xcm_runtime_apis/
fees.rs

1// Copyright (C) Parity Technologies (UK) Ltd.
2// This file is part of Polkadot.
3// SPDX-License-Identifier: Apache-2.0
4
5// Licensed under the Apache License, Version 2.0 (the "License");
6// you may not use this file except in compliance with the License.
7// You may obtain a copy of the License at
8//
9// 	http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing, software
12// distributed under the License is distributed on an "AS IS" BASIS,
13// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14// See the License for the specific language governing permissions and
15// limitations under the License.
16
17//! Runtime API definition for getting XCM fees.
18
19use alloc::vec::Vec;
20use codec::{Decode, Encode};
21use frame_support::pallet_prelude::TypeInfo;
22use sp_weights::Weight;
23use xcm::{Version, VersionedAssetId, VersionedAssets, VersionedLocation, VersionedXcm};
24
25sp_api::decl_runtime_apis! {
26	/// A trait of XCM payment API.
27	///
28	/// API provides functionality for obtaining:
29	///
30	/// * the weight required to execute an XCM message,
31	/// * a list of acceptable `AssetId`s for message execution payment,
32	/// * the cost of the weight in the specified acceptable `AssetId`.
33	/// * the fees for an XCM message delivery.
34	///
35	/// To determine the execution weight of the calls required for
36	/// [`xcm::latest::Instruction::Transact`] instruction, `TransactionPaymentCallApi` can be used.
37	pub trait XcmPaymentApi {
38		/// Returns a list of acceptable payment assets.
39		///
40		/// # Arguments
41		///
42		/// * `xcm_version`: Version.
43		fn query_acceptable_payment_assets(xcm_version: Version) -> Result<Vec<VersionedAssetId>, Error>;
44
45		/// Returns a weight needed to execute a XCM.
46		///
47		/// # Arguments
48		///
49		/// * `message`: `VersionedXcm`.
50		fn query_xcm_weight(message: VersionedXcm<()>) -> Result<Weight, Error>;
51
52		/// Converts a weight into a fee for the specified `AssetId`.
53		///
54		/// # Arguments
55		///
56		/// * `weight`: convertible `Weight`.
57		/// * `asset`: `VersionedAssetId`.
58		fn query_weight_to_asset_fee(weight: Weight, asset: VersionedAssetId) -> Result<u128, Error>;
59
60		/// Get delivery fees for sending a specific `message` to a `destination`.
61		/// These always come in a specific asset, defined by the chain.
62		///
63		/// # Arguments
64		/// * `message`: The message that'll be sent, necessary because most delivery fees are based on the
65		///   size of the message.
66		/// * `destination`: The destination to send the message to. Different destinations may use
67		///   different senders that charge different fees.
68		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>) -> Result<VersionedAssets, Error>;
69	}
70}
71
72#[derive(Copy, Clone, Encode, Decode, Eq, PartialEq, Debug, TypeInfo)]
73pub enum Error {
74	/// An API part is unsupported.
75	#[codec(index = 0)]
76	Unimplemented,
77
78	/// Converting a versioned data structure from one version to another failed.
79	#[codec(index = 1)]
80	VersionedConversionFailed,
81
82	/// XCM message weight calculation failed.
83	#[codec(index = 2)]
84	WeightNotComputable,
85
86	/// XCM version not able to be handled.
87	#[codec(index = 3)]
88	UnhandledXcmVersion,
89
90	/// The given asset is not handled as a fee asset.
91	#[codec(index = 4)]
92	AssetNotFound,
93
94	/// Destination is known to be unroutable.
95	#[codec(index = 5)]
96	Unroutable,
97}
xcm_runtime_apis/fees.rs

xcm_runtime_apis/
fees.rs
