Add metadata versions v8-v11 (#28)

* add v11 metadata

* add v10 metadata

* add v8/v9 metadata

* add version and legacy features

* add debug impl for legacy metadata

* any for features in RuntimeMetadata enum

* revert codec version change

* spaces

* add v8-v13 test metadata

* remove runtime version from meta bin name

* move test_data outside of src/

* add tests for v9-v14 metadata

* remove println

* Update frame-metadata/src/lib.rs

Co-authored-by: David <dvdplm@gmail.com>

* add docs per meta version upto 13

* cargo fmt

Co-authored-by: David <dvdplm@gmail.com>

frame-metadata/Cargo.toml

@@ -20,8 +20,13 @@ serde = { version = "1.0.101", optional = true, features = ["derive"] }
 
 [features]
 default = ["std", "v14"]
+v8  = []
+v9  = []
+v10 = []
+v11 = []
 v12 = []
 v13 = []
+legacy = ["v13", "v12", "v11", "v10", "v9", "v8"]
 v14 = ["scale-info"]
 std = [
 	"codec/std",

frame-metadata/src/lib.rs

@@ -34,9 +34,29 @@ cfg_if::cfg_if! {
 
 use codec::{Encode, Output};
 
-#[cfg(any(feature = "v12", feature = "v13"))]
+#[cfg(any(
+	feature = "v13",
+	feature = "v12",
+	feature = "v11",
+	feature = "v10",
+	feature = "v9",
+	feature = "v8",
+	feature = "legacy"
+))]
 pub mod decode_different;
 
+#[cfg(feature = "v8")]
+pub mod v8;
+
+#[cfg(feature = "v9")]
+pub mod v9;
+
+#[cfg(feature = "v10")]
+pub mod v10;
+
+#[cfg(feature = "v11")]
+pub mod v11;
+
 #[cfg(feature = "v12")]
 pub mod v12;
 
