pallet_bridge_parachains/
weights_ext.rs

1// Copyright (C) Parity Technologies (UK) Ltd.
2// This file is part of Parity Bridges Common.
3
4// Parity Bridges Common is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// Parity Bridges Common is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
16
17//! Weight-related utilities.
18
19use crate::weights::{BridgeWeight, WeightInfo};
20
21use bp_runtime::Size;
22use frame_support::weights::{RuntimeDbWeight, Weight};
23
24/// Size of the regular parachain head.
25///
26/// It's not that we are expecting all parachain heads to share the same size or that we would
27/// reject all heads that have larger/lesser size. It is about head size that we use in benchmarks.
28/// Relayer would need to pay additional fee for extra bytes.
29///
30/// 384 is a bit larger (1.3 times) than the size of the randomly chosen Polkadot block.
31pub const DEFAULT_PARACHAIN_HEAD_SIZE: u32 = 384;
32
33/// Number of extra bytes (excluding size of storage value itself) of storage proof, built at
34/// some generic chain.
35pub const EXTRA_STORAGE_PROOF_SIZE: u32 = 1024;
36
37/// Extended weight info.
38pub trait WeightInfoExt: WeightInfo {
39	// Our configuration assumes that the runtime has special signed extensions used to:
40	//
41	// 1) boost priority of `submit_parachain_heads` transactions;
42	//
43	// 2) slash relayer if he submits an invalid transaction.
44	//
45	// We read and update storage values of other pallets (`pallet-bridge-relayers` and
46	// balances/assets pallet). So we need to add this weight to the weight of our call.
47	// Hence two following methods.
48
49	/// Extra weight that is added to the `submit_finality_proof` call weight by signed extensions
50	/// that are declared at runtime level.
51	fn submit_parachain_heads_overhead_from_runtime() -> Weight;
52
53	/// Storage proof overhead, that is included in every storage proof.
54	///
55	/// The relayer would pay some extra fee for additional proof bytes, since they mean
56	/// more hashing operations.
57	fn expected_extra_storage_proof_size() -> u32;
58
59	/// Weight of the parachain heads delivery extrinsic.
60	fn submit_parachain_heads_weight(
61		db_weight: RuntimeDbWeight,
62		proof: &impl Size,
63		parachains_count: u32,
64	) -> Weight {
65		// weight of the `submit_parachain_heads` with exactly `parachains_count` parachain
66		// heads of the default size (`DEFAULT_PARACHAIN_HEAD_SIZE`)
67		let base_weight = Self::submit_parachain_heads_with_n_parachains(parachains_count);
68
69		// overhead because of extra storage proof bytes
70		let expected_proof_size = parachains_count
71			.saturating_mul(DEFAULT_PARACHAIN_HEAD_SIZE)
72			.saturating_add(Self::expected_extra_storage_proof_size());
73		let actual_proof_size = proof.size();
74		let proof_size_overhead = Self::storage_proof_size_overhead(
75			actual_proof_size.saturating_sub(expected_proof_size),
76		);
77
78		// potential pruning weight (refunded if hasn't happened)
79		let pruning_weight =
80			Self::parachain_head_pruning_weight(db_weight).saturating_mul(parachains_count as u64);
81
82		base_weight
83			.saturating_add(proof_size_overhead)
84			.saturating_add(pruning_weight)
85			.saturating_add(Self::submit_parachain_heads_overhead_from_runtime())
86	}
87
88	/// Returns weight of single parachain head storage update.
89	///
90	/// This weight only includes db write operations that happens if parachain head is actually
91	/// updated. All extra weights (weight of storage proof validation, additional checks, ...) is
92	/// not included.
93	fn parachain_head_storage_write_weight(db_weight: RuntimeDbWeight) -> Weight {
94		// it's just a couple of operations - we need to write the hash (`ImportedParaHashes`) and
95		// the head itself (`ImportedParaHeads`. Pruning is not included here
96		db_weight.writes(2)
97	}
98
99	/// Returns weight of single parachain head pruning.
100	fn parachain_head_pruning_weight(db_weight: RuntimeDbWeight) -> Weight {
101		// it's just one write operation, we don't want any benchmarks for that
102		db_weight.writes(1)
103	}
104
105	/// Returns weight that needs to be accounted when storage proof of given size is received.
106	fn storage_proof_size_overhead(extra_proof_bytes: u32) -> Weight {
107		let extra_byte_weight = (Self::submit_parachain_heads_with_16kb_proof() -
108			Self::submit_parachain_heads_with_1kb_proof()) /
109			(15 * 1024);
110		extra_byte_weight.saturating_mul(extra_proof_bytes as u64)
111	}
112}
113
114impl WeightInfoExt for () {
115	fn submit_parachain_heads_overhead_from_runtime() -> Weight {
116		Weight::zero()
117	}
118
119	fn expected_extra_storage_proof_size() -> u32 {
120		EXTRA_STORAGE_PROOF_SIZE
121	}
122}
123
124impl<T: frame_system::Config> WeightInfoExt for BridgeWeight<T> {
125	fn submit_parachain_heads_overhead_from_runtime() -> Weight {
126		Weight::zero()
127	}
128
129	fn expected_extra_storage_proof_size() -> u32 {
130		EXTRA_STORAGE_PROOF_SIZE
131	}
132}
pallet_bridge_parachains/weights_ext.rs

pallet_bridge_parachains/
weights_ext.rs
