db-functions

#!/bin/bash

shopt -s extglob

# Some PKGBUILDs need CARCH to be set
CARCH="x86_64"

# Useful functions
UMASK=""
set_umask () {
	[ "$UMASK" == "" ] && UMASK="$(umask)"
	export UMASK
	umask 002
}

restore_umask () {
	umask $UMASK >/dev/null
}

# just like mv -f, but we touch the file and then copy the content so
# default ACLs in the target dir will be applied
mv_acl() {
	rm -f "$2"
	touch "$2"
	cat "$1" >"$2" || return 1
	rm -f "$1"
}

if [[ $USER != $DBSCRIPTS_USER ]]; then
	exec sudo -H -u $DBSCRIPTS_USER "$0" "$@"
else
	cd "$TMPDIR"
fi

# set up general environment
WORKDIR=$(mktemp -d "${TMPDIR}/${0##*/}.XXXXXXXXXX")
LOCKS=()
REPO_MODIFIED=0
declare -a HISTORY_add_files=()
declare -a HISTORY_remove_files=()

# check if messages are to be printed using color
unset ALL_OFF BOLD BLUE CYAN GREEN RED YELLOW
if [[ -t 2 ]]; then
	ALL_OFF="$(tput sgr0)"
	BOLD="$(tput bold)"
	BLUE="${BOLD}$(tput setaf 4)"
	CYAN="${BOLD}$(tput setaf 6)"
	GREEN="${BOLD}$(tput setaf 2)"
	RED="${BOLD}$(tput setaf 1)"
	YELLOW="${BOLD}$(tput setaf 3)"
fi
readonly ALL_OFF BOLD BLUE CYAN GREEN RED YELLOW

plain() {
	local mesg=$1; shift
	printf "${BOLD}    ${mesg}${ALL_OFF}\n" "$@"
}

msg() {
	local mesg=$1; shift
	printf "${GREEN}==>${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@"
}

msg2() {
	local mesg=$1; shift
	printf "${BLUE}  ->${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@"
}

warning() {
	local mesg=$1; shift
	printf "${YELLOW}==> WARNING:${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

error() {
	local mesg=$1; shift
	printf "${RED}==> ERROR:${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

debug() {
	local mesg=$1; shift
	[[ ${DBSCRIPTS_DEBUG} -eq 1 ]] && printf "${CYAN}==> DEBUG:${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

stat_busy() {
	local mesg=$1; shift
	printf "${GREEN}==>${ALL_OFF}${BOLD} ${mesg}...${ALL_OFF}" >&2
}

stat_done() {
	printf "${BOLD}done${ALL_OFF}\n" >&2
}

##
#  usage : in_array( $needle, $haystack )
# return : 0 - found
#          1 - not found
##
in_array() {
	local needle=$1; shift
	[[ -z $1 ]] && return 1 # Not Found
	local item
	for item in "$@"; do
		[[ $item = $needle ]] && return 0 # Found
	done
	return 1 # Not Found
}

##
#   usage : uniq_array( $item... ). items cannot have spaces
#  return : items that appear only once
# remarks : can be used to diff arrays
##
uniq_array() {
	echo $@ | tr ' ' '\n' | sort | uniq -u
}

##
#  usage : dedup_array( $item... ). items cannot have spaces
# return : array with duplicates removed
##
dedup_array() {
	echo $@ | tr ' ' '\n' | sort -u
}

##
#  usage : get_full_version( [$pkgname] )
# return : full version spec, including epoch (if necessary), pkgver, pkgrel
##
get_full_version() {
	# set defaults if they weren't specified in buildfile
	pkgbase=${pkgbase:-${pkgname[0]}}
	epoch=${epoch:-0}
	if [[ -z $1 ]]; then
		if (( ! epoch )); then
			echo $pkgver-$pkgrel
		else
			echo $epoch:$pkgver-$pkgrel
		fi
	else
		for i in pkgver pkgrel epoch; do
			local indirect="${i}_override"
			eval $(declare -f package_$1 | sed -n "s/\(^[[:space:]]*$i=\)/${i}_override=/p")
			[[ -z ${!indirect} ]] && eval ${indirect}=\"${!i}\"
		done
		if (( ! $epoch_override )); then
			echo $pkgver_override-$pkgrel_override
		else
			echo $epoch_override:$pkgver_override-$pkgrel_override
		fi
	fi
}