@@ -85,22 +105,38 @@ pub enum RuntimeMetadata {
 	V6(RuntimeMetadataDeprecated),
 	/// Version 7 for runtime metadata. No longer used.
 	V7(RuntimeMetadataDeprecated),
-	/// Version 8 for runtime metadata. No longer used.
-	V8(RuntimeMetadataDeprecated),
-	/// Version 9 for runtime metadata. No longer used.
-	V9(RuntimeMetadataDeprecated),
-	/// Version 10 for runtime metadata. No longer used.
-	V10(RuntimeMetadataDeprecated),
-	/// Version 11 for runtime metadata. No longer used.
-	V11(RuntimeMetadataDeprecated),
+	/// Version 8 for runtime metadata.
+	#[cfg(any(feature = "v8", feature = "legacy"))]
+	V8(v8::RuntimeMetadataV8),
+	/// Version 8 for runtime metadata, as raw encoded bytes.
+	#[cfg(not(feature = "v8"))]
+	V8(OpaqueMetadata),
+	/// Version 9 for runtime metadata.
+	#[cfg(any(feature = "v9", feature = "legacy"))]
+	V9(v9::RuntimeMetadataV9),
+	/// Version 9 for runtime metadata, as raw encoded bytes.
+	#[cfg(not(feature = "v9"))]
+	V9(OpaqueMetadata),
+	/// Version 10 for runtime metadata.
+	#[cfg(any(feature = "v10", feature = "legacy"))]
+	V10(v10::RuntimeMetadataV10),
+	/// Version 10 for runtime metadata, as raw encoded bytes.
+	#[cfg(not(feature = "v10"))]
+	V10(OpaqueMetadata),
+	/// Version 11 for runtime metadata.
+	#[cfg(any(feature = "v11", feature = "legacy"))]
+	V11(v11::RuntimeMetadataV11),
+	/// Version 11 for runtime metadata, as raw encoded bytes.
+	#[cfg(not(feature = "v11"))]
+	V11(OpaqueMetadata),
 	/// Version 12 for runtime metadata
-	#[cfg(feature = "v12")]
+	#[cfg(any(feature = "v12", feature = "legacy"))]
 	V12(v12::RuntimeMetadataV12),
 	/// Version 12 for runtime metadata, as raw encoded bytes.
 	#[cfg(not(feature = "v12"))]
 	V12(OpaqueMetadata),
 	/// Version 13 for runtime metadata.
-	#[cfg(feature = "v13")]
+	#[cfg(any(feature = "v13", feature = "legacy"))]
 	V13(v13::RuntimeMetadataV13),
 	/// Version 13 for runtime metadata, as raw encoded bytes.
 	#[cfg(not(feature = "v13"))]
@@ -135,3 +171,55 @@ impl Decode for RuntimeMetadataDeprecated {
 		Err("Decoding is not supported".into())
 	}
 }
+
+#[cfg(test)]
+mod test {
+	use super::*;
+	use std::fs;
+
+	fn load_metadata(version: u32) -> Vec<u8> {
+		fs::read(format!("./test_data/ksm_metadata_v{}.bin", version)).unwrap()
+	}
+
+	#[test]
+	fn should_decode_metadatav9() {
+		let meta: RuntimeMetadataPrefixed =
+			Decode::decode(&mut load_metadata(9).as_slice()).unwrap();
+		assert!(matches!(meta.1, RuntimeMetadata::V9(_)));
+	}
+
+	#[test]
+	fn should_decode_metadatav10() {
+		let meta: RuntimeMetadataPrefixed =
+			Decode::decode(&mut load_metadata(10).as_slice()).unwrap();
+		assert!(matches!(meta.1, RuntimeMetadata::V10(_)));
+	}
+
+	#[test]
+	fn should_decode_metadatav11() {
+		let meta: RuntimeMetadataPrefixed =
+			Decode::decode(&mut load_metadata(11).as_slice()).unwrap();
+		assert!(matches!(meta.1, RuntimeMetadata::V11(_)));
+	}
+
+	#[test]
+	fn should_decode_metadatav12() {
+		let meta: RuntimeMetadataPrefixed =
+			Decode::decode(&mut load_metadata(12).as_slice()).unwrap();
+		assert!(matches!(meta.1, RuntimeMetadata::V12(_)));
+	}
+
+	#[test]
+	fn should_decode_metadatav13() {
+		let meta: RuntimeMetadataPrefixed =
+			Decode::decode(&mut load_metadata(13).as_slice()).unwrap();
+		assert!(matches!(meta.1, RuntimeMetadata::V13(_)));
+	}
+
+	#[test]
+	fn should_decode_metadatav14() {
+		let meta: RuntimeMetadataPrefixed =
+			Decode::decode(&mut load_metadata(14).as_slice()).unwrap();
+		assert!(matches!(meta.1, RuntimeMetadata::V14(_)));
+	}
+}

