Add Change Commission command

framework/src/modules/dpos_v2/commands/change_commission.ts

@@ -0,0 +1,109 @@
+/*
+ * Copyright © 2021 Lisk Foundation
+ *
+ * See the LICENSE file at the top-level directory of this distribution
+ * for licensing information.
+ *
+ * Unless otherwise agreed in a custom licensing agreement with the Lisk Foundation,
+ * no part of this software, including this file, may be copied, modified,
+ * propagated, or distributed except according to the terms contained in the
+ * LICENSE file.
+ *
+ * Removal or modification of this copyright notice is prohibited.
+ */
+
+import { validator } from '@liskhq/lisk-validator';
+import {
+	CommandVerifyContext,
+	VerificationResult,
+	VerifyStatus,
+	CommandExecuteContext,
+} from '../../../state_machine';
+import { BaseCommand } from '../../base_command';
+import { CommissionChangeEvent } from '../events/commission_change';
+import { changeCommissionCommandParamsSchema } from '../schemas';
+import { DelegateStore } from '../stores/delegate';
+import { ChangeCommissionParams } from '../types';
+
+export class ChangeCommissionCommand extends BaseCommand {
+	public schema = changeCommissionCommandParamsSchema;
+
+	private _commissionIncreasePeriod!: number;
+	private _maxCommissionIncreaseRate!: number;
+
+	public init(args: { commissionIncreasePeriod: number; maxCommissionIncreaseRate: number }) {
+		this._commissionIncreasePeriod = args.commissionIncreasePeriod;
+		this._maxCommissionIncreaseRate = args.maxCommissionIncreaseRate;
+	}
+
+	public async verify(
+		context: CommandVerifyContext<ChangeCommissionParams>,
+	): Promise<VerificationResult> {
+		try {
+			validator.validate(changeCommissionCommandParamsSchema, context.params);
+		} catch (err) {
+			return {
+				status: VerifyStatus.FAIL,
+				error: err as Error,
+			};
+		}
+
+		const delegateStore = this.stores.get(DelegateStore);
+		const delegateExists = await delegateStore.has(context, context.transaction.senderAddress);
+
+		if (!delegateExists) {
+			return {
+				status: VerifyStatus.FAIL,
+				error: new Error('Transaction sender has not registered as a delegate.'),
+			};
+		}
+
+		const delegate = await delegateStore.get(context, context.transaction.senderAddress);
+		const oldCommission = delegate.commission;
+		const hasIncreasedCommissionRecently =
+			context.header.height - delegate.lastCommissionIncreaseHeight <
+			this._commissionIncreasePeriod;
+
+		if (context.params.newCommission >= oldCommission && hasIncreasedCommissionRecently) {
+			return {
+				status: VerifyStatus.FAIL,
+				error: new Error(
+					`Can only increase the commission again ${this._commissionIncreasePeriod} blocks after the last commission increase.`,
+				),
+			};
+		}
+
+		if (context.params.newCommission - oldCommission > this._maxCommissionIncreaseRate) {
+			return {
+				status: VerifyStatus.FAIL,
+				error: new Error(
+					`Invalid argument: Commission increase larger than ${this._maxCommissionIncreaseRate}.`,
+				),
+			};
+		}
+
+		return {
+			status: VerifyStatus.OK,
+		};
+	}
+
+	public async execute(context: CommandExecuteContext<ChangeCommissionParams>): Promise<void> {
+		const delegateStore = this.stores.get(DelegateStore);
+
+		const delegate = await delegateStore.get(context, context.transaction.senderAddress);
+		const oldCommission = delegate.commission;
+
+		delegate.commission = context.params.newCommission;
+		if (delegate.commission > oldCommission) {
+			delegate.lastCommissionIncreaseHeight = context.header.height;
+		}
+
+		await delegateStore.set(context, context.transaction.senderAddress, delegate);
+
+		this.events.get(CommissionChangeEvent).log(context, {
+			delegateAddress: context.transaction.senderAddress,
+			oldCommission,
+			newCommission: context.params.newCommission,
+		});
+	}
+}

framework/src/modules/dpos_v2/constants.ts

@@ -39,6 +39,8 @@ export const LOCAL_ID_LENGTH = 4;
 export const TOKEN_ID_LENGTH = CHAIN_ID_LENGTH + LOCAL_ID_LENGTH;
 export const MAX_NUMBER_BYTES_Q96 = 24;
 export const COMMISSION = 10000;
+export const COMMISSION_INCREASE_PERIOD = 260000;
+export const MAX_COMMISSION_INCREASE_RATE = 500;
 
