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Diffstat (limited to 'node_modules/ws/lib/buffer-util.js')
| -rw-r--r-- | node_modules/ws/lib/buffer-util.js | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/node_modules/ws/lib/buffer-util.js b/node_modules/ws/lib/buffer-util.js new file mode 100644 index 0000000..8fcb88f --- /dev/null +++ b/node_modules/ws/lib/buffer-util.js @@ -0,0 +1,144 @@ +'use strict'; + +const { EMPTY_BUFFER } = require('./constants'); + +/** + * 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 + */ +function concat(list, totalLength) { + if (list.length === 0) return EMPTY_BUFFER; + if (list.length === 1) return list[0]; + + 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; +} + +/** + * 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 + */ +function _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 + */ +function _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]; + } +} + +/** + * Converts a buffer to an `ArrayBuffer`. + * + * @param {Buffer} buf The buffer to convert + * @return {ArrayBuffer} Converted buffer + * @public + */ +function toArrayBuffer(buf) { + if (buf.byteLength === buf.buffer.byteLength) { + return buf.buffer; + } + + return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength); +} + +/** + * Converts `data` to a `Buffer`. + * + * @param {*} data The data to convert + * @return {Buffer} The buffer + * @throws {TypeError} + * @public + */ +function toBuffer(data) { + toBuffer.readOnly = true; + + if (Buffer.isBuffer(data)) return data; + + var buf; + + if (data instanceof ArrayBuffer) { + buf = Buffer.from(data); + } else if (ArrayBuffer.isView(data)) { + buf = viewToBuffer(data); + } else { + buf = Buffer.from(data); + toBuffer.readOnly = false; + } + + return buf; +} + +/** + * Converts an `ArrayBuffer` view into a buffer. + * + * @param {(DataView|TypedArray)} view The view to convert + * @return {Buffer} Converted view + * @private + */ +function viewToBuffer(view) { + const buf = Buffer.from(view.buffer); + + if (view.byteLength !== view.buffer.byteLength) { + return buf.slice(view.byteOffset, view.byteOffset + view.byteLength); + } + + return buf; +} + +try { + const bufferUtil = require('bufferutil'); + const bu = bufferUtil.BufferUtil || bufferUtil; + + module.exports = { + concat, + mask(source, mask, output, offset, length) { + if (length < 48) _mask(source, mask, output, offset, length); + else bu.mask(source, mask, output, offset, length); + }, + toArrayBuffer, + toBuffer, + unmask(buffer, mask) { + if (buffer.length < 32) _unmask(buffer, mask); + else bu.unmask(buffer, mask); + } + }; +} catch (e) /* istanbul ignore next */ { + module.exports = { + concat, + mask: _mask, + toArrayBuffer, + toBuffer, + unmask: _unmask + }; +} |