frame-metadata/src/v10.rs

@@ -0,0 +1,235 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2018-2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Metadata Version 10. Networks like Kusama contain this version on-chain.
+//! Chains old enough to contain this metadata need a way to decode it.
+
+use crate::decode_different::*;
+use codec::{Encode, Output};
+
+cfg_if::cfg_if! {
+	if #[cfg(feature = "std")] {
+		use codec::Decode;
+		use serde::Serialize;
+
+		type StringBuf = String;
+	} else {
+		extern crate alloc;
+		use alloc::vec::Vec;
+
+		/// On `no_std` we do not support `Decode` and thus `StringBuf` is just `&'static str`.
+		/// So, if someone tries to decode this stuff on `no_std`, they will get a compilation error.
+		type StringBuf = &'static str;
+	}
+}
+
+/// Curent prefix of metadata
+pub const META_RESERVED: u32 = 0x6174656d; // 'meta' warn endianness
+
+/// All the metadata about a function.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct FunctionMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<FunctionArgumentMetadata>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a function argument.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct FunctionArgumentMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+}
+
+/// All the metadata about an outer event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct OuterEventMetadata {
+	pub name: DecodeDifferentStr,
+	pub events: DecodeDifferentArray<
+		(&'static str, FnEncode<&'static [EventMetadata]>),
+		(StringBuf, Vec<EventMetadata>),
+	>,
+}
+
+/// All the metadata about an event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct EventMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<&'static str, StringBuf>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one storage entry.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct StorageEntryMetadata {
+	pub name: DecodeDifferentStr,
+	pub modifier: StorageEntryModifier,
+	pub ty: StorageEntryType,
+	pub default: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one module constant.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ModuleConstantMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+	pub value: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a module error.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ErrorMetadata {
+	pub name: DecodeDifferentStr,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about errors in a module.
+pub trait ModuleErrorMetadata {
+	fn metadata() -> &'static [ErrorMetadata];
+}
+
+impl ModuleErrorMetadata for &'static str {
+	fn metadata() -> &'static [ErrorMetadata] {
+		&[]
+	}
+}
+
+/// A technical trait to store lazy initiated vec value as static dyn pointer.
+pub trait DefaultByte: Send + Sync {
+	fn default_byte(&self) -> Vec<u8>;
+}
+
+/// Wrapper over dyn pointer for accessing a cached once byte value.
+#[derive(Clone)]
+pub struct DefaultByteGetter(pub &'static dyn DefaultByte);
+
+/// Decode different for static lazy initiated byte value.
+pub type ByteGetter = DecodeDifferent<DefaultByteGetter, Vec<u8>>;
+
+impl Encode for DefaultByteGetter {
+	fn encode_to<W: Output + ?Sized>(&self, dest: &mut W) {
+		self.0.default_byte().encode_to(dest)
+	}
+}
+
+impl codec::EncodeLike for DefaultByteGetter {}
+
+impl PartialEq<DefaultByteGetter> for DefaultByteGetter {
+	fn eq(&self, other: &DefaultByteGetter) -> bool {
+		let left = self.0.default_byte();
+		let right = other.0.default_byte();
+		left.eq(&right)
+	}
+}
+
+impl Eq for DefaultByteGetter {}
+
+#[cfg(feature = "std")]
+impl serde::Serialize for DefaultByteGetter {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		self.0.default_byte().serialize(serializer)
+	}
+}
+
+impl core::fmt::Debug for DefaultByteGetter {
+	fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+		self.0.default_byte().fmt(f)
+	}
+}
+
+/// Hasher used by storage maps
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageHasher {
+	Blake2_128,
+	Blake2_256,
+	Blake2_128Concat,
+	Twox128,
+	Twox256,
+	Twox64Concat,
+}
+
+/// A storage entry type.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageEntryType {
+	Plain(DecodeDifferentStr),
+	Map {
+		hasher: StorageHasher,
+		key: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		is_linked: bool,
+	},
+	DoubleMap {
+		hasher: StorageHasher,
+		key1: DecodeDifferentStr,
+		key2: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		key2_hasher: StorageHasher,
+	},
+}
+
+/// A storage entry modifier.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageEntryModifier {
+	Optional,
+	Default,
+}
+
+/// All metadata of the storage.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct StorageMetadata {
+	/// The common prefix used by all storage entries.
+	pub prefix: DecodeDifferent<&'static str, StringBuf>,
+	pub entries: DecodeDifferent<&'static [StorageEntryMetadata], Vec<StorageEntryMetadata>>,
+}
+
+/// The metadata of a runtime.
+#[derive(Eq, Encode, PartialEq)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct RuntimeMetadataV10 {
+	pub modules: DecodeDifferentArray<ModuleMetadata>,
+}
+
+/// All metadata about an runtime module.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ModuleMetadata {
+	pub name: DecodeDifferentStr,
+	pub storage: Option<DecodeDifferent<FnEncode<StorageMetadata>, StorageMetadata>>,
+	pub calls: ODFnA<FunctionMetadata>,
+	pub event: ODFnA<EventMetadata>,
+	pub constants: DFnA<ModuleConstantMetadata>,
+	pub errors: DFnA<ErrorMetadata>,
+}
+
+type ODFnA<T> = Option<DFnA<T>>;
+type DFnA<T> = DecodeDifferent<FnEncode<&'static [T]>, Vec<T>>;