 // Key length
 export const ED25519_PUBLIC_KEY_LENGTH = 32;
@@ -62,6 +64,8 @@ export const defaultConfig = {
 	tokenIDFee: TOKEN_ID_FEE.toString('hex'),
 	delegateRegistrationFee: DELEGATE_REGISTRATION_FEE.toString(),
 	maxBFTWeightCap: 500,
+	commissionIncreasePeriod: COMMISSION_INCREASE_PERIOD,
+	maxCommissionIncreaseRate: MAX_COMMISSION_INCREASE_RATE,
 };
 
 export const enum PoSEventResult {

framework/src/modules/dpos_v2/endpoint.ts

@@ -141,6 +141,8 @@ export class DPoSEndpoint extends BaseEndpoint {
 			tokenIDFee: this._moduleConfig.tokenIDFee.toString('hex'),
 			delegateRegistrationFee: this._moduleConfig.delegateRegistrationFee.toString(),
 			maxBFTWeightCap: this._moduleConfig.maxBFTWeightCap,
+			commissionIncreasePeriod: this._moduleConfig.commissionIncreasePeriod,
+			maxCommissionIncreaseRate: this._moduleConfig.maxCommissionIncreaseRate,
 		};
 	}
 

framework/src/modules/dpos_v2/module.ts

@@ -24,6 +24,7 @@ import { ReportDelegateMisbehaviorCommand } from './commands/pom';
 import { UnlockCommand } from './commands/unlock';
 import { UpdateGeneratorKeyCommand } from './commands/update_generator_key';
 import { VoteDelegateCommand } from './commands/vote_delegate';
+import { ChangeCommissionCommand } from './commands/change_commission';
 import {
 	DELEGATE_LIST_ROUND_OFFSET,
 	EMPTY_KEY,
@@ -82,6 +83,7 @@ import { DelegateBannedEvent } from './events/delegate_banned';
 import { DelegatePunishedEvent } from './events/delegate_punished';
 import { DelegateRegisteredEvent } from './events/delegate_registered';
 import { DelegateVotedEvent } from './events/delegate_voted';
+import { CommissionChangeEvent } from './events/commission_change';
 
 export class DPoSModule extends BaseModule {
 	public method = new DPoSMethod(this.stores, this.events);
@@ -102,6 +104,7 @@ export class DPoSModule extends BaseModule {
 		this.events,
 	);
 	private readonly _voteCommand = new VoteDelegateCommand(this.stores, this.events);
+	private readonly _changeCommissionCommand = new ChangeCommissionCommand(this.stores, this.events);
 
 	// eslint-disable-next-line @typescript-eslint/member-ordering
 	public commands = [
@@ -110,6 +113,7 @@ export class DPoSModule extends BaseModule {
 		this._unlockCommand,
 		this._updateGeneratorKeyCommand,
 		this._voteCommand,
+		this._changeCommissionCommand,
 	];
 
 	private _randomMethod!: RandomMethod;
@@ -131,6 +135,7 @@ export class DPoSModule extends BaseModule {
 		this.events.register(DelegatePunishedEvent, new DelegatePunishedEvent(this.name));
 		this.events.register(DelegateRegisteredEvent, new DelegateRegisteredEvent(this.name));
 		this.events.register(DelegateVotedEvent, new DelegateVotedEvent(this.name));
+		this.events.register(CommissionChangeEvent, new CommissionChangeEvent(this.name));
 	}
 
 	public get name() {
@@ -256,6 +261,10 @@ export class DPoSModule extends BaseModule {
 			roundLength: this._moduleConfig.roundLength,
 		});
 		this._voteCommand.init({ governanceTokenID: this._moduleConfig.governanceTokenID });
+		this._changeCommissionCommand.init({
+			commissionIncreasePeriod: this._moduleConfig.commissionIncreasePeriod,
+			maxCommissionIncreaseRate: this._moduleConfig.maxCommissionIncreaseRate,
+		});
 
 		this.stores.get(EligibleDelegatesStore).init(this._moduleConfig);
 	}

framework/src/modules/dpos_v2/schemas.ts

@@ -114,6 +114,19 @@ export const pomCommandParamsSchema = {
 	},
 };
 
+export const changeCommissionCommandParamsSchema = {
+	$id: '/dpos/command/changeCommissionCommandParams',
+	type: 'object',
+	required: ['newCommission'],
+	properties: {
+		newCommission: {
+			dataType: 'uint32',
+			fieldNumber: 1,
+			maximum: MAX_COMMISSION,
+		},
+	},
+};
+
 export const configSchema = {
 	$id: '/dpos/config',
 	type: 'object',
@@ -180,6 +193,14 @@ export const configSchema = {
 			minimum: 1,
 			maximum: 9999,
 		},
+		commissionIncreasePeriod: {
+			type: 'integer',
+			format: 'uint32',
+		},
+		maxCommissionIncreaseRate: {
+			type: 'integer',
+			format: 'uint32',
+		},
 	},
 	required: [
 		'factorSelfVotes',

framework/src/modules/dpos_v2/types.ts

@@ -37,6 +37,8 @@ export interface ModuleConfig {
 	tokenIDFee: Buffer;
 	delegateRegistrationFee: bigint;
 	maxBFTWeightCap: number;
+	commissionIncreasePeriod: number;
+	maxCommissionIncreaseRate: number;
 }
 
 export type ModuleConfigJSON = JSONObject<ModuleConfig>;
@@ -214,6 +216,10 @@ export interface PomCommandDependencies {
 	validatorsMethod: ValidatorsMethod;
 }
 
+export interface ChangeCommissionParams {
+	newCommission: number;
+}
+
 export interface ValidatorKeys {
 	generatorKey: Buffer;
 	blsKey: Buffer;