(opcode)
| 29 | } |
| 30 | |
| 31 | createFrame (opcode) { |
| 32 | const frameData = this.frameData |
| 33 | const maskKey = generateMask() |
| 34 | const bodyLength = frameData?.byteLength ?? 0 |
| 35 | |
| 36 | /** @type {number} */ |
| 37 | let payloadLength = bodyLength // 0-125 |
| 38 | let offset = 6 |
| 39 | |
| 40 | if (bodyLength > maxUnsigned16Bit) { |
| 41 | offset += 8 // payload length is next 8 bytes |
| 42 | payloadLength = 127 |
| 43 | } else if (bodyLength > 125) { |
| 44 | offset += 2 // payload length is next 2 bytes |
| 45 | payloadLength = 126 |
| 46 | } |
| 47 | |
| 48 | const buffer = Buffer.allocUnsafe(bodyLength + offset) |
| 49 | |
| 50 | // Clear first 2 bytes, everything else is overwritten |
| 51 | buffer[0] = buffer[1] = 0 |
| 52 | buffer[0] |= 0x80 // FIN |
| 53 | buffer[0] = (buffer[0] & 0xF0) + opcode // opcode |
| 54 | |
| 55 | /*! ws. MIT License. Einar Otto Stangvik <einaros@gmail.com> */ |
| 56 | buffer[offset - 4] = maskKey[0] |
| 57 | buffer[offset - 3] = maskKey[1] |
| 58 | buffer[offset - 2] = maskKey[2] |
| 59 | buffer[offset - 1] = maskKey[3] |
| 60 | |
| 61 | buffer[1] = payloadLength |
| 62 | |
| 63 | if (payloadLength === 126) { |
| 64 | buffer.writeUInt16BE(bodyLength, 2) |
| 65 | } else if (payloadLength === 127) { |
| 66 | // Clear extended payload length |
| 67 | buffer[2] = buffer[3] = 0 |
| 68 | buffer.writeUIntBE(bodyLength, 4, 6) |
| 69 | } |
| 70 | |
| 71 | buffer[1] |= 0x80 // MASK |
| 72 | |
| 73 | // mask body |
| 74 | for (let i = 0; i < bodyLength; ++i) { |
| 75 | buffer[offset + i] = frameData[i] ^ maskKey[i & 3] |
| 76 | } |
| 77 | |
| 78 | return buffer |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * @param {Uint8Array} buffer |
no test coverage detected