From 9dd21b1eed1a96e5028c9e03269c1454a2bc5075 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexander=20Thei=C3=9Fen?= <alex.theissen@me.com>
Date: Thu, 21 May 2020 12:16:04 +0200
Subject: [PATCH] Allow fee calculation to happen off-chain (#6076)
* Emit a PaymentParameters event once per block
This contains per-block paramaters need to calculate
fees off-chain.
* Add WeightToFee trait
* Add documentation to polynomial types
* Ignore pseudo code snippet for doc tests
* Use `Mul` implementation of Perbill
* Add tests for WeightToFeePolynomial
* Revert "Emit a PaymentParameters event once per block"
This reverts commit 6c4763baff3d8179676a3c1660fe7063fd56a8ca.
Co-authored-by: Gavin Wood <gavin@parity.io>
---
substrate/Cargo.lock | 46 +++---
.../bin/node-template/runtime/src/lib.rs | 7 +-
substrate/bin/node/executor/tests/basic.rs | 11 +-
substrate/bin/node/executor/tests/fees.rs | 11 +-
substrate/bin/node/runtime/src/impls.rs | 21 +--
substrate/bin/node/runtime/src/lib.rs | 11 +-
.../frame/balances/src/tests_composite.rs | 6 +-
substrate/frame/balances/src/tests_local.rs | 6 +-
substrate/frame/contracts/src/tests.rs | 4 +-
substrate/frame/executive/src/lib.rs | 12 +-
substrate/frame/support/Cargo.toml | 1 +
substrate/frame/support/src/weights.rs | 147 ++++++++++++++++++
.../frame/transaction-payment/Cargo.toml | 1 +
.../frame/transaction-payment/src/lib.rs | 36 +++--
14 files changed, 241 insertions(+), 79 deletions(-)
diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index 42a3c10cbfd..8bd5963b81c 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -749,7 +749,7 @@ dependencies = [
"log",
"regalloc",
"serde",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"target-lexicon",
"thiserror",
]
@@ -787,7 +787,7 @@ checksum = "e45f82e3446dd1ebb8c2c2f6a6b0e6cd6cd52965c7e5f7b1b35e9a9ace31ccde"
dependencies = [
"cranelift-codegen",
"log",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"target-lexicon",
]
@@ -1488,6 +1488,7 @@ dependencies = [
"paste",
"pretty_assertions",
"serde",
+ "smallvec 1.4.0",
"sp-arithmetic",
"sp-core",
"sp-inherents",
@@ -1875,7 +1876,7 @@ dependencies = [
"byteorder 1.3.4",
"fallible-iterator",
"indexmap",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"stable_deref_trait",
]
@@ -2495,7 +2496,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e763b2a9b500ba47948061d1e8bc3b5f03a8a1f067dbcf822a4d2c84d2b54a3a"
dependencies = [
"parity-util-mem",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
]
[[package]]
@@ -2524,7 +2525,7 @@ dependencies = [
"parking_lot 0.10.2",
"regex",
"rocksdb",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
]
[[package]]
@@ -2630,7 +2631,7 @@ dependencies = [
"parity-multiaddr 0.9.0",
"parking_lot 0.10.2",
"pin-project",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"wasm-timer",
]
@@ -2661,7 +2662,7 @@ dependencies = [
"ring",
"rw-stream-sink",
"sha2",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"thiserror",
"unsigned-varint",
"void",
@@ -2714,7 +2715,7 @@ dependencies = [
"prost",
"prost-build",
"rand 0.7.3",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
]
[[package]]
@@ -2737,7 +2738,7 @@ dependencies = [
"prost-build",
"rand 0.7.3",
"sha2",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"unsigned-varint",
"wasm-timer",
]
@@ -2754,7 +2755,7 @@ dependencies = [
"log",
"prost",
"prost-build",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"wasm-timer",
]
@@ -2778,7 +2779,7 @@ dependencies = [
"prost-build",
"rand 0.7.3",
"sha2",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"uint",
"unsigned-varint",
"void",
@@ -2802,7 +2803,7 @@ dependencies = [
"log",
"net2",
"rand 0.7.3",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"void",
"wasm-timer",
]
