build/android/resource_sizes.py

#!/usr/bin/env vpython
# Copyright (c) 2011 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Reports binary size metrics for an APK.

More information at //docs/speed/binary_size/metrics.md.
"""

from __future__ import print_function

import argparse
import collections
from contextlib import contextmanager
import json
import logging
import os
import posixpath
import re
import struct
import sys
import tempfile
import zipfile
import zlib

import devil_chromium
from devil.android.sdk import build_tools
from devil.utils import cmd_helper
from devil.utils import lazy
import method_count
from pylib import constants
from pylib.constants import host_paths

_AAPT_PATH = lazy.WeakConstant(lambda: build_tools.GetPath('aapt'))
_BUILD_UTILS_PATH = os.path.join(
    host_paths.DIR_SOURCE_ROOT, 'build', 'android', 'gyp')

with host_paths.SysPath(os.path.join(host_paths.DIR_SOURCE_ROOT, 'build')):
  import gn_helpers  # pylint: disable=import-error

with host_paths.SysPath(host_paths.BUILD_COMMON_PATH):
  import perf_tests_results_helper  # pylint: disable=import-error

with host_paths.SysPath(host_paths.TRACING_PATH):
  from tracing.value import convert_chart_json  # pylint: disable=import-error

with host_paths.SysPath(_BUILD_UTILS_PATH, 0):
  from util import build_utils  # pylint: disable=import-error
  from util import zipalign  # pylint: disable=import-error


zipalign.ApplyZipFileZipAlignFix()

# Captures an entire config from aapt output.
_AAPT_CONFIG_PATTERN = r'config %s:(.*?)config [a-zA-Z-]+:'
# Matches string resource entries from aapt output.
_AAPT_ENTRY_RE = re.compile(
    r'resource (?P<id>\w{10}) [\w\.]+:string/.*?"(?P<val>.+?)"', re.DOTALL)
_BASE_CHART = {
    'format_version': '0.1',
    'benchmark_name': 'resource_sizes',
    'benchmark_description': 'APK resource size information.',
    'trace_rerun_options': [],
    'charts': {}
}
# Macro definitions look like (something, 123) when
# enable_resource_allowlist_generation=true.
_RC_HEADER_RE = re.compile(r'^#define (?P<name>\w+).* (?P<id>\d+)\)?$')
_RE_NON_LANGUAGE_PAK = re.compile(r'^assets/.*(resources|percent)\.pak$')
_READELF_SIZES_METRICS = {
    'text': ['.text'],
    'data': ['.data', '.rodata', '.data.rel.ro', '.data.rel.ro.local'],
    'relocations': ['.rel.dyn', '.rel.plt', '.rela.dyn', '.rela.plt'],
    'unwind': [
        '.ARM.extab', '.ARM.exidx', '.eh_frame', '.eh_frame_hdr',
        '.ARM.exidxsentinel_section_after_text'
    ],
    'symbols': [
        '.dynsym', '.dynstr', '.dynamic', '.shstrtab', '.got', '.plt',
        '.got.plt', '.hash', '.gnu.hash'
    ],
    'other': [
        '.init_array', '.preinit_array', '.ctors', '.fini_array', '.comment',
        '.note.gnu.gold-version', '.note.crashpad.info', '.note.android.ident',
        '.ARM.attributes', '.note.gnu.build-id', '.gnu.version',
        '.gnu.version_d', '.gnu.version_r', '.interp', '.gcc_except_table'
    ]
}


class _AccumulatingReporter(object):
  def __init__(self):
    self._combined_metrics = collections.defaultdict(int)

  def __call__(self, graph_title, trace_title, value, units):
    self._combined_metrics[(graph_title, trace_title, units)] += value

  def DumpReports(self, report_func):
    for (graph_title, trace_title,
         units), value in sorted(self._combined_metrics.iteritems()):
      report_func(graph_title, trace_title, value, units)


class _ChartJsonReporter(_AccumulatingReporter):
  def __init__(self, chartjson):
    super(_ChartJsonReporter, self).__init__()
    self._chartjson = chartjson
    self.trace_title_prefix = ''

  def __call__(self, graph_title, trace_title, value, units):
    super(_ChartJsonReporter, self).__call__(graph_title, trace_title, value,
                                             units)

    perf_tests_results_helper.ReportPerfResult(
        self._chartjson, graph_title, self.trace_title_prefix + trace_title,
        value, units)

  def SynthesizeTotals(self, unique_method_count):
    for tup, value in sorted(self._combined_metrics.iteritems()):
      graph_title, trace_title, units = tup
      if trace_title == 'unique methods':
        value = unique_method_count
      perf_tests_results_helper.ReportPerfResult(self._chartjson, graph_title,
                                                 'Combined_' + trace_title,
                                                 value, units)


def _PercentageDifference(a, b):
  if a == 0:
    return 0
  return float(b - a) / a


def _ReadZipInfoExtraFieldLength(zip_file, zip_info):
  """Reads the value of |extraLength| from |zip_info|'s local file header.

