86 lines
2.1 KiB
JavaScript
86 lines
2.1 KiB
JavaScript
'use strict';
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const common = require('../common.js');
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const bench = common.createBenchmark(main, {
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aligned: ['true', 'false'],
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method: ['swap16', 'swap32', 'swap64'/* , 'htons', 'htonl', 'htonll' */],
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len: [64, 256, 768, 1024, 2056, 8192],
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n: [1e6]
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}, {
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test: { len: 16 }
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});
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// The htons and htonl methods below are used to benchmark the
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// performance difference between doing the byteswap in pure
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// javascript regardless of Buffer size as opposed to dropping
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// down to the native layer for larger Buffer sizes. Commented
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// out by default because they are slow for big buffers. If
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// re-evaluating the crossover point, uncomment those methods
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// and comment out their implementations in lib/buffer.js so
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// C++ version will always be used.
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function swap(b, n, m) {
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const i = b[n];
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b[n] = b[m];
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b[m] = i;
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}
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Buffer.prototype.htons = function htons() {
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if (this.length % 2 !== 0)
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throw new RangeError();
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for (let i = 0; i < this.length; i += 2) {
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swap(this, i, i + 1);
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}
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return this;
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};
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Buffer.prototype.htonl = function htonl() {
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if (this.length % 4 !== 0)
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throw new RangeError();
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for (let i = 0; i < this.length; i += 4) {
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swap(this, i, i + 3);
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swap(this, i + 1, i + 2);
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}
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return this;
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};
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Buffer.prototype.htonll = function htonll() {
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if (this.length % 8 !== 0)
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throw new RangeError();
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for (let i = 0; i < this.length; i += 8) {
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swap(this, i, i + 7);
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swap(this, i + 1, i + 6);
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swap(this, i + 2, i + 5);
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swap(this, i + 3, i + 4);
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}
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return this;
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};
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function createBuffer(len, aligned) {
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len += aligned ? 0 : 1;
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const buf = Buffer.allocUnsafe(len);
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for (let i = 1; i <= len; i++)
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buf[i - 1] = i;
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return aligned ? buf : buf.slice(1);
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}
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function genMethod(method) {
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const fnString = `
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return function ${method}(n, buf) {
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for (let i = 0; i <= n; i++)
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buf.${method}();
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}`;
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return (new Function(fnString))();
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}
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function main({ method, len, n, aligned = 'true' }) {
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const buf = createBuffer(len, aligned === 'true');
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const bufferSwap = genMethod(method);
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bufferSwap(n, buf);
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bench.start();
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bufferSwap(n, buf);
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bench.end(n);
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}
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