##
#  usage : get_arch( [$pkgname] )
# return : return arch from buildfile, including package override if defined
##
get_arch() {
	if [[ -z $1 ]]; then
		echo ${arch[@]}
	else
		eval $(declare -f package_$1 | sed -n "s/\(^[[:space:]]*arch=\)/arch_override=/p")
		[[ -z ${arch_override} ]] && eval arch_override=\"${arch[@]}\"

		echo ${arch_override[@]}
	fi
}

##
# usage: pkgver_equal( $pkgver1, $pkgver2 )
##
pkgver_equal() {
	if [[ $1 = *-* && $2 = *-* ]]; then
		# if both versions have a pkgrel, then they must be an exact match
		[[ $1 = "$2" ]]
	else
		# otherwise, trim any pkgrel and compare the bare version.
		[[ ${1%%-*} = "${2%%-*}" ]]
	fi
}

##
#  usage: find_cached_package( $pkgname, $pkgver, $arch, $search_dirs... )
#
#    $pkgver can be supplied with or without a pkgrel appended.
#    If not supplied, any pkgrel will be matched.
##
find_cached_package() {
	local targetname=$1 targetver=$2 targetarch=$3
	local searchdirs=("$PKGDEST" "${@:4}") results=()
	local dir pkg pkgbasename pkgparts name ver rel arch size r results

	for dir in "${searchdirs[@]}"; do
		[[ -d $dir ]] || continue

		for pkg in "$dir"/*.pkg.tar?(.?z); do
			[[ -f $pkg ]] || continue

			# avoid adding duplicates of the same inode
			for r in "${results[@]}"; do
				[[ $r -ef $pkg ]] && continue 2
			done

			# split apart package filename into parts
			pkgbasename=${pkg##*/}
			pkgbasename=${pkgbasename%.pkg.tar?(.?z)}

			arch=${pkgbasename##*-}
			pkgbasename=${pkgbasename%-"$arch"}

			rel=${pkgbasename##*-}
			pkgbasename=${pkgbasename%-"$rel"}

			ver=${pkgbasename##*-}
			name=${pkgbasename%-"$ver"}

			if [[ $targetname = "$name" && $targetarch = "$arch" ]] &&
					pkgver_equal "$targetver" "$ver-$rel"; then
				results+=("$pkg")
			fi
		done
	done

	case ${#results[*]} in
		0)
			return 1
			;;
		1)
			printf '%s\n' "$results"
			return 0
			;;
		*)
			error 'Multiple packages found:'
			printf '\t%s\n' "${results[@]}" >&2
			return 1
	esac
}

script_lock() {
	local LOCKDIR="$TMPDIR/.scriptlock.${0##*/}"
	if ! mkdir "$LOCKDIR" >/dev/null 2>&1 ; then
		local _owner="$(/usr/bin/stat -c %U $LOCKDIR)"
		error "Script ${0##*/} is already locked by $_owner."
		exit 1
	else
		set_umask
		return 0
	fi
}

script_unlock() {
	local LOCKDIR="$TMPDIR/.scriptlock.${0##*/}"
	if [ ! -d "$LOCKDIR" ]; then
		warning "Script ${0##*/} was not locked!"
		restore_umask
		return 1
	else
		rmdir "$LOCKDIR"
		restore_umask
		return 0
	fi
}

cleanup() {
	local l
	local repo
	local arch

	trap - EXIT INT QUIT TERM
	for l in ${LOCKS[@]}; do
		repo=${l%.*}
		arch=${l#*.}
		if [ -d "$TMPDIR/.repolock.$repo.$arch" ]; then
			msg "Removing left over lock from [${repo}] (${arch})"
			repo_unlock $repo $arch
		fi
	done
	if [ -d "$TMPDIR/.scriptlock.${0##*/}" ]; then
		msg "Removing left over lock from ${0##*/}"
		script_unlock
	fi
	rm -rf "$WORKDIR"