@@ -2931,7 +2932,7 @@ dependencies = [
"libp2p-core",
"log",
"rand 0.7.3",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"void",
"wasm-timer",
]
@@ -3299,7 +3300,7 @@ dependencies = [
"futures 0.3.4",
"log",
"pin-project",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"unsigned-varint",
]
@@ -4652,6 +4653,7 @@ dependencies = [
"pallet-balances",
"pallet-transaction-payment-rpc-runtime-api",
"parity-scale-codec",
+ "smallvec 1.4.0",
"sp-core",
"sp-io",
"sp-runtime",
@@ -4847,7 +4849,7 @@ dependencies = [
"parity-util-mem-derive",
"parking_lot 0.10.2",
"primitive-types",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"winapi 0.3.8",
]
@@ -4923,7 +4925,7 @@ dependencies = [
"cloudabi",
"libc",
"redox_syscall",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"winapi 0.3.8",
]
@@ -5614,7 +5616,7 @@ checksum = "b27b256b41986ac5141b37b8bbba85d314fbf546c182eb255af6720e07e4f804"
dependencies = [
"log",
"rustc-hash",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
]
[[package]]
@@ -7198,9 +7200,9 @@ dependencies = [
[[package]]
name = "smallvec"
-version = "1.3.0"
+version = "1.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05720e22615919e4734f6a99ceae50d00226c3c5aca406e102ebc33298214e0a"
+checksum = "c7cb5678e1615754284ec264d9bb5b4c27d2018577fd90ac0ceb578591ed5ee4"
[[package]]
name = "snow"
@@ -7247,7 +7249,7 @@ dependencies = [
"log",
"rand 0.7.3",
"sha1",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
"static_assertions",
"thiserror",
]
@@ -8973,7 +8975,7 @@ dependencies = [
"hashbrown",
"log",
"rustc-hex",
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
]
[[package]]
@@ -9077,7 +9079,7 @@ version = "0.1.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5479532badd04e128284890390c1e876ef7a993d0570b3597ae43dfa1d59afa4"
dependencies = [
- "smallvec 1.3.0",
+ "smallvec 1.4.0",
]
[[package]]
diff --git a/substrate/bin/node-template/runtime/src/lib.rs b/substrate/bin/node-template/runtime/src/lib.rs
index 2037f7bb77f..55fa4cd4aa7 100644
--- a/substrate/bin/node-template/runtime/src/lib.rs
+++ b/substrate/bin/node-template/runtime/src/lib.rs
@@ -15,8 +15,7 @@ use sp_runtime::{
transaction_validity::{TransactionValidity, TransactionSource},
};
use sp_runtime::traits::{
- BlakeTwo256, Block as BlockT, IdentityLookup, Verify, ConvertInto, IdentifyAccount, NumberFor,
- Saturating,
+ BlakeTwo256, Block as BlockT, IdentityLookup, Verify, IdentifyAccount, NumberFor, Saturating,
};
use sp_api::impl_runtime_apis;
use sp_consensus_aura::sr25519::AuthorityId as AuraId;
@@ -36,7 +35,7 @@ pub use frame_support::{
construct_runtime, parameter_types, StorageValue,
traits::{KeyOwnerProofSystem, Randomness},
weights::{
- Weight,
+ Weight, IdentityFee,
constants::{BlockExecutionWeight, ExtrinsicBaseWeight, RocksDbWeight, WEIGHT_PER_SECOND},
},
};
@@ -244,7 +243,7 @@ impl transaction_payment::Trait for Runtime {
type Currency = balances::Module<Runtime>;
type OnTransactionPayment = ();
type TransactionByteFee = TransactionByteFee;
- type WeightToFee = ConvertInto;
+ type WeightToFee = IdentityFee<Balance>;
type FeeMultiplierUpdate = ();
}
diff --git a/substrate/bin/node/executor/tests/basic.rs b/substrate/bin/node/executor/tests/basic.rs
index 9350c3546ff..857f438e1c1 100644
--- a/substrate/bin/node/executor/tests/basic.rs
+++ b/substrate/bin/node/executor/tests/basic.rs
@@ -19,12 +19,15 @@ use codec::{Encode, Decode, Joiner};
use frame_support::{
StorageValue, StorageMap,
traits::Currency,
- weights::{GetDispatchInfo, DispatchInfo, DispatchClass, constants::ExtrinsicBaseWeight},
+ weights::{
+ GetDispatchInfo, DispatchInfo, DispatchClass, constants::ExtrinsicBaseWeight,
+ WeightToFeePolynomial,
+ },
};
use sp_core::{NeverNativeValue, traits::Externalities, storage::well_known_keys};
