feat(starknet_l1_provider): add the trait interface for L1 gas price provider

Cargo.toml

@@ -41,6 +41,7 @@ members = [
   "crates/starknet_http_server",
   "crates/starknet_infra_utils",
   "crates/starknet_integration_tests",
+  "crates/starknet_l1_gas_price",
   "crates/starknet_l1_provider",
   "crates/starknet_l1_provider_types",
   "crates/starknet_mempool",

crates/starknet_l1_gas_price/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "starknet_l1_gas_price"
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+license.workspace = true
+
+[dependencies]
+starknet_api.workspace = true
+thiserror.workspace = true
+
+[lints]
+workspace = true

crates/starknet_l1_gas_price/src/l1_gas_price_provider.rs

@@ -0,0 +1,31 @@
+use starknet_api::block::{BlockNumber, BlockTimestamp};
+use thiserror::Error;
+
+// TODO(guyn): both these constants need to go into VersionedConstants.
+pub const MEAN_NUMBER_OF_BLOCKS: u64 = 300;
+pub const LAG_MARGIN_SECONDS: u64 = 60;
+
+// TODO(guyn, Gilad): consider moving this to starknet_l1_provider_types/lib.rs?
+// This is an interface that allows sharing the provider with the scraper across threads.
+pub trait L1GasPriceProviderClient: Send + Sync {
+    fn add_price_info(
+        &self,
+        height: BlockNumber,
+        timestamp: BlockTimestamp,
+        gas_price: u128,
+        data_gas_price: u128,
+    ) -> Result<(), L1GasPriceProviderError>;
+
+    fn get_price_info(
+        &self,
+        timestamp: BlockTimestamp,
+    ) -> Result<(u128, u128), L1GasPriceProviderError>;
+}
+
+#[derive(Clone, Debug, Error)]
+pub enum L1GasPriceProviderError {
+    #[error("Failed to add price info: {0}")]
+    AddPriceInfoError(String),
+    #[error("Failed to get price info: {0}")]
+    GetPriceInfoError(String),
+}

crates/starknet_l1_gas_price/src/lib.rs

@@ -0,0 +1 @@
+pub mod l1_gas_price_provider;