NativeChannel,
     preimage_chan: NativeChannel,
 ) -> Result<()>

bin/host/src/preimage.rs

@@ -1,6 +1,6 @@
 //! Contains the implementations of the [HintRouter] and [PreimageFetcher] traits.]
 
-use crate::{extended_fetcher::ExtendedFetcher, kv::KeyValueStore};
+use crate::{extended_fetcher::FetcherWithEigenDASupport, kv::KeyValueStore};
 use async_trait::async_trait;
 use kona_preimage::{
     errors::{PreimageOracleError, PreimageOracleResult},
@@ -15,7 +15,7 @@ pub struct OnlinePreimageFetcher<KV>
 where
     KV: KeyValueStore + ?Sized,
 {
-    inner: Arc<RwLock<ExtendedFetcher<KV>>>,
+    inner: Arc<RwLock<FetcherWithEigenDASupport<KV>>>,
 }
 
 #[async_trait]
@@ -37,7 +37,7 @@ where
     KV: KeyValueStore + ?Sized,
 {
     /// Create a new [OnlinePreimageFetcher] from the given [ExtendedFetcher].
-    pub const fn new(fetcher: Arc<RwLock<ExtendedFetcher<KV>>>) -> Self {
+    pub const fn new(fetcher: Arc<RwLock<FetcherWithEigenDASupport<KV>>>) -> Self {
         Self { inner: fetcher }
     }
 }
@@ -80,7 +80,7 @@ pub struct OnlineHintRouter<KV>
 where
     KV: KeyValueStore + ?Sized,
 {
-    inner: Arc<RwLock<ExtendedFetcher<KV>>>,
+    inner: Arc<RwLock<FetcherWithEigenDASupport<KV>>>,
 }
 
 #[async_trait]
@@ -90,7 +90,9 @@ where
 {
     async fn route_hint(&self, hint: String) -> PreimageOracleResult<()> {
         let mut fetcher = self.inner.write().await;
-        fetcher.hint(&hint);
+        fetcher
+            .hint(&hint)
+            .map_err(|e| PreimageOracleError::Other(e.to_string()))?;
         Ok(())
     }
 }
@@ -100,18 +102,7 @@ where
     KV: KeyValueStore + ?Sized,
 {
     /// Create a new [OnlineHintRouter] from the given [ExtendedFetcher].
-    pub const fn new(fetcher: Arc<RwLock<ExtendedFetcher<KV>>>) -> Self {
+    pub const fn new(fetcher: Arc<RwLock<FetcherWithEigenDASupport<KV>>>) -> Self {
         Self { inner: fetcher }
     }
 }
-
-/// An [OfflineHintRouter] is a [HintRouter] that does nothing.
-#[derive(Debug)]
-pub struct OfflineHintRouter;
-
-#[async_trait]
-impl HintRouter for OfflineHintRouter {
-    async fn route_hint(&self, _hint: String) -> PreimageOracleResult<()> {
-        Ok(())
-    }
-}

bin/host/src/server.rs

@@ -1,13 +1,12 @@
 //! This module contains the [PreimageServer] struct and its implementation.
 
 use crate::{
-    extended_fetcher::ExtendedFetcher,
+    extended_fetcher::FetcherWithEigenDASupport,
     kv::KeyValueStore,
-    preimage::{
-        OfflineHintRouter, OfflinePreimageFetcher, OnlineHintRouter, OnlinePreimageFetcher,
-    },
+    preimage::{OfflinePreimageFetcher, OnlineHintRouter, OnlinePreimageFetcher},
 };
 use anyhow::{anyhow, Result};
+use kona_host::preimage::OfflineHintRouter;
 use kona_preimage::{
     errors::PreimageOracleError, HintReaderServer, HintRouter, PreimageFetcher,
     PreimageOracleServer,
@@ -33,7 +32,7 @@ where
     kv_store: Arc<RwLock<KV>>,
     /// The fetcher for fetching preimages from a remote source. If [None], the server will only
     /// serve preimages that are already in the key-value store.
-    fetcher: Option<Arc<RwLock<ExtendedFetcher<KV>>>>,
+    fetcher: Option<Arc<RwLock<FetcherWithEigenDASupport<KV>>>>,
 }
 
