nixpkgs/pkgs/build-support/fetchgit/nix-prefetch-git
Ludovic Courtès 3369508fa9 nix-prefetch-git: Add rudimentary TopGit support.
svn path=/nixpkgs/trunk/; revision=26305
2011-03-14 22:00:20 +00:00

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#! /bin/sh -e
url=$1
rev=$2
expHash=$3
hashType=$NIX_HASH_ALGO
if test -z "$hashType"; then
hashType=sha256
fi
if test -z "$url"; then
echo "syntax: nix-prefetch-git URL [REVISION [EXPECTED-HASH]]" >&2
exit 1
fi
# If the hash was given, a file with that hash may already be in the
# store.
if test -n "$expHash"; then
finalPath=$(nix-store --print-fixed-path --recursive "$hashType" "$expHash" git-export)
if ! nix-store --check-validity "$finalPath" 2> /dev/null; then
finalPath=
fi
hash=$expHash
fi
init_remote(){
local url=$1;
git init;
git remote add origin $url;
}
# Return the reference of an hash if it exists on the remote repository.
ref_from_hash(){
local hash=$1;
git ls-remote origin | sed -n "\,$hash\t, { s,\(.*\)\t\(.*\),\2,; p; q}"
}
# Return the hash of a reference if it exists on the remote repository.
hash_from_ref(){
local ref=$1
git ls-remote origin | sed -n "\,\t$ref, { s,\(.*\)\t\(.*\),\1,; p; q}"
}
# Fetch everything and checkout the right sha1
checkout_hash(){
local hash="$1";
local ref="$2";
if test -z "$hash"; then
hash=$(hash_from_ref $ref);
fi;
git fetch origin || return 1
git checkout $hash || return 1
}
# Fetch only a branch/tag and checkout it.
checkout_ref(){
local hash="$1";
local ref="$2";
if test -n "$NIX_PREFETCH_GIT_DEEP_CLONE"; then
# The caller explicitly asked for a deep clone. Deep clones
# allow "git describe" and similar tools to work. See
# http://thread.gmane.org/gmane.linux.distributions.nixos/3569
# for a discussion.
return 1
fi
if test -z "$ref"; then
ref=$(ref_from_hash $hash);
fi;
if test -n "$ref"; then
# --depth option is ignored on http repository.
git fetch --depth 1 origin +"$ref" || return 1
git checkout FETCH_HEAD || return 1
else
return 1;
fi;
}
# Update submodules
init_submodules(){
# Add urls into .git/config file
git submodule init
# list submodule directories and their hashes
git submodule status |
while read l; do
# checkout each submodule
local hash=$(echo $l | sed 's,^-\([0-9a-f]*\) \(.*\)$,\1,');
local dir=$(echo $l | sed 's,^-\([0-9a-f]*\) \(.*\)$,\2,');
local url=$(sed -n "\,$dir, { :loop; n; s,^.*url = ,,; T loop; p; q }" .git/config);
clone "$dir" "$url" "$hash" "";
done;
}
clone(){
local top=$(pwd)
local dir="$1"
local url="$2"
local hash="$3"
local ref="$4"
cd $dir;
# Initialize the repository.
init_remote "$url";
# Download data from the repository.
checkout_ref "$hash" "$ref" ||
checkout_hash "$hash" "$ref" || (
echo 1>&2 "Unable to checkout $hash$ref from $url.";
exit 1;
)
# Checkout linked sources.
init_submodules;
if [ -f .topdeps ]; then
if tg help 2>&1 > /dev/null
then
echo "populating TopGit branches..."
tg remote --populate origin
else
echo "WARNING: would populate TopGit branches but TopGit is not available" >&2
echo "WARNING: install TopGit to fix the problem" >&2
fi
fi
cd $top;
}
# If we don't know the hash or a path with that hash doesn't exist,
# download the file and add it to the store.
if test -z "$finalPath"; then
tmpPath=/tmp/git-checkout-tmp-$$
tmpFile=$tmpPath/git-export
mkdir $tmpPath $tmpFile
trap "rm -rf $tmpPath" EXIT
# Perform the checkout.
case "$rev" in
HEAD|refs/*)
clone "$tmpFile" "$url" "" "$rev" 1>&2;;
[0-9a-f]*)
if test -z "$(echo $rev | tr -d 0123456789abcdef)"; then
clone "$tmpFile" "$url" "$rev" "" 1>&2;
else
echo 1>&2 "Bad commit hash or bad reference.";
exit 1;
fi;;
"")
clone "$tmpFile" "$url" "" "HEAD" 1>&2;;
esac
# Allow doing additional processing before .git removal
eval "$NIX_PREFETCH_GIT_CHECKOUT_HOOK"
if test "$NIX_PREFETCH_GIT_LEAVE_DOT_GIT" != 1
then
echo "removing \`.git'..." >&2
rm -rf $tmpFile/.git
fi
# Compute the hash.
hash=$(nix-hash --type $hashType $hashFormat $tmpFile)
if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
# Add the downloaded file to the Nix store.
finalPath=$(nix-store --add-fixed --recursive "$hashType" $tmpFile)
if test -n "$expHash" -a "$expHash" != "$hash"; then
echo "hash mismatch for URL \`$url'"
exit 1
fi
fi
if ! test -n "$QUIET"; then echo "path is $finalPath" >&2; fi
echo $hash
if test -n "$PRINT_PATH"; then
echo $finalPath
fi