73 lines
1.9 KiB
JavaScript
73 lines
1.9 KiB
JavaScript
'use strict';
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/**
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* Merges an array of buffers into a new buffer.
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*
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* @param {Buffer[]} list The array of buffers to concat
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* @param {Number} totalLength The total length of buffers in the list
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* @return {Buffer} The resulting buffer
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* @public
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*/
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function concat (list, totalLength) {
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const target = Buffer.allocUnsafe(totalLength);
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var offset = 0;
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for (var i = 0; i < list.length; i++) {
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const buf = list[i];
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buf.copy(target, offset);
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offset += buf.length;
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}
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return target;
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}
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/**
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* Masks a buffer using the given mask.
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*
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* @param {Buffer} source The buffer to mask
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* @param {Buffer} mask The mask to use
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* @param {Buffer} output The buffer where to store the result
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* @param {Number} offset The offset at which to start writing
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* @param {Number} length The number of bytes to mask.
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* @public
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*/
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function _mask (source, mask, output, offset, length) {
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for (var i = 0; i < length; i++) {
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output[offset + i] = source[i] ^ mask[i & 3];
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}
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}
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/**
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* Unmasks a buffer using the given mask.
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*
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* @param {Buffer} buffer The buffer to unmask
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* @param {Buffer} mask The mask to use
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* @public
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*/
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function _unmask (buffer, mask) {
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// Required until https://github.com/nodejs/node/issues/9006 is resolved.
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const length = buffer.length;
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for (var i = 0; i < length; i++) {
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buffer[i] ^= mask[i & 3];
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}
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}
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try {
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const bufferUtil = require('bufferutil');
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const bu = bufferUtil.BufferUtil || bufferUtil;
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module.exports = {
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mask (source, mask, output, offset, length) {
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if (length < 48) _mask(source, mask, output, offset, length);
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else bu.mask(source, mask, output, offset, length);
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},
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unmask (buffer, mask) {
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if (buffer.length < 32) _unmask(buffer, mask);
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else bu.unmask(buffer, mask);
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},
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concat
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};
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} catch (e) /* istanbul ignore next */ {
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module.exports = { concat, mask: _mask, unmask: _unmask };
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}
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