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

crates/starknet_l1_provider/src/l1_gas_price_provider.rs

@@ -0,0 +1,36 @@
+use std::collections::BTreeMap;
+
+use papyrus_config::dumping::{ser_param, SerializeConfig};
+use papyrus_config::{ParamPath, ParamPrivacyInput, SerializedParam};
+use serde::{Deserialize, Serialize};
+use starknet_api::block::{BlockNumber, BlockTimestamp};
+use thiserror::Error;
+use validator::Validate;
+
+// TODO(guyn): both these constants need to go into VersionedConstants.
+pub const MEAN_NUMBER_OF_BLOCKS: u64 = 300;
+pub const LAG_MARGIN_SECONDS: u32 = 60;
+
+// TODO(guyn, Gilda): 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<u64, 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),
+}
+
+// TODO(guyn): add the concrete implementation of the gas price provider client here.

crates/starknet_l1_provider/src/lib.rs

@@ -1,5 +1,6 @@
 pub mod bootstrapper;
 pub mod communication;
+pub mod l1_gas_price_provider;
 pub mod l1_provider;
 pub mod l1_scraper;
 pub mod soft_delete_index_map;