frame-metadata/src/v11.rs

@@ -0,0 +1,250 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2018-2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Metadata Version 11. Networks like Kusama contain this version on-chain.
+//! Chains old enough to contain this metadata need a way to decode it.
+
+use crate::decode_different::*;
+use codec::{Encode, Output};
+
+cfg_if::cfg_if! {
+	if #[cfg(feature = "std")] {
+		use codec::Decode;
+		use serde::Serialize;
+
+		type StringBuf = String;
+	} else {
+		extern crate alloc;
+		use alloc::vec::Vec;
+
+		/// On `no_std` we do not support `Decode` and thus `StringBuf` is just `&'static str`.
+		/// So, if someone tries to decode this stuff on `no_std`, they will get a compilation error.
+		type StringBuf = &'static str;
+	}
+}
+
+/// Current prefix of metadata
+pub const META_RESERVED: u32 = 0x6174656d; // 'meta' warn endianness
+
+/// All the metadata about a function.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct FunctionMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<FunctionArgumentMetadata>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a function argument.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct FunctionArgumentMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+}
+
+/// All the metadata about an outer event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct OuterEventMetadata {
+	pub name: DecodeDifferentStr,
+	pub events: DecodeDifferentArray<
+		(&'static str, FnEncode<&'static [EventMetadata]>),
+		(StringBuf, Vec<EventMetadata>),
+	>,
+}
+
+/// All the metadata about an event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct EventMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<&'static str, StringBuf>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one storage entry.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct StorageEntryMetadata {
+	pub name: DecodeDifferentStr,
+	pub modifier: StorageEntryModifier,
+	pub ty: StorageEntryType,
+	pub default: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one module constant.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ModuleConstantMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+	pub value: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a module error.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ErrorMetadata {
+	pub name: DecodeDifferentStr,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about errors in a module.
+pub trait ModuleErrorMetadata {
+	fn metadata() -> &'static [ErrorMetadata];
+}
+
+impl ModuleErrorMetadata for &'static str {
+	fn metadata() -> &'static [ErrorMetadata] {
+		&[]
+	}
+}
+
+/// A technical trait to store lazy initiated vec value as static dyn pointer.
+pub trait DefaultByte: Send + Sync {
+	fn default_byte(&self) -> Vec<u8>;
+}
+
+/// Wrapper over dyn pointer for accessing a cached once byte value.
+#[derive(Clone)]
+pub struct DefaultByteGetter(pub &'static dyn DefaultByte);
+
+/// Decode different for static lazy initiated byte value.
+pub type ByteGetter = DecodeDifferent<DefaultByteGetter, Vec<u8>>;
+
+impl Encode for DefaultByteGetter {
+	fn encode_to<W: Output + ?Sized>(&self, dest: &mut W) {
+		self.0.default_byte().encode_to(dest)
+	}
+}
+
+impl codec::EncodeLike for DefaultByteGetter {}
+
+impl PartialEq<DefaultByteGetter> for DefaultByteGetter {
+	fn eq(&self, other: &DefaultByteGetter) -> bool {
+		let left = self.0.default_byte();
+		let right = other.0.default_byte();
+		left.eq(&right)
+	}
+}
+
+impl Eq for DefaultByteGetter {}
+
+#[cfg(feature = "std")]
+impl serde::Serialize for DefaultByteGetter {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		self.0.default_byte().serialize(serializer)
+	}
+}
+
+impl core::fmt::Debug for DefaultByteGetter {
+	fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+		self.0.default_byte().fmt(f)
+	}
+}
+
+/// Hasher used by storage maps
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageHasher {
+	Blake2_128,
+	Blake2_256,
+	Blake2_128Concat,
+	Twox128,
+	Twox256,
+	Twox64Concat,
+	Identity,
+}
+
+/// A storage entry type.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageEntryType {
+	Plain(DecodeDifferentStr),
+	Map {
+		hasher: StorageHasher,
+		key: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		// is_linked flag previously, unused now to keep backwards compat
+		unused: bool,
+	},
+	DoubleMap {
+		hasher: StorageHasher,
+		key1: DecodeDifferentStr,
+		key2: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		key2_hasher: StorageHasher,
+	},
+}
+
+/// A storage entry modifier.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageEntryModifier {
+	Optional,
+	Default,
+}
+
+/// All metadata of the storage.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct StorageMetadata {
+	/// The common prefix used by all storage entries.
+	pub prefix: DecodeDifferent<&'static str, StringBuf>,
+	pub entries: DecodeDifferent<&'static [StorageEntryMetadata], Vec<StorageEntryMetadata>>,
+}
+
+/// Metadata of the extrinsic used by the runtime.
+#[derive(Eq, Encode, PartialEq)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ExtrinsicMetadata {
+	/// Extrinsic version.
+	pub version: u8,
+	/// The signed extensions in the order they appear in the extrinsic.
+	pub signed_extensions: Vec<DecodeDifferentStr>,
+}
+
+/// The metadata of a runtime.
+#[derive(Eq, Encode, PartialEq)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct RuntimeMetadataV11 {
+	/// Metadata of all the modules.
+	pub modules: DecodeDifferentArray<ModuleMetadata>,
+	/// Metadata of the extrinsic.
+	pub extrinsic: ExtrinsicMetadata,
+}
+
+/// All metadata about an runtime module.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ModuleMetadata {
+	pub name: DecodeDifferentStr,
+	pub storage: Option<DecodeDifferent<FnEncode<StorageMetadata>, StorageMetadata>>,
+	pub calls: ODFnA<FunctionMetadata>,
+	pub event: ODFnA<EventMetadata>,
+	pub constants: DFnA<ModuleConstantMetadata>,
+	pub errors: DFnA<ErrorMetadata>,
+}
+
+type ODFnA<T> = Option<DFnA<T>>;
+type DFnA<T> = DecodeDifferent<FnEncode<&'static [T]>, Vec<T>>;

