http2-1.6.0: HTTP/2.0 library including frames and HPACK

Safe HaskellNone
LanguageHaskell2010

Network.HTTP2

Contents

Description

Synopsis

Frame

data Frame

The data type for HTTP/2 frames.

Constructors

Frame 

Instances

data FrameHeader

The data type for HTTP/2 frame headers.

Constructors

FrameHeader 

type HeaderBlockFragment = ByteString

The type for fragments of a header encoded with HPACK.

type Padding = ByteString

The type for padding in payloads.

isPaddingDefined :: FramePayload -> Bool

Checking if padding is defined in this frame type.

>>> isPaddingDefined $ DataFrame ""
True
>>> isPaddingDefined $ PingFrame ""
False

Encoding

encodeFrame :: EncodeInfo -> FramePayload -> ByteString

Encoding an HTTP/2 frame to ByteString. This function is not efficient enough for high performace program because of the concatenation of ByteString.

>>> encodeFrame (encodeInfo id 1) (DataFrame "body")
"\NUL\NUL\EOT\NUL\NUL\NUL\NUL\NUL\SOHbody"

encodeFrameChunks :: EncodeInfo -> FramePayload -> [ByteString]

Encoding an HTTP/2 frame to [ByteString]. This is suitable for sendMany.

encodeFrameHeader :: FrameTypeId -> FrameHeader -> ByteString

Encoding an HTTP/2 frame header. The frame header must be completed.

encodeFrameHeaderBuf :: FrameTypeId -> FrameHeader -> Ptr Word8 -> IO ()

Writing an encoded HTTP/2 frame header to the buffer. The length of the buffer must be larger than or equal to 9 bytes.

encodeFramePayload :: EncodeInfo -> FramePayload -> (FrameHeader, [ByteString])

Encoding an HTTP/2 frame payload. This returns a complete frame header and chunks of payload.

data EncodeInfo

Auxiliary information for frame encoding.

Constructors

EncodeInfo 

Fields

encodeFlags :: !FrameFlags

Flags to be set in a frame header

encodeStreamId :: !StreamId

Stream id to be set in a frame header

encodePadding :: !(Maybe Padding)

Padding if any. In the case where this value is set but the priority flag is not set, this value gets preference over the priority flag. So, if this value is set, the priority flag is also set.

encodeInfo

Arguments

:: (FrameFlags -> FrameFlags) 
-> Int

stream identifier

-> EncodeInfo 

A smart builder of EncodeInfo.

>>> encodeInfo setAck 0
EncodeInfo {encodeFlags = 1, encodeStreamId = 0, encodePadding = Nothing}

Decoding

decodeFrame

Arguments

:: Settings

HTTP/2 settings

-> ByteString

Input byte-stream

-> Either HTTP2Error Frame

Decoded frame

Decoding an HTTP/2 frame to ByteString. The second argument must be include the entire of frame. So, this function is not useful for real applications but useful for testing.

decodeFrameHeader :: ByteString -> (FrameTypeId, FrameHeader)

Decoding an HTTP/2 frame header. Must supply 9 bytes.

checkFrameHeader :: Settings -> (FrameTypeId, FrameHeader) -> Either HTTP2Error (FrameTypeId, FrameHeader)

Checking a frame header and reporting an error if any.

>>> checkFrameHeader defaultSettings (FrameData,(FrameHeader 100 0 0))
Left (ConnectionError ProtocolError "cannot used in control stream")

Decoding payload

decodeFramePayload :: FrameTypeId -> FramePayloadDecoder

Decoding an HTTP/2 frame payload. This function is considered to return a frame payload decoder according to a frame type.

type FramePayloadDecoder = FrameHeader -> ByteString -> Either HTTP2Error FramePayload

The type for frame payload decoder.

decodeDataFrame :: FramePayloadDecoder

Frame payload decoder for DATA frame.

decodeHeadersFrame :: FramePayloadDecoder

Frame payload decoder for HEADERS frame.