use sp_runtime::{
ApplyExtrinsicResult, Fixed128,
- traits::{Hash as HashT, Convert},
+ traits::Hash as HashT,
transaction_validity::InvalidTransaction,
};
use pallet_contracts::ContractAddressFor;
@@ -54,9 +57,9 @@ fn transfer_fee<E: Encode>(extrinsic: &E, fee_multiplier: Fixed128) -> Balance {
let length_fee = TransactionByteFee::get() * (extrinsic.encode().len() as Balance);
let base_weight = ExtrinsicBaseWeight::get();
- let base_fee = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::convert(base_weight);
+ let base_fee = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::calc(&base_weight);
let weight = default_transfer_call().get_dispatch_info().weight;
- let weight_fee = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::convert(weight);
+ let weight_fee = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::calc(&weight);
base_fee + fee_multiplier.saturated_multiply_accumulate(length_fee + weight_fee)
}
diff --git a/substrate/bin/node/executor/tests/fees.rs b/substrate/bin/node/executor/tests/fees.rs
index 0e55f781e78..c4c3ca0bfc6 100644
--- a/substrate/bin/node/executor/tests/fees.rs
+++ b/substrate/bin/node/executor/tests/fees.rs
@@ -19,16 +19,15 @@ use codec::{Encode, Joiner};
use frame_support::{
StorageValue, StorageMap,
traits::Currency,
- weights::{GetDispatchInfo, constants::ExtrinsicBaseWeight},
+ weights::{GetDispatchInfo, constants::ExtrinsicBaseWeight, IdentityFee, WeightToFeePolynomial},
};
use sp_core::NeverNativeValue;
-use sp_runtime::{Fixed128, Perbill, traits::Convert};
+use sp_runtime::{Fixed128, Perbill};
use node_runtime::{
CheckedExtrinsic, Call, Runtime, Balances, TransactionPayment,
- TransactionByteFee, WeightFeeCoefficient,
+ TransactionByteFee,
constants::currency::*,
};
-use node_runtime::impls::LinearWeightToFee;
use node_primitives::Balance;
use node_testing::keyring::*;
@@ -181,13 +180,13 @@ fn transaction_fee_is_correct_ultimate() {
let mut balance_alice = (100 - 69) * DOLLARS;
let base_weight = ExtrinsicBaseWeight::get();
- let base_fee = LinearWeightToFee::<WeightFeeCoefficient>::convert(base_weight);
+ let base_fee = IdentityFee::<Balance>::calc(&base_weight);
let length_fee = TransactionByteFee::get() * (xt.clone().encode().len() as Balance);
balance_alice -= length_fee;
let weight = default_transfer_call().get_dispatch_info().weight;
- let weight_fee = LinearWeightToFee::<WeightFeeCoefficient>::convert(weight);
+ let weight_fee = IdentityFee::<Balance>::calc(&weight);
// we know that weight to fee multiplier is effect-less in block 1.
// current weight of transfer = 200_000_000
diff --git a/substrate/bin/node/runtime/src/impls.rs b/substrate/bin/node/runtime/src/impls.rs
index ef994392b52..884bde08df3 100644
--- a/substrate/bin/node/runtime/src/impls.rs
+++ b/substrate/bin/node/runtime/src/impls.rs
@@ -21,7 +21,9 @@ use core::num::NonZeroI128;
use node_primitives::Balance;
use sp_runtime::traits::{Convert, Saturating};
use sp_runtime::{Fixed128, Perquintill};
-use frame_support::{traits::{OnUnbalanced, Currency, Get}, weights::Weight};
+use frame_support::{
+ traits::{OnUnbalanced, Currency, Get},
+};
use crate::{Balances, System, Authorship, MaximumBlockWeight, NegativeImbalance};
pub struct Author;
@@ -47,18 +49,6 @@ impl Convert<u128, Balance> for CurrencyToVoteHandler {
fn convert(x: u128) -> Balance { x * Self::factor() }
}
-/// Convert from weight to balance via a simple coefficient multiplication
-/// The associated type C encapsulates a constant in units of balance per weight
-pub struct LinearWeightToFee<C>(sp_std::marker::PhantomData<C>);
-
-impl<C: Get<Balance>> Convert<Weight, Balance> for LinearWeightToFee<C> {
- fn convert(w: Weight) -> Balance {
- // setting this to zero will disable the weight fee.
