add storage_double_map_key_prefix

examples/examples/get_storage.rs

@@ -16,6 +16,8 @@
 //! Very simple example that shows how to get some simple storage values.
 
 use frame_system::AccountInfo as GenericAccountInfo;
+use kitchensink_runtime::{AccountId, Runtime, Signature};
+use pallet_staking::Exposure;
 use sp_keyring::AccountKeyring;
 use substrate_api_client::{
 	ac_primitives::{Config, ExtrinsicSigner, SubstrateKitchensinkConfig},
@@ -83,4 +85,19 @@ async fn main() {
 			api.get_storage_by_key(storage_key.clone(), None).unwrap().unwrap();
 		println!("Retrieved data {:?}", storage_data);
 	}
+
+	let storage_double_map_key_prefix =
+		api.get_storage_double_map_key_prefix("Staking", "ErasStakers", 0).unwrap();
+	let double_map_storage_keys = api
+		.get_storage_keys_paged(Some(storage_double_map_key_prefix), max_keys, None, None)
+		.unwrap();
+
+	// Get the storage values that belong to the retrieved storage keys.
+	for storage_key in double_map_storage_keys.iter() {
+		println!("Retrieving value for key {:?}", storage_key);
+		// We're expecting account info as return value because we fetch added a prefix of "System" + "Account".
+		let storage_data: Exposure<AccountId, u128> =
+			api.get_storage_by_key(storage_key.clone(), None).unwrap().unwrap();
+		println!("Retrieved data {:?}", storage_data);
+	}
 }

node-api/src/metadata.rs

@@ -480,6 +480,17 @@ impl Metadata {
 		self.pallet(pallet)?.storage(storage_item)?.get_map_prefix(pallet)
 	}
 
+	pub fn storage_double_map_key_prefix<K: Encode>(
+		&self,
+		storage_prefix: &'static str,
+		storage_key_name: &'static str,
+		first: K,
+	) -> Result<StorageKey, MetadataError> {
+		self.pallet(storage_prefix)?
+			.storage(storage_key_name)?
+			.get_double_map_prefix::<K>(storage_prefix, first)
+	}
+
 	pub fn storage_double_map_key<K: Encode, Q: Encode>(
 		&self,
 		pallet: &'static str,

node-api/src/storage.rs

@@ -81,6 +81,11 @@ pub trait GetStorageTypes {
 	fn get_map<K: Encode>(&self, pallet_prefix: &str) -> Result<StorageMap<K>, MetadataError>;
 	fn get_map_prefix(&self, pallet_prefix: &str) -> Result<StorageKey, MetadataError>;
 	fn get_value(&self, pallet_prefix: &str) -> Result<StorageValue, MetadataError>;
+	fn get_double_map_prefix<K: Encode>(
+		&self,
+		pallet_prefix: &str,
+		key1: K,
+	) -> Result<StorageKey, MetadataError>;
 }
 
 impl GetStorageTypes for StorageEntryMetadata<PortableForm> {
@@ -145,6 +150,28 @@ impl GetStorageTypes for StorageEntryMetadata<PortableForm> {
 		}
 	}
 
+	fn get_double_map_prefix<K: Encode>(
+		&self,
+		pallet_prefix: &str,
+		key1: K,
+	) -> Result<StorageKey, MetadataError> {
+		match &self.ty {
+			StorageEntryType::Map { hashers, .. } => {
+				let module_prefix = pallet_prefix.as_bytes();
+				let storage_prefix = self.name.as_bytes();
+
+				let hasher1 = hashers.get(0).ok_or(MetadataError::StorageTypeError)?;
+
+				let mut bytes = sp_core::twox_128(module_prefix).to_vec();
+				bytes.extend(&sp_core::twox_128(storage_prefix)[..]);
+				bytes.extend(key_hash(&key1, hasher1));
+
+				Ok(StorageKey(bytes))
+			},
+			_ => Err(MetadataError::StorageTypeError),
+		}
+	}
+
 	fn get_value(&self, pallet_prefix: &str) -> Result<StorageValue, MetadataError> {
 		match &self.ty {
 			StorageEntryType::Plain { .. } => {

src/api/rpc_api/state.rs

@@ -58,6 +58,13 @@ pub trait GetStorage {
 		storage_item: &'static str,
 	) -> Result<StorageKey>;
 
+	async fn get_storage_double_map_key_prefix<K: Encode>(
+		&self,
+		storage_prefix: &'static str,
+		storage_key_name: &'static str,
+		first: K,
+	) -> Result<StorageKey>;
+
 	/// Retrieve the storage value from a double map for the given keys: `first_double_map_key` and `second_double_map_key`.
 	///
 	/// `at_block`: the state is queried at this block, set to `None` to get the state from the latest known block.
@@ -215,6 +222,17 @@ where
 		self.get_storage_by_key(storagekey, at_block).await
 	}
 
+	async fn get_storage_double_map_key_prefix<K: Encode>(
+		&self,
+		storage_prefix: &'static str,
+		storage_key_name: &'static str,
+		first: K,
+	) -> Result<StorageKey> {
+		self.metadata()
+			.storage_double_map_key_prefix(storage_prefix, storage_key_name, first)
+			.map_err(|e| e.into())
+	}
+
 	async fn get_storage_by_key<V: Decode>(
 		&self,
 		storage_key: StorageKey,

src/rpc/jsonrpsee_client/mod.rs

@@ -42,7 +42,7 @@ impl JsonrpseeClient {
 		Self::new("ws://127.0.0.1:9944")
 	}
 
-	async fn async_new(url: &str) -> Result<Self> {
+	pub async fn async_new(url: &str) -> Result<Self> {
 		let uri: Uri = url.parse().map_err(|e| Error::Client(Box::new(e)))?;
 		let (tx, rx) = WsTransportClientBuilder::default()
 			.build(uri)