frame-metadata/src/v12.rs

@@ -15,6 +15,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//! Metadata Version 12. Networks like Kusama contain this version on-chain.
+//! Chains old enough to contain this metadata need a way to decode it.
+
 use crate::decode_different::*;
 use codec::{Encode, Output};
 

frame-metadata/src/v13.rs

@@ -15,6 +15,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//! Metadata Version 13. Networks like Kusama contain this version on-chain.
+//! Chains old enough to contain this metadata need a way to decode it.
+
 use crate::decode_different::*;
 use codec::{Encode, Output};
 

frame-metadata/src/v8.rs

@@ -0,0 +1,237 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2018-2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Metadata Version 8. Chains old enough to contain this metadata need a way to decode it.
+
+use crate::decode_different::*;
+use codec::{Encode, Output};
+
+cfg_if::cfg_if! {
+	if #[cfg(feature = "std")] {
+		use codec::Decode;
+		use serde::Serialize;
+
+		type StringBuf = String;
+	} else {
+		extern crate alloc;
+		use alloc::vec::Vec;
+
+		/// On `no_std` we do not support `Decode` and thus `StringBuf` is just `&'static str`.
+		/// So, if someone tries to decode this stuff on `no_std`, they will get a compilation error.
+		type StringBuf = &'static str;
+	}
+}
+
+/// Curent prefix of metadata
+pub const META_RESERVED: u32 = 0x6174656d; // 'meta' warn endianness
+
+/// All the metadata about a function.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct FunctionMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<FunctionArgumentMetadata>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a function argument.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct FunctionArgumentMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+}
+
+/// All the metadata about an outer event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct OuterEventMetadata {
+	pub name: DecodeDifferentStr,
+	pub events: DecodeDifferentArray<
+		(&'static str, FnEncode<&'static [EventMetadata]>),
+		(StringBuf, Vec<EventMetadata>),
+	>,
+}
+
+/// All the metadata about an event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct EventMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<&'static str, StringBuf>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one storage entry.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct StorageEntryMetadata {
+	pub name: DecodeDifferentStr,
+	pub modifier: StorageEntryModifier,
+	pub ty: StorageEntryType,
+	pub default: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one module constant.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct ModuleConstantMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+	pub value: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a module error.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct ErrorMetadata {
+	pub name: DecodeDifferentStr,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about errors in a module.
+pub trait ModuleErrorMetadata {
+	fn metadata() -> &'static [ErrorMetadata];
+}
+
+impl ModuleErrorMetadata for &'static str {