	if (( REPO_MODIFIED )); then
		date +%s > "${FTP_BASE}/lastupdate"
	fi

	[ "$1" ] && exit $1
}

abort() {
	msg 'Aborting...'
	cleanup 0
}

die() {
	error "$*"
	cleanup 1
}

trap abort INT QUIT TERM HUP
trap cleanup EXIT


#repo_lock <repo-name> <arch> [timeout]
repo_lock () {
	local LOCKDIR="$TMPDIR/.repolock.$1.$2"
	local DBLOCKFILE="${FTP_BASE}/${1}/os/${2}/${1}${DBEXT}.lck"
	local _count
	local _trial
	local _timeout
	local _lockblock
	local _owner

	debug "Locking repo [${1}] (${2})"

	# This is the lock file used by repo-add and repo-remove
	if [ -f "${DBLOCKFILE}" ]; then
		error "Repo [${1}] (${2}) is already locked by repo-{add,remove} process $(cat $DBLOCKFILE)"
		return 1
	fi

	if [ $# -eq 2 ]; then
		_lockblock=true
		_trial=0
	elif [ $# -eq 3 ]; then
		_lockblock=false
		_timeout=$3
		let _trial=$_timeout/$LOCK_DELAY
	fi

	_count=0
	while [ $_count -le $_trial ] || $_lockblock ; do
		if ! mkdir "$LOCKDIR" >/dev/null 2>&1 ; then
			_owner="$(/usr/bin/stat -c %U $LOCKDIR)"
			warning "Repo [${1}] (${2}) is already locked by $_owner. "
			msg2 "Retrying in $LOCK_DELAY seconds..."
		else
			LOCKS+=("$1.$2")
			set_umask
			return 0
		fi
		sleep $LOCK_DELAY
		let _count=$_count+1
	done

	error "Repo [${1}] (${2}) is already locked by $_owner. Giving up!"
	return 1
}

repo_unlock () { #repo_unlock <repo-name> <arch>
	debug "Unlocking repo [${1}] (${2})"

	local LOCKDIR="$TMPDIR/.repolock.$1.$2"
	if [ ! -d "$LOCKDIR" ]; then
		warning "Repo lock [${1}] (${2}) was not locked!"
		restore_umask
		return 1
	else
		rmdir "$LOCKDIR"
		restore_umask
		return 0
	fi
}

# usage: _grep_pkginfo pkgfile pattern
_grep_pkginfo() {
	local _ret

	_ret="$(/usr/bin/bsdtar -xOqf "$1" .PKGINFO | grep -m 1 "^${2} = ")"
	echo "${_ret#${2} = }"
}

# usage: _grep_buildinfo pkgfile pattern
_grep_buildinfo() {
	local _ret

	_ret="$(/usr/bin/bsdtar -xOqf "$1" .BUILDINFO | grep -m 1 "^${2} = ")"
	echo "${_ret#${2} = }"
}

# Get the package base or name as fallback
getpkgbase() {
	local _base

	_base="$(_grep_pkginfo "$1" "pkgbase")"
	if [ -z "$_base" ]; then
		getpkgname "$1"
	else
		echo "$_base"
	fi
}

issplitpkg() {
	local _base

	_base="$(_grep_pkginfo "$1" "pkgbase")"
	if [ -z "$_base" ]; then
		return 1
	else
		return 0
	fi
}

# Get the package name
getpkgname() {
	local _name

	_name="$(_grep_pkginfo "$1" "pkgname")"
	if [ -z "$_name" ]; then
		error "Package '$1' has no pkgname in the PKGINFO. Fail!"
		exit 1
	fi

	echo "$_name"
}

# Get the pkgver-pkgrel of this package
getpkgver() {
	local _ver

	_ver="$(_grep_pkginfo "$1" "pkgver")"
	if [ -z "$_ver" ]; then
		error "Package '$1' has no pkgver in the PKGINFO. Fail!"
		exit 1
	fi

	echo "$_ver"
}

getpkgarch() {
	local _ver

	_ver="$(_grep_pkginfo "$1" "arch")"
	if [ -z "$_ver" ]; then
		error "Package '$1' has no arch in the PKGINFO. Fail!"
		exit 1
	fi

