Introduce new storage type: prefixed map

srml/metadata/src/lib.rs

@@ -278,6 +278,15 @@ pub enum StorageHasher {
 	Twox64Concat,
 }
 
+/// The kind of map for a map storage entry type.
+#[derive(Clone, PartialEq, Eq, Encode, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize))]
+pub enum StorageMapKind {
+	Map,
+	LinkedMap,
+	PrefixedMap,
+}
+
 /// A storage entry type.
 #[derive(Clone, PartialEq, Eq, Encode, RuntimeDebug)]
 #[cfg_attr(feature = "std", derive(Decode, Serialize))]
@@ -287,7 +296,7 @@ pub enum StorageEntryType {
 		hasher: StorageHasher,
 		key: DecodeDifferentStr,
 		value: DecodeDifferentStr,
-		is_linked: bool,
+		kind: StorageMapKind,
 	},
 	DoubleMap {
 		hasher: StorageHasher,
@@ -342,8 +351,10 @@ pub enum RuntimeMetadata {
 	V6(RuntimeMetadataDeprecated),
 	/// Version 7 for runtime metadata. No longer used.
 	V7(RuntimeMetadataDeprecated),
-	/// Version 8 for runtime metadata.
-	V8(RuntimeMetadataV8),
+	/// Version 8 for runtime metadata. No longer used.
+	V8(RuntimeMetadataDeprecated),
+	/// Version 9 for runtime metadata.
+	V9(RuntimeMetadataV9),
 }
 
 /// Enum that should fail.
@@ -367,12 +378,12 @@ impl Decode for RuntimeMetadataDeprecated {
 /// The metadata of a runtime.
 #[derive(Eq, Encode, PartialEq, RuntimeDebug)]
 #[cfg_attr(feature = "std", derive(Decode, Serialize))]
-pub struct RuntimeMetadataV8 {
+pub struct RuntimeMetadataV9 {
 	pub modules: DecodeDifferentArray<ModuleMetadata>,
 }
 
 /// The latest version of the metadata.
-pub type RuntimeMetadataLastVersion = RuntimeMetadataV8;
+pub type RuntimeMetadataLastVersion = RuntimeMetadataV9;
 
 /// All metadata about an runtime module.
 #[derive(Clone, PartialEq, Eq, Encode, RuntimeDebug)]
@@ -397,6 +408,6 @@ impl Into<primitives::OpaqueMetadata> for RuntimeMetadataPrefixed {
 
 impl Into<RuntimeMetadataPrefixed> for RuntimeMetadataLastVersion {
 	fn into(self) -> RuntimeMetadataPrefixed {
-		RuntimeMetadataPrefixed(META_RESERVED, RuntimeMetadata::V8(self))
+		RuntimeMetadataPrefixed(META_RESERVED, RuntimeMetadata::V9(self))
 	}
 }

srml/support/procedural/src/storage/genesis_config/builder_def.rs

@@ -66,7 +66,10 @@ impl BuilderDef {
 							<#storage_struct as #scrate::#storage_trait>::put::<&#value_type>(v);
 						}}
 					},
-					StorageLineTypeDef::Map(map) | StorageLineTypeDef::LinkedMap(map) => {
+					StorageLineTypeDef::Map(map)
+						| StorageLineTypeDef::LinkedMap(map)
+						| StorageLineTypeDef::PrefixedMap(map)
+					=> {
 						let key = &map.key;
 						quote!{{
 							let data: &#scrate::rstd::vec::Vec<(#key, #value_type)> = #data;

srml/support/procedural/src/storage/genesis_config/genesis_config_def.rs

@@ -91,7 +91,10 @@ impl GenesisConfigDef {
 
 			let typ = match &line.storage_type {
 				StorageLineTypeDef::Simple(_) => (*value_type).clone(),
-				StorageLineTypeDef::Map(map) | StorageLineTypeDef::LinkedMap(map) => {
+				StorageLineTypeDef::Map(map)
+					| StorageLineTypeDef::LinkedMap(map)
+					| StorageLineTypeDef::PrefixedMap(map)
+				=> {
 					let key = &map.key;
 					parse_quote!( Vec<(#key, #value_type)> )
 				},

