Add option to enable zucchini

Change-Id: Id952826c9c5af912fba679af61f2a2e1645641dd

tools/releasetools/ota_from_target_files.py

@@ -230,6 +230,9 @@ A/B OTA specific options
 
   --compressor_types
       A colon ':' separated list of compressors. Allowed values are bz2 and brotli.
+
+  --enable_zucchini
+      Whether to enable to zucchini feature. Will generate smaller OTA but uses more memory.
 """
 
 from __future__ import print_function
@@ -299,6 +302,7 @@ OPTIONS.vabc_downgrade = False
 OPTIONS.enable_vabc_xor = True
 OPTIONS.force_minor_version = None
 OPTIONS.compressor_types = None
+OPTIONS.enable_zucchini = None
 
 POSTINSTALL_CONFIG = 'META/postinstall_config.txt'
 DYNAMIC_PARTITION_INFO = 'META/dynamic_partitions_info.txt'
@@ -1141,6 +1145,14 @@ def GenerateAbOtaPackage(target_file, output_file, source_file=None):
     partition_timestamps_flags = GeneratePartitionTimestampFlags(
         metadata.postcondition.partition_state)
 
+  # Auto-check for compatibility only if --enable_zucchini omitted. Otherwise
+  # let user override zucchini settings. This is useful for testing.
+  if OPTIONS.enable_zucchini is None:
+    if not ota_utils.IsZucchiniCompatible(source_file, target_file):
+      additional_args += ["--enable_zucchini", "false"]
+  else:
+    additional_args += ["--enable_zucchini", str(OPTIONS.enable_zucchini).lower()]
+
   if OPTIONS.disable_vabc:
     additional_args += ["--disable_vabc", "true"]
   if OPTIONS.enable_vabc_xor:
@@ -1326,6 +1338,8 @@ def main(argv):
       OPTIONS.force_minor_version = a
     elif o == "--compressor_types":
       OPTIONS.compressor_types = a
+    elif o == "--enable_zucchini":
+      OPTIONS.enable_zucchini = a.lower() != "false"
     else:
       return False
     return True
@@ -1373,6 +1387,7 @@ def main(argv):
                                  "enable_vabc_xor=",
                                  "force_minor_version=",
                                  "compressor_types=",
+                                 "enable_zucchin=",
                              ], extra_option_handler=option_handler)
 
   if len(args) != 2:

tools/releasetools/ota_utils.py

@@ -638,3 +638,38 @@ def ConstructOtaApexInfo(target_zip, source_file=None):
       target_apex.source_version = source_apex_versions[name]
 
   return target_apex_proto.SerializeToString()
+
+
+def IsZucchiniCompatible(source_file: str, target_file: str):
+  """Check whether zucchini versions in two builds are compatible
+
+  Args:
+    source_file: Path to source build's target_file.zip
+    target_file: Path to target build's target_file.zip
+
+  Returns:
+    bool true if and only if zucchini versions are compatible
+  """
+  if source_file is None or target_file is None:
+    return False
+  assert os.path.exists(source_file)
+  assert os.path.exists(target_file)
+
+  assert zipfile.is_zipfile(source_file) or os.path.isdir(source_file)
+  assert zipfile.is_zipfile(target_file) or os.path.isdir(target_file)
+  _ZUCCHINI_CONFIG_ENTRY_NAME = "META/zucchini_config.txt"
+
+  def ReadEntry(path, entry):
+    # Read an entry inside a .zip file or extracted dir of .zip file
+    if zipfile.is_zipfile(path):
+      with zipfile.ZipFile(path, "r", allowZip64=True) as zfp:
+        if entry in zfp.namelist():
+          return zfp.read(entry).decode()
+    else:
+      entry_path = os.path.join(entry, path)
+      if os.path.exists(entry_path):
+        with open(entry_path, "r") as fp:
+          return fp.read()
+      else:
+        return ""
+  return ReadEntry(source_file, _ZUCCHINI_CONFIG_ENTRY_NAME) == ReadEntry(target_file, _ZUCCHINI_CONFIG_ENTRY_NAME)