+	fn metadata() -> &'static [ErrorMetadata] {
+		&[]
+	}
+}
+
+/// A technical trait to store lazy initiated vec value as static dyn pointer.
+pub trait DefaultByte: Send + Sync {
+	fn default_byte(&self) -> Vec<u8>;
+}
+
+/// Wrapper over dyn pointer for accessing a cached once byte value.
+#[derive(Clone)]
+pub struct DefaultByteGetter(pub &'static dyn DefaultByte);
+
+/// Decode different for static lazy initiated byte value.
+pub type ByteGetter = DecodeDifferent<DefaultByteGetter, Vec<u8>>;
+
+impl Encode for DefaultByteGetter {
+	fn encode_to<W: Output + ?Sized>(&self, dest: &mut W) {
+		self.0.default_byte().encode_to(dest)
+	}
+}
+
+impl codec::EncodeLike for DefaultByteGetter {}
+
+impl PartialEq<DefaultByteGetter> for DefaultByteGetter {
+	fn eq(&self, other: &DefaultByteGetter) -> bool {
+		let left = self.0.default_byte();
+		let right = other.0.default_byte();
+		left.eq(&right)
+	}
+}
+
+impl Eq for DefaultByteGetter {}
+
+#[cfg(feature = "std")]
+impl serde::Serialize for DefaultByteGetter {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		self.0.default_byte().serialize(serializer)
+	}
+}
+
+#[cfg(feature = "std")]
+impl std::fmt::Debug for DefaultByteGetter {
+	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+		self.0.default_byte().fmt(f)
+	}
+}
+
+/// Hasher used by storage maps
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub enum StorageHasher {
+	Blake2_128,
+	Blake2_256,
+	Twox128,
+	Twox256,
+	Twox64Concat,
+}
+
+/// A storage entry type.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub enum StorageEntryType {
+	Plain(DecodeDifferentStr),
+	Map {
+		hasher: StorageHasher,
+		key: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		is_linked: bool,
+	},
+	DoubleMap {
+		hasher: StorageHasher,
+		key1: DecodeDifferentStr,
+		key2: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		key2_hasher: StorageHasher,
+	},
+}
+
+/// A storage entry modifier.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub enum StorageEntryModifier {
+	Optional,
+	Default,
+}
+
+/// All metadata of the storage.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct StorageMetadata {
+	/// The common prefix used by all storage entries.
+	pub prefix: DecodeDifferent<&'static str, StringBuf>,
+	pub entries: DecodeDifferent<&'static [StorageEntryMetadata], Vec<StorageEntryMetadata>>,
+}
+
+/// The metadata of a runtime.
+#[derive(Eq, Encode, PartialEq)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct RuntimeMetadataV8 {
+	pub modules: DecodeDifferentArray<ModuleMetadata>,
+}
+
+/// The latest version of the metadata.
+pub type RuntimeMetadataLastVersion = RuntimeMetadataV8;
+
+/// All metadata about an runtime module.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
+pub struct ModuleMetadata {
+	pub name: DecodeDifferentStr,
+	pub storage: Option<DecodeDifferent<FnEncode<StorageMetadata>, StorageMetadata>>,
+	pub calls: ODFnA<FunctionMetadata>,
+	pub event: ODFnA<EventMetadata>,
+	pub constants: DFnA<ModuleConstantMetadata>,
+	pub errors: DFnA<ErrorMetadata>,
+}
+
+type ODFnA<T> = Option<DFnA<T>>;
+type DFnA<T> = DecodeDifferent<FnEncode<&'static [T]>, Vec<T>>;

