From f4544b82a6d53a413bd093ec0bb490e21c04801a Mon Sep 17 00:00:00 2001
From: Enno Boland <g@s01.de>
Date: Mon, 11 Aug 2014 18:05:13 +0200
Subject: [PATCH] common/hooks: add support for vcdiff creation

---
 common/hooks/post-pkg/01-xdelta_repolist.sh | 24 +++++++++++++++++++++
 common/hooks/pre-pkg/01-xdelta_repolist.sh  | 11 ++++++++++
 xbps-src                                    |  3 ++-
 3 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 common/hooks/post-pkg/01-xdelta_repolist.sh
 create mode 100644 common/hooks/pre-pkg/01-xdelta_repolist.sh

diff --git a/common/hooks/post-pkg/01-xdelta_repolist.sh b/common/hooks/post-pkg/01-xdelta_repolist.sh
new file mode 100644
index 00000000000..a18f6ae3071
--- /dev/null
+++ b/common/hooks/post-pkg/01-xdelta_repolist.sh
@@ -0,0 +1,24 @@
+# This hook generates vcdiffs
+
+hook() {
+	set -x
+	[ -z "$XBPS_GENERATE_VCDIFF" ] && return 0;
+
+	find $XBPS_REPOSITORY -name '*.genVcdiff' | xargs -r sha256sum | \
+		while read chk oldfile; do
+			newfile=${oldfile/.genVcdiff/}
+
+			if ! cmp -s "${newfile}" "${oldfile}"; then
+				newdiff="${newfile}.${chk}.vcdiff"
+				xdelta3 -D -R -f -e -s "${oldfile}" "${newfile}" "${newdiff}"
+				for diff in ${newfile}.*.vcdiff; do
+					[ "${diff}" = "${newdiff}" ] && continue;
+					cp -- "${diff}" "${diff}.tmp"
+					xdelta3 -f merge -m "${diff}.tmp" "${newdiff}" "${diff}"
+					rm -- "${diff}.tmp"
+				done
+			fi
+
+			rm -- "${oldfile}"
+		done
+}
diff --git a/common/hooks/pre-pkg/01-xdelta_repolist.sh b/common/hooks/pre-pkg/01-xdelta_repolist.sh
new file mode 100644
index 00000000000..6d6b21d739a
--- /dev/null
+++ b/common/hooks/pre-pkg/01-xdelta_repolist.sh
@@ -0,0 +1,11 @@
+# this hook marks files which are about to change for generating vcdiffs
+
+hook() {
+	[ -z "$XBPS_GENERATE_VCDIFF" ] && return 0;
+
+	# create links to preserve old versions of repodata
+	find $XBPS_REPOSITORY -name '*-repodata' | \
+		while read; do
+			ln "${REPLY}" "${REPLY}.genVcdiff"
+		done
+}
diff --git a/xbps-src b/xbps-src
index dc3535ee677..684e19aa149 100755
--- a/xbps-src
+++ b/xbps-src
@@ -469,7 +469,8 @@ export XBPS_SHUTILSDIR XBPS_CROSSPFDIR XBPS_TRIGGERSDIR \
     XBPS_CCACHE XBPS_DISTCC XBPS_DISTCC_HOSTS XBPS_SKIP_DEPS \
     XBPS_SKIP_REMOTEREPOS XBPS_CROSS_BUILD XBPS_PKG_OPTIONS \
     XBPS_CONFIG_FILE XBPS_KEEP_ALL XBPS_HOSTDIR XBPS_MASTERDIR \
-    XBPS_SRC_VERSION XBPS_DESTDIR FAKEROOT_CMD CHROOT_CMD XBPS_MACHINE
+    XBPS_SRC_VERSION XBPS_DESTDIR FAKEROOT_CMD CHROOT_CMD XBPS_MACHINE \
+    XBPS_GENERATE_VCDIFF
 
 for i in REPOSITORY DESTDIR BUILDDIR SRCDISTDIR; do
     eval val="\$XBPS_$i"