fix

book/node_modules/undici/lib/web/websocket/frame.js

@@ -0,0 +1,96 @@
+'use strict'
+
+const { maxUnsigned16Bit } = require('./constants')
+
+const BUFFER_SIZE = 16386
+
+/** @type {import('crypto')} */
+let crypto
+let buffer = null
+let bufIdx = BUFFER_SIZE
+
+try {
+  crypto = require('node:crypto')
+/* c8 ignore next 3 */
+} catch {
+  crypto = {
+    // not full compatibility, but minimum.
+    randomFillSync: function randomFillSync (buffer, _offset, _size) {
+      for (let i = 0; i < buffer.length; ++i) {
+        buffer[i] = Math.random() * 255 | 0
+      }
+      return buffer
+    }
+  }
+}
+
+function generateMask () {
+  if (bufIdx === BUFFER_SIZE) {
+    bufIdx = 0
+    crypto.randomFillSync((buffer ??= Buffer.allocUnsafe(BUFFER_SIZE)), 0, BUFFER_SIZE)
+  }
+  return [buffer[bufIdx++], buffer[bufIdx++], buffer[bufIdx++], buffer[bufIdx++]]
+}
+
+class WebsocketFrameSend {
+  /**
+   * @param {Buffer|undefined} data
+   */
+  constructor (data) {
+    this.frameData = data
+  }
+
+  createFrame (opcode) {
+    const frameData = this.frameData
+    const maskKey = generateMask()
+    const bodyLength = frameData?.byteLength ?? 0
+
+    /** @type {number} */
+    let payloadLength = bodyLength // 0-125
+    let offset = 6
+
+    if (bodyLength > maxUnsigned16Bit) {
+      offset += 8 // payload length is next 8 bytes
+      payloadLength = 127
+    } else if (bodyLength > 125) {
+      offset += 2 // payload length is next 2 bytes
+      payloadLength = 126
+    }
+
+    const buffer = Buffer.allocUnsafe(bodyLength + offset)
+
+    // Clear first 2 bytes, everything else is overwritten
+    buffer[0] = buffer[1] = 0
+    buffer[0] |= 0x80 // FIN
+    buffer[0] = (buffer[0] & 0xF0) + opcode // opcode
+
+    /*! ws. MIT License. Einar Otto Stangvik <einaros@gmail.com> */
+    buffer[offset - 4] = maskKey[0]
+    buffer[offset - 3] = maskKey[1]
+    buffer[offset - 2] = maskKey[2]
+    buffer[offset - 1] = maskKey[3]
+
+    buffer[1] = payloadLength
+
+    if (payloadLength === 126) {
+      buffer.writeUInt16BE(bodyLength, 2)
+    } else if (payloadLength === 127) {
+      // Clear extended payload length
+      buffer[2] = buffer[3] = 0
+      buffer.writeUIntBE(bodyLength, 4, 6)
+    }
+
+    buffer[1] |= 0x80 // MASK
+
+    // mask body
+    for (let i = 0; i < bodyLength; ++i) {
+      buffer[offset + i] = frameData[i] ^ maskKey[i & 3]
+    }
+
+    return buffer
+  }
+}
+
+module.exports = {
+  WebsocketFrameSend
+}