WIP new storage APIs

core/src/blocks/extrinsics.rs

@@ -11,7 +11,6 @@ use crate::{
 };
 use alloc::sync::Arc;
 use alloc::vec::Vec;
-use core::ops::Deref;
 use frame_decode::extrinsics::Extrinsic;
 use scale_decode::DecodeAsType;
 use subxt_metadata::PalletMetadata;

historic/src/error.rs

@@ -295,6 +295,10 @@ pub enum StorageKeyError {
         index: usize,
         reason: scale_decode::Error,
     },
+    #[error("Could not decode values out of the storage key: {reason}")]
+    DecodeKeyValueError {
+        reason: frame_decode::storage::StorageKeyValueDecodeError
+    }
 }
 
 #[allow(missing_docs)]

historic/src/storage/storage_key.rs

@@ -3,7 +3,7 @@ use crate::{error::StorageKeyError, storage::storage_info::with_info};
 use scale_info_legacy::{LookupName, TypeRegistrySet};
 
 // This is part of our public interface.
-pub use frame_decode::storage::StorageHasher;
+pub use frame_decode::storage::{ StorageHasher, IntoDecodableValues };
 
 enum AnyStorageKeyInfo<'atblock> {
     Legacy(StorageKeyInfo<'atblock, LookupName, TypeRegistrySet<'atblock>>),
@@ -78,6 +78,23 @@ impl<'entry, 'atblock> StorageKey<'entry, 'atblock> {
         })
     }
 
+    /// Attempt to decode the values contained within this storage key to the `Target` type
+    /// provided. This type is typically a tuple of types which each implement [`scale_decode::DecodeAsType`]
+    /// and correspond to each of the key types present, in order.
+    pub fn decode<Target: IntoDecodableValues>(&self) -> Result<Target,StorageKeyError> {
+        with_key_info!(info = &self.info => {
+            let values = frame_decode::storage::decode_storage_key_values(
+                self.bytes, 
+                &info.info, 
+                info.resolver
+            ).map_err(|e| {
+                StorageKeyError::DecodeKeyValueError { reason: e }
+            })?;
+
+            Ok(values)
+        })
+    }
+
     /// Iterate over the parts of this storage key. Each part of a storage key corresponds to a
     /// single value that has been hashed.
     pub fn parts(&'_ self) -> impl ExactSizeIterator<Item = StorageKeyPart<'_, 'entry, 'atblock>> {