	echo "$_ver"
}

check_packager() {
	local _packager

	_packager=$(_grep_pkginfo "$1" "packager")
	[[ $_packager && $_packager != 'Unknown Packager' ]]
}

check_buildinfo() {
	/usr/bin/bsdtar -tf "$1" .BUILDINFO >/dev/null 2>&1
}

check_builddir() {
	local _builddir

	_builddir=$(_grep_buildinfo "$1" "builddir")
	[[ $_builddir && $_builddir = '/build' ]]
}

getpkgfile() {
	if [[ ${#} -ne 1 ]]; then
		error 'No canonical package found!'
		exit 1
	elif [ ! -f "${1}" ]; then
		error "Package ${1} not found!"
		exit 1
	elif ${REQUIRE_SIGNATURE} && [ ! -f "${1}.sig" ]; then
		error "Package signature ${1}.sig not found!"
		exit 1
	fi

	echo ${1}
}

getpkgfiles() {
	local f
	if [ ! -z "$(echo ${@%\.*} | sed "s/ /\n/g" | sort | uniq -D)" ]; then
		error 'Duplicate packages found!'
		exit 1
	fi

	for f in ${@}; do
		if  [ ! -f "${f}" ]; then
			error "Package ${f} not found!"
			exit 1
		elif ${REQUIRE_SIGNATURE} && [ ! -f "${f}.sig" ]; then
			error "Package signature ${f}.sig not found!"
			exit 1
		fi
	done

	echo ${@}
}

check_pkgfile() {
	local pkgfile=$1

	local pkgname="$(getpkgname ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local pkgver="$(getpkgver ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local pkgarch="$(getpkgarch ${pkgfile})"
	[ $? -ge 1 ] && return 1

	in_array "${pkgarch}" ${ARCHES[@]} 'any' || return 1

	if echo "${pkgfile##*/}" | grep -q "${pkgname}-${pkgver}-${pkgarch}"; then
		return 0
	else
		return 1
	fi
}

check_pkgrepos() {
	local pkgfile=$1

	local pkgname="$(getpkgname ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local pkgver="$(getpkgver ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local pkgarch="$(getpkgarch ${pkgfile})"
	[ $? -ge 1 ] && return 1

	[ -f "${FTP_BASE}/${PKGPOOL}/${pkgname}-${pkgver}-${pkgarch}"${PKGEXT} ] && return 1
	[ -f "${FTP_BASE}/${PKGPOOL}/${pkgname}-${pkgver}-${pkgarch}"${PKGEXT}.sig ] && return 1
	[ -f "${FTP_BASE}/${PKGPOOL}/${pkgfile##*/}" ] && return 1
	[ -f "${FTP_BASE}/${PKGPOOL}/${pkgfile##*/}.sig" ] && return 1

	return 0
}

#usage: chk_license ${license[@]}"
chk_license() {
	local l
	for l in ${@}; do
		in_array ${l} ${ALLOWED_LICENSES[@]} && return 0
	done

	return 1
}

check_repo_permission() {
	local repo=$1

	[ ${#PKGREPOS[@]} -eq 0 ] && return 1
	[ -z "${PKGPOOL}" ] && return 1

	in_array "${repo}" ${PKGREPOS[@]} ${PKGREPOS[@]/%/-${DEBUGSUFFIX}} || return 1

	[ -w "$FTP_BASE/${PKGPOOL}" ] || return 1

	local arch
	for arch in "${ARCHES[@]}"; do
		local dir="${FTP_BASE}/${repo}/os/${arch}/"
		[ -w "${dir}" ] || return 1
		[ -f "${dir}"${repo}${DBEXT} -a ! -w "${dir}"${repo}${DBEXT} ] && return 1
		[ -f "${dir}"${repo}${FILESEXT} -a ! -w "${dir}"${repo}${FILESEXT} ] && return 1
	done

