@node-dlc/bitcoin/lib/TxIn.ts

DLC bitcoin

import { BufferWriter, StreamReader } from '@node-dlc/bufio';

import { ICloneable } from './ICloneable';
import { OutPoint } from './OutPoint';
import { Script } from './Script';
import { Sequence } from './Sequence';
import { Witness } from './Witness';

export class TxIn implements ICloneable<TxIn> {
  /**
   * Parses a TxIn from a a stream reader.
   * @param stream
   */
  public static parse(reader: StreamReader): TxIn {
    const outpoint = OutPoint.parse(reader);
    const scriptSig = Script.parse(reader);
    const sequence = new Sequence(reader.readUInt32LE());
    return new TxIn(outpoint, scriptSig, sequence);
  }

  /**
   * Parses a hex string serialization of a transaction input. This
   * is a helper function instead of having to do `StreamReader.fromHex`
   * on a string directly.
   * @param hex
   */
  public static fromHex(hex: string): TxIn {
    const reader = StreamReader.fromHex(hex);
    return this.parse(reader);
  }

  /**
   * The previous transaction output tuple
   */
  public outpoint: OutPoint;

  /**
   * ScriptSig for the input
   */
  public scriptSig: Script;

  /**
   * nSequence value for the transaction. Defaults to 0xffffffff which
   * disables the absolute timelock.
   */
  public sequence: Sequence;

  /**
   * Witness data that is required by the input
   */
  public witness: Witness[];

  /**
   * Constructs a new transaction input from the values
   * @param outpoint
   * @param scriptSig
   * @param sequence
   * @param witness
   */
  constructor(
    outpoint: OutPoint,
    scriptSig: Script = new Script(),
    sequence: Sequence = new Sequence(),
    witness: Witness[] = [],
  ) {
    this.outpoint = outpoint;
    this.scriptSig = scriptSig;
    this.sequence = sequence;
    this.witness = witness;
  }

  /**
   * Creates a string of the transaction input that includes all of the
   * properties.
   */
  public toString(): string {
    return `prev=${this.outpoint.toString()}, scriptSig=${this.scriptSig.toString()}, sequence=${this.sequence.toString()}`; // prettier-ignore
  }

  /**
   * Creates a JSON object of the transaction input that includes all
   * of the properties.
   */
  // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
  public toJSON() {
    return {
      outpoint: this.outpoint.toJSON(),
      scriptSig: this.scriptSig.toJSON(),
      sequence: this.sequence.toJSON(),
    };
  }

  /**
   * Returns the byte serialization of the transaction input
   */
  public serialize(): Buffer {
    const writer = new BufferWriter();
    writer.writeBytes(this.outpoint.serialize());
    writer.writeBytes(this.scriptSig.serialize());
    writer.writeBytes(this.sequence.serialize());
    return writer.toBuffer();
  }

  /**
   * Clone via deep copy
   */
  public clone(): TxIn {
    return new TxIn(
      this.outpoint.clone(),
      this.scriptSig.clone(),
      this.sequence.clone(),
      this.witness.map((p) => p.clone()),
    );
  }
}