decodePriorityFrame :: FramePayloadDecoder

Frame payload decoder for PRIORITY frame.

decoderstStreamFrame :: FramePayloadDecoder

Frame payload decoder for RST_STREAM frame.

decodeSettingsFrame :: FramePayloadDecoder

Frame payload decoder for SETTINGS frame.

decodePushPromiseFrame :: FramePayloadDecoder

Frame payload decoder for PUSH_PROMISE frame.

decodePingFrame :: FramePayloadDecoder

Frame payload decoder for PING frame.

decodeGoAwayFrame :: FramePayloadDecoder

Frame payload decoder for GOAWAY frame.

decodeWindowUpdateFrame :: FramePayloadDecoder

Frame payload decoder for WINDOW_UPDATE frame.

decodeContinuationFrame :: FramePayloadDecoder

Frame payload decoder for CONTINUATION frame.

Frame type ID

framePayloadToFrameTypeId :: FramePayload -> FrameTypeId

Getting FrameType from FramePayload.

>>> framePayloadToFrameTypeId (DataFrame "body")
FrameData

Frame type

type FrameType = Word8

The type for raw frame type.

fromFrameTypeId :: FrameTypeId -> FrameType

Converting FrameTypeId to FrameType.

>>> fromFrameTypeId FrameData
0
>>> fromFrameTypeId FrameContinuation
9
>>> fromFrameTypeId (FrameUnknown 10)
10

toFrameTypeId :: FrameType -> FrameTypeId

Converting FrameType to FrameTypeId.

>>> toFrameTypeId 0
FrameData
>>> toFrameTypeId 9
FrameContinuation
>>> toFrameTypeId 10
FrameUnknown 10

Priority

data Priority

Type for stream priority

Constructors

Priority 

type Weight = Int

The type for weight in priority. Its values are from 1 to 256.

defaultPriority :: Priority

Default priority which depends on stream 0.

>>> defaultPriority
Priority {exclusive = False, streamDependency = 0, weight = 16}

highestPriority :: Priority

Highest priority which depends on stream 0.

>>> highestPriority
Priority {exclusive = False, streamDependency = 0, weight = 256}

Stream identifier

type StreamId = Int

The type for stream identifier

isControl :: StreamId -> Bool

Checking if the stream identifier for control.

>>> isControl 0
True
>>> isControl 1
False

isRequest :: StreamId -> Bool

Checking if the stream identifier for request.

>>> isRequest 0
False
>>> isRequest 1
True

isResponse :: StreamId -> Bool

Checking if the stream identifier for response.

>>> isResponse 0
False
>>> isResponse 2
True

Stream identifier related

testExclusive :: StreamId -> Bool

Checking if the exclusive flag is set.

setExclusive :: StreamId -> StreamId

Setting the exclusive flag.

clearExclusive :: StreamId -> StreamId

Clearing the exclusive flag.

Flags

type FrameFlags = Word8

The type for flags.

defaultFlags :: FrameFlags

The initial value of flags. No flags are set.

>>> defaultFlags
0

testEndStream :: FrameFlags -> Bool

Checking if the END_STREAM flag is set. >>> testEndStream 0x1 True

testAck :: FrameFlags -> Bool

Checking if the ACK flag is set. >>> testAck 0x1 True

testEndHeader :: FrameFlags -> Bool

Checking if the END_HEADERS flag is set.

>>> testEndHeader 0x4
True

testPadded :: FrameFlags -> Bool

Checking if the PADDED flag is set.

>>> testPadded 0x8
True

testPriority :: FrameFlags -> Bool

Checking if the PRIORITY flag is set.

>>> testPriority 0x20
True

setEndStream :: FrameFlags -> FrameFlags

Setting the END_STREAM flag.

>>> setEndStream 0
1

setAck :: FrameFlags -> FrameFlags

Setting the ACK flag.