	return 0
}

set_repo_permission() {
	local repo=$1
	local arch=$2
	local dbfile="${FTP_BASE}/${repo}/os/${arch}/${repo}${DBEXT}"
	local filesfile="${FTP_BASE}/${repo}/os/${arch}/${repo}${FILESEXT}"

	if [ -w "${dbfile}" ]; then
		local group=$(/usr/bin/stat --printf='%G' "$(dirname "${dbfile}")")
		chgrp $group "${dbfile}" || error "Could not change group of ${dbfile} to $group"
		chgrp $group "${filesfile}" || error "Could not change group of ${filesfile} to $group"
		chmod g+w "${dbfile}" || error "Could not set write permission for group $group to ${dbfile}"
		chmod g+w "${filesfile}" || error "Could not set write permission for group $group to ${filesfile}"
	else
		error "You don't have permission to change ${dbfile}"
	fi
}

arch_repo_add() {
	local repo=$1
	local arch=$2
	local pkgs=(${@:3})

	# package files might be relative to repo dir
	pushd "${FTP_BASE}/${repo}/os/${arch}" >/dev/null
	/usr/bin/repo-add -q "${repo}${DBEXT}" ${pkgs[@]} \
		|| error "repo-add ${repo}${DBEXT} ${pkgs[@]}"
	popd >/dev/null
	set_repo_permission "${repo}" "${arch}"

	REPO_MODIFIED=1
}

arch_repo_remove() {
	local repo=$1
	local arch=$2
	local pkgs=(${@:3})
	local dbfile="${FTP_BASE}/${repo}/os/${arch}/${repo}${DBEXT}"

	if [ ! -f "${dbfile}" ]; then
		error "No database found at '${dbfile}'"
		return 1
	fi
	/usr/bin/repo-remove -q "${dbfile}" ${pkgs[@]} \
		|| error "repo-remove ${dbfile} ${pkgs[@]}"
	set_repo_permission "${repo}" "${arch}"

	REPO_MODIFIED=1
}

check_pkgfile_pkgbuild() {
	local pkgfile="${1}"
	local _pkgbase="$(getpkgbase ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local _pkgname="$(getpkgname ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local _pkgver="$(getpkgver ${pkgfile})"
	[ $? -ge 1 ] && return 1
	local _pkgarch="$(getpkgarch ${pkgfile})"
	[ $? -ge 1 ] && return 1

	get_pkgbuild ${repo} ${_pkgbase} ${_pkgver} || return 1

	local pkgbuild_ver="$(. "${WORKDIR}/pkgbuilds/${repo}/${_pkgbase}-${_pkgver}"; get_full_version ${_pkgname})"
	[ "${pkgbuild_ver}" == "${_pkgver}" ] || return 1

	local pkgbuild_names=($(. "${WORKDIR}/pkgbuilds/${repo}/${_pkgbase}-${_pkgver}"; echo ${pkgname[@]}))
	in_array "${_pkgname}" ${pkgbuild_names[@]} ${pkgbuild_names[@]/%/-${DEBUGSUFFIX}} || return 1

	return 0
}

arch_add_to_pool() {
	local pkgfile="$1"
	if [ -f "${pkgfile}" ]; then
		if ! check_pkgfile_pkgbuild "$pkgfile"; then
			warning "package $pkgfile failed check against PKGBUILD. skipping"
			return 0
		fi
		mv "${pkgfile}" "$FTP_BASE/${PKGPOOL}"
	fi

	# also move signatures
	if [ -f "${pkgfile}.sig" ]; then
		mv "${pkgfile}.sig" "$FTP_BASE/${PKGPOOL}"
	fi
}

# add a package file (from the pool) to the database
# call arch_add_to_pool first
arch_db_add() {
	local repo="$1"
	local tarch="$2"
	local pkgfiles=("${@:3}")
	pkgfiles=("${pkgfiles[@]##*/}")
	local dstdir="$FTP_BASE/$repo/os/$tarch"
	local pkgfile

	for pkgfile in "${pkgfiles[@]}"; do
		local srcfile="$FTP_BASE/${PKGPOOL}/${pkgfile}"

		if [[ ! -f "${srcfile}" ]]; then
			warning "Package file ${pkgfile} not found in ${FTP_BASE}/${PKGPOOL}. skipping"
			return 0
		fi