srml/support/procedural/src/storage/getters.rs

@@ -40,7 +40,10 @@ pub fn impl_getters(scrate: &TokenStream, def: &DeclStorageDefExt) -> TokenStrea
 					}
 				}
 			},
-			StorageLineTypeDef::Map(map) | StorageLineTypeDef::LinkedMap(map) => {
+			StorageLineTypeDef::Map(map)
+				| StorageLineTypeDef::LinkedMap(map)
+				| StorageLineTypeDef::PrefixedMap(map)
+			=> {
 				let key = &map.key;
 				let value = &map.value;
 				quote!{

srml/support/procedural/src/storage/metadata.rs

@@ -41,7 +41,7 @@ fn storage_line_metadata_type(scrate: &TokenStream, line: &StorageLineDefExt) ->
 					hasher: #scrate::metadata::#hasher,
 					key: #scrate::metadata::DecodeDifferent::Encode(#key),
 					value: #scrate::metadata::DecodeDifferent::Encode(#value_type),
-					is_linked: false,
+					kind: #scrate::metadata::StorageMapKind::Map,
 				}
 			}
 		},
@@ -54,7 +54,20 @@ fn storage_line_metadata_type(scrate: &TokenStream, line: &StorageLineDefExt) ->
 					hasher: #scrate::metadata::#hasher,
 					key: #scrate::metadata::DecodeDifferent::Encode(#key),
 					value: #scrate::metadata::DecodeDifferent::Encode(#value_type),
-					is_linked: true,
+					kind: #scrate::metadata::StorageMapKind::LinkedMap,
+				}
+			}
+		},
+		StorageLineTypeDef::PrefixedMap(map) => {
+			let hasher = map.hasher.into_metadata();
+			let key = &map.key;
+			let key = clean_type_string(&quote!(#key).to_string());
+			quote!{
+				#scrate::metadata::StorageEntryType::Map {
+					hasher: #scrate::metadata::#hasher,
+					key: #scrate::metadata::DecodeDifferent::Encode(#key),
+					value: #scrate::metadata::DecodeDifferent::Encode(#value_type),
+					kind: #scrate::metadata::StorageMapKind::PrefixedMap,
 				}
 			}
 		},

srml/support/procedural/src/storage/mod.rs

@@ -239,6 +239,10 @@ impl StorageLineDefExt {
 				ext::type_contains_ident(&map.key, &def.module_runtime_generic)
 					|| ext::type_contains_ident(&map.value, &def.module_runtime_generic)
 			}
+			StorageLineTypeDef::PrefixedMap(map) => {
+				ext::type_contains_ident(&map.key, &def.module_runtime_generic)
+					|| ext::type_contains_ident(&map.value, &def.module_runtime_generic)
+			}
 			StorageLineTypeDef::DoubleMap(map) => {
 				ext::type_contains_ident(&map.key1, &def.module_runtime_generic)
 					|| ext::type_contains_ident(&map.key2, &def.module_runtime_generic)
@@ -250,6 +254,7 @@ impl StorageLineDefExt {
 			StorageLineTypeDef::Simple(value) => value.clone(),
 			StorageLineTypeDef::Map(map) => map.value.clone(),
 			StorageLineTypeDef::LinkedMap(map) => map.value.clone(),
+			StorageLineTypeDef::PrefixedMap(map) => map.value.clone(),
 			StorageLineTypeDef::DoubleMap(map) => map.value.clone(),
 		};
 		let is_option = ext::extract_type_option(&query_type).is_some();
@@ -295,6 +300,10 @@ impl StorageLineDefExt {
 				let key = &map.key;
 				quote!( StorageLinkedMap<#key, #value_type> )
 			},
+			StorageLineTypeDef::PrefixedMap(map) => {
+				let key = &map.key;
+				quote!( StoragePrefixedMap<#key, #value_type> )
+			},
 			StorageLineTypeDef::DoubleMap(map) => {
 				let key1 = &map.key1;
 				let key2 = &map.key2;
@@ -337,6 +346,7 @@ impl StorageLineDefExt {
 pub enum StorageLineTypeDef {
 	Map(MapDef),
 	LinkedMap(MapDef),
+	PrefixedMap(MapDef),
 	DoubleMap(DoubleMapDef),
 	Simple(syn::Type),
 }
@@ -418,6 +428,7 @@ pub fn decl_storage_impl(input: proc_macro::TokenStream) -> proc_macro::TokenStr
 			StorageValue as _,
 			StorageMap as _,
 			StorageLinkedMap as _,
+			StoragePrefixedMap as _,
 			StorageDoubleMap as _
 		};
 

