Network.HTTP2.Client

Running HTTP/2 client.

Client configuration

The default client config.

The authority field will be used to set the HTTP2 :authority pseudo-header. In most cases you will want to override it to be equal to host.

Further background on authority: RFC 3986 also allows host:port, and most servers will accept this too. However, when using TLS, many servers will expect the TLS SNI server name and the :authority pseudo-header to be equal, and for TLS SNI the server name should not include the port. Note that HTTP2 explicitly disallows using userinfo@ as part of the authority.

>>> defaultClientConfigClientConfig {scheme = "http", authority = "localhost", cacheLimit = 64, connectionWindowSize = 16777216, settings = Settings {headerTableSize = 4096, enablePush = True, maxConcurrentStreams = Just 64, initialWindowSize = 262144, maxFrameSize = 16384, maxHeaderListSize = Nothing, pingRateLimit = 10, emptyFrameRateLimit = 4, settingsRateLimit = 4, rstRateLimit = 4}}

https or http

Server name

The maximum number of incoming streams on the net

The window size of connection.

Settings

HTTP/2 settings. See https://datatracker.ietf.org/doc/html/rfc9113#name-defined-settings.

The default settings.

>>> defaultSettingsSettings {headerTableSize = 4096, enablePush = True, maxConcurrentStreams = Just 64, initialWindowSize = 262144, maxFrameSize = 16384, maxHeaderListSize = Nothing, pingRateLimit = 10, emptyFrameRateLimit = 4, settingsRateLimit = 4, rstRateLimit = 4}

SETTINGS_HEADER_TABLE_SIZE

SETTINGS_ENABLE_PUSH

SETTINGS_MAX_CONCURRENT_STREAMS

SETTINGS_INITIAL_WINDOW_SIZE

SETTINGS_MAX_FRAME_SIZE

SETTINGS_MAX_HEADER_LIST_SIZE

HTTP/2 configuration.

Default config. This is just a template to modify via field names. Don't use this without modifications.

This is used only by frameSender. This MUST be freed after frameSender is terminated.

The size of the write buffer. We assume that the read buffer is the same size. So, this value is announced via SETTINGS_MAX_FRAME_SIZE to the peer.

This is copied into Aux, if exist, on server.

This is copied into Aux, if exist, on server.

Client only: called when a 1xx informational response (e.g. 103 Early Hints) is received on the given stream, ahead of the final response. No-op by default.

Making simple configuration whose IO is not efficient. A write buffer is allocated internally. WAI timeout manger is initialized with 30_000_000 microseconds.

Making simple configuration whose IO is not efficient. A write buffer is allocated internally. The third argument is microseconds to initialize WAI timeout manager.

Deallocating the resource of the simple configuration.

This does not cancel timeout actions registered with confTimeoutManager. Since time-manager 0.3, a manager holds no registrations, so there is nothing to kill: an action registered with register runs even after this returns unless it is cancelled with cancel. Use withHandle, which cancels it when the scope ends.

Reading a chunk of the response body. An empty ByteString returned when finished.

Generalization of getResponseBodyChunk which also returns if the ByteString is the final one

Reading response trailers. This function must be called after getResponseBodyChunk returns an empty.

Creating request with builder.

Creating request with file.

Creating request without body.

Creating request with streaming.

Generalized version of requestStreaming,

Like requestStreaming, but run the action with exceptions masked

Getting the body size from a response.

Getting the headers from a response.

Getting the status of a response.

Setting TrailersMaker to Response.

Position read based on Handle.

Naive implementation for readN.

NOTE: This function is intended to be used by a single thread only. (It is probably quite rare anyway to want concurrent reads from the same network socket.)

TrailersMake to create no trailers.

Client type.

Send a request and receive its response.

Additional information.

How many streams can be created without blocking.

Sending a ping.

Request from client.

Response from server.

Position read for files.

Making a position read and its closer.

Reading n bytes.

Either the next trailers maker or final trailers.

Trailers maker. A chunks of the response body is passed with Just. The maker should update internal state with the ByteString and return the next trailers maker. When response body reaches its end, Nothing is passed and the maker should generate trailers. An example:

{-# LANGUAGE BangPatterns #-}
import Data.ByteString (ByteString)
import qualified Data.ByteString.Char8 as C8
import Crypto.Hash (Context, SHA1) -- cryptonite
import qualified Crypto.Hash as CH

-- Strictness is important for Context.
trailersMaker :: Context SHA1 -> Maybe ByteString -> IO NextTrailersMaker
trailersMaker ctx Nothing = return $ Trailers [("X-SHA1", sha1)]
  where
    !sha1 = C8.pack $ show $ CH.hashFinalize ctx
trailersMaker ctx (Just bs) = return $ NextTrailersMaker $ trailersMaker ctx'
  where
    !ctx' = CH.hashUpdate ctx bs

Usage example:

let h2rsp = responseFile ...
    maker = trailersMaker (CH.hashInit :: Context SHA1)
    h2rsp' = setResponseTrailersMaker h2rsp maker

Authority.

How many bytes to read

Offset for file.

File specification.

Path.

"http" or "https".

HTTP method (flat ByteString type).

The connection error or the stream error. A stream error resets that stream and the connection carries on, as RFC 9113 section 5.4.2 asks. One kind of trouble is a connection error even though the spec calls it a stream error, because this implementation cannot carry on through it: a field block abandoned part-way leaves the HPACK tables disagreeing with the peer's, and nothing sent afterwards would decode. ErrorCode in connection errors should be the highest stream identifier but in this implementation it identifies the stream that caused this error.

The type for raw error code.

The type for error code. See https://www.rfc-editor.org/rfc/rfc9113#ErrorCodes.