Better Parameterisation for Fee system (#3823)

* Better fee parameters

* Fix build

* Better runtime tests

* Price to Weight ratio as type parameter (#3856)

* Price to Weight ration as type parameter

* Kian feedback

* Some renames.

* Fix executor tests

* Getting Closer.

* Phantom Data

* Actually fix executor tests.

* Fix tests.

* Remove todo

* Fix build

core/sr-arithmetic/src/biguint.rs

@@ -21,7 +21,7 @@ use rstd::{cmp::Ordering, ops, prelude::*, cell::RefCell, convert::TryFrom};
 
 // A sensible value for this would be half of the dword size of the host machine. Since the
 // runtime is compiled to 32bit webassembly, using 32 and 64 for single and double respectively
-// should yield the most performance. TODO #3745 we could benchmark this and verify.
+// should yield the most performance.
 /// Representation of a single limb.
 pub type Single = u32;
 /// Representation of two limbs.

core/sr-arithmetic/src/fixed64.rs

@@ -48,6 +48,12 @@ impl Fixed64 {
 		DIV
 	}
 
+	/// Consume self and return the inner value.
+	///
+	/// This should only be used for testing.
+	#[cfg(any(feature = "std", test))]
+	pub fn into_inner(self) -> i64 { self.0 }
+
 	/// Raw constructor. Equal to `parts / 1_000_000_000`.
 	pub fn from_parts(parts: i64) -> Self {
 		Self(parts)

node/executor/src/lib.rs

@@ -38,9 +38,7 @@ mod tests {
 	use super::Executor;
 	use {balances, contracts, indices, system, timestamp};
 	use codec::{Encode, Decode, Joiner};
-	use runtime_support::{
-		Hashable, StorageValue, StorageMap, traits::Currency,
-	};
+	use runtime_support::{Hashable, StorageValue, StorageMap, traits::Currency};
 	use state_machine::TestExternalities as CoreTestExternalities;
 	use primitives::{
 		Blake2Hasher, NeverNativeValue, NativeOrEncoded, map,
@@ -57,8 +55,9 @@ mod tests {
 	use node_runtime::{
 		Header, Block, UncheckedExtrinsic, CheckedExtrinsic, Call, Runtime, Balances, BuildStorage,
 		System, TransactionPayment, Event, TransferFee, TransactionBaseFee, TransactionByteFee,
-		constants::currency::*, impls::WeightToFee,
+		WeightFeeCoefficient, constants::currency::*,
 	};
+	use node_runtime::impls::LinearWeightToFee;
 	use node_primitives::{Balance, Hash, BlockNumber};
 	use node_testing::keyring::*;
 	use wabt;
@@ -501,8 +500,6 @@ mod tests {
 		).0.unwrap();
 
 		t.execute_with(|| {
-			// NOTE: fees differ slightly in tests that execute more than one block due to the
-			// weight update. Hence, using `assert_eq_error_rate`.
 			assert_eq!(
 				Balances::total_balance(&alice()),
 				alice_last_known_balance - 10 * DOLLARS - transfer_fee(&xt(), fm),
@@ -1069,7 +1066,7 @@ mod tests {
 			balance_alice -= length_fee;
 
 			let weight = default_transfer_call().get_dispatch_info().weight;
-			let weight_fee = WeightToFee::convert(weight);
+			let weight_fee = LinearWeightToFee::<WeightFeeCoefficient>::convert(weight);
 
 			// we know that weight to fee multiplier is effect-less in block 1.
 			assert_eq!(weight_fee as Balance, MILLICENTS);

node/runtime/Cargo.toml

@@ -57,6 +57,9 @@ transaction-payment = { package = "srml-transaction-payment", path = "../../srml
 [build-dependencies]
 wasm-builder-runner = { package = "substrate-wasm-builder-runner", version = "1.0.4", path = "../../core/utils/wasm-builder-runner" }
 
+[dev-dependencies]
+runtime_io = { package = "sr-io", path = "../../core/sr-io" }
+
 [features]
 default = ["std"]
 std = [

node/runtime/src/constants.rs

@@ -66,19 +66,3 @@ pub mod time {
 	pub const HOURS: BlockNumber = MINUTES * 60;
 	pub const DAYS: BlockNumber = HOURS * 24;
 }
-
-// CRITICAL NOTE: The system module maintains two constants: a _maximum_ block weight and a _ratio_
-// of it yielding the portion which is accessible to normal transactions (reserving the rest for
-// operational ones). `TARGET_BLOCK_FULLNESS` is entirely independent and the system module is not
-// aware of if, nor should it care about it. This constant simply denotes on which ratio of the
-// _maximum_ block weight we tweak the fees. It does NOT care about the type of the dispatch.
-//
-// For the system to be configured in a sane way, `TARGET_BLOCK_FULLNESS` should always be less than
-// the ratio that `system` module uses to find normal transaction quota.
-/// Fee-related.
-pub mod fee {
-	pub use sr_primitives::Perbill;
-
-	/// The block saturation level. Fees will be updates based on this value.
-	pub const TARGET_BLOCK_FULLNESS: Perbill = Perbill::from_percent(25);
-}