fees.rs

// This file is part of Substrate.

// Copyright (C) 2018-2022 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.

use codec::{Encode, Joiner};
use frame_support::{
	dispatch::GetDispatchInfo,
	traits::Currency,
	weights::{constants::ExtrinsicBaseWeight, IdentityFee, WeightToFee},
};
use kitchensink_runtime::{
	constants::{currency::*, time::SLOT_DURATION},
	Balances, CheckedExtrinsic, Multiplier, Runtime, RuntimeCall, TransactionByteFee,
	TransactionPayment,
};
use node_primitives::Balance;
use node_testing::keyring::*;
use sp_runtime::{traits::One, Perbill};

pub mod common;
use self::common::{sign, *};

#[test]
fn fee_multiplier_increases_and_decreases_on_big_weight() {
	let mut t = new_test_ext(compact_code_unwrap());

	// initial fee multiplier must be one.
	let mut prev_multiplier = Multiplier::one();

	t.execute_with(|| {
		assert_eq!(TransactionPayment::next_fee_multiplier(), prev_multiplier);
	});

	let mut tt = new_test_ext(compact_code_unwrap());

	let time1 = 42 * 1000;
	// big one in terms of weight.
	let block1 = construct_block(
		&mut tt,
		1,
		GENESIS_HASH.into(),
		vec![
			CheckedExtrinsic {
				signed: None,
				function: RuntimeCall::Timestamp(pallet_timestamp::Call::set { now: time1 }),
			},
			CheckedExtrinsic {
				signed: Some((charlie(), signed_extra(0, 0))),
				function: RuntimeCall::Sudo(pallet_sudo::Call::sudo {
					call: Box::new(RuntimeCall::RootTesting(
						pallet_root_testing::Call::fill_block { ratio: Perbill::from_percent(60) },
					)),
				}),
			},
		],
		(time1 / SLOT_DURATION).into(),
	);

	let time2 = 52 * 1000;
	// small one in terms of weight.
	let block2 = construct_block(
		&mut tt,
		2,
		block1.1,
		vec![
			CheckedExtrinsic {
				signed: None,
				function: RuntimeCall::Timestamp(pallet_timestamp::Call::set { now: time2 }),
			},
			CheckedExtrinsic {
				signed: Some((charlie(), signed_extra(1, 0))),
				function: RuntimeCall::System(frame_system::Call::remark { remark: vec![0; 1] }),
			},
		],
		(time2 / SLOT_DURATION).into(),
	);

	println!(
		"++ Block 1 size: {} / Block 2 size {}",
		block1.0.encode().len(),
		block2.0.encode().len(),
	);

	// execute a big block.
	executor_call(&mut t, "Core_execute_block", &block1.0, true).0.unwrap();

	// weight multiplier is increased for next block.
	t.execute_with(|| {
		let fm = TransactionPayment::next_fee_multiplier();
		println!("After a big block: {:?} -> {:?}", prev_multiplier, fm);
		assert!(fm > prev_multiplier);
		prev_multiplier = fm;
	});

	// execute a big block.
	executor_call(&mut t, "Core_execute_block", &block2.0, true).0.unwrap();

	// weight multiplier is increased for next block.
	t.execute_with(|| {
		let fm = TransactionPayment::next_fee_multiplier();
		println!("After a small block: {:?} -> {:?}", prev_multiplier, fm);
		assert!(fm < prev_multiplier);
	});
}

fn new_account_info(free_dollars: u128) -> Vec<u8> {
	frame_system::AccountInfo {
		nonce: 0u32,
		consumers: 0,
		providers: 0,
		sufficients: 0,
		data: (free_dollars * DOLLARS, 0 * DOLLARS, 0 * DOLLARS, 0 * DOLLARS),
	}
	.encode()
}

#[test]
fn transaction_fee_is_correct() {
	// This uses the exact values of substrate-node.
	//
	// weight of transfer call as of now: 1_000_000
	// if weight of the cheapest weight would be 10^7, this would be 10^9, which is:
	//   - 1 MILLICENTS in substrate node.
	//   - 1 milli-dot based on current polkadot runtime.
	// (this baed on assigning 0.1 CENT to the cheapest tx with `weight = 100`)
	let mut t = new_test_ext(compact_code_unwrap());
	t.insert(<frame_system::Account<Runtime>>::hashed_key_for(alice()), new_account_info(100));
	t.insert(<frame_system::Account<Runtime>>::hashed_key_for(bob()), new_account_info(10));
	t.insert(
		<pallet_balances::TotalIssuance<Runtime>>::hashed_key().to_vec(),
		(110 * DOLLARS).encode(),
	);
	t.insert(<frame_system::BlockHash<Runtime>>::hashed_key_for(0), vec![0u8; 32]);

	let tip = 1_000_000;
	let xt = sign(CheckedExtrinsic {
		signed: Some((alice(), signed_extra(0, tip))),
		function: RuntimeCall::Balances(default_transfer_call()),
	});

	let r =
		executor_call(&mut t, "Core_initialize_block", &vec![].and(&from_block_number(1u32)), true)
			.0;

