apollo_storage: split get_casm into two functions for separate location and data retrieval (#11283)

Author: nadin-Starkware

crates/apollo_storage/src/compiled_class.rs

@@ -73,6 +73,13 @@ pub trait CasmStorageReader {
         &self,
         class_hash: &ClassHash,
     ) -> StorageResult<(Option<CasmContractClass>, Option<SierraContractClass>)>;
+
+    /// Returns the file location for a CASM with the given class hash.
+    fn get_casm_location(&self, class_hash: &ClassHash) -> StorageResult<Option<LocationInFile>>;
+
+    /// Returns the CASM from a specific file location.
+    fn get_casm_from_location(&self, location: LocationInFile) -> StorageResult<CasmContractClass>;
+
     /// The block marker is the first block number that doesn't exist yet.
     ///
     /// Note: If the last blocks don't contain any declared classes, the marker will point at the
@@ -92,9 +99,8 @@ where
 
 impl<Mode: TransactionKind> CasmStorageReader for StorageTxn<'_, Mode> {
     fn get_casm(&self, class_hash: &ClassHash) -> StorageResult<Option<CasmContractClass>> {
-        let casm_table = self.open_table(&self.tables.casms)?;
-        let casm_location = casm_table.get(&self.txn, class_hash)?;
-        casm_location.map(|location| self.file_handlers.get_casm_unchecked(location)).transpose()
+        let casm_location = self.get_casm_location(class_hash)?;
+        casm_location.map(|location| self.get_casm_from_location(location)).transpose()
     }
 
     fn get_casm_and_sierra(
@@ -104,6 +110,16 @@ impl<Mode: TransactionKind> CasmStorageReader for StorageTxn<'_, Mode> {
         Ok((self.get_casm(class_hash)?, self.get_class(class_hash)?))
     }
 
+    fn get_casm_location(&self, class_hash: &ClassHash) -> StorageResult<Option<LocationInFile>> {
+        let casm_table = self.open_table(&self.tables.casms)?;
+        let casm_location = casm_table.get(&self.txn, class_hash)?;
+        Ok(casm_location)
+    }
+
+    fn get_casm_from_location(&self, location: LocationInFile) -> StorageResult<CasmContractClass> {
+        self.file_handlers.get_casm_unchecked(location)
+    }
+
     fn get_compiled_class_marker(&self) -> StorageResult<BlockNumber> {
         let markers_table = self.open_table(&self.tables.markers)?;
         Ok(markers_table.get(&self.txn, &MarkerKind::CompiledClass)?.unwrap_or_default())