- let coefficient = C::get();
- Balance::from(w).saturating_mul(coefficient)
- }
-}
-
/// Update the given multiplier based on the following formula
///
/// diff = (previous_block_weight - target_weight)/max_weight
@@ -120,7 +110,7 @@ mod tests {
use sp_runtime::assert_eq_error_rate;
use crate::{MaximumBlockWeight, AvailableBlockRatio, Runtime};
use crate::{constants::currency::*, TransactionPayment, TargetBlockFullness};
- use frame_support::weights::Weight;
+ use frame_support::weights::{Weight, WeightToFeePolynomial};
use core::num::NonZeroI128;
fn max() -> Weight {
@@ -228,7 +218,8 @@ mod tests {
if fm == next { panic!("The fee should ever increase"); }
fm = next;
iterations += 1;
- let fee = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::convert(tx_weight);
+ let fee =
+ <Runtime as pallet_transaction_payment::Trait>::WeightToFee::calc(&tx_weight);
let adjusted_fee = fm.saturated_multiply_accumulate(fee);
println!(
"iteration {}, new fm = {:?}. Fee at this point is: {} units / {} millicents, \
diff --git a/substrate/bin/node/runtime/src/lib.rs b/substrate/bin/node/runtime/src/lib.rs
index eb8344d3e95..209e86e7470 100644
--- a/substrate/bin/node/runtime/src/lib.rs
+++ b/substrate/bin/node/runtime/src/lib.rs
@@ -26,7 +26,7 @@ use sp_std::prelude::*;
use frame_support::{
construct_runtime, parameter_types, debug,
weights::{
- Weight,
+ Weight, IdentityFee,
constants::{BlockExecutionWeight, ExtrinsicBaseWeight, RocksDbWeight, WEIGHT_PER_SECOND},
},
traits::{Currency, Imbalance, KeyOwnerProofSystem, OnUnbalanced, Randomness, LockIdentifier},
@@ -74,7 +74,7 @@ pub use pallet_staking::StakerStatus;
/// Implementations of some helper traits passed into runtime modules as associated types.
pub mod impls;
-use impls::{CurrencyToVoteHandler, Author, LinearWeightToFee, TargetedFeeAdjustment};
+use impls::{CurrencyToVoteHandler, Author, TargetedFeeAdjustment};
/// Constant values used within the runtime.
pub mod constants;
@@ -228,9 +228,6 @@ impl pallet_balances::Trait for Runtime {
parameter_types! {
pub const TransactionByteFee: Balance = 10 * MILLICENTS;
- // In the Substrate node, a weight of 10_000_000 (smallest non-zero weight)
- // is mapped to 10_000_000 units of fees, hence:
- pub const WeightFeeCoefficient: Balance = 1;
// for a sane configuration, this should always be less than `AvailableBlockRatio`.
pub const TargetBlockFullness: Perquintill = Perquintill::from_percent(25);
}
@@ -239,7 +236,9 @@ impl pallet_transaction_payment::Trait for Runtime {
type Currency = Balances;
type OnTransactionPayment = DealWithFees;
type TransactionByteFee = TransactionByteFee;
- type WeightToFee = LinearWeightToFee<WeightFeeCoefficient>;
+ // In the Substrate node, a weight of 10_000_000 (smallest non-zero weight)
+ // is mapped to 10_000_000 units of fees, hence:
+ type WeightToFee = IdentityFee<Balance>;
type FeeMultiplierUpdate = TargetedFeeAdjustment<TargetBlockFullness>;
}
diff --git a/substrate/frame/balances/src/tests_composite.rs b/substrate/frame/balances/src/tests_composite.rs
index 78cdc3838b2..7b9ec1f91ea 100644
--- a/substrate/frame/balances/src/tests_composite.rs
+++ b/substrate/frame/balances/src/tests_composite.rs
@@ -21,14 +21,14 @@
use sp_runtime::{
Perbill,
- traits::{ConvertInto, IdentityLookup},
+ traits::IdentityLookup,
testing::Header,
};
use sp_core::H256;
use sp_io;
use frame_support::{impl_outer_origin, parameter_types};
use frame_support::traits::Get;
-use frame_support::weights::{Weight, DispatchInfo};
+use frame_support::weights::{Weight, DispatchInfo, IdentityFee};
use std::cell::RefCell;
use crate::{GenesisConfig, Module, Trait, decl_tests, tests::CallWithDispatchInfo};
@@ -87,7 +87,7 @@ impl pallet_transaction_payment::Trait for Test {