srml/support/procedural/src/storage/parse.rs

@@ -28,6 +28,7 @@ mod keyword {
 	syn::custom_keyword!(get);
 	syn::custom_keyword!(map);
 	syn::custom_keyword!(linked_map);
+	syn::custom_keyword!(prefixed_map);
 	syn::custom_keyword!(double_map);
 	syn::custom_keyword!(blake2_256);
 	syn::custom_keyword!(blake2_128);
@@ -141,6 +142,7 @@ struct DeclStorageBuild {
 enum DeclStorageType {
 	Map(DeclStorageMap),
 	LinkedMap(DeclStorageLinkedMap),
+	PrefixedMap(DeclStoragePrefixedMap),
 	DoubleMap(DeclStorageDoubleMap),
 	Simple(syn::Type),
 }
@@ -163,6 +165,15 @@ struct DeclStorageLinkedMap {
 	pub value: syn::Type,
 }
 
+#[derive(Parse, ToTokens, Debug)]
+struct DeclStoragePrefixedMap {
+	pub map_keyword: keyword::prefixed_map,
+	pub hasher: ext::Opt<SetHasher>,
+	pub key: syn::Type,
+	pub ass_keyword: Token![=>],
+	pub value: syn::Type,
+}
+
 #[derive(Parse, ToTokens, Debug)]
 struct DeclStorageDoubleMap {
 	pub map_keyword: keyword::double_map,
@@ -375,6 +386,14 @@ fn parse_storage_line_defs(
 					value: map.value,
 				}
 			),
+			DeclStorageType::PrefixedMap(map) => super::StorageLineTypeDef::PrefixedMap(
+				super::MapDef {
+					hasher: map.hasher.inner.map(Into::into)
+						.unwrap_or(super::HasherKind::Blake2_256),
+					key: map.key,
+					value: map.value,
+				}
+			),
 			DeclStorageType::DoubleMap(map) => super::StorageLineTypeDef::DoubleMap(
 				super::DoubleMapDef {
 					hasher1: map.hasher.inner.map(Into::into)

srml/support/procedural/src/storage/storage_struct.rs

@@ -181,6 +181,29 @@ pub fn decl_and_impl(scrate: &TokenStream, def: &DeclStorageDefExt) -> TokenStre
 					}
 				)
 			},
+			StorageLineTypeDef::PrefixedMap(map) => {
+				let hasher = map.hasher.to_storage_hasher_struct();
+				quote!(
+					impl<#impl_trait> #scrate::#storage_generator_trait for #storage_struct
+					#optional_storage_where_clause
+					{
+						type Query = #query_type;
+						type Hasher = #scrate::#hasher;
+
+						fn prefix() -> &'static [u8] {
+							#final_prefix
+						}
+
+						fn from_optional_value_to_query(v: Option<#value_type>) -> Self::Query {
+							#from_optional_value_to_query
+						}
+
+						fn from_query_to_optional_value(v: Self::Query) -> Option<#value_type> {
+							#from_query_to_optional_value
+						}
+					}
+				)
+			},
 			StorageLineTypeDef::DoubleMap(map) => {
 				let hasher1 = map.hasher1.to_storage_hasher_struct();
 				let hasher2 = map.hasher2.to_storage_hasher_struct();

srml/support/src/lib.rs

@@ -66,7 +66,7 @@ pub mod error;
 pub mod traits;
 
 pub use self::hash::{Twox256, Twox128, Blake2_256, Blake2_128, Twox64Concat, Hashable};
-pub use self::storage::{StorageValue, StorageMap, StorageLinkedMap, StorageDoubleMap};
+pub use self::storage::{StorageValue, StorageMap, StorageLinkedMap, StoragePrefixedMap, StorageDoubleMap};
 pub use self::dispatch::{Parameter, Callable, IsSubType};
 pub use sr_primitives::{self, ConsensusEngineId, print, traits::Printable};
 