		ln -sr "$srcfile" "$dstdir/"
		if [ -f "${srcfile}.sig" ]; then
			ln -sr "${srcfile}.sig" "$dstdir/"
		fi
	done

	arch_repo_add "${repo}" "${tarch}" "${pkgfiles[@]}"

	for pkgfile in "${pkgfiles[@]}"; do
		arch_history_add "$repo" "$dstdir/$pkgfile" "$tarch"
	done
}

arch_db_remove() {
	local repo=$1
	local arch=$2
	local pkgs=(${@:3})
	local pkgname

	arch_repo_remove "$@"

	for pkgname in "${pkgs[@]}"; do
		arch_history_remove "$repo" "$pkgname" "$arch"
	done
}

arch_db_move() {
	local repo_from=$1
	local repo_to=$2
	local arch=$3
	local pkgnames=(${@:4})
	local pkgname

	local ftppath_from="${FTP_BASE}/${repo_from}/os"

	for pkgname in "${pkgnames[@]}"; do
		pkgentry=$(pkgentry_from_db "$repo_from" "$arch" "$pkgname")
		pkgs=($(getpkgfiles "$ftppath_from/$arch/$pkgentry"*${PKGEXT}))

		if [[ -z $pkgentry ]]; then
			warning "Failed to detect pkgentry for $pkgname"
			return 1
		fi

		for pkg in "${pkgs[@]}"; do
			pkgname=$(getpkgname "$pkg")
			arch_db_add "${repo_to}" "$arch" "${pkg##*/}"
			arch_db_remove "${repo_from}" "$arch" "$pkgname"
		done
	done
}

find_removed_split_packages() {
	local repo_from=$1
	local repo_to=$2
	local arch=$3
	local pkgname=$4

	local ftppath_from="${FTP_BASE}/${repo_from}/os"

	pkgver_from=$(pkgver_from_db "${repo_from}" "${arch}" "${pkgname}")
	pkgver_to=$(pkgver_from_db "${repo_to}" "${arch}" "${pkgname}")

	# package isn't in target repo
	[[ -z ${pkgver_to} ]] && return

	pkg=$(getpkgfile "${ftppath_from}/${arch}/${pkgname}-${pkgver_from}"*${PKGEXT})
	pkgbase=$(getpkgbase "${pkg}")

	get_pkgbuild ${repo_from} ${pkgbase} ${pkgver_from} || die "PKGBUILD not found for ${pkgbase}-${pkgver_from}"
	get_pkgbuild ${repo_to} ${pkgbase} ${pkgver_to} || die "PKGBUILD not found for ${pkgbase}-${pkgver_to}"

	pkgnames_from=($(. "${WORKDIR}/pkgbuilds/${repo_from}/${pkgbase}-${pkgver_from}"; echo ${pkgname[@]}))
	pkgnames_to=($(. "${WORKDIR}/pkgbuilds/${repo_to}/${pkgbase}-${pkgver_to}"; echo ${pkgname[@]}))

	# list pkgnames_from twice to make them non-unique
	uniq_array ${pkgnames_from[@]} ${pkgnames_from[@]} ${pkgnames_to[@]}
}

find_repo_for_package() {
	local pkgname=$1
	local pkgarch=$2
	local repo

	for repo in ${STABLE_REPOS[@]}; do
		path="${HISTORYREPO}/${repo}/${pkgarch}/${pkgname}"
		if [ -e "${path}" ]; then
			echo "${repo}"
			return
		fi
	done
	return 1
}

arch_history_add() {
	local repo="$1"
	local pkgfile="$2"
	local tarch="$3"
	local pkgname=$(getpkgname "$pkgfile")
	local pkgbase=$(getpkgbase "$pkgfile")
	local pkgver=$(getpkgver "$pkgfile")

	local staging_dir="$WORKDIR/history"
	local history_file="$staging_dir/$repo/$tarch/$pkgname"

	mkdir -p "${history_file%/*}"
	echo "$pkgbase $pkgver" > "$history_file"

	debug "History: Adding $pkgname $pkgver [$repo] ($tarch)"