type Currency = Module<Test>;
type OnTransactionPayment = ();
type TransactionByteFee = TransactionByteFee;
- type WeightToFee = ConvertInto;
+ type WeightToFee = IdentityFee<u64>;
type FeeMultiplierUpdate = ();
}
impl Trait for Test {
diff --git a/substrate/frame/balances/src/tests_local.rs b/substrate/frame/balances/src/tests_local.rs
index 4b0700748c8..9ff76839f4c 100644
--- a/substrate/frame/balances/src/tests_local.rs
+++ b/substrate/frame/balances/src/tests_local.rs
@@ -21,14 +21,14 @@
use sp_runtime::{
Perbill,
- traits::{ConvertInto, IdentityLookup},
+ traits::IdentityLookup,
testing::Header,
};
use sp_core::H256;
use sp_io;
use frame_support::{impl_outer_origin, parameter_types};
use frame_support::traits::{Get, StorageMapShim};
-use frame_support::weights::{Weight, DispatchInfo};
+use frame_support::weights::{Weight, DispatchInfo, IdentityFee};
use std::cell::RefCell;
use crate::{GenesisConfig, Module, Trait, decl_tests, tests::CallWithDispatchInfo};
@@ -87,7 +87,7 @@ impl pallet_transaction_payment::Trait for Test {
type Currency = Module<Test>;
type OnTransactionPayment = ();
type TransactionByteFee = TransactionByteFee;
- type WeightToFee = ConvertInto;
+ type WeightToFee = IdentityFee<u64>;
type FeeMultiplierUpdate = ();
}
impl Trait for Test {
diff --git a/substrate/frame/contracts/src/tests.rs b/substrate/frame/contracts/src/tests.rs
index 4dfaa8035ff..23c0417dac5 100644
--- a/substrate/frame/contracts/src/tests.rs
+++ b/substrate/frame/contracts/src/tests.rs
@@ -37,7 +37,7 @@ use frame_support::{
assert_ok, assert_err, assert_err_ignore_postinfo, impl_outer_dispatch, impl_outer_event,
impl_outer_origin, parameter_types,
storage::child, StorageMap, StorageValue, traits::{Currency, Get},
- weights::{DispatchInfo, DispatchClass, Weight, PostDispatchInfo, Pays},
+ weights::{DispatchInfo, DispatchClass, Weight, PostDispatchInfo, Pays, IdentityFee},
};
use std::{cell::RefCell, sync::atomic::{AtomicUsize, Ordering}};
use sp_core::storage::well_known_keys;
@@ -152,7 +152,7 @@ impl pallet_transaction_payment::Trait for Test {
type Currency = Balances;
type OnTransactionPayment = ();
type TransactionByteFee = TransactionByteFee;
- type WeightToFee = Test;
+ type WeightToFee = IdentityFee<BalanceOf<Self>>;
type FeeMultiplierUpdate = ();
}
diff --git a/substrate/frame/executive/src/lib.rs b/substrate/frame/executive/src/lib.rs
index 9ac323828d0..f7ac060a6ce 100644
--- a/substrate/frame/executive/src/lib.rs
+++ b/substrate/frame/executive/src/lib.rs
@@ -454,12 +454,12 @@ mod tests {
use sp_core::H256;
use sp_runtime::{
generic::Era, Perbill, DispatchError, testing::{Digest, Header, Block},
- traits::{Header as HeaderT, BlakeTwo256, IdentityLookup, Convert, ConvertInto},
+ traits::{Header as HeaderT, BlakeTwo256, IdentityLookup},
transaction_validity::{InvalidTransaction, UnknownTransaction, TransactionValidityError},
};
use frame_support::{
impl_outer_event, impl_outer_origin, parameter_types, impl_outer_dispatch,
- weights::{Weight, RuntimeDbWeight},
+ weights::{Weight, RuntimeDbWeight, IdentityFee, WeightToFeePolynomial},
traits::{Currency, LockIdentifier, LockableCurrency, WithdrawReasons, WithdrawReason},
};
use frame_system::{self as system, Call as SystemCall, ChainContext, LastRuntimeUpgradeInfo};
@@ -589,7 +589,7 @@ mod tests {
type Currency = Balances;
type OnTransactionPayment = ();
type TransactionByteFee = TransactionByteFee;
- type WeightToFee = ConvertInto;
+ type WeightToFee = IdentityFee<Balance>;
type FeeMultiplierUpdate = ();
}
impl custom::Trait for Runtime {}
@@ -675,7 +675,8 @@ mod tests {
}.assimilate_storage(&mut t).unwrap();
let xt = TestXt::new(Call::Balances(BalancesCall::transfer(2, 69)), sign_extra(1, 0, 0));