@@ -240,7 +240,7 @@ mod tests {
 	use codec::{Codec, EncodeLike};
 	use srml_metadata::{
 		DecodeDifferent, StorageEntryMetadata, StorageMetadata, StorageEntryType,
-		StorageEntryModifier, DefaultByteGetter, StorageHasher,
+		StorageEntryModifier, DefaultByteGetter, StorageHasher, StorageMapKind,
 	};
 	use rstd::marker::PhantomData;
 
@@ -470,7 +470,7 @@ mod tests {
 						hasher: StorageHasher::Twox64Concat,
 						key: DecodeDifferent::Encode("u32"),
 						value: DecodeDifferent::Encode("u64"),
-						is_linked: true,
+						kind: StorageMapKind::LinkedMap,
 					},
 					default: DecodeDifferent::Encode(
 						DefaultByteGetter(&__GetByteStructData(PhantomData::<Test>))
@@ -484,7 +484,7 @@ mod tests {
 						hasher: StorageHasher::Blake2_256,
 						key: DecodeDifferent::Encode("u32"),
 						value: DecodeDifferent::Encode("u32"),
-						is_linked: true,
+						kind: StorageMapKind::LinkedMap,
 					},
 					default: DecodeDifferent::Encode(
 						DefaultByteGetter(&__GetByteStructOptionLinkedMap(PhantomData::<Test>))
@@ -498,7 +498,7 @@ mod tests {
 						hasher: StorageHasher::Twox128,
 						key: DecodeDifferent::Encode("T::BlockNumber"),
 						value: DecodeDifferent::Encode("T::BlockNumber"),
-						is_linked: true
+						kind: StorageMapKind::LinkedMap
 					},
 					default: DecodeDifferent::Encode(
 						DefaultByteGetter(&__GetByteStructGenericData(PhantomData::<Test>))
@@ -512,7 +512,7 @@ mod tests {
 						hasher: StorageHasher::Blake2_256,
 						key: DecodeDifferent::Encode("T::BlockNumber"),
 						value: DecodeDifferent::Encode("T::BlockNumber"),
-						is_linked: true
+						kind: StorageMapKind::LinkedMap
 					},
 					default: DecodeDifferent::Encode(
 						DefaultByteGetter(&__GetByteStructGenericData2(PhantomData::<Test>))

srml/support/src/metadata.rs

@@ -17,7 +17,8 @@
 pub use srml_metadata::{
 	DecodeDifferent, FnEncode, RuntimeMetadata, ModuleMetadata, RuntimeMetadataLastVersion,
 	DefaultByteGetter, RuntimeMetadataPrefixed, StorageEntryMetadata, StorageMetadata,
-	StorageEntryType, StorageEntryModifier, DefaultByte, StorageHasher, ModuleErrorMetadata
+	StorageEntryType, StorageEntryModifier, DefaultByte, StorageHasher, ModuleErrorMetadata,
+	StorageMapKind
 };
 
 /// Implements the metadata support for the given runtime and all its modules.

srml/support/src/storage/generator/mod.rs

@@ -23,15 +23,16 @@
 
 mod linked_map;
 mod map;
+mod prefixed_map;
 mod double_map;
 mod value;
 
 pub use linked_map::{StorageLinkedMap, Enumerator, Linkage};
 pub use map::StorageMap;
+pub use prefixed_map::StoragePrefixedMap;
 pub use double_map::StorageDoubleMap;
 pub use value::StorageValue;
 
-
 #[cfg(test)]
 #[allow(dead_code)]
 mod tests {