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'use strict';
const common = require('../common.js');
const bench = common.createBenchmark(main, {
aligned: ['true', 'false'],
method: ['swap16', 'swap32', 'swap64'/* , 'htons', 'htonl', 'htonll' */],
len: [8, 64, 128, 256, 512, 768, 1024, 1536, 2056, 4096, 8192],
n: [5e7]
});
// The htons and htonl methods below are used to benchmark the
// performance difference between doing the byteswap in pure
// javascript regardless of Buffer size as opposed to dropping
// down to the native layer for larger Buffer sizes. Commented
// out by default because they are slow for big buffers. If
// re-evaluating the crossover point, uncomment those methods
// and comment out their implementations in lib/buffer.js so
// C++ version will always be used.
function swap(b, n, m) {
const i = b[n];
b[n] = b[m];
b[m] = i;
}
Buffer.prototype.htons = function htons() {
if (this.length % 2 !== 0)
throw new RangeError();
for (var i = 0; i < this.length; i += 2) {
swap(this, i, i + 1);
}
return this;
};
Buffer.prototype.htonl = function htonl() {
if (this.length % 4 !== 0)
throw new RangeError();
for (var i = 0; i < this.length; i += 4) {
swap(this, i, i + 3);
swap(this, i + 1, i + 2);
}
return this;
};
Buffer.prototype.htonll = function htonll() {
if (this.length % 8 !== 0)
throw new RangeError();
for (var i = 0; i < this.length; i += 8) {
swap(this, i, i + 7);
swap(this, i + 1, i + 6);
swap(this, i + 2, i + 5);
swap(this, i + 3, i + 4);
}
return this;
};
function createBuffer(len, aligned) {
len += aligned ? 0 : 1;
const buf = Buffer.allocUnsafe(len);
for (var i = 1; i <= len; i++)
buf[i - 1] = i;
return aligned ? buf : buf.slice(1);
}
function genMethod(method) {
const fnString = `
return function ${method}(n, buf) {
for (var i = 0; i <= n; i++)
buf.${method}();
}`;
return (new Function(fnString))();
}
function main({ method, len, n, aligned = 'true' }) {
const buf = createBuffer(len, aligned === 'true');
const bufferSwap = genMethod(method || 'swap16');
bufferSwap(n, buf);
bench.start();
bufferSwap(n, buf);
bench.end(n);
}
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