frame-metadata/src/v9.rs

@@ -0,0 +1,235 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2018-2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Metadata Version 9. Networks like/as old as Kusama start here.
+//! Chains old enough to contain this metadata need a way to decode it.
+
+use crate::decode_different::*;
+use codec::{Encode, Output};
+
+cfg_if::cfg_if! {
+	if #[cfg(feature = "std")] {
+		use codec::Decode;
+		use serde::Serialize;
+
+		type StringBuf = String;
+	} else {
+		extern crate alloc;
+		use alloc::vec::Vec;
+
+		/// On `no_std` we do not support `Decode` and thus `StringBuf` is just `&'static str`.
+		/// So, if someone tries to decode this stuff on `no_std`, they will get a compilation error.
+		type StringBuf = &'static str;
+	}
+}
+
+/// Curent prefix of metadata
+pub const META_RESERVED: u32 = 0x6174656d; // 'meta' warn endianness
+
+/// All the metadata about a function.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct FunctionMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<FunctionArgumentMetadata>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a function argument.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct FunctionArgumentMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+}
+
+/// All the metadata about an outer event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize))]
+pub struct OuterEventMetadata {
+	pub name: DecodeDifferentStr,
+	pub events: DecodeDifferentArray<
+		(&'static str, FnEncode<&'static [EventMetadata]>),
+		(StringBuf, Vec<EventMetadata>),
+	>,
+}
+
+/// All the metadata about an event.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct EventMetadata {
+	pub name: DecodeDifferentStr,
+	pub arguments: DecodeDifferentArray<&'static str, StringBuf>,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one storage entry.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct StorageEntryMetadata {
+	pub name: DecodeDifferentStr,
+	pub modifier: StorageEntryModifier,
+	pub ty: StorageEntryType,
+	pub default: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about one module constant.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ModuleConstantMetadata {
+	pub name: DecodeDifferentStr,
+	pub ty: DecodeDifferentStr,
+	pub value: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about a module error.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ErrorMetadata {
+	pub name: DecodeDifferentStr,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
+}
+
+/// All the metadata about errors in a module.
+pub trait ModuleErrorMetadata {
+	fn metadata() -> &'static [ErrorMetadata];
+}
+
+impl ModuleErrorMetadata for &'static str {
+	fn metadata() -> &'static [ErrorMetadata] {
+		&[]
+	}
+}
+
+/// A technical trait to store lazy initiated vec value as static dyn pointer.
+pub trait DefaultByte: Send + Sync {
+	fn default_byte(&self) -> Vec<u8>;
+}
+
+/// Wrapper over dyn pointer for accessing a cached once byte value.
+#[derive(Clone)]
+pub struct DefaultByteGetter(pub &'static dyn DefaultByte);
+
+/// Decode different for static lazy initiated byte value.
+pub type ByteGetter = DecodeDifferent<DefaultByteGetter, Vec<u8>>;
+
+impl Encode for DefaultByteGetter {
+	fn encode_to<W: Output + ?Sized>(&self, dest: &mut W) {
+		self.0.default_byte().encode_to(dest)
+	}
+}
+
+impl codec::EncodeLike for DefaultByteGetter {}
+
+impl PartialEq<DefaultByteGetter> for DefaultByteGetter {
+	fn eq(&self, other: &DefaultByteGetter) -> bool {
+		let left = self.0.default_byte();
+		let right = other.0.default_byte();
+		left.eq(&right)
+	}
+}
+
+impl Eq for DefaultByteGetter {}
+
+#[cfg(feature = "std")]
+impl serde::Serialize for DefaultByteGetter {
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+	where
+		S: serde::Serializer,
+	{
+		self.0.default_byte().serialize(serializer)
+	}
+}
+
+impl core::fmt::Debug for DefaultByteGetter {
+	fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+		self.0.default_byte().fmt(f)
+	}
+}
+
+/// Hasher used by storage maps
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageHasher {
+	Blake2_128,
+	Blake2_256,
+	Blake2_128Concat,
+	Twox128,
+	Twox256,
+	Twox64Concat,
+}
+
+/// A storage entry type.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageEntryType {
+	Plain(DecodeDifferentStr),
+	Map {
+		hasher: StorageHasher,
+		key: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		is_linked: bool,
+	},
+	DoubleMap {
+		hasher: StorageHasher,
+		key1: DecodeDifferentStr,
+		key2: DecodeDifferentStr,
+		value: DecodeDifferentStr,
+		key2_hasher: StorageHasher,
+	},
+}
+
+/// A storage entry modifier.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub enum StorageEntryModifier {
+	Optional,
+	Default,
+}
+
+/// All metadata of the storage.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct StorageMetadata {
+	/// The common prefix used by all storage entries.
+	pub prefix: DecodeDifferent<&'static str, StringBuf>,
+	pub entries: DecodeDifferent<&'static [StorageEntryMetadata], Vec<StorageEntryMetadata>>,
+}
+
+/// The metadata of a runtime.
+#[derive(Eq, Encode, PartialEq)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct RuntimeMetadataV9 {
+	pub modules: DecodeDifferentArray<ModuleMetadata>,
+}
+
+/// All metadata about an runtime module.
+#[derive(Clone, PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Decode, Serialize, Debug))]
+pub struct ModuleMetadata {
+	pub name: DecodeDifferentStr,
+	pub storage: Option<DecodeDifferent<FnEncode<StorageMetadata>, StorageMetadata>>,
+	pub calls: ODFnA<FunctionMetadata>,
+	pub event: ODFnA<EventMetadata>,
+	pub constants: DFnA<ModuleConstantMetadata>,
+	pub errors: DFnA<ErrorMetadata>,
+}
+
+type ODFnA<T> = Option<DFnA<T>>;
+type DFnA<T> = DecodeDifferent<FnEncode<&'static [T]>, Vec<T>>;