>>> setAck 0
1

setEndHeader :: FrameFlags -> FrameFlags

Setting the END_HEADERS flag.

>>> setEndHeader 0
4

setPadded :: FrameFlags -> FrameFlags

Setting the PADDED flag.

>>> setPadded 0
8

setPriority :: FrameFlags -> FrameFlags

Setting the PRIORITY flag.

>>> setPriority 0
32

SettingsList

type SettingsList = [(SettingsKeyId, SettingsValue)]

Association list of SETTINGS.

type SettingsValue = Int

The type for raw SETTINGS value.

fromSettingsKeyId :: SettingsKeyId -> Word16

Converting SettingsKeyId to raw value.

>>> fromSettingsKeyId SettingsHeaderTableSize
1
>>> fromSettingsKeyId SettingsMaxHeaderBlockSize
6

toSettingsKeyId :: Word16 -> Maybe SettingsKeyId

Converting raw value to SettingsKeyId.

>>> toSettingsKeyId 0
Nothing
>>> toSettingsKeyId 1
Just SettingsHeaderTableSize
>>> toSettingsKeyId 6
Just SettingsMaxHeaderBlockSize
>>> toSettingsKeyId 7
Nothing

checkSettingsList :: SettingsList -> Maybe HTTP2Error

Checking SettingsList and reporting an error if any.

>>> checkSettingsList [(SettingsEnablePush,2)]
Just (ConnectionError ProtocolError "enable push must be 0 or 1")

Settings

data Settings

Cooked version of settings. This is suitable to be stored in a HTTP/2 context.

Instances

defaultSettings :: Settings

The default settings.

>>> defaultSettings
Settings {headerTableSize = 4096, enablePush = True, maxConcurrentStreams = Nothing, initialWindowSize = 65535, maxFrameSize = 16384, maxHeaderBlockSize = Nothing}

updateSettings :: Settings -> SettingsList -> Settings

Updating settings.

>>> updateSettings defaultSettings [(SettingsEnablePush,0),(SettingsMaxHeaderBlockSize,200)]
Settings {headerTableSize = 4096, enablePush = False, maxConcurrentStreams = Nothing, initialWindowSize = 65535, maxFrameSize = 16384, maxHeaderBlockSize = Just 200}

Window

type WindowSize = Int

The type for window size.

defaultInitialWindowSize :: WindowSize

The default initial window size.

>>> defaultInitialWindowSize
65535

maxWindowSize :: WindowSize

The maximum window size.

>>> maxWindowSize
2147483647

isWindowOverflow :: WindowSize -> Bool

Checking if a window size exceeds the maximum window size.

>>> isWindowOverflow 10
False
>>> isWindowOverflow maxWindowSize
False
>>> isWindowOverflow (maxWindowSize + 1)
True

Error code

type ErrorCode = Word32

The type for raw error code.

fromErrorCodeId :: ErrorCodeId -> ErrorCode

Converting ErrorCodeId to ErrorCode.

>>> fromErrorCodeId NoError
0
>>> fromErrorCodeId InadequateSecurity
12

toErrorCodeId :: ErrorCode -> ErrorCodeId

Converting ErrorCode to ErrorCodeId.

>>> toErrorCodeId 0
NoError
>>> toErrorCodeId 0xc
InadequateSecurity
>>> toErrorCodeId 0xe
UnknownErrorCode 14

Error

data HTTP2Error

The connection error or the stream error.

Predefined values

connectionPreface :: ByteString

The preface of HTTP/2.

>>> connectionPreface
"PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"

connectionPrefaceLength :: Int

Length of the preface.

>>> connectionPrefaceLength
24

frameHeaderLength :: Int

The length of HTTP/2 frame header.

>>> frameHeaderLength
9

maxPayloadLength :: Int

The maximum length of HTTP/2 payload.

>>> maxPayloadLength
16384

recommendedConcurrency :: Int

Default concurrency.

>>> recommendedConcurrency
100