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* nix-prefetch-url: rewritten in Perl.

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This commit is contained in:
Eelco Dolstra 2011-12-02 12:09:50 +00:00
parent 92d6a5ed73
commit 3964d95abf
1 changed files with 95 additions and 132 deletions
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217
scripts/nix-prefetch-url.in
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@ -1,165 +1,128 @@
#! @shell@ -e #! @perl@ -w @perlFlags@
url=$1 use strict;
expHash=$2 use File::Basename;
use File::Temp qw(tempdir);
use File::stat;
use Nix::Store;
use Nix::Config;
binDir=@bindir@ my $url = shift;
if [ -n "$NIX_BIN_DIR" ]; then binDir="$NIX_BIN_DIR"; fi my $expHash = shift;
my $hashType = $ENV{'NIX_HASH_ALGO'} || "sha256";
my $cacheDir = $ENV{'NIX_DOWNLOAD_CACHE'};
# needed to make it work on NixOS if (!defined $url || $url eq "") {
export PATH=$PATH:@coreutils@ print STDERR <<EOF
Usage: nix-prefetch-url URL [EXPECTED-HASH]
EOF
;
exit 1;
}
hashType=$NIX_HASH_ALGO sub writeFile {
if test -z "$hashType"; then my ($fn, $s) = @_;
hashType=sha256 open TMP, ">$fn" or die;
fi print TMP "$s" or die;
close TMP or die;
}
hashFormat= sub readFile {
if test "$hashType" != "md5"; then local $/ = undef;
hashFormat=--base32 my ($fn) = @_;
fi open TMP, "<$fn" or die;
my $s = <TMP>;
close TMP or die;
return $s;
}
if test -z "$url"; then my $tmpDir = tempdir("nix-prefetch-url.XXXXXX", CLEANUP => 1, TMPDIR => 1)
echo "syntax: nix-prefetch-url URL [EXPECTED-HASH]" >&2 or die "cannot create a temporary directory";
exit 1
fi # Hack to support the mirror:// scheme from Nixpkgs.
if ($url =~ /^mirror:\/\//) {
system("$Nix::Config::binDir/nix-build '<nixpkgs>' -A resolveMirrorURLs --argstr url '$url' -o $tmpDir/urls > /dev/null") == 0
or die "$0: nix-build failed; maybe \$NIX_PATH is not set properly\n";
my @expanded = split ' ', readFile("$tmpDir/urls");
die "$0: cannot resolve ‘$url’" unless scalar @expanded > 0;
print STDERR "$url expands to $expanded[0]\n";
$url = $expanded[0];
}
# Handle escaped characters in the URI. `+', `=' and `?' are the only # Handle escaped characters in the URI. `+', `=' and `?' are the only
# characters that are valid in Nix store path names but have a special # characters that are valid in Nix store path names but have a special
# meaning in URIs. # meaning in URIs.
name=$(basename "$url" | @sed@ -e 's/%2b/+/g' -e 's/%3d/=/g' -e 's/%3f/\?/g') my $name = basename $url;
if test -z "$name"; then echo "invalid url"; exit 1; fi die "cannot figure out file name for ‘$url’\n" if $name eq "";
$name =~ s/%2b/+/g;
$name =~ s/%3d/=/g;
$name =~ s/%3f/?/g;
my $finalPath;
my $hash;
# If the hash was given, a file with that hash may already be in the # If the hash was given, a file with that hash may already be in the
# store. # store.
if test -n "$expHash"; then if (defined $expHash) {
finalPath=$($binDir/nix-store --print-fixed-path "$hashType" "$expHash" "$name") $finalPath = makeFixedOutputPath(0, $hashType, $expHash, $name);
if ! $bindir/nix-store --check-validity "$finalPath" 2> /dev/null; then if (isValidPath($finalPath)) { $hash = $expHash; } else { $finalPath = undef; }
finalPath=
fi
hash=$expHash
fi
mkTempDir() {
if test -n "$tmpPath"; then return; fi
local i=0
while true; do
if test -z "$TMPDIR"; then TMPDIR=/tmp; fi
tmpPath=$TMPDIR/nix-prefetch-url-$$-$i
if mkdir "$tmpPath"; then break; fi
# !!! to bad we can't check for ENOENT in mkdir, so this check
# is slightly racy (it bombs out if somebody just removed
# $tmpPath...).
if ! test -e "$tmpPath"; then exit 1; fi
i=$((i + 1))
done
trap removeTempDir EXIT SIGINT SIGQUIT
} }
removeTempDir() {
if test -n "$tmpPath"; then
rm -rf "$tmpPath" || true
fi
}
doDownload() {
@curl@ $cacheFlags --fail --location --max-redirs 20 --disable-epsv \
--cookie-jar $tmpPath/cookies "$url" -o $tmpFile
}
# Hack to support the mirror:// scheme from Nixpkgs.
if test "${url:0:9}" = "mirror://"; then
if test -z "$NIXPKGS_ALL"; then
echo "Resolving mirror:// URLs requires Nixpkgs. Please point \$NIXPKGS_ALL at a Nixpkgs tree." >&2
exit 1
fi
mkTempDir
nix-build "$NIXPKGS_ALL" -A resolveMirrorURLs --argstr url "$url" -o $tmpPath/urls > /dev/null
expanded=($(cat $tmpPath/urls))
if test "${#expanded[*]}" = 0; then
echo "$0: cannot resolve $url." >&2
exit 1
fi
echo "$url expands to ${expanded[*]} (using ${expanded[0]})" >&2
url="${expanded[0]}"
fi
# If we don't know the hash or a file with that hash doesn't exist, # If we don't know the hash or a file with that hash doesn't exist,
# download the file and add it to the store. # download the file and add it to the store.
if test -z "$finalPath"; then if (!defined $finalPath) {
mkTempDir my $tmpFile = "$tmpDir/$name";
