Mine maximum block

Mine-Max-Block.js

  it('should mine a big block', async () => {
    const OPRETURN = Script.fromNulldata(Buffer.alloc(70, 1));
    const start = chain.height - 2000;
    const end = chain.height - 200;
    const job = await cpu.createJob();
    const maxSigops = consensus.maxBlockSigops(consensus.MAX_FORK_BLOCK_SIZE);
    const perTxSigops = Math.floor((maxSigops - 1000) / 1801) - 2;
    const perTxSize = Math.floor(consensus.MAX_FORK_BLOCK_SIZE / 1801);

    // fill max tx
    // with 1801 transactions,
    // limits sigops to maxSigops for a block
    // and calculates expected tx size for each one
    // that is filled with OP_RETURN

    // consensus size: 117 bytes
    for (let i = start; i <= end; i++) {
      const block = await chain.getBlock(i);
      const cb = block.txs[0]; // 117 bytes

      const mtx = new MTX();
      mtx.addTX(cb, 0); // 51 bytes

      const fillSize = perTxSize - (51 + 107 + (perTxSigops * 34));
      const opreturns = Math.floor(fillSize / 81);

      for (let j = 0; j < perTxSigops; j++)
        mtx.addOutput(wallet.getAddress(), 1); // 34 bytes

      for (let j = 0; j < opreturns; j++)
        mtx.addOutput({ script: OPRETURN });

      wallet.sign(mtx); // 107 bytes

      job.pushTX(mtx.toTX());
    }

    job.refresh();

    assert.strictEqual(await mineBlock(job), 'OK');
  });