GenerateUniqueIntervalV2 Class — drizzle-orm Architecture

Source Code

drizzle-seed/src/services/versioning/v2.ts lines 5–110

export class GenerateUniqueIntervalV2 extends AbstractGenerator<{
	fields?:
		| 'year'
		| 'month'
		| 'day'
		| 'hour'
		| 'minute'
		| 'second'
		| 'year to month'
		| 'day to hour'
		| 'day to minute'
		| 'day to second'
		| 'hour to minute'
		| 'hour to second'
		| 'minute to second';
	isUnique?: boolean;
}> {
	static override readonly 'entityKind': string = 'GenerateUniqueInterval';
	static override readonly version: number = 2;

	private state: {
		rng: prand.RandomGenerator;
		fieldsToGenerate: string[];
		intervalSet: Set<string>;
	} | undefined;
	public override isUnique = true;
	private config: { [key: string]: { from: number; to: number } } = {
		year: {
			from: 0,
			to: 5,
		},
		month: {
			from: 0,
			to: 11,
		},
		day: {
			from: 0,
			to: 29,
		},
		hour: {
			from: 0,
			to: 23,
		},
		minute: {
			from: 0,
			to: 59,
		},
		second: {
			from: 0,
			to: 59,
		},
	};

	override init({ count, seed }: { count: number; seed: number }) {
		const allFields = ['year', 'month', 'day', 'hour', 'minute', 'second'];
		let fieldsToGenerate: string[] = allFields;

		if (this.params.fields !== undefined && this.params.fields?.includes(' to ')) {
			const tokens = this.params.fields.split(' to ');
			const endIdx = allFields.indexOf(tokens[1]!);
			fieldsToGenerate = allFields.slice(0, endIdx + 1);
		} else if (this.params.fields !== undefined) {
			const endIdx = allFields.indexOf(this.params.fields);
			fieldsToGenerate = allFields.slice(0, endIdx + 1);
		}

		let maxUniqueIntervalsNumber = 1;
		for (const field of fieldsToGenerate) {
			const from = this.config[field]!.from, to = this.config[field]!.to;
			maxUniqueIntervalsNumber *= from - to + 1;
		}

		if (count > maxUniqueIntervalsNumber) {
			throw new RangeError(`count exceeds max number of unique intervals(${maxUniqueIntervalsNumber})`);
		}

		const rng = prand.xoroshiro128plus(seed);
		const intervalSet = new Set<string>();
		this.state = { rng, fieldsToGenerate, intervalSet };
	}