bitmessage-js/lib/pow.js
2015-01-08 00:28:13 +03:00

37 lines
1.1 KiB
JavaScript

/**
* Implements proof of work.
* @see {@link https://bitmessage.org/wiki/Proof_of_work}
* @module bitmessage/pow
*/
"use strict";
var platform = require("./platform");
var DEFAULT_TRIALS_PER_BYTE = 1000;
var DEFAULT_EXTRA_BYTES = 1000;
/**
* Calculate target
* @param {{ttl: number, payloadLength: number}} opts - Target options
* @return {number} Target.
*/
// Just a wrapper around platform-specific implementation.
exports.getTarget = function(opts) {
var nonceTrialsPerByte = opts.nonceTrialsPerByte;
// Automatically raise lower values per spec.
if (!nonceTrialsPerByte || nonceTrialsPerByte < DEFAULT_TRIALS_PER_BYTE) {
nonceTrialsPerByte = DEFAULT_TRIALS_PER_BYTE;
}
var payloadLengthExtraBytes = opts.payloadLengthExtraBytes;
if (!payloadLengthExtraBytes || payloadLengthExtraBytes < DEFAULT_EXTRA_BYTES) {
payloadLengthExtraBytes = DEFAULT_EXTRA_BYTES;
}
return platform.getTarget({
ttl: opts.ttl,
payloadLength: opts.payloadLength,
nonceTrialsPerByte: nonceTrialsPerByte,
payloadLengthExtraBytes: payloadLengthExtraBytes,
});
};