@arkade-os/sdk
Version:
Bitcoin wallet SDK with Taproot and Ark integration
108 lines (107 loc) • 3.78 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.TxWeightEstimator = void 0;
class TxWeightEstimator {
constructor(hasWitness, inputCount, outputCount, inputSize, inputWitnessSize, outputSize) {
this.hasWitness = hasWitness;
this.inputCount = inputCount;
this.outputCount = outputCount;
this.inputSize = inputSize;
this.inputWitnessSize = inputWitnessSize;
this.outputSize = outputSize;
}
static create() {
return new TxWeightEstimator(false, 0, 0, 0, 0, 0);
}
addP2AInput() {
this.inputCount++;
this.inputSize += TxWeightEstimator.INPUT_SIZE;
return this;
}
addKeySpendInput(isDefault = true) {
this.inputCount++;
this.inputWitnessSize += 64 + 1 + (isDefault ? 0 : 1);
this.inputSize += TxWeightEstimator.INPUT_SIZE;
this.hasWitness = true;
return this;
}
addP2PKHInput() {
this.inputCount++;
this.inputWitnessSize++;
this.inputSize +=
TxWeightEstimator.INPUT_SIZE +
TxWeightEstimator.P2PKH_SCRIPT_SIG_SIZE;
return this;
}
addTapscriptInput(leafWitnessSize, leafScriptSize, leafControlBlockSize) {
const controlBlockWitnessSize = 1 +
TxWeightEstimator.BASE_CONTROL_BLOCK_SIZE +
1 +
leafScriptSize +
1 +
leafControlBlockSize;
this.inputCount++;
this.inputWitnessSize += leafWitnessSize + controlBlockWitnessSize;
this.inputSize += TxWeightEstimator.INPUT_SIZE;
this.hasWitness = true;
this.inputCount++;
return this;
}
addP2WKHOutput() {
this.outputCount++;
this.outputSize +=
TxWeightEstimator.OUTPUT_SIZE + TxWeightEstimator.P2WKH_OUTPUT_SIZE;
return this;
}
addP2TROutput() {
this.outputCount++;
this.outputSize +=
TxWeightEstimator.OUTPUT_SIZE + TxWeightEstimator.P2TR_OUTPUT_SIZE;
return this;
}
vsize() {
const getVarIntSize = (n) => {
if (n < 0xfd)
return 1;
if (n < 0xffff)
return 3;
if (n < 0xffffffff)
return 5;
return 9;
};
const inputCount = getVarIntSize(this.inputCount);
const outputCount = getVarIntSize(this.outputCount);
// Calculate the size of the transaction without witness data
const txSizeStripped = TxWeightEstimator.BASE_TX_SIZE +
inputCount +
this.inputSize +
outputCount +
this.outputSize;
// Calculate the total weight
let weight = txSizeStripped * TxWeightEstimator.WITNESS_SCALE_FACTOR;
// Add witness data if present
if (this.hasWitness) {
weight +=
TxWeightEstimator.WITNESS_HEADER_SIZE + this.inputWitnessSize;
}
// Convert weight to vsize (weight / 4, rounded up)
return vsize(weight);
}
}
exports.TxWeightEstimator = TxWeightEstimator;
TxWeightEstimator.P2PKH_SCRIPT_SIG_SIZE = 1 + 73 + 1 + 33;
TxWeightEstimator.INPUT_SIZE = 32 + 4 + 1 + 4;
TxWeightEstimator.BASE_CONTROL_BLOCK_SIZE = 1 + 32;
TxWeightEstimator.OUTPUT_SIZE = 8 + 1;
TxWeightEstimator.P2WKH_OUTPUT_SIZE = 1 + 1 + 20;
TxWeightEstimator.BASE_TX_SIZE = 8 + 2; // Version + LockTime
TxWeightEstimator.WITNESS_HEADER_SIZE = 2; // Flag + Marker
TxWeightEstimator.WITNESS_SCALE_FACTOR = 4;
TxWeightEstimator.P2TR_OUTPUT_SIZE = 1 + 1 + 32;
const vsize = (weight) => {
const value = BigInt(Math.ceil(weight / TxWeightEstimator.WITNESS_SCALE_FACTOR));
return {
value,
fee: (feeRate) => feeRate * value,
};
};