  |zip_info| has an |extra| field, but it's read from the central directory.
  Android's zipalign tool sets the extra field only in local file headers.
  """
  # Refer to https://en.wikipedia.org/wiki/Zip_(file_format)#File_headers
  zip_file.fp.seek(zip_info.header_offset + 28)
  return struct.unpack('<H', zip_file.fp.read(2))[0]


def _MeasureApkSignatureBlock(zip_file):
  """Measures the size of the v2 / v3 signing block.

  Refer to: https://source.android.com/security/apksigning/v2
  """
  # Seek to "end of central directory" struct.
  eocd_offset_from_end = -22 - len(zip_file.comment)
  zip_file.fp.seek(eocd_offset_from_end, os.SEEK_END)
  assert zip_file.fp.read(4) == b'PK\005\006', (
      'failed to find end-of-central-directory')

  # Read out the "start of central directory" offset.
  zip_file.fp.seek(eocd_offset_from_end + 16, os.SEEK_END)
  start_of_central_directory = struct.unpack('<I', zip_file.fp.read(4))[0]

  # Compute the offset after the last zip entry.
  last_info = max(zip_file.infolist(), key=lambda i: i.header_offset)
  last_header_size = (30 + len(last_info.filename) +
                      _ReadZipInfoExtraFieldLength(zip_file, last_info))
  end_of_last_file = (last_info.header_offset + last_header_size +
                      last_info.compress_size)
  return start_of_central_directory - end_of_last_file


def _RunReadelf(so_path, options, tool_prefix=''):
  return cmd_helper.GetCmdOutput(
      [tool_prefix + 'readelf'] + options + [so_path])


def _ExtractLibSectionSizesFromApk(apk_path, lib_path, tool_prefix):
  with Unzip(apk_path, filename=lib_path) as extracted_lib_path:
    grouped_section_sizes = collections.defaultdict(int)
    no_bits_section_sizes, section_sizes = _CreateSectionNameSizeMap(
        extracted_lib_path, tool_prefix)
    for group_name, section_names in _READELF_SIZES_METRICS.iteritems():
      for section_name in section_names:
        if section_name in section_sizes:
          grouped_section_sizes[group_name] += section_sizes.pop(section_name)

    # Consider all NOBITS sections as .bss.
    grouped_section_sizes['bss'] = sum(
        v for v in no_bits_section_sizes.itervalues())

    # Group any unknown section headers into the "other" group.
    for section_header, section_size in section_sizes.iteritems():
      sys.stderr.write('Unknown elf section header: %s\n' % section_header)
      grouped_section_sizes['other'] += section_size

    return grouped_section_sizes


def _CreateSectionNameSizeMap(so_path, tool_prefix):
  stdout = _RunReadelf(so_path, ['-S', '--wide'], tool_prefix)
  section_sizes = {}
  no_bits_section_sizes = {}
  # Matches  [ 2] .hash HASH 00000000006681f0 0001f0 003154 04   A  3   0  8
  for match in re.finditer(r'\[[\s\d]+\] (\..*)$', stdout, re.MULTILINE):
    items = match.group(1).split()
    target = no_bits_section_sizes if items[1] == 'NOBITS' else section_sizes
    target[items[0]] = int(items[4], 16)

  return no_bits_section_sizes, section_sizes


def _ParseManifestAttributes(apk_path):
  # Check if the manifest specifies whether or not to extract native libs.
  output = cmd_helper.GetCmdOutput([
      _AAPT_PATH.read(), 'd', 'xmltree', apk_path, 'AndroidManifest.xml'])

  def parse_attr(name):
    # android:extractNativeLibs(0x010104ea)=(type 0x12)0x0
    # android:extractNativeLibs(0x010104ea)=(type 0x12)0xffffffff
    # dist:onDemand=(type 0x12)0xffffffff
    m = re.search(name + r'(?:\(.*?\))?=\(type .*?\)(\w+)', output)
    return m and int(m.group(1), 16)

  skip_extract_lib = bool(parse_attr('android:extractNativeLibs'))
  sdk_version = parse_attr('android:minSdkVersion')
  is_feature_split = parse_attr('android:isFeatureSplit')
  # Can use <dist:on-demand>, or <module dist:onDemand="true">.
  on_demand = parse_attr('dist:onDemand') or 'dist:on-demand' in output
  on_demand = bool(on_demand and is_feature_split)

