Network.HTTP.Download

Documentation

verifiedDownload

Arguments

:: (MonadIO m, MonadLogger m)

=> DownloadRequest

-> Path Abs File

destination

-> (Maybe Integer -> Sink ByteString IO ())

custom hook to observe progress

-> m Bool

Whether a download was performed

Copied and extended version of Network.HTTP.Download.download.

Has the following additional features: * Verifies that response content-length header (if present) matches expected length * Limits the download to (close to) the expected # of bytes * Verifies that the expected # bytes were downloaded (not too few) * Verifies md5 if response includes content-md5 header * Verifies the expected hashes

Throws VerifiedDownloadException. Throws IOExceptions related to file system operations. Throws HttpException.

data DownloadRequest

A request together with some checks to perform.

Constructors

DownloadRequest

Fields

• drRequest :: Request
• drHashChecks :: [HashCheck]
• drLengthCheck :: Maybe LengthCheck
• drRetryPolicy :: RetryPolicy

drRetryPolicyDefault :: RetryPolicy

Default to retrying thrice with a short constant delay.

data HashCheck

Constructors

(Show a, HashAlgorithm a) => HashCheck

Fields

• hashCheckAlgorithm :: a
• hashCheckHexDigest :: CheckHexDigest

Instances

Show HashCheck

Methods

showsPrec :: Int -> HashCheck -> ShowS

show :: HashCheck -> String

showList :: [HashCheck] -> ShowS

data DownloadException

Constructors

RedownloadFailed Request (Path Abs File) (Response ())

Instances

Show DownloadException

Methods

showsPrec :: Int -> DownloadException -> ShowS

show :: DownloadException -> String

showList :: [DownloadException] -> ShowS

Exception DownloadException

Methods

toException :: DownloadException -> SomeException

fromException :: SomeException -> Maybe DownloadException

displayException :: DownloadException -> String

data CheckHexDigest

Constructors

CheckHexDigestString String

CheckHexDigestByteString ByteString

CheckHexDigestHeader ByteString

Instances

Show CheckHexDigest

Methods

showsPrec :: Int -> CheckHexDigest -> ShowS

show :: CheckHexDigest -> String

showList :: [CheckHexDigest] -> ShowS

IsString CheckHexDigest

Methods

fromString :: String -> CheckHexDigest

type LengthCheck = Int

data VerifiedDownloadException

An exception regarding verification of a download.

Constructors

WrongContentLength Request Int ByteString

WrongStreamLength Request Int Int

WrongDigest Request String CheckHexDigest String

Instances

Show VerifiedDownloadException

Methods

showsPrec :: Int -> VerifiedDownloadException -> ShowS

show :: VerifiedDownloadException -> String

showList :: [VerifiedDownloadException] -> ShowS

Exception VerifiedDownloadException

Methods

toException :: VerifiedDownloadException -> SomeException

fromException :: SomeException -> Maybe VerifiedDownloadException

displayException :: VerifiedDownloadException -> String

download

Arguments

:: (MonadIO m, MonadLogger m)

=> Request

-> Path Abs File

destination

-> m Bool

Was a downloaded performed (True) or did the file already exist (False)?

Download the given URL to the given location. If the file already exists, no download is performed. Otherwise, creates the parent directory, downloads to a temporary file, and on file download completion moves to the appropriate destination.

Throws an exception if things go wrong

redownload

Arguments

:: (MonadIO m, MonadLogger m)

=> Request

-> Path Abs File

destination

-> m Bool

Same as download, but will download a file a second time if it is already present.

Returns True if the file was downloaded, False otherwise

httpJSON :: (MonadIO m, FromJSON a) => Request -> m (Response a)

Perform an HTTP request and parse the body as JSON. In the event of an JSON parse errors, a JSONException runtime exception will be thrown.

Since: 2.1.10

parseRequest :: MonadThrow m => String -> m Request

Convert a URL into a Request.

This defaults some of the values in Request, such as setting method to GET and requestHeaders to [].

Since this function uses MonadThrow, the return monad can be anything that is an instance of MonadThrow, such as IO or Maybe.

You can place the request method at the beginning of the URL separated by a space, e.g.:

@@ parseRequeset "POST http://httpbin.org/post" @@

Note that the request method must be provided as all capital letters.

Request created by this function won't cause exceptions on non-2XX response status codes.

Since: 0.4.30

parseUrlThrow :: MonadThrow m => String -> m Request

Same as parseRequest, except will throw an HttpException in the event of a non-2XX response.

Since: 0.4.30

setGithubHeaders :: Request -> Request

Set the user-agent request header