const kFrameData = Symbol('frame-data');

const FLAG_EOS = 0x1;

const FLAG_ACK = 0x1;

const FLAG_EOH = 0x4;

const FLAG_PADDED = 0x8;

const PADDING = Buffer.alloc(255);

const kClientMagic = Buffer.from('505249202a20485454502f322' +

'e300d0a0d0a534d0d0a0d0a', 'hex');

const kFakeRequestHeaders = Buffer.from('828684410f7777772e65' +

'78616d706c652e636f6d', 'hex');

const kFakeResponseHeaders = Buffer.from('4803333032580770726976617465611d' +

'4d6f6e2c203231204f63742032303133' +

'2032303a31333a323120474d546e1768' +

'747470733a2f2f7777772e6578616d70' +

'6c652e636f6d', 'hex');

function isUint32(val) {

return val >>> 0 === val;

function isUint24(val) {

return val >>> 0 === val && val <= 0xFFFFFF;

function isUint8(val) {

return val >>> 0 === val && val <= 0xFF;

function write32BE(array, pos, val) {

function write24BE(array, pos, val) {

function write8(array, pos, val) {

class Frame {

class SettingsFrame extends Frame {

class DataFrame extends Frame {

class HeadersFrame extends Frame {

class PingFrame extends Frame {

module.exports = {

Frame,

DataFrame,

HeadersFrame,

SettingsFrame,

PingFrame,

kFakeRequestHeaders,

kFakeResponseHeaders,

kClientMagic