better patching for zip files

Adds a zip mode ("-z") to imgdiff to construct efficient patches for
zip files (including jars and apks).  We identify the regions within
the zip file containing deflated data, and when a corresponding file
can be found in the source zip, a patch is generated for the
uncompressed version of the data.

The GZIP chunk type is replaced with a DEFLATE chunk type that handles
a raw deflated data stream.  This new DEFLATE chunk can be used for
both gzipped pieces (as found within boot and recovery images) and zip
files (apks, etc.)  The gzip header and footer are handled by NORMAL
chunks on either side of the main DEFLATE chunks.  (Typically these
tiny NORMAL chunks will get merged with adjacent chunks, so the number
of output chunks is unaffected.)

Add a test script that tests the generate-apply cycle on all the zips
and images within a pair of full OTA packages.

1 files changed, 118 insertions, 0 deletions

diff --git a/tools/applypatch/imgdiff_test.sh b/tools/applypatch/imgdiff_test.sh
new file mode 100755
index 0000000..dcdb922
--- /dev/null
+++ b/tools/applypatch/imgdiff_test.sh
@@ -0,0 +1,118 @@
+#!/bin/bash
+#
+# A script for testing imgdiff/applypatch.  It takes two full OTA
+# packages as arguments.  It generates (on the host) patches for all
+# the zip/jar/apk files they have in common, as well as boot and
+# recovery images.  It then applies the patches on the device (or
+# emulator) and checks that the resulting file is correct.
+
+EMULATOR_PORT=5580
+
+# set to 0 to use a device instead
+USE_EMULATOR=0
+
+# where on the device to do all the patching.
+WORK_DIR=/data/local/tmp
+
+START_OTA_PACKAGE=$1
+END_OTA_PACKAGE=$2
+
+# ------------------------
+
+tmpdir=$(mktemp -d)
+
+if [ "$USE_EMULATOR" == 1 ]; then
+  emulator -wipe-data -noaudio -no-window -port $EMULATOR_PORT &
+  pid_emulator=$!
+  ADB="adb -s emulator-$EMULATOR_PORT "
+else
+  ADB="adb -d "
+fi
+
+echo "waiting to connect to device"
+$ADB wait-for-device
+
+# run a command on the device; exit with the exit status of the device
+# command.
+run_command() {
+  $ADB shell "$@" \; echo \$? | awk '{if (b) {print a}; a=$0; b=1} END {exit a}'
+}
+
+testname() {
+  echo
+  echo "$1"...
+  testname="$1"
+}
+
+fail() {
+  echo
+  echo FAIL: $testname
+  echo
+  [ "$open_pid" == "" ] || kill $open_pid
+  [ "$pid_emulator" == "" ] || kill $pid_emulator
+  exit 1
+}
+
+sha1() {
+  sha1sum $1 | awk '{print $1}'
+}
+
+size() {
+  stat -c %s $1 | tr -d '\n'
+}
+
+cleanup() {
+  # not necessary if we're about to kill the emulator, but nice for
+  # running on real devices or already-running emulators.
+  testname "removing test files"
+  run_command rm $WORK_DIR/applypatch
+  run_command rm $WORK_DIR/source
+  run_command rm $WORK_DIR/target
+  run_command rm $WORK_DIR/patch
+
+  [ "$pid_emulator" == "" ] || kill $pid_emulator
+
+  rm -rf $tmpdir
+}
+
+$ADB push $ANDROID_PRODUCT_OUT/system/bin/applypatch $WORK_DIR/applypatch
+
+patch_and_apply() {
+  local fn=$1
+  shift
+
+  unzip -p $START_OTA_PACKAGE $fn > $tmpdir/source
+  unzip -p $END_OTA_PACKAGE $fn > $tmpdir/target
+  imgdiff "$@" $tmpdir/source $tmpdir/target $tmpdir/patch
+  bsdiff $tmpdir/source $tmpdir/target $tmpdir/patch.bs
+  echo "patch for $fn is $(size $tmpdir/patch) [of $(size $tmpdir/target)] ($(size $tmpdir/patch.bs) with bsdiff)"
+  echo "$fn $(size $tmpdir/patch) of $(size $tmpdir/target) bsdiff $(size $tmpdir/patch.bs)" >> /tmp/stats.txt
+  $ADB push $tmpdir/source $WORK_DIR/source || fail "source push failed"
+  run_command rm /data/local/tmp/target
+  $ADB push $tmpdir/patch $WORK_DIR/patch || fail "patch push failed"
+  run_command /data/local/tmp/applypatch /data/local/tmp/source \
+    /data/local/tmp/target $(sha1 $tmpdir/target) $(size $tmpdir/target) \
+    $(sha1 $tmpdir/source):/data/local/tmp/patch \
+    || fail "applypatch of $fn failed"
+  $ADB pull /data/local/tmp/target $tmpdir/result
+  diff -q $tmpdir/target $tmpdir/result || fail "patch output not correct!"
+}
+
+# --------------- basic execution ----------------------
+
+for i in $((zipinfo -1 $START_OTA_PACKAGE; zipinfo -1 $END_OTA_PACKAGE) | \
+           sort | uniq -d | egrep -e '[.](apk|jar|zip)$'); do
+  patch_and_apply $i -z
+done
+patch_and_apply boot.img
+patch_and_apply system/recovery.img
+
+
+# --------------- cleanup ----------------------
+
+cleanup
+
+echo
+echo PASS
+echo
+