  return sdk_version, skip_extract_lib, on_demand


def _NormalizeLanguagePaks(translations, factor):
  english_pak = translations.FindByPattern(r'.*/en[-_][Uu][Ss]\.l?pak')
  num_translations = translations.GetNumEntries()
  ret = 0
  if english_pak:
    ret -= translations.ComputeZippedSize()
    ret += int(english_pak.compress_size * num_translations * factor)
  return ret


def _NormalizeResourcesArsc(apk_path, num_arsc_files, num_translations,
                            out_dir):
  """Estimates the expected overhead of untranslated strings in resources.arsc.

  See http://crbug.com/677966 for why this is necessary.
  """
  # If there are multiple .arsc files, use the resource packaged APK instead.
  if num_arsc_files > 1:
    if not out_dir:
      return -float('inf')
    ap_name = os.path.basename(apk_path).replace('.apk', '.ap_')
    ap_path = os.path.join(out_dir, 'arsc/apks', ap_name)
    if not os.path.exists(ap_path):
      raise Exception('Missing expected file: %s, try rebuilding.' % ap_path)
    apk_path = ap_path

  aapt_output = _RunAaptDumpResources(apk_path)
  # en-rUS is in the default config and may be cluttered with non-translatable
  # strings, so en-rGB is a better baseline for finding missing translations.
  en_strings = _CreateResourceIdValueMap(aapt_output, 'en-rGB')
  fr_strings = _CreateResourceIdValueMap(aapt_output, 'fr')

  # en-US and en-GB will never be translated.
  config_count = num_translations - 2

  size = 0
  for res_id, string_val in en_strings.iteritems():
    if string_val == fr_strings[res_id]:
      string_size = len(string_val)
      # 7 bytes is the per-entry overhead (not specific to any string). See
      # https://android.googlesource.com/platform/frameworks/base.git/+/android-4.2.2_r1/tools/aapt/StringPool.cpp#414.
      # The 1.5 factor was determined experimentally and is meant to account for
      # other languages generally having longer strings than english.
      size += config_count * (7 + string_size * 1.5)

  return int(size)


def _CreateResourceIdValueMap(aapt_output, lang):
  """Return a map of resource ids to string values for the given |lang|."""
  config_re = _AAPT_CONFIG_PATTERN % lang
  return {entry.group('id'): entry.group('val')
          for config_section in re.finditer(config_re, aapt_output, re.DOTALL)
          for entry in re.finditer(_AAPT_ENTRY_RE, config_section.group(0))}


def _RunAaptDumpResources(apk_path):
  cmd = [_AAPT_PATH.read(), 'dump', '--values', 'resources', apk_path]
  status, output = cmd_helper.GetCmdStatusAndOutput(cmd)
  if status != 0:
    raise Exception('Failed running aapt command: "%s" with output "%s".' %
                    (' '.join(cmd), output))
  return output


class _FileGroup(object):
  """Represents a category that apk files can fall into."""

  def __init__(self, name):
    self.name = name
    self._zip_infos = []
    self._extracted_multipliers = []

  def AddZipInfo(self, zip_info, extracted_multiplier=0):
    self._zip_infos.append(zip_info)
    self._extracted_multipliers.append(extracted_multiplier)

  def AllEntries(self):
    return iter(self._zip_infos)

  def GetNumEntries(self):
    return len(self._zip_infos)

  def FindByPattern(self, pattern):
    return next((i for i in self._zip_infos if re.match(pattern, i.filename)),
                None)

  def FindLargest(self):
    if not self._zip_infos:
      return None
    return max(self._zip_infos, key=lambda i: i.file_size)

  def ComputeZippedSize(self):
    return sum(i.compress_size for i in self._zip_infos)

  def ComputeUncompressedSize(self):
    return sum(i.file_size for i in self._zip_infos)

  def ComputeExtractedSize(self):
    ret = 0
    for zi, multiplier in zip(self._zip_infos, self._extracted_multipliers):
      ret += zi.file_size * multiplier
    return ret

  def ComputeInstallSize(self):
    return self.ComputeExtractedSize() + self.ComputeZippedSize()


def _AnalyzeInternal(apk_path,
                     sdk_version,
                     report_func,
                     dex_stats_collector,
                     out_dir,
                     tool_prefix,
                     apks_path=None,
                     split_name=None):
  """Analyse APK to determine size contributions of different file classes.

