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Commit ef1bb436 authored by Tao Bao's avatar Tao Bao
Browse files

releasetools: Generate streamable A/B OTA packages. 

In order to support streaming A/B OTA packages, we pack
payload_properties.txt and care_map.txt in ZIP_STORED mode. These two
entries along with payload.bin (already in ZIP_STORED prior to this CL)
can be fetched directly based on the offset and length info.

We write the offset and length info into the package metadata entry
(META-INF/com/android/metadata), which can be parsed by the OTA server.

payload_properties.txt and care_map.txt are usually less than 1-KiB. So
the change only incurs marginal size increase.

Bug: 33382114
Test: Generate an A/B OTA package. Verify the 'streaming-property-files'
      entry in the metadata file.

Change-Id: I04504e834eb36e18876c5f5a5a09289ee05c6f9a
parent f8acdc50

tools/releasetools/ota_from_target_files.py

+52 −6
Original line number Diff line number Diff line
@@ -1226,6 +1226,21 @@ def WriteABOTAPackageWithBrilloScript(target_file, output_file, 
                                      source_file=None):

  """Generate an Android OTA package that has A/B update payload."""



  def ComputeStreamingMetadata(zip_file):

    """Compute the streaming metadata for a given zip."""



    def ComputeEntryOffsetSize(name):

      """Compute the zip entry offset and size."""

      info = zip_file.getinfo(name)

      offset = info.header_offset + len(info.FileHeader())

      size = info.file_size

      return '%s:%d:%d' % (name, offset, size)



    offsets = [ComputeEntryOffsetSize('payload.bin'),

               ComputeEntryOffsetSize('payload_properties.txt'),

               ComputeEntryOffsetSize('care_map.txt')]

    return ','.join(offsets)



  # The place where the output from the subprocess should go.

  log_file = sys.stdout if OPTIONS.verbose else subprocess.PIPE
@@ -1363,11 +1378,15 @@ def WriteABOTAPackageWithBrilloScript(target_file, output_file, 
      f.write("POWERWASH=1\n")

    metadata["ota-wipe"] = "yes"



  # Add the signed payload file and properties into the zip.

  common.ZipWrite(output_zip, properties_file, arcname="payload_properties.txt")

  # Add the signed payload file and properties into the zip. In order to

  # support streaming, we pack payload.bin, payload_properties.txt and

  # care_map.txt as ZIP_STORED. So these entries can be read directly with

  # the offset and length pairs.

  common.ZipWrite(output_zip, signed_payload_file, arcname="payload.bin",

                  compress_type=zipfile.ZIP_STORED)

  WriteMetadata(metadata, output_zip)

  common.ZipWrite(output_zip, properties_file,

                  arcname="payload_properties.txt",

                  compress_type=zipfile.ZIP_STORED)



  # If dm-verity is supported for the device, copy contents of care_map

  # into A/B OTA package.
@@ -1377,16 +1396,43 @@ def WriteABOTAPackageWithBrilloScript(target_file, output_file, 
    namelist = target_zip.namelist()

    if care_map_path in namelist:

      care_map_data = target_zip.read(care_map_path)

      common.ZipWriteStr(output_zip, "care_map.txt", care_map_data)

      common.ZipWriteStr(output_zip, "care_map.txt", care_map_data,

          compress_type=zipfile.ZIP_STORED)

    else:

      print("Warning: cannot find care map file in target_file package")

    common.ZipClose(target_zip)



  # Sign the whole package to comply with the Android OTA package format.

  # SignOutput(), which in turn calls signapk.jar, will possibly reorder the

  # zip entries, as well as padding the entry headers. We sign the current

  # package (without the metadata entry) to allow that to happen. Then compute

  # the zip entry offsets, write the metadata and do the signing again.

  common.ZipClose(output_zip)

  SignOutput(temp_zip_file.name, output_file)

  temp_signing = tempfile.NamedTemporaryFile()

  SignOutput(temp_zip_file.name, temp_signing.name)

  temp_zip_file.close()



  # Open the signed zip. Compute the metadata that's needed for streaming.

  output_zip = zipfile.ZipFile(temp_signing, "a",

                               compression=zipfile.ZIP_DEFLATED)

  metadata['streaming-property-files'] = ComputeStreamingMetadata(output_zip)



  # Write the metadata entry into the zip.

  WriteMetadata(metadata, output_zip)

  common.ZipClose(output_zip)



  # Re-sign the package after adding the metadata entry, which should not

  # affect the entries that are needed for streaming. Because signapk packs

  # ZIP_STORED entries first, then the ZIP_DEFLATED entries such as metadata.

  SignOutput(temp_signing.name, output_file)

  temp_signing.close()



  # Reopen the signed zip to double check the streaming metadata.

  output_zip = zipfile.ZipFile(output_file, "r")

  assert (metadata['streaming-property-files'] ==

          ComputeStreamingMetadata(output_zip)), \

              "Mismatching streaming metadata."

  common.ZipClose(output_zip)





class FileDifference(object):

  def __init__(self, partition, source_zip, target_zip, output_zip):