nixpkgs/pkgs/build-support/fetchgit/nix-prefetch-git
2014-03-25 20:03:55 +01:00

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#! /bin/sh -e
url=
rev=
expHash=
hashType=$NIX_HASH_ALGO
deepClone=$NIX_PREFETCH_GIT_DEEP_CLONE
leaveDotGit=$NIX_PREFETCH_GIT_LEAVE_DOT_GIT
fetchSubmodules=
builder=
if test -n "$deepClone"; then
deepClone=true
else
deepClone=false
fi
if test "$leaveDotGit" != 1; then
leaveDotGit=
else
leaveDotGit=true
fi
argi=0
argfun=""
for arg; do
if test -z "$argfun"; then
case $arg in
--out) argfun=set_out;;
--url) argfun=set_url;;
--rev) argfun=set_rev;;
--hash) argfun=set_hashType;;
--deepClone) deepClone=true;;
--no-deepClone) deepClone=false;;
--leave-dotGit) leaveDotGit=true;;
--fetch-submodules) fetchSubmodules=true;;
--builder) builder=true;;
*)
argi=$(($argi + 1))
case $argi in
1) url=$arg;;
2) rev=$arg;;
3) expHash=$arg;;
*) exit 1;;
esac
;;
esac
else
case $argfun in
set_*)
var=$(echo $argfun | sed 's,^set_,,')
eval $var=$arg
;;
esac
argfun=""
fi
done
usage(){
echo >&2 "syntax: nix-prefetch-git [options] [URL [REVISION [EXPECTED-HASH]]]
Options:
--out path Path where the output would be stored.
--url url Any url understand by 'git clone'.
--rev ref Any sha1 or references (such as refs/heads/master)
--hash h Expected hash.
--deepClone Clone submodules recursively.
--no-deepClone Do not clone submodules.
--leave-dotGit Keep the .git directories.
--fetch-submodules Fetch submodules.
--builder Clone as fetchgit does, but url, rev, and out option are mandatory.
"
exit 1
}
if test -z "$url"; then
usage
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 ${builder:+--progress} origin || return 1
git checkout -b fetchgit $hash || return 1
}
# Fetch only a branch/tag and checkout it.
checkout_ref(){
local hash="$1";
local ref="$2";
if "$deepClone"; 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 ${builder:+--progress} --depth 1 origin +"$ref" || return 1
git checkout -b fetchgit 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 | awk '{print substr($1,2)}');
local dir=$(echo $l | awk '{print $2}');
local name=$(
git config -f .gitmodules --get-regexp submodule\.[^.]*\.path |
sed -n "s,^\(.*\)\.path $dir\$,\\1,p")
local url=$(git config -f .gitmodules --get ${name}.url);
# Get Absolute URL if we have a relative URL
if ! echo "$url" | grep '^[a-zA-Z]\+://' >/dev/null 2>&1; then
url="$(git config --get remote.origin.url)/$url"
fi
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 $url.";
exit 1;
)
# Checkout linked sources.
if test -n "$fetchSubmodules"; then
init_submodules;
fi
if [ -z "$builder" -a -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;
}
clone_user_rev() {
local dir="$1"
local url="$2"
local rev="${3:-HEAD}"
# Perform the checkout.
case "$rev" in
HEAD|refs/*)
clone "$dir" "$url" "" "$rev" 1>&2;;
*)
if test -z "$(echo $rev | tr -d 0123456789abcdef)"; then
clone "$dir" "$url" "$rev" "" 1>&2;
else
echo 1>&2 "Bad commit hash or bad reference.";
exit 1;
fi;;
esac
# Allow doing additional processing before .git removal
eval "$NIX_PREFETCH_GIT_CHECKOUT_HOOK"
if test -z "$leaveDotGit"; then
echo "removing \`.git'..." >&2
find $dir -name .git\* | xargs rm -rf
fi
}
if test -n "$builder"; then
test -n "$out" -a -n "$url" -a -n "$rev" || usage
mkdir $out
clone_user_rev "$out" "$url" "$rev"
else
if test -z "$hashType"; then
hashType=sha256
fi
# If the hash was given, a file with that hash may already be in the
# store.
if test -n "$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=$expHash
fi
# If we don't know the hash or a path with that hash doesn't exist,
# download the file and add it to the store.
if test -z "$finalPath"; then
tmpPath=/tmp/git-checkout-tmp-$$
tmpFile=$tmpPath/git-export
mkdir $tmpPath $tmpFile
trap "rm -rf $tmpPath" EXIT
# Perform the checkout.
clone_user_rev "$tmpFile" "$url" "$rev"
# 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
fi