Introduce a way for callers to get CCIP requests (#7)

Author: Antony1060

src/ccip.rs

@@ -11,6 +11,7 @@ use serde::Deserialize;
 use crate::errors::{CCIPFetchError, CCIPRequestError};
 use crate::utils::truncate_str;
 use crate::CCIPReadMiddlewareError;
+use crate::CCIPRequest;
 
 #[derive(Debug, Clone, Deserialize)]
 pub struct CCIPResponse {
@@ -98,22 +99,29 @@ pub async fn handle_ccip<M: Middleware>(
     tx: &TypedTransaction,
     calldata: &[u8],
     urls: Vec<String>,
-) -> Result<Bytes, CCIPReadMiddlewareError<M>> {
+) -> Result<(Bytes, Vec<CCIPRequest>), CCIPReadMiddlewareError<M>> {
     // If there are no URLs or the transaction's destination is empty, return an empty result
     if urls.is_empty() || tx.to().is_none() {
-        return Ok(Bytes::new());
+        return Ok((Bytes::new(), Vec::new()));
     }
 
     let urls = dedup_ord(&urls);
 
     // url —> [error_message]
     let mut errors: HashMap<String, Vec<String>> = HashMap::new();
 
+    let mut requests = Vec::new();
+
     for url in urls {
         let result = handle_ccip_raw(client, &url, sender, calldata).await;
+        requests.push(CCIPRequest {
+            url: url.clone(),
+            sender: *sender,
+            calldata: calldata.to_vec().into(),
+        });
 
         match result {
-            Ok(result) => return Ok(result),
+            Ok(result) => return Ok((result, requests)),
             Err(err) => {
                 errors.entry(url).or_default().push(err.to_string());
             }

src/lib.rs

@@ -2,9 +2,17 @@
 //!
 //! Provides an [ethers](https://docs.rs/ethers) compatible middleware for submitting
 pub use errors::CCIPReadMiddlewareError;
+use ethers_core::types::{Address, Bytes};
 pub use middleware::CCIPReadMiddleware;
 
 mod ccip;
 mod errors;
 mod middleware;
 pub mod utils;
+
+#[derive(Debug, Clone)]
+pub struct CCIPRequest {
+    pub url: String,
+    pub sender: Address,
+    pub calldata: Bytes,
+}

src/middleware.rs

@@ -19,7 +19,7 @@ use serde_json::Value;
 
 use crate::ccip::handle_ccip;
 use crate::utils::{build_reqwest, decode_bytes, dns_encode};
-use crate::CCIPReadMiddlewareError;
+use crate::{CCIPReadMiddlewareError, CCIPRequest};
 
 #[derive(Debug, Clone)]
 pub struct CCIPReadMiddleware<M> {
@@ -229,7 +229,8 @@ impl<M: Middleware> CCIPReadMiddleware<M> {
         transaction: &TypedTransaction,
         block_id: Option<BlockId>,
         attempt: u8,
-    ) -> Result<Bytes, CCIPReadMiddlewareError<M>> {
+        requests_buffer: &mut Vec<CCIPRequest>,
+    ) -> Result<(Bytes, Vec<CCIPRequest>), CCIPReadMiddlewareError<M>> {
         if attempt >= self.max_redirect_attempt {
             // may need more info
             return Err(CCIPReadMiddlewareError::MaxRedirectionError);
@@ -258,14 +259,14 @@ impl<M: Middleware> CCIPReadMiddleware<M> {
 
         if !matches!(block_id.unwrap_or(BlockId::Number(BlockNumber::Latest)), BlockId::Number(block) if block.is_latest())
         {
-            return Ok(result);
+            return Ok((result, requests_buffer.to_vec()));
         }
 
         if tx_sender.is_zero()
             || !result.starts_with(OFFCHAIN_LOOKUP_SELECTOR)
             || result.len() % 32 != 4
         {
-            return Ok(result);
+            return Ok((result, requests_buffer.to_vec()));
         }
 
         let output_types = vec![
@@ -292,7 +293,7 @@ impl<M: Middleware> CCIPReadMiddleware<M> {
             decoded_data.get(4),
         )
         else {
-            return Ok(result);
+            return Ok((result, requests_buffer.to_vec()));
         };
 
         let urls: Vec<String> = urls
@@ -310,9 +311,11 @@ impl<M: Middleware> CCIPReadMiddleware<M> {
             });
         }
 
-        let ccip_result =
+        let (ccip_result, requests) =
             handle_ccip(&self.reqwest_client, sender, transaction, calldata, urls).await?;
 
+        requests_buffer.extend(requests);
+
         if ccip_result.is_empty() {
             return Err(CCIPReadMiddlewareError::GatewayNotFoundError);
         }
@@ -327,7 +330,19 @@ impl<M: Middleware> CCIPReadMiddleware<M> {
             [callback_selector.clone(), encoded_data.clone()].concat(),
         ));
 
-        self._call(&callback_tx, block_id, attempt + 1).await
+        self._call(&callback_tx, block_id, attempt + 1, requests_buffer)
+            .await
+    }
+
+    /// Call the underlying middleware with the provided transaction and block,
+    /// returning both the result of the call and the CCIP requests made during the call
+    pub async fn call_ccip(
+        &self,
+        tx: &TypedTransaction,
+        block: Option<BlockId>,
+    ) -> Result<(Bytes, Vec<CCIPRequest>), CCIPReadMiddlewareError<M>> {
+        let mut requests = Vec::new();
+        self._call(tx, block, 0, &mut requests).await
     }
 }
 
@@ -353,7 +368,7 @@ where
         tx: &TypedTransaction,
         block: Option<BlockId>,
     ) -> Result<Bytes, Self::Error> {
-        return self._call(tx, block, 0).await;
+        Ok(self.call_ccip(tx, block).await?.0)
     }
 
     /**