let weight = xt.get_dispatch_info().weight + <Runtime as frame_system::Trait>::ExtrinsicBaseWeight::get();
- let fee: Balance = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::convert(weight);
+ let fee: Balance
+ = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::calc(&weight);
let mut t = sp_io::TestExternalities::new(t);
t.execute_with(|| {
Executive::initialize_block(&Header::new(
@@ -871,7 +872,8 @@ mod tests {
);
let weight = xt.get_dispatch_info().weight
+ <Runtime as frame_system::Trait>::ExtrinsicBaseWeight::get();
- let fee: Balance = <Runtime as pallet_transaction_payment::Trait>::WeightToFee::convert(weight);
+ let fee: Balance =
+ <Runtime as pallet_transaction_payment::Trait>::WeightToFee::calc(&weight);
Executive::initialize_block(&Header::new(
1,
H256::default(),
diff --git a/substrate/frame/support/Cargo.toml b/substrate/frame/support/Cargo.toml
index 3213f0dfe4f..61363be2df6 100644
--- a/substrate/frame/support/Cargo.toml
+++ b/substrate/frame/support/Cargo.toml
@@ -29,6 +29,7 @@ once_cell = { version = "1", default-features = false, optional = true }
sp-state-machine = { version = "0.8.0-dev", optional = true, path = "../../primitives/state-machine" }
bitmask = { version = "0.5.0", default-features = false }
impl-trait-for-tuples = "0.1.3"
+smallvec = "1.4.0"
[dev-dependencies]
pretty_assertions = "0.6.1"
diff --git a/substrate/frame/support/src/weights.rs b/substrate/frame/support/src/weights.rs
index a0d150cbe93..771f908ecf7 100644
--- a/substrate/frame/support/src/weights.rs
+++ b/substrate/frame/support/src/weights.rs
@@ -135,6 +135,9 @@ use sp_runtime::{
generic::{CheckedExtrinsic, UncheckedExtrinsic},
};
use crate::dispatch::{DispatchErrorWithPostInfo, DispatchResultWithPostInfo, DispatchError};
+use sp_runtime::traits::SaturatedConversion;
+use sp_arithmetic::{Perbill, traits::{BaseArithmetic, Saturating}};
+use smallvec::{smallvec, SmallVec};
/// Re-export priority as type
pub use sp_runtime::transaction_validity::TransactionPriority;
@@ -530,6 +533,90 @@ impl RuntimeDbWeight {
}
}
+/// One coefficient and its position in the `WeightToFeePolynomial`.
+///
+/// One term of polynomial is calculated as:
+///
+/// ```ignore
+/// coeff_integer * x^(degree) + coeff_frac * x^(degree)
+/// ```
+///
+/// The `negative` value encodes whether the term is added or substracted from the
+/// overall polynomial result.
+#[derive(Clone, Encode, Decode)]
+pub struct WeightToFeeCoefficient<Balance> {
+ /// The integral part of the coefficient.
+ pub coeff_integer: Balance,
+ /// The fractional part of the coefficient.
+ pub coeff_frac: Perbill,
+ /// True iff the coefficient should be interpreted as negative.
+ pub negative: bool,
+ /// Degree/exponent of the term.
+ pub degree: u8,
+}
+
+/// A list of coefficients that represent one polynomial.
+pub type WeightToFeeCoefficients<T> = SmallVec<[WeightToFeeCoefficient<T>; 4]>;
+
+/// A trait that describes the weight to fee calculation as polynomial.
+///
+/// An implementor should only implement the `polynomial` function.
+pub trait WeightToFeePolynomial {
+ /// The type that is returned as result from polynomial evaluation.
+ type Balance: BaseArithmetic + From<u32> + Copy;
+
+ /// Returns a polynomial that describes the weight to fee conversion.
+ ///
+ /// This is the only function that should be manually implemented. Please note
+ /// that all calculation is done in the probably unsigned `Balance` type. This means
+ /// that the order of coefficients is important as putting the negative coefficients
+ /// first will most likely saturate the result to zero mid evaluation.
+ fn polynomial() -> WeightToFeeCoefficients<Self::Balance>;
+
+ /// Calculates the fee from the passed `weight` according to the `polynomial`.
