4014ecbfb4
* Speed up buffer.swap16 and swap32 by using builtins. Up to ~6x gain. Drop transition point between JS and C++ implementations accordingly. Amount of performance improvement not only depends on buffer size but also memory alignment. * Fix tests: C++ impl tests were testing 0-filled buffers so were always passing. * Add similar buffer.swap64 method. * Make buffer-swap benchmark mirror JS impl. doc/api/buffer.markdown has an entry of "added: REPLACEME" that should be changed to the correct release number before tagged. Because node is currently using a very old version of cpplint.py it doesn't know that std::swap() has moved from <algorithm> to <utility> in c++11. So until cpplint.py is updated simply NOLINT the line. Technically it should be NOLINT(build/include_what_you_use), but that puts the line over 80 characters causing another lint error. PR-URL: https://github.com/nodejs/node/pull/7157 Reviewed-By: Trevor Norris <trev.norris@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Backport-URL: https://github.com/nodejs/node/pull/7546
90 lines
2.3 KiB
JavaScript
90 lines
2.3 KiB
JavaScript
'use strict';
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const common = require('../common.js');
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const v8 = require('v8');
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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: [8, 64, 128, 256, 512, 768, 1024, 1536, 2056, 4096, 8192],
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n: [5e7]
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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 (var 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 (var 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 htonl() {
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if (this.length % 8 !== 0)
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throw new RangeError();
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for (var 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 (var 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 (var 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(conf) {
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const method = conf.method;
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const len = conf.len | 0;
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const n = conf.n | 0;
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const aligned = conf.aligned || 'true';
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const buf = createBuffer(len, aligned === 'true');
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const bufferSwap = genMethod(method);
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v8.setFlagsFromString('--allow_natives_syntax');
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eval('%OptimizeFunctionOnNextCall(bufferSwap)');
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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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