	HISTORY_add_files=("${HISTORY_add_files[@]}" "${history_file/$staging_dir/$HISTORYREPO}")
}

arch_history_remove() {
	local repo="$1"
	local pkgname="$2"
	local tarch="$3"

	local history_file="$HISTORYREPO/$repo/$tarch/$pkgname"

	[[ -f "$history_file" ]] || return 1

	debug "History: Removing $pkgname [$repo] ($tarch)"

	HISTORY_remove_files=("${HISTORY_remove_files[@]}" "$history_file")
}

arch_history_commit() {
	flock -e 9

	pushd "$HISTORYREPO" >/dev/null
		did_work=0
		if ((${#HISTORY_add_files[@]} > 0)); then
			cp -r -- "$WORKDIR/history/"* .
			git add -- "${HISTORY_add_files[@]}"
			did_work=1
		fi
		if ((${#HISTORY_remove_files[@]} > 0)); then
			git rm -q -- "${HISTORY_remove_files[@]}"
			did_work=1
		fi
		if ((did_work)); then
			debug "History: Commiting \"$1\""
			git commit -q -m "$1"
		fi
	popd >/dev/null
} 9> $HISTORYREPO/.git/dbscripts.gitlock

pkgentry_from_db() {
	local repo="$1"
	local arch="$2"
	local pkgname="$3"

	local db="$FTP_BASE/$repo/os/$arch/$repo$DBEXT"
	local line

	if [[ ! -e $db ]]; then
		debug "Database not found at \"$db\""
		return 1
	fi

	for line in $(tar tf "$db" | sed -n 's#^\([^/]*\)/$#\1#p'); do
		local name=${line##*/}
		if [[ ${line%-*-*} = $pkgname ]]; then
			echo $name
			return 0
		fi
	done

	return 1
}

pkgver_from_db() {
	local pkgentry
	local pkgver

	pkgentry="$(pkgentry_from_db $1 $2 $3)" || return 1
	pkgver="${pkgentry##*-}"
	pkgentry=${pkgentry%-*}
	pkgver="${pkgentry##*-}-$pkgver"

	echo $pkgver
}

get_pkgbuild() {
	repo=$1
	pkgbase=$2
	pkgver=$3
	[ -f "$WORKDIR/pkgbuilds/$repo/$pkgbase-$pkgver" ] && return
	mkdir -p "$WORKDIR/pkgbuilds/$repo"
	get_file_from_pkgrepo "$pkgbase" "$pkgver" PKGBUILD \
		> "$WORKDIR/pkgbuilds/$repo/$pkgbase-$pkgver"
}

# get_file_from_pkgrepo pkgbase tag filename
#
# Get a file from the package's git/svn/whatever repo.
# tag is the full package version (epoch:pkgver-pkgrel) or depending on how
# the VCS is used any other recognized tag.
#
# Implementation note: This function should be the only one directly
# interacting with the given VCS and should automatically detect
# where a pkgbase is stored if multiple VCSs are used.
get_file_from_pkgrepo() {
	local pkgbase="$1"
	local tag="$2"
	local filename="$3"

	# TODO: implement svn/git extraction
	# for git: cd $whereever; git show $tag:$filename
	#curl -s https://projects.archlinux.org/svntogit/community.git/plain/trunk/$filename?h=packages/$pkgbase
	# TODO: this requires us to restructure the repos
	arch_svn cat "${SVNREPO}/${pkgbase}/tags/$tag/$filename"
	#arch_svn cat "${SVNREPO}/${pkgbase}/trunk/$filename"
}

get_dir_from_pkgrepo() {
	local pkgbase="$1"
	local tag="$2"
	local src="$3"
	local dest="$4"

	# TODO: implement svn/git extraction
	# for git: use git archive?
	arch_svn export -q "${SVNREPO}/${pkgbase}/tags/${tag}/${src}" "${dest}"
}

arch_svn() {
	if [ -z "${SVNUSER}" ]; then
		/usr/bin/svn "${@}"
	else
		sudo -u "${SVNUSER}" -- /usr/bin/svn --username "${SUDO_USER}" "${@}"
	fi
}