  Returns: Normalized APK size.
  """
  dex_stats_collector.CollectFromZip(split_name or '', apk_path)
  file_groups = []

  def make_group(name):
    group = _FileGroup(name)
    file_groups.append(group)
    return group

  def has_no_extension(filename):
    return os.path.splitext(filename)[1] == ''

  native_code = make_group('Native code')
  java_code = make_group('Java code')
  native_resources_no_translations = make_group('Native resources (no l10n)')
  translations = make_group('Native resources (l10n)')
  stored_translations = make_group('Native resources stored (l10n)')
  icu_data = make_group('ICU (i18n library) data')
  v8_snapshots = make_group('V8 Snapshots')
  png_drawables = make_group('PNG drawables')
  res_directory = make_group('Non-compiled Android resources')
  arsc = make_group('Compiled Android resources')
  metadata = make_group('Package metadata')
  unknown = make_group('Unknown files')
  notices = make_group('licenses.notice file')
  unwind_cfi = make_group('unwind_cfi (dev and canary only)')

  with zipfile.ZipFile(apk_path, 'r') as apk:
    apk_contents = apk.infolist()
    # Account for zipalign overhead that exists in local file header.
    zipalign_overhead = sum(
        _ReadZipInfoExtraFieldLength(apk, i) for i in apk_contents)
    # Account for zipalign overhead that exists in central directory header.
    # Happens when python aligns entries in apkbuilder.py, but does not
    # exist when using Android's zipalign. E.g. for bundle .apks files.
    zipalign_overhead += sum(len(i.extra) for i in apk_contents)
    signing_block_size = _MeasureApkSignatureBlock(apk)

  _, skip_extract_lib, _ = _ParseManifestAttributes(apk_path)

  # Pre-L: Dalvik - .odex file is simply decompressed/optimized dex file (~1x).
  # L, M: ART - .odex file is compiled version of the dex file (~4x).
  # N: ART - Uses Dalvik-like JIT for normal apps (~1x), full compilation for
  #    shared apps (~4x).
  # Actual multipliers calculated using "apk_operations.py disk-usage".
  # Will need to update multipliers once apk obfuscation is enabled.
  # E.g. with obfuscation, the 4.04 changes to 4.46.
  speed_profile_dex_multiplier = 1.17
  orig_filename = apks_path or apk_path
  is_webview = 'WebView' in orig_filename
  is_monochrome = 'Monochrome' in orig_filename
  is_library = 'Library' in orig_filename
  is_shared_apk = sdk_version >= 24 and (is_monochrome or is_webview
                                         or is_library)
  # Dex decompression overhead varies by Android version.
  if sdk_version < 21:
    # JellyBean & KitKat
    dex_multiplier = 1.16
  elif sdk_version < 24:
    # Lollipop & Marshmallow
    dex_multiplier = 4.04
  elif is_shared_apk:
    # Oreo and above, compilation_filter=speed
    dex_multiplier = 4.04
  else:
    # Oreo and above, compilation_filter=speed-profile
    dex_multiplier = speed_profile_dex_multiplier

  total_apk_size = os.path.getsize(apk_path)
  for member in apk_contents:
    filename = member.filename
    if filename.endswith('/'):
      continue
    if filename.endswith('.so'):
      basename = posixpath.basename(filename)
      should_extract_lib = not skip_extract_lib and basename.startswith('lib')
      native_code.AddZipInfo(
          member, extracted_multiplier=int(should_extract_lib))
    elif filename.endswith('.dex'):
      java_code.AddZipInfo(member, extracted_multiplier=dex_multiplier)
    elif re.search(_RE_NON_LANGUAGE_PAK, filename):
      native_resources_no_translations.AddZipInfo(member)
    elif filename.endswith('.pak') or filename.endswith('.lpak'):
      compressed = member.compress_type != zipfile.ZIP_STORED
      bucket = translations if compressed else stored_translations
      extracted_multiplier = 0
      if compressed:
        extracted_multiplier = int('en_' in filename or 'en-' in filename)
      bucket.AddZipInfo(member, extracted_multiplier=extracted_multiplier)
    elif 'icu' in filename and filename.endswith('.dat'):
      icu_data.AddZipInfo(member)
    elif filename.endswith('.bin'):
      v8_snapshots.AddZipInfo(member)
    elif filename.startswith('res/'):
      if (filename.endswith('.png') or filename.endswith('.webp')
          or has_no_extension(filename)):
        png_drawables.AddZipInfo(member)
      else:
        res_directory.AddZipInfo(member)
    elif filename.endswith('.arsc'):
      arsc.AddZipInfo(member)
    elif filename.startswith('META-INF') or filename in (
        'AndroidManifest.xml', 'assets/webapk_dex_version.txt'):
      metadata.AddZipInfo(member)
    elif filename.endswith('.notice'):
      notices.AddZipInfo(member)
    elif filename.startswith('assets/unwind_cfi'):
      unwind_cfi.AddZipInfo(member)
    else:
      unknown.AddZipInfo(member)

