lepu-test-platform-web/node_modules/ws/lib/buffer-util.js

66 lines
1.7 KiB
JavaScript

'use strict';
const safeBuffer = require('safe-buffer');
const Buffer = safeBuffer.Buffer;
/**
* Merges an array of buffers into a new buffer.
*
* @param {Buffer[]} list The array of buffers to concat
* @param {Number} totalLength The total length of buffers in the list
* @return {Buffer} The resulting buffer
* @public
*/
const concat = (list, totalLength) => {
const target = Buffer.allocUnsafe(totalLength);
var offset = 0;
for (var i = 0; i < list.length; i++) {
const buf = list[i];
buf.copy(target, offset);
offset += buf.length;
}
return target;
};
try {
const bufferUtil = require('bufferutil');
module.exports = Object.assign({ concat }, bufferUtil.BufferUtil || bufferUtil);
} catch (e) /* istanbul ignore next */ {
/**
* Masks a buffer using the given mask.
*
* @param {Buffer} source The buffer to mask
* @param {Buffer} mask The mask to use
* @param {Buffer} output The buffer where to store the result
* @param {Number} offset The offset at which to start writing
* @param {Number} length The number of bytes to mask.
* @public
*/
const mask = (source, mask, output, offset, length) => {
for (var i = 0; i < length; i++) {
output[offset + i] = source[i] ^ mask[i & 3];
}
};
/**
* Unmasks a buffer using the given mask.
*
* @param {Buffer} buffer The buffer to unmask
* @param {Buffer} mask The mask to use
* @public
*/
const unmask = (buffer, mask) => {
// Required until https://github.com/nodejs/node/issues/9006 is resolved.
const length = buffer.length;
for (var i = 0; i < length; i++) {
buffer[i] ^= mask[i & 3];
}
};
module.exports = { concat, mask, unmask };
}