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|
#!/bin/sh
set -eu
quiet=
name="fetchdarcs"
repository=
tag=
context=
darcs_hash=
exp_hash=
usage() {
echo "Usage: nix-prefetch-darcs [options] [REPOSITORY] [FILENAME [EXPECTED-HASH]]"
echo
echo "Options:"
echo " --quiet Suppress most error messages."
echo " --name <NAME> Symbolic store path name to use for the result."
echo " --repo <REPOSITORY> URL for the Darcs repository."
echo " --tag <REGEXP> Clone specified by tag matching a regular expression."
echo " --context <FILENAME> Clone specified by context file."
echo " --darcs-hash <HASH> Clone specified by hash. WARN: hash order is fickle by design."
echo " --hash <HASH> Expected hash."
echo " --help Show this help message."
}
# Argument parsing
while [ $# -gt 0 ]; do
case "$1" in
--quiet)
quiet=1; shift 1 ;;
--name)
name="$2"; shift 2 ;;
--repo)
repository="$2"; shift 2 ;;
--tag)
tag="$2"; shift 2 ;;
--context)
context="$2"; shift 2 ;;
--darcs-hash)
darcs_hash="$2"; shift 2 ;;
--hash)
exp_hash="$2"; shift 2 ;;
--help)
usage; exit 0 ;;
*)
# Positional arguments
if [ -z "$repository" ]; then
repository="$1"
shift
elif [ -z "$context" ]; then
context="$1"
shift
elif [ -z "$exp_hash" ]; then
exp_hash="$1"
shift
else
echo "Error: Too many arguments" >&2
usage
exit 1
fi
;;
esac
done
if [ -z "$repository" ]; then
echo "Error: URL for repository is required." >&2
echo >&2
usage
exit 1
fi
state_flag_count=0
[ -n "$tag" ] && state_flag_count=$(( state_flag_count + 1 ))
[ -n "$context" ] && state_flag_count=$(( state_flag_count + 1 ))
[ -n "$darcs_hash" ] && state_flag_count=$(( state_flag_count + 1 ))
if [ "$state_flag_count" -gt 1 ]; then
echo "Error: no more than 1 of --tag, --context, --darcs-hash flags can be set. $state_flag_count were set." >&2
echo >&2
usage
exit 1
elif [ -n "$context" ]; then
if [ ! -s "$context" ]; then
echo "Error: context file must be readable & non-empty @ “$context”" >&2
echo >&2
usage
exit 1
else
context="$(realpath "$context")"
fi
fi
weak_hash=
hash=
hash_algo="${NIX_HASH_ALGO:-"sha256"}"
hash_format="${hashFormat:-"--base32"}"
final_path=
final_context=
# If the hash was given, a file with that hash may already be in the
# store.
if [ -n "$exp_hash" ]; then
final_path=$(nix-store --print-fixed-path --recursive "$hash_algo" "$exp_hash" "$name")
if ! nix-store --check-validity "$final_path" 2> /dev/null; then
final_path=""
fi
hash="$exp_hash"
fi
# If we don’t know the hash or a path with that hash doesn’t exist,
# download the file and add it to the store.
if [ -z "$final_path" ]; then
tmp_clone="$(realpath ${quiet:+--quiet} "$(mktemp ${quiet:+--quiet} -d --tmpdir darcs-clone-tmp-XXXXXXXX)")"
trap "rm -rf \"$tmp_clone\"" EXIT
clone_args="--lazy"
if [ -n "$quiet" ]; then
clone_args="$clone_args --quiet"
fi
if [ -n "$tag" ]; then
clone_args="$clone_args --tag=$tag"
elif [ -n "$context" ]; then
clone_args="$clone_args --context=$context"
elif [ -n "$darcs_hash" ]; then
clone_args="$clone_args --to-hash=$darcs_hash"
fi
cd "$tmp_clone"
# Do not print Darcs progress to stdout (else stdout isn’t parsable JSON)
darcs clone "$clone_args" "$repository" "$name" 1>&2
# Will put the current Darcs context into the store.
new_context="$tmp_clone/${name}-context.txt"
darcs log --repodir="$tmp_clone/$name" --context > "$new_context"
final_context="$(nix-store --add-fixed "$hash_algo" "$new_context")"
# Darcs has a weak hash using the XOR of the patch hashes which is useful
# for other scripts
# https://darcs.net/Internals/Hashes
weak_hash="$(darcs show repo --repodir="$tmp_clone/$name" | awk '/^[[:space:]]*Weak Hash:/ { sub(/^[[:space:]]*Weak Hash:[[:space:]]*/, "", $0); printf $0 }')"
date="$(darcs log --repodir="$tmp_clone/$name" --max-count 1 | awk '/^Date:/ { sub(/^Date:[[:space:]]*/, "", $0); printf $0 }')"
date="$(date -u -d "$date" "+%Y-%m-%dT%H:%M:%SZ")"
rm -rf "$tmp_clone/$name/_darcs"
hash="$(nix-hash --type "$hash_algo" "$hash_format" "$tmp_clone/$name")"
final_path=$(nix-store --add-fixed --recursive "$hash_algo" "$tmp_clone/$name")
if [ -n "$exp_hash" ] && [ "$exp_hash" != "$hash" ]; then
echo "Hash mismatch for “$repository”" >&2
echo "Expected: $exp_hash" >&2
echo "Got: $hash" >&2
exit 1
fi
fi
json_escape() {
printf '%s' "$1" | jq -Rs .
}
cat <<EOF
{
"repository": $(json_escape "$repository"),
EOF
if [ -n "$tag" ]; then cat <<EOF
"tag": $(json_escape "$tag"),
EOF
elif [ -n "$darcs_hash" ]; then cat <<EOF
"darcs-hash": $(json_escape "$darcs_hash"),
EOF
fi; if [ -n "$weak_hash" ]; then cat <<EOF
"weak-hash": $(json_escape "$weak_hash"),
EOF
fi; if [ -s "$final_context" ]; then cat <<EOF
"context": $(json_escape "$final_context"),
EOF
fi; cat <<EOF
"date": "$date",
"path": "$final_path",
$(json_escape "$hash_algo"): $(json_escape "$hash"),
"hash": "$(nix-hash --to-sri --type "$hash_algo" "$hash")"
}
EOF
# vim: noet ci pi sts=0
|