  if apks_path:
    # We're mostly focused on size of Chrome for non-English locales, so assume
    # Hindi (arbitrarily chosen) locale split is installed.
    with zipfile.ZipFile(apks_path) as z:
      subpath = 'splits/{}-hi.apk'.format(split_name)
      if subpath in z.namelist():
        hindi_apk_info = z.getinfo(subpath)
        total_apk_size += hindi_apk_info.file_size
      else:
        assert split_name != 'base', 'splits/base-hi.apk should always exist'

  total_install_size = total_apk_size
  total_install_size_android_go = total_apk_size
  zip_overhead = total_apk_size

  for group in file_groups:
    actual_size = group.ComputeZippedSize()
    install_size = group.ComputeInstallSize()
    uncompressed_size = group.ComputeUncompressedSize()
    extracted_size = group.ComputeExtractedSize()
    total_install_size += extracted_size
    zip_overhead -= actual_size

    report_func('Breakdown', group.name + ' size', actual_size, 'bytes')
    report_func('InstallBreakdown', group.name + ' size', int(install_size),
                'bytes')
    # Only a few metrics are compressed in the first place.
    # To avoid over-reporting, track uncompressed size only for compressed
    # entries.
    if uncompressed_size != actual_size:
      report_func('Uncompressed', group.name + ' size', uncompressed_size,
                  'bytes')

    if group is java_code and is_shared_apk:
      # Updates are compiled using quicken, but system image uses speed-profile.
      extracted_size = int(uncompressed_size * speed_profile_dex_multiplier)
      total_install_size_android_go += extracted_size
      report_func('InstallBreakdownGo', group.name + ' size',
                  actual_size + extracted_size, 'bytes')
    elif group is translations and apks_path:
      # Assume Hindi rather than English (accounted for above in total_apk_size)
      total_install_size_android_go += actual_size
    else:
      total_install_size_android_go += extracted_size

  # Per-file zip overhead is caused by:
  # * 30 byte entry header + len(file name)
  # * 46 byte central directory entry + len(file name)
  # * 0-3 bytes for zipalign.
  report_func('Breakdown', 'Zip Overhead', zip_overhead, 'bytes')
  report_func('InstallSize', 'APK size', total_apk_size, 'bytes')
  report_func('InstallSize', 'Estimated installed size',
              int(total_install_size), 'bytes')
  if is_shared_apk:
    report_func('InstallSize', 'Estimated installed size (Android Go)',
                int(total_install_size_android_go), 'bytes')
  transfer_size = _CalculateCompressedSize(apk_path)
  report_func('TransferSize', 'Transfer size (deflate)', transfer_size, 'bytes')

  # Size of main dex vs remaining.
  main_dex_info = java_code.FindByPattern('classes.dex')
  if main_dex_info:
    main_dex_size = main_dex_info.file_size
    report_func('Specifics', 'main dex size', main_dex_size, 'bytes')
    secondary_size = java_code.ComputeUncompressedSize() - main_dex_size
    report_func('Specifics', 'secondary dex size', secondary_size, 'bytes')

  main_lib_info = native_code.FindLargest()
  native_code_unaligned_size = 0
  for lib_info in native_code.AllEntries():
    section_sizes = _ExtractLibSectionSizesFromApk(apk_path, lib_info.filename,
                                                   tool_prefix)
    native_code_unaligned_size += sum(
        v for k, v in section_sizes.iteritems() if k != 'bss')
    # Size of main .so vs remaining.
    if lib_info == main_lib_info:
      main_lib_size = lib_info.file_size
      report_func('Specifics', 'main lib size', main_lib_size, 'bytes')
      secondary_size = native_code.ComputeUncompressedSize() - main_lib_size
      report_func('Specifics', 'other lib size', secondary_size, 'bytes')

      for metric_name, size in section_sizes.iteritems():
        report_func('MainLibInfo', metric_name, size, 'bytes')

  # Main metric that we want to monitor for jumps.
  normalized_apk_size = total_apk_size
  # unwind_cfi exists only in dev, canary, and non-channel builds.
  normalized_apk_size -= unwind_cfi.ComputeZippedSize()
  # Sections within .so files get 4kb aligned, so use section sizes rather than
  # file size. Also gets rid of compression.
  normalized_apk_size -= native_code.ComputeZippedSize()
  normