refactor BlockDifference into common

Move BlockDifference into common and make its script generation code
more complete, so that it can be use by releasetools.py to do diffs on
baseband images.

Bug: 16984795
Change-Id: Iba9afc1c7755458ce47468b5170672612b2cb4b3

1 files changed, 7 insertions, 58 deletions

diff --git a/tools/releasetools/ota_from_target_files b/tools/releasetools/ota_from_target_files
index bcc3210..8b7342b 100755
--- a/tools/releasetools/ota_from_target_files
+++ b/tools/releasetools/ota_from_target_files
@@ -455,35 +455,6 @@ def GetImage(which, tmpdir, info_dict):
   return sparse_img.SparseImage(path, mappath)
 
 
-class BlockDifference:
-  def __init__(self, partition, tgt, src=None):
-    self.partition = partition
-
-    b = blockimgdiff.BlockImageDiff(tgt, src, threads=OPTIONS.worker_threads)
-    tmpdir = tempfile.mkdtemp()
-    OPTIONS.tempfiles.append(tmpdir)
-    self.path = os.path.join(tmpdir, partition)
-    b.Compute(self.path)
-
-    _, self.device = common.GetTypeAndDevice("/" + partition, OPTIONS.info_dict)
-
-  def WriteScript(self, script, output_zip):
-    partition = self.partition
-    with open(self.path + ".transfer.list", "rb") as f:
-      common.ZipWriteStr(output_zip, partition + ".transfer.list", f.read())
-    with open(self.path + ".new.dat", "rb") as f:
-      common.ZipWriteStr(output_zip, partition + ".new.dat", f.read())
-    with open(self.path + ".patch.dat", "rb") as f:
-      common.ZipWriteStr(output_zip, partition + ".patch.dat", f.read(),
-                         compression=zipfile.ZIP_STORED)
-
-    call = (('block_image_update("%s", '
-             'package_extract_file("%s.transfer.list"), '
-             '"%s.new.dat", "%s.patch.dat");\n') %
-            (self.device, partition, partition, partition))
-    script.AppendExtra(script._WordWrap(call))
-
-
 def WriteFullOTAPackage(input_zip, output_zip):
   # TODO: how to determine this?  We don't know what version it will
   # be installed on top of.  For now, we expect the API just won't
@@ -586,7 +557,7 @@ else if get_stage("%(bcb_dev)s", "stage") == "3/3" then
     # writes incrementals to do it.
     system_tgt = GetImage("system", OPTIONS.input_tmp, OPTIONS.info_dict)
     system_tgt.ResetFileMap()
-    system_diff = BlockDifference("system", system_tgt, src=None)
+    system_diff = common.BlockDifference("system", system_tgt, src=None)
     system_diff.WriteScript(script, output_zip)
   else:
     script.FormatPartition("/system")
@@ -619,7 +590,7 @@ else if get_stage("%(bcb_dev)s", "stage") == "3/3" then
     if block_based:
       vendor_tgt = GetImage("vendor", OPTIONS.input_tmp, OPTIONS.info_dict)
       vendor_tgt.ResetFileMap()
-      vendor_diff = BlockDifference("vendor", vendor_tgt)
+      vendor_diff = common.BlockDifference("vendor", vendor_tgt)
       vendor_diff.WriteScript(script, output_zip)
     else:
       script.FormatPartition("/vendor")
@@ -760,14 +731,14 @@ def WriteBlockIncrementalOTAPackage(target_zip, source_zip, output_zip):
 
   system_src = GetImage("system", OPTIONS.source_tmp, OPTIONS.source_info_dict)
   system_tgt = GetImage("system", OPTIONS.target_tmp, OPTIONS.target_info_dict)
-  system_diff = BlockDifference("system", system_tgt, system_src)
+  system_diff = common.BlockDifference("system", system_tgt, system_src)
 
   if HasVendorPartition(target_zip):
     if not HasVendorPartition(source_zip):
       raise RuntimeError("can't generate incremental that adds /vendor")
     vendor_src = GetImage("vendor", OPTIONS.source_tmp, OPTIONS.source_info_dict)
     vendor_tgt = GetImage("vendor", OPTIONS.target_tmp, OPTIONS.target_info_dict)
-    vendor_diff = BlockDifference("vendor", vendor_tgt, vendor_src)
+    vendor_diff = common.BlockDifference("vendor", vendor_tgt, vendor_src)
   else:
     vendor_diff = None
 
@@ -867,32 +838,10 @@ else
 
   device_specific.IncrementalOTA_InstallBegin()
 
-  script.AppendExtra('if range_sha1("%s", "%s") == "%s" then' %
-                     (system_diff.device, system_src.care_map.to_string_raw(),
-                      system_src.TotalSha1()))
-  script.Print("Patching system image...")
-  script.ShowProgress(0.8 if vendor_diff else 0.9, 0)
-  system_diff.WriteScript(script, output_zip)
-  script.AppendExtra(('else\n'
-                      '  (range_sha1("%s", "%s") == "%s") ||\n'
-                      '  abort("system partition has unexpected contents");\n'
-                      'endif;') %
-                     (system_diff.device, system_tgt.care_map.to_string_raw(),
-                      system_tgt.TotalSha1()))
-
+  system_diff.WriteScript(script, output_zip,
+                          progress=0.8 if vendor_diff else 0.9)
   if vendor_diff:
-    script.AppendExtra('if range_sha1("%s", "%s") == "%s" then' %
-                       (vendor_diff.device, vendor_src.care_map.to_string_raw(),
-                        vendor_src.TotalSha1()))
-    script.Print("Patching vendor image...")
-    script.ShowProgress(0.1, 0)
-    vendor_diff.WriteScript(script, output_zip)
-    script.AppendExtra(('else\n'
-                        '  (range_sha1("%s", "%s") == "%s") ||\n'
-                        '  abort("vendor partition has unexpected contents");\n'
-                        'endif;') %
-                       (vendor_diff.device, vendor_tgt.care_map.to_string_raw(),
-                        vendor_tgt.TotalSha1()))
+    vendor_diff.WriteScript(script, output_zip, progress=0.1)
 
   if OPTIONS.two_step:
     common.ZipWriteStr(output_zip, "boot.img", target_boot.data)