70 lines
1.3 KiB
JavaScript
70 lines
1.3 KiB
JavaScript
/*!
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* mine.js - mining function for bcoin
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* Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
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* https://github.com/bcoin-org/bcoin
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*/
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var crypto = require('../crypto/crypto');
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var assert = require('assert');
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/**
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* Hash until the nonce overflows.
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* @param {Buffer} data
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* @param {Buffer} target - Big endian.
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* @param {Number} min
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* @param {Number} max
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* @returns {Number} Nonce or -1.
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*/
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function mine(data, target, min, max) {
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var nonce = min;
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data.writeUInt32LE(nonce, 76, true);
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// The heart and soul of the miner: match the target.
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while (nonce <= max) {
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// Hash and test against the next target.
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if (rcmp(crypto.hash256(data), target) <= 0)
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return nonce;
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// Increment the nonce to get a different hash
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nonce++;
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// Update the raw buffer (faster than
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// constantly serializing the headers).
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data.writeUInt32LE(nonce, 76, true);
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}
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return -1;
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}
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/**
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* "Reverse" comparison so we don't have
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* to waste time reversing the block hash.
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* @memberof Miner
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* @param {Buffer} a
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* @param {Buffer} b
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* @returns {Number}
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*/
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function rcmp(a, b) {
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var i;
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assert(a.length === b.length);
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for (i = a.length - 1; i >= 0; i--) {
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if (a[i] < b[i])
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return -1;
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if (a[i] > b[i])
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return 1;
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}
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return 0;
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}
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/*
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* Expose
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*/
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module.exports = mine;
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