tmpFile=$tmpPath/$name
# Optionally do timestamp-based caching of the download. # Optionally do timestamp-based caching of the download.
# Actually, the only thing that we cache in $NIX_DOWNLOAD_CACHE is # Actually, the only thing that we cache in $NIX_DOWNLOAD_CACHE is
# the hash and the timestamp of the file at $url. The caching of # the hash and the timestamp of the file at $url. The caching of
# the file *contents* is done in Nix store, where it can be # the file *contents* is done in Nix store, where it can be
# garbage-collected independently. # garbage-collected independently.
if test -n "$NIX_DOWNLOAD_CACHE"; then my ($cachedTimestampFN, $cachedHashFN, @cacheFlags);
echo -n "$url" > $tmpPath/url if (defined $cacheDir) {
urlHash=$($binDir/nix-hash --type sha256 --base32 --flat $tmpPath/url) my $urlHash = hashString("sha256", 1, $url);
echo "$url" > "$NIX_DOWNLOAD_CACHE/$urlHash.url" writeFile "$cacheDir/$urlHash.url", $url;
cachedHashFN="$NIX_DOWNLOAD_CACHE/$urlHash.$hashType" $cachedHashFN = "$cacheDir/$urlHash.$hashType";
cachedTimestampFN="$NIX_DOWNLOAD_CACHE/$urlHash.stamp" $cachedTimestampFN = "$cacheDir/$urlHash.stamp";
cacheFlags="--remote-time" @cacheFlags = ("--time-cond", $cachedTimestampFN) if -f $cachedHashFN && -f $cachedTimestampFN;
if test -e "$cachedTimestampFN" -a -e "$cachedHashFN"; then }
# Only download the file if it is newer than the cached version.
cacheFlags="$cacheFlags --time-cond $cachedTimestampFN"
fi
fi
# Perform the download. # Perform the download.
doDownload my @curlFlags = ("curl", $url, "-o", $tmpFile, "--fail", "--location", "--max-redirs", "20", "--disable-epsv", "--cookie-jar", "$tmpDir/cookies", "--remote-time", (split " ", ($ENV{NIX_CURL_FLAGS} || "")));
(system $Nix::Config::curl @curlFlags, @cacheFlags) == 0 or die "$0: download of ‘$url’ failed\n";
if test -n "$NIX_DOWNLOAD_CACHE" -a ! -e $tmpFile; then if (defined $cacheDir && ! -e $tmpFile) {
# Curl didn't create $tmpFile, so apparently there's no newer # Curl didn't create $tmpFile, so apparently there's no newer
# file on the server. # file on the server.
hash=$(cat $cachedHashFN) $hash = readFile $cachedHashFN or die;
finalPath=$($binDir/nix-store --print-fixed-path "$hashType" "$hash" "$name") $finalPath = makeFixedOutputPath(0, $hashType, $hash, $name);
if ! $binDir/nix-store --check-validity "$finalPath" 2> /dev/null; then unless (isValidPath $finalPath) {
echo "cached contents of \`$url' disappeared, redownloading..." >&2 print STDERR "cached contents of ‘$url’ disappeared, redownloading...\n";
finalPath= $finalPath = undef;
cacheFlags="--remote-time" (system $Nix::Config::curl @curlFlags) == 0 or die "$0: download of ‘$url’ failed\n";
doDownload }
fi }
fi
if test -z "$finalPath"; then if (!defined $finalPath) {
# Compute the hash. # Compute the hash.
hash=$($binDir/nix-hash --type "$hashType" $hashFormat --flat $tmpFile) $hash = hashFile($hashType, $hashType ne "md5", $tmpFile);
if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
if test -n "$NIX_DOWNLOAD_CACHE"; then if (defined $cacheDir) {
echo $hash > $cachedHashFN writeFile $cachedHashFN, $hash;
touch -r $tmpFile $cachedTimestampFN my $st = stat($tmpFile) or die;
fi open STAMP, ">$cachedTimestampFN" or die; close STAMP;
utime($st->atime, $st->mtime, $cachedTimestampFN) or die;
}
# Add the downloaded file to the Nix store. # Add the downloaded file to the Nix store.
finalPath=$($binDir/nix-store --add-fixed "$hashType" $tmpFile) $finalPath = addToStore($tmpFile, 0, $hashType);
}
if test -n "$expHash" -a "$expHash" != "$hash"; then die "$0: hash mismatch for ‘$url’\n" if defined $expHash && $expHash ne $hash;
echo "hash mismatch for URL \`$url'" >&2 }
exit 1
fi
fi print STDERR "path is ‘$finalPath’\n" unless $ENV{'QUIET'};
fi print "$hash\n";
print "$finalPath\n" if $ENV{'PRINT_PATH'};
if ! test -n "$QUIET"; then echo "path is $finalPath" >&2; fi
echo $hash
if test -n "$PRINT_PATH"; then
echo $finalPath
fi