	assert!(r.is_ok());
	let r = executor_call(&mut t, "BlockBuilder_apply_extrinsic", &vec![].and(&xt.clone()), true).0;
	assert!(r.is_ok());

	t.execute_with(|| {
		assert_eq!(Balances::total_balance(&bob()), (10 + 69) * DOLLARS);
		// Components deducted from alice's balances:
		// - Base fee
		// - Weight fee
		// - Length fee
		// - Tip
		// - Creation-fee of bob's account.
		let mut balance_alice = (100 - 69) * DOLLARS;

		let base_weight = ExtrinsicBaseWeight::get();
		let base_fee = IdentityFee::<Balance>::weight_to_fee(&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 = IdentityFee::<Balance>::weight_to_fee(&weight);

		// we know that weight to fee multiplier is effect-less in block 1.
		// current weight of transfer = 200_000_000
		// Linear weight to fee is 1:1 right now (1 weight = 1 unit of balance)
		assert_eq!(weight_fee, weight.ref_time() as Balance);
		balance_alice -= base_fee;
		balance_alice -= weight_fee;
		balance_alice -= tip;

		assert_eq!(Balances::total_balance(&alice()), balance_alice);
	});
}

#[test]
#[should_panic]
#[cfg(feature = "stress-test")]
fn block_weight_capacity_report() {
	// Just report how many transfer calls you could fit into a block. The number should at least
	// be a few hundred (250 at the time of writing but can change over time). Runs until panic.
	use node_primitives::Index;

	// execution ext.
	let mut t = new_test_ext(compact_code_unwrap());
	// setup ext.
	let mut tt = new_test_ext(compact_code_unwrap());

	let factor = 50;
	let mut time = 10;
	let mut nonce: Index = 0;
	let mut block_number = 1;
	let mut previous_hash: node_primitives::Hash = GENESIS_HASH.into();

	loop {
		let num_transfers = block_number * factor;
		let mut xts = (0..num_transfers)
			.map(|i| CheckedExtrinsic {
				signed: Some((charlie(), signed_extra(nonce + i as Index, 0))),
				function: RuntimeCall::Balances(pallet_balances::Call::transfer {
					dest: bob().into(),
					value: 0,
				}),
			})
			.collect::<Vec<CheckedExtrinsic>>();

		xts.insert(
			0,
			CheckedExtrinsic {
				signed: None,
				function: RuntimeCall::Timestamp(pallet_timestamp::Call::set { now: time * 1000 }),
			},
		);

		// NOTE: this is super slow. Can probably be improved.
		let block = construct_block(
			&mut tt,
			block_number,
			previous_hash,
			xts,
			(time * 1000 / SLOT_DURATION).into(),
		);

		let len = block.0.len();
		print!(
			"++ Executing block with {} transfers. Block size = {} bytes / {} kb / {} mb",
			num_transfers,
			len,
			len / 1024,
			len / 1024 / 1024,
		);

		let r = executor_call(&mut t, "Core_execute_block", &block.0, true).0;

		println!(" || Result = {:?}", r);
		assert!(r.is_ok());

		previous_hash = block.1;
		nonce += num_transfers;
		time += 10;
		block_number += 1;
	}
}

#[test]
#[should_panic]
#[cfg(feature = "stress-test")]
fn block_length_capacity_report() {
	// Just report how big a block can get. Executes until panic. Should be ignored unless if
	// manually inspected. The number should at least be a few megabytes (5 at the time of
	// writing but can change over time).
	use node_primitives::Index;

	// execution ext.
	let mut t = new_test_ext(compact_code_unwrap());
	// setup ext.
	let mut tt = new_test_ext(compact_code_unwrap());

	let factor = 256 * 1024;
	let mut time = 10;
	let mut nonce: Index = 0;
	let mut block_number = 1;
	let mut previous_hash: node_primitives::Hash = GENESIS_HASH.into();

	loop {
		// NOTE: this is super slow. Can probably be improved.
		let block = construct_block(
			&mut tt,
			block_number,
			previous_hash,
			vec![
				CheckedExtrinsic {
					signed: None,
					function: RuntimeCall::Timestamp(pallet_timestamp::Call::set {
						now: time * 1000,
					}),
				},
				CheckedExtrinsic {
					signed: Some((charlie(), signed_extra(nonce, 0))),
					function: RuntimeCall::System(frame_system::Call::remark {
						remark: vec![0u8; (block_number * factor) as usize],
					}),
				},
			],
			(time * 1000 / SLOT_DURATION).into(),
		);

		let len = block.0.len();
		print!(
			"++ Executing block with big remark. Block size = {} bytes / {} kb / {} mb",
			len,
			len / 1024,
			len / 1024 / 1024,
		);

		let r = executor_call(&mut t, "Core_execute_block", &block.0, true).0;

		println!(" || Result = {:?}", r);
		assert!(r.is_ok());

		previous_hash = block.1;
		nonce += 1;
		time += 10;
		block_number += 1;
	}
}