+ ///
+ /// This should not be overriden in most circumstances. Calculation is done in the
+ /// `Balance` type and never overflows. All evaluation is saturating.
+ fn calc(weight: &Weight) -> Self::Balance {
+ Self::polynomial().iter().fold(Self::Balance::saturated_from(0u32), |mut acc, args| {
+ let w = Self::Balance::saturated_from(*weight).saturating_pow(args.degree.into());
+
+ // The sum could get negative. Therefore we only sum with the accumulator.
+ // The Perbill Mul implementation is non overflowing.
+ let frac = args.coeff_frac * w;
+ let integer = args.coeff_integer.saturating_mul(w);
+
+ if args.negative {
+ acc = acc.saturating_sub(frac);
+ acc = acc.saturating_sub(integer);
+ } else {
+ acc = acc.saturating_add(frac);
+ acc = acc.saturating_add(integer);
+ }
+
+ acc
+ })
+ }
+}
+
+/// Implementor of `WeightToFeePolynomial` that maps one unit of weight to one unit of fee.
+pub struct IdentityFee<T>(sp_std::marker::PhantomData<T>);
+
+impl<T> WeightToFeePolynomial for IdentityFee<T> where
+ T: BaseArithmetic + From<u32> + Copy
+{
+ type Balance = T;
+
+ fn polynomial() -> WeightToFeeCoefficients<Self::Balance> {
+ smallvec!(WeightToFeeCoefficient {
+ coeff_integer: 1u32.into(),
+ coeff_frac: Perbill::zero(),
+ negative: false,
+ degree: 1,
+ })
+ }
+}
+
#[cfg(test)]
#[allow(dead_code)]
mod tests {
@@ -651,4 +738,64 @@ mod tests {
1000
);
}
+
+ type Balance = u64;
+
+ // 0.5x^3 + 2.333x2 + 7x - 10_000
+ struct Poly;
+ impl WeightToFeePolynomial for Poly {
+ type Balance = Balance;
+
+ fn polynomial() -> WeightToFeeCoefficients<Self::Balance> {
+ smallvec![
+ WeightToFeeCoefficient {
+ coeff_integer: 0,
+ coeff_frac: Perbill::from_fraction(0.5),
+ negative: false,
+ degree: 3
+ },
+ WeightToFeeCoefficient {
+ coeff_integer: 2,
+ coeff_frac: Perbill::from_rational_approximation(1u32, 3u32),
+ negative: false,
+ degree: 2
+ },
+ WeightToFeeCoefficient {
+ coeff_integer: 7,
+ coeff_frac: Perbill::zero(),
+ negative: false,
+ degree: 1
+ },
+ WeightToFeeCoefficient {
+ coeff_integer: 10_000,
+ coeff_frac: Perbill::zero(),
+ negative: true,
+ degree: 0
+ },
+ ]
+ }
+ }
+
+ #[test]
+ fn polynomial_works() {
+ assert_eq!(Poly::calc(&100), 514033);
+ assert_eq!(Poly::calc(&10_123), 518917034928);
+ }
+
+ #[test]
+ fn polynomial_does_not_underflow() {
+ assert_eq!(Poly::calc(&0), 0);
+ }
+
+ #[test]
+ fn polynomial_does_not_overflow() {
+ assert_eq!(Poly::calc(&Weight::max_value()), Balance::max_value() - 10_000);
+ }
+
+ #[test]
+ fn identity_fee_works() {
+ assert_eq!(IdentityFee::<Balance>::calc(&0), 0);
+ assert_eq!(IdentityFee::<Balance>::calc(&50), 50);
+ assert_eq!(IdentityFee::<Balance>::calc(&Weight::max_value()), Balance::max_value());
+ }
}
diff --git a/substrate/frame/transaction-payment/Cargo.toml b/substrate/frame/transaction-payment/Cargo.toml
index 0f8b05c3ddd..56efe907f5e 100644
--- a/substrate/frame/transaction-payment/Cargo.toml
+++ b/substrate/frame/transaction-payment/Cargo.toml
@@ -18,6 +18,7 @@ sp-runtime = { version = "2.0.0-dev", default-features = false, path = "../../pr
frame-support = { version = "2.0.0-dev", default-features = false, path = "../support" }
frame-system = { version = "2.0.0-dev", default-features = false, path = "../system" }
pallet-transaction-payment-rpc-runtime-api = { version = "2.0.0-dev", default-features = false, path = "./rpc/runtime-api" }
+smallvec = "1.4.0"
[dev-dependencies]
sp-io = { version = "2.0.0-dev", path = "../../primitives/io" }
diff --git a/substrate/frame/transaction-payment/src/lib.rs b/substrate/frame/transaction-payment/src/lib.rs
index 17fe11db6c4..71ef8a56c2f 100644
--- a/substrate/frame/transaction-payment/src/lib.rs
+++ b/substrate/frame/transaction-payment/src/lib.rs
@@ -37,7 +37,10 @@ use codec::{Encode, Decode};
use frame_support::{
decl_storage, decl_module,
traits::{Currency, Get, OnUnbalanced, ExistenceRequirement, WithdrawReason, Imbalance},
- weights::{Weight, DispatchInfo, PostDispatchInfo, GetDispatchInfo, Pays},
+ weights::{
+ Weight, DispatchInfo, PostDispatchInfo, GetDispatchInfo, Pays, WeightToFeePolynomial,
+ WeightToFeeCoefficient,
+ },
dispatch::DispatchResult,
};
use sp_runtime::{
@@ -72,7 +75,7 @@ pub trait Trait: frame_system::Trait {
type TransactionByteFee: Get<BalanceOf<Self>>;
/// Convert a weight value into a deductible fee based on the currency type.
