import base64
import hashlib
import os
import struct
import io

# "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
CLIENT_CONNECTION_PREFACE = '505249202a20485454502f322e300d0a0d0a534d0d0a0d0a'

ERROR_CODES = utils.BiDi(
    NO_ERROR = 0x0,
    PROTOCOL_ERROR = 0x1,
    INTERNAL_ERROR = 0x2,
    FLOW_CONTROL_ERROR = 0x3,
    SETTINGS_TIMEOUT = 0x4,
    STREAM_CLOSED = 0x5,
    FRAME_SIZE_ERROR = 0x6,
    REFUSED_STREAM = 0x7,
    CANCEL = 0x8,
    COMPRESSION_ERROR = 0x9,
    CONNECT_ERROR = 0xa,
    ENHANCE_YOUR_CALM = 0xb,
    INADEQUATE_SECURITY = 0xc,
    HTTP_1_1_REQUIRED = 0xd
    )