 impl<P, H, KV> PreimageServer<P, H, KV>
@@ -49,7 +48,7 @@ where
         oracle_server: P,
         hint_reader: H,
         kv_store: Arc<RwLock<KV>>,
-        fetcher: Option<Arc<RwLock<ExtendedFetcher<KV>>>>,
+        fetcher: Option<Arc<RwLock<FetcherWithEigenDASupport<KV>>>>,
     ) -> Self {
         Self {
             oracle_server,
@@ -80,7 +79,7 @@ where
     /// client.
     async fn start_oracle_server(
         kv_store: Arc<RwLock<KV>>,
-        fetcher: Option<Arc<RwLock<ExtendedFetcher<KV>>>>,
+        fetcher: Option<Arc<RwLock<FetcherWithEigenDASupport<KV>>>>,
         oracle_server: P,
     ) -> Result<()> {
         #[inline(always)]
@@ -121,7 +120,7 @@ where
     /// handler.
     async fn start_hint_router(
         hint_reader: H,
-        fetcher: Option<Arc<RwLock<ExtendedFetcher<KV>>>>,
+        fetcher: Option<Arc<RwLock<FetcherWithEigenDASupport<KV>>>>,
     ) -> Result<()> {
         #[inline(always)]
         async fn do_loop<R, H>(router: &R, server: &H) -> Result<()>

crates/proof/src/eigenda_provider.rs

@@ -29,7 +29,7 @@ impl<T: CommsClient + Sync + Send> EigenDABlobProvider for OracleEigenDAProvider
 
     async fn get_blob(&mut self, cert: &Bytes) -> Result<Bytes, Self::Error> {
         self.oracle
-            .write(&ExtendedHintType::AltDACommitment.encode_with(&[cert]))
+            .write(&ExtendedHintType::EigenDACommitment.encode_with(&[cert]))
             .await
             .map_err(OracleProviderError::Preimage)?;
         let data = self
@@ -45,14 +45,14 @@ impl<T: CommsClient + Sync + Send> EigenDABlobProvider for OracleEigenDAProvider
 
     async fn get_element(&mut self, cert: &Bytes, element: &Bytes) -> Result<Bytes, Self::Error> {
         self.oracle
-            .write(&ExtendedHintType::AltDACommitment.encode_with(&[cert]))
+            .write(&ExtendedHintType::EigenDACommitment.encode_with(&[cert]))
             .await
             .map_err(OracleProviderError::Preimage)?;
 
         let cert_point_key = Bytes::copy_from_slice(&[cert.to_vec(), element.to_vec()].concat());
 
         self.oracle
-            .write(&ExtendedHintType::AltDACommitment.encode_with(&[&cert_point_key]))
+            .write(&ExtendedHintType::EigenDACommitment.encode_with(&[&cert_point_key]))
             .await
             .map_err(OracleProviderError::Preimage)?;
         let data = self

crates/proof/src/hint.rs

@@ -52,7 +52,7 @@ impl ExtendedHint {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub enum ExtendedHintType {
     Original(HintType),
-    AltDACommitment,
+    EigenDACommitment,
 }
 
 impl ExtendedHintType {
@@ -68,7 +68,7 @@ impl TryFrom<&str> for ExtendedHintType {
 
     fn try_from(value: &str) -> Result<Self, Self::Error> {
         match value {
-            "altda-commitment" => Ok(Self::AltDACommitment),
+            "eigenda-commitment" => Ok(Self::EigenDACommitment),
             _ => Ok(Self::Original(HintType::try_from(value)?)),
         }
     }
@@ -77,7 +77,7 @@ impl TryFrom<&str> for ExtendedHintType {
 impl From<ExtendedHintType> for &str {
     fn from(value: ExtendedHintType) -> Self {
         match value {
-            ExtendedHintType::AltDACommitment => "altda-commitment",
+            ExtendedHintType::EigenDACommitment => "eigenda-commitment",
             ExtendedHintType::Original(hint_type) => hint_type.into(),
         }
     }