- type WeightToFee: Convert<Weight, BalanceOf<Self>>;
+ type WeightToFee: WeightToFeePolynomial<Balance=BalanceOf<Self>>;
/// Update the multiplier of the next block, based on the previous block's weight.
type FeeMultiplierUpdate: Convert<Multiplier, Multiplier>;
@@ -89,9 +92,13 @@ decl_module! {
/// The fee to be paid for making a transaction; the per-byte portion.
const TransactionByteFee: BalanceOf<T> = T::TransactionByteFee::get();
+ /// The polynomial that is applied in order to derive fee from weight.
+ const WeightToFee: Vec<WeightToFeeCoefficient<BalanceOf<T>>> =
+ T::WeightToFee::polynomial().to_vec();
+
fn on_finalize() {
NextFeeMultiplier::mutate(|fm| {
- *fm = T::FeeMultiplierUpdate::convert(*fm)
+ *fm = T::FeeMultiplierUpdate::convert(*fm);
});
}
}
@@ -183,7 +190,7 @@ impl<T: Trait> Module<T> {
// cap the weight to the maximum defined in runtime, otherwise it will be the
// `Bounded` maximum of its data type, which is not desired.
let capped_weight = weight.min(<T as frame_system::Trait>::MaximumBlockWeight::get());
- T::WeightToFee::convert(capped_weight)
+ T::WeightToFee::calc(&capped_weight)
}
}
@@ -318,7 +325,10 @@ mod tests {
use codec::Encode;
use frame_support::{
impl_outer_dispatch, impl_outer_origin, parameter_types,
- weights::{DispatchClass, DispatchInfo, PostDispatchInfo, GetDispatchInfo, Weight},
+ weights::{
+ DispatchClass, DispatchInfo, PostDispatchInfo, GetDispatchInfo, Weight,
+ WeightToFeePolynomial, WeightToFeeCoefficients, WeightToFeeCoefficient,
+ },
};
use pallet_balances::Call as BalancesCall;
use pallet_transaction_payment_rpc_runtime_api::RuntimeDispatchInfo;
@@ -329,6 +339,7 @@ mod tests {
Perbill,
};
use std::cell::RefCell;
+ use smallvec::smallvec;
const CALL: &<Runtime as frame_system::Trait>::Call =
&Call::Balances(BalancesCall::transfer(2, 69));
@@ -411,10 +422,17 @@ mod tests {
fn get() -> u64 { TRANSACTION_BYTE_FEE.with(|v| *v.borrow()) }
}
- pub struct WeightToFee(u64);
- impl Convert<Weight, u64> for WeightToFee {
- fn convert(t: Weight) -> u64 {
- WEIGHT_TO_FEE.with(|v| *v.borrow() * (t as u64))
+ pub struct WeightToFee;
+ impl WeightToFeePolynomial for WeightToFee {
+ type Balance = u64;
+
+ fn polynomial() -> WeightToFeeCoefficients<Self::Balance> {
+ smallvec![WeightToFeeCoefficient {
+ degree: 1,
+ coeff_frac: Perbill::zero(),
+ coeff_integer: WEIGHT_TO_FEE.with(|v| *v.borrow()),
+ negative: false,
+ }]
}
}
--
GitLab