Introduce multibuild_merge_root, as an universal interim-install merging function.

3 files changed, 61 insertions, 43 deletions

diff --git a/eclass/ChangeLog b/eclass/ChangeLog
index f3080af4ebd7..ff57e98ec36b 100644
--- a/eclass/ChangeLog
+++ b/eclass/ChangeLog
@@ -1,6 +1,11 @@
 # ChangeLog for eclass directory
 # Copyright 1999-2013 Gentoo Foundation; Distributed under the GPL v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.761 2013/04/01 09:16:07 mgorny Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.762 2013/04/01 09:17:53 mgorny Exp $
+
+  01 Apr 2013; Michał Górny <mgorny@gentoo.org> distutils-r1.eclass,
+  multibuild.eclass:
+  Introduce multibuild_merge_root, as an universal interim-install merging
+  function.
 
   01 Apr 2013; Michał Górny <mgorny@gentoo.org> autotools-utils.eclass:
   Support setting mode of prune_libtool_files through
diff --git a/eclass/distutils-r1.eclass b/eclass/distutils-r1.eclass
index 0982e6cb4c5b..74fb014c86a2 100644
--- a/eclass/distutils-r1.eclass
+++ b/eclass/distutils-r1.eclass
@@ -1,6 +1,6 @@
 # Copyright 1999-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/distutils-r1.eclass,v 1.65 2013/03/19 06:13:41 mgorny Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/distutils-r1.eclass,v 1.66 2013/04/01 09:17:53 mgorny Exp $
 
 # @ECLASS: distutils-r1
 # @MAINTAINER:
@@ -449,49 +449,10 @@ distutils-r1_python_install() {
 
 	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
 		_distutils-r1_rename_scripts "${root}"
-		_distutils-r1_merge_root "${root}" "${D}"
+		multibuild_merge_root "${root}" "${D}"
 	fi
 }
 
-# @FUNCTION: distutils-r1_merge_root
-# @USAGE: <src-root> <dest-root>
-# @INTERNAL
-# @DESCRIPTION:
-# Merge the directory tree from <src-root> to <dest-root>, removing
-# the <src-root> in the process.
-_distutils-r1_merge_root() {
-	local src=${1}
-	local dest=${2}
-
-	local lockfile=${T}/distutils-r1-merge-lock
-
-	if type -P lockf &>/dev/null; then
-		# On BSD, we have 'lockf' wrapper.
-		tar -C "${src}" -f - -c . \
-			| lockf "${lockfile}" tar -x -f - -C "${dest}"
-	else
-		local lock_fd
-		if type -P flock &>/dev/null; then
-			# On Linux, we have 'flock' which can lock fd.
-			redirect_alloc_fd lock_fd "${lockfile}" '>>'
-			flock ${lock_fd}
-		else
-			ewarn "distutils-r1: no locking service found, please report."
-		fi
-
-		cp -a -l -n "${src}"/. "${dest}"/
-
-		if [[ ${lock_fd} ]]; then
-			# Close the lock file when we are done with it.
-			# Prevents deadlock if we aren't in a subshell.
-			eval "exec ${lock_fd}>&-"
-		fi
-	fi
-	[[ ${?} == 0 ]] || die "Merging ${EPYTHON} image failed."
-
-	rm -rf "${src}"
-}
-
 # @FUNCTION: distutils-r1_python_install_all
 # @DESCRIPTION:
 # The default python_install_all(). It installs the documentation.
diff --git a/eclass/multibuild.eclass b/eclass/multibuild.eclass
index a3f1402088ab..acfdbbd23745 100644
--- a/eclass/multibuild.eclass
+++ b/eclass/multibuild.eclass
@@ -1,6 +1,6 @@
 # Copyright 1999-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/multibuild.eclass,v 1.8 2013/03/10 21:44:01 mgorny Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/multibuild.eclass,v 1.9 2013/04/01 09:17:53 mgorny Exp $
 
 # @ECLASS: multibuild
 # @MAINTAINER:
@@ -238,5 +238,57 @@ run_in_build_dir() {
 	return ${ret}
 }
 
+# @FUNCTION: multibuild_merge_root
+# @USAGE: <src-root> <dest-root>
+# @DESCRIPTION:
+# Merge the directory tree (fake root) from <src-root> to <dest-root>
+# (the real root). Both directories have to be real, absolute paths
+# (i.e. including ${D}). Source root will be removed.
+#
+# This functions uses locking to support merging during parallel
+# installs.
+multibuild_merge_root() {
+	local src=${1}
+	local dest=${2}
+
+	local lockfile=${T}/multibuild_merge_lock
+	local ret
+
+	if use userland_BSD; then
+		# Locking is done by 'lockf' which can wrap a command.
+		# 'cp -a -n' is broken:
+		# http://www.freebsd.org/cgi/query-pr.cgi?pr=174489
+		# using tar instead which is universal but terribly slow.
+
+		tar -C "${src}" -f - -c . \
+			| lockf "${lockfile}" tar -x -f - -C "${dest}"
+		[[ ${PIPESTATUS[*]} == '0 0' ]]
+		ret=${?}
+	elif use userland_GNU; then
+		# GNU has 'flock' which can't wrap commands but can lock
+		# a fd which is good enough for us.
+		# and cp works with '-a -n'.
+
+		local lock_fd
+		redirect_alloc_fd lock_fd "${lockfile}" '>>'
+		flock ${lock_fd}
+
+		cp -a -l -n "${src}"/. "${dest}"/
+		ret=${?}
+
+		# Close the lock file when we are done with it.
+		# Prevents deadlock if we aren't in a subshell.
+		eval "exec ${lock_fd}>&-"
+	else
+		die "Unsupported userland (${USERLAND}), please report."
+	fi
+
+	if [[ ${ret} -ne 0 ]]; then
+		die "${MULTIBUILD_VARIANT:-(unknown)}: merging image failed."
+	fi
+
+	rm -rf "${src}"
+}
+
 _MULTIBUILD=1
 fi