refactor(katana): fix feeder gateway types

crates/katana/feeder-gateway/src/client.rs

@@ -1,12 +1,16 @@
 use katana_primitives::block::{BlockIdOrTag, BlockTag};
 use katana_primitives::class::CasmContractClass;
 use katana_primitives::Felt;
+use reqwest::header::{HeaderMap, HeaderValue};
 use reqwest::{Client, StatusCode};
 use serde::de::DeserializeOwned;
 use serde::{Deserialize, Serialize};
 use url::Url;
 
-use crate::types::{ContractClass, StateUpdate, StateUpdateWithBlock};
+use crate::types::{Block, ContractClass, StateUpdate, StateUpdateWithBlock};
+
+/// HTTP request header for the feeder gateway API key. This allow bypassing the rate limiting.
+const X_THROTTLING_BYPASS: &str = "X-Throttling-Bypass";
 
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
@@ -16,15 +20,22 @@
     #[error(transparent)]
     Sequencer(SequencerError),
 
-    #[error("Request rate limited")]
+    #[error("failed to parse header value '{value}'")]
+    InvalidHeaderValue { value: String },
+
+    #[error("request rate limited")]
     RateLimited,
 }
 
 /// Client for interacting with the Starknet's feeder gateway.
 #[derive(Debug, Clone)]
 pub struct SequencerGateway {
+    /// The feeder gateway base URL.
     base_url: Url,
-    client: Client,
+    /// The HTTP client used to send the requests.
+    http_client: Client,
+    /// The API key used to bypass the rate limiting of the feeder gateway.
+    api_key: Option<String>,
 }
 
 impl SequencerGateway {
@@ -44,8 +55,19 @@
 
     /// Creates a new gateway client at the given base URL.
     pub fn new(base_url: Url) -> Self {
+        let api_key = None;
         let client = Client::new();
-        Self { client, base_url }
+        Self { http_client: client, base_url, api_key }
+    }
+
+    /// Sets the API key.
+    pub fn with_api_key(mut self, api_key: String) -> Self {
+        self.api_key = Some(api_key);
+        self
+    }
+
+    pub async fn get_block(&self, block_id: BlockIdOrTag) -> Result<Block, Error> {
+        self.feeder_gateway("get_block").with_block_id(block_id).send().await
     }
 
     pub async fn get_state_update(&self, block_id: BlockIdOrTag) -> Result<StateUpdate, Error> {
@@ -90,7 +112,7 @@
     fn feeder_gateway(&self, method: &str) -> RequestBuilder<'_> {
         let mut url = self.base_url.clone();
         url.path_segments_mut().expect("invalid base url").extend(["feeder_gateway", method]);
-        RequestBuilder { client: &self.client, url }
+        RequestBuilder { gateway_client: self, url }
     }
 }
 
@@ -103,7 +125,7 @@
 
 #[derive(Debug, Clone)]
 struct RequestBuilder<'a> {
-    client: &'a Client,
+    gateway_client: &'a SequencerGateway,
     url: Url,
 }
 
@@ -124,7 +146,17 @@
     }
 
     async fn send<T: DeserializeOwned>(self) -> Result<T, Error> {
-        let response = self.client.get(self.url).send().await?;
+        let mut headers = HeaderMap::new();
+
+        if let Some(key) = self.gateway_client.api_key.as_ref() {
+            let value = HeaderValue::from_str(key)
+                .map_err(|_| Error::InvalidHeaderValue { value: key.to_string() })?;
+            headers.insert(X_THROTTLING_BYPASS, value);
+        }
+
+        let response =
+            self.gateway_client.http_client.get(self.url).headers(headers).send().await?;
+
         if response.status() == StatusCode::TOO_MANY_REQUESTS {
             Err(Error::RateLimited)
         } else {
@@ -186,9 +218,9 @@
 
     #[test]
     fn request_block_id() {
-        let client = Client::new();
         let base_url = Url::parse("https://example.com/").unwrap();
-        let req = RequestBuilder { client: &client, url: base_url };
+        let client = SequencerGateway::new(base_url);
+        let req = client.feeder_gateway("test");
 
         // Test pending block
         let pending_url = req.clone().with_block_id(BlockIdOrTag::Tag(BlockTag::Pending)).url;
@@ -210,9 +242,9 @@
 
     #[test]
     fn multiple_query_params() {
-        let client = Client::new();
         let base_url = Url::parse("https://example.com/").unwrap();
-        let req = RequestBuilder { client: &client, url: base_url };
+        let client = SequencerGateway::new(base_url);
+        let req = client.feeder_gateway("test");
 
         let url = req
             .add_query_param("param1", "value1")
@@ -229,9 +261,9 @@
     #[test]
     #[ignore]
     fn request_block_id_overwrite() {
-        let client = Client::new();
         let base_url = Url::parse("https://example.com/").unwrap();
-        let req = RequestBuilder { client: &client, url: base_url };
+        let client = SequencerGateway::new(base_url);
+        let req = client.feeder_gateway("test");
 
         let url = req
             .clone()

crates/katana/feeder-gateway/src/types/mod.rs

@@ -16,6 +16,7 @@ use starknet::core::types::ResourcePrice;
 use starknet::providers::sequencer::models::BlockStatus;
 
 mod receipt;
+mod serde_utils;
 mod transaction;
 
 pub use receipt::*;

crates/katana/feeder-gateway/src/types/serde_utils.rs

@@ -0,0 +1,106 @@
+use serde::de::Visitor;
+use serde::Deserialize;
+
+pub fn deserialize_u64<'de, D>(deserializer: D) -> Result<u64, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    struct U64HexVisitor;
+
+    impl<'de> Visitor<'de> for U64HexVisitor {
+        type Value = u64;
+
+        fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            write!(formatter, "0x-prefix hex string or decimal number")
+        }
+
+        fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+        where
+            E: serde::de::Error,
+        {
+            if let Some(hex) = v.strip_prefix("0x") {
+                u64::from_str_radix(hex, 16).map_err(serde::de::Error::custom)
+            } else {
+                v.parse::<u64>().map_err(serde::de::Error::custom)
+            }
+        }
+    }
+
+    deserializer.deserialize_any(U64HexVisitor)
+}
+
+pub fn deserialize_u128<'de, D>(deserializer: D) -> Result<u128, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    struct U128HexVisitor;
+
+    impl<'de> Visitor<'de> for U128HexVisitor {
+        type Value = u128;
+
+        fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            write!(formatter, "0x-prefix hex string or decimal number")
+        }
+
+        fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+        where
+            E: serde::de::Error,
+        {
+            if let Some(hex) = v.strip_prefix("0x") {
+                u128::from_str_radix(hex, 16).map_err(serde::de::Error::custom)
+            } else {
+                v.parse::<u128>().map_err(serde::de::Error::custom)
+            }
+        }
+    }
+
+    deserializer.deserialize_any(U128HexVisitor)
+}
+
+pub fn deserialize_optional_u64<'de, D>(deserializer: D) -> Result<Option<u64>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    #[derive(Deserialize)]
+    #[serde(untagged)]
+    enum StringOrNum {
+        String(String),
+        Number(u64),
+    }
+
+    match Option::<StringOrNum>::deserialize(deserializer)? {
+        None => Ok(None),
+        Some(StringOrNum::Number(n)) => Ok(Some(n)),
+        Some(StringOrNum::String(s)) => {
+            if let Some(hex) = s.strip_prefix("0x") {
+                u64::from_str_radix(hex, 16).map(Some).map_err(serde::de::Error::custom)
+            } else {
+                s.parse().map(Some).map_err(serde::de::Error::custom)
+            }
+        }
+    }
+}
+
+pub fn deserialize_optional_u128<'de, D>(deserializer: D) -> Result<Option<u128>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    #[derive(Deserialize)]
+    #[serde(untagged)]
+    enum StringOrNum {
+        String(String),
+        Number(u128),
+    }
+
+    match Option::<StringOrNum>::deserialize(deserializer)? {
+        None => Ok(None),
+        Some(StringOrNum::Number(n)) => Ok(Some(n)),
+        Some(StringOrNum::String(s)) => {
+            if let Some(hex) = s.strip_prefix("0x") {
+                u128::from_str_radix(hex, 16).map(Some).map_err(serde::de::Error::custom)
+            } else {
+                s.parse().map(Some).map_err(serde::de::Error::custom)
+            }
+        }
+    }
+}