Distribution.Client.Security.HTTP

cabal-install-3.12.1.0: The command-line interface for Cabal and Hackage.

Safe Haskell | None
Language | Haskell2010

Distribution.Client.Security.HTTP

Description

Implementation of `HttpLib` using cabal-install's own `HttpTransport`

Synopsis

- data HttpLib
- transportAdapter :: Verbosity -> IO HttpTransport -> HttpLib

# Documentation

data HttpLib #

Abstraction over HTTP clients

This avoids insisting on a particular implementation (such as the HTTP package) and allows for other implementations (such as a conduit based one).

NOTE: Library-specific exceptions MUST be wrapped in `SomeRemoteError`.

transportAdapter :: Verbosity -> IO HttpTransport -> HttpLib #

Translate from hackage-security's `HttpLib` to cabal-install's `HttpTransport`

NOTE: The match between these two APIs is currently not perfect:

- We don't get any response headers back from the `HttpTransport`, so we don't know if the server supports range requests. For now we optimistically assume that it does.
- The `HttpTransport` wants to know where to place the resulting file, whereas the `HttpLib` expects an `IO` action which streams the download; the security library then makes sure that the file gets written to a location which is suitable (in particular, to a temporary file in the directory where the file needs to end up, so that it can "finalize" the file simply by doing `renameFile`). Right now we write the file to a temporary file in the system temp directory here and then read it again to pass it to the security library; this is a problem for two reasons: it is a source of inefficiency; and it means that the security library cannot insist on a minimum download rate (potential security attack). Fixing it however would require changing the `HttpTransport`.