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nixpkgs/pkgs/build-support/fetchzip/default.nix
Alexey Shmalko 1893e2be4d
fetchzip: add extension parameter
fetchzip downloads the file from specified URL, renames it to basename
of that url, and then relies on unzip to do the unpacking.

The first consequence is that this requires URL to end with proper
extension—otherwise it will fail to unpack. This is not always the
case and input-fonts workarounds this by adding “&.zip” query
parameter (which is obviously a hack and is not guaranteed to work
with every URL).

The second consequence is that basename of the url must be a valid
filename. I’ve tried to build a custom configuration of input-fonts
and I get an error from mv that the filename is too long:

> trying https://input.djr.com/build/?fontSelection=fourStyleFamily&regular=InputMonoNarrow-Regular&italic=InputMonoNarrow-Italic&bold=InputMonoNarrow-Bold&boldItalic=InputMonoNarrow-BoldItalic&a=0&g=0&i=topserif&l=serifs_round&zero=0&asterisk=height&braces=straight&preset=default&line-height=1.2&accept=I+do&email=&.zip
>   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
>                                  Dload  Upload   Total   Spent    Left  Speed
> 100  406k  100  406k    0     0   230k      0  0:00:01  0:00:01 --:--:--  230k
> mv: failed to access '/build/?fontSelection=fourStyleFamily&regular=InputMonoNarrow-Regular&italic=InputMonoNarrow-Italic&bold=InputMonoNarrow-Bold&boldItalic=InputMonoNarrow-BoldItalic&a=0&g=0&i=topserif&l=serifs_round&zero=0&asterisk=height&braces=straight&preset=default&line-height=1.2&accept=I+do&email=&.zip': File name too long

We could use “name” parameter as the filename (that’s how it is used
in fetchurl). However, the previous attempt to do
so (fc01353703) was
reverted (24b5eb61eb) because of the
introduced regression—many fetchzip invocations use names without
extension (also the default name is just “source”).

This commit adds an optional “extension” parameter. If it is set,
fetchzip renames the downloaded file to “download.${extension}”
effectively solving both problems above without introducing a massive
regression.

This is a no-op for all existing packages.

Tested by updating my NixOS setup + the extra inputs-fonts
configuration mentioned above + tons of unstable emacs packages after
a nix-collect-garbage (3Gb downloaded) with this patch applied.
2021-08-10 19:57:08 +03:00

70 lines
2 KiB
Nix

# This function downloads and unpacks an archive file, such as a zip
# or tar file. This is primarily useful for dynamically generated
# archives, such as GitHub's /archive URLs, where the unpacked content
# of the zip file doesn't change, but the zip file itself may
# (e.g. due to minor changes in the compression algorithm, or changes
# in timestamps).
{ lib, fetchurl, unzip }:
{ # Optionally move the contents of the unpacked tree up one level.
stripRoot ? true
, url ? ""
, urls ? []
, extraPostFetch ? ""
, name ? "source"
, # Allows to set the extension for the intermediate downloaded
# file. This can be used as a hint for the unpackCmdHooks to select
# an appropriate unpacking tool.
extension ? null
, ... } @ args:
(fetchurl (let
tmpFilename =
if extension != null
then "download.${extension}"
else baseNameOf (if url != "" then url else builtins.head urls);
in {
inherit name;
recursiveHash = true;
downloadToTemp = true;
postFetch =
''
unpackDir="$TMPDIR/unpack"
mkdir "$unpackDir"
cd "$unpackDir"
renamed="$TMPDIR/${tmpFilename}"
mv "$downloadedFile" "$renamed"
unpackFile "$renamed"
''
+ (if stripRoot then ''
if [ $(ls "$unpackDir" | wc -l) != 1 ]; then
echo "error: zip file must contain a single file or directory."
echo "hint: Pass stripRoot=false; to fetchzip to assume flat list of files."
exit 1
fi
fn=$(cd "$unpackDir" && echo *)
if [ -f "$unpackDir/$fn" ]; then
mkdir $out
fi
mv "$unpackDir/$fn" "$out"
'' else ''
mv "$unpackDir" "$out"
'')
+ ''
${extraPostFetch}
''
# Remove non-owner write permissions
# Fixes https://github.com/NixOS/nixpkgs/issues/38649
+ ''
chmod 755 "$out"
'';
} // removeAttrs args [ "stripRoot" "extraPostFetch" "extension" ])).overrideAttrs (x: {
# Hackety-hack: we actually need unzip hooks, too
nativeBuildInputs = x.nativeBuildInputs ++ [ unzip ];
})