http-download-0.2.1.0: Verified downloads with retries
Safe HaskellSafe-Inferred
LanguageHaskell2010

Network.HTTP.Download

Synopsis

Documentation

data DownloadRequest Source #

A request together with some checks to perform.

Construct using the downloadRequest smart constructor and associated setters. The constructor itself is not exposed to avoid breaking changes with additional fields.

Since: 0.2.0.0

mkDownloadRequest :: Request -> DownloadRequest Source #

Construct a new DownloadRequest from the given Request. Use associated setters to modify the value further.

Since: 0.2.0.0

modifyRequest :: (Request -> Request) -> DownloadRequest -> DownloadRequest Source #

Modify the Request inside a DownloadRequest. Especially intended for modifying the User-Agent request header.

Since: 0.2.0.0

setHashChecks :: [HashCheck] -> DownloadRequest -> DownloadRequest Source #

Set the hash checks to be run when verifying.

Since: 0.2.0.0

setLengthCheck :: Maybe LengthCheck -> DownloadRequest -> DownloadRequest Source #

Set the length check to be run when verifying.

Since: 0.2.0.0

setRetryPolicy :: RetryPolicy -> DownloadRequest -> DownloadRequest Source #

Set the retry policy to be used when downloading.

Since: 0.2.0.0

setForceDownload :: Bool -> DownloadRequest -> DownloadRequest Source #

If True, force download even if the file already exists. Useful for download a resource which may change over time.

drRetryPolicyDefault :: RetryPolicy Source #

Default to retrying seven times with exponential backoff starting from one hundred milliseconds.

This means the tries will occur after these delays if necessary:

  • 0.1s
  • 0.2s
  • 0.4s
  • 0.8s
  • 1.6s
  • 3.2s
  • 6.4s

data HashCheck Source #

Constructors

forall a.(Show a, HashAlgorithm a) => HashCheck 

Instances

Instances details
Show HashCheck Source # 
Instance details

Defined in Network.HTTP.Download.Verified

download Source #

Arguments

:: HasTerm env 
=> Request 
-> Path Abs File

destination

-> RIO env 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 Source #

Arguments

:: HasTerm env 
=> Request 
-> Path Abs File

destination

-> RIO env 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

verifiedDownload Source #

Arguments

:: HasTerm env 
=> DownloadRequest 
-> Path Abs File

destination

-> (Maybe Integer -> ConduitM ByteString Void (RIO env) ())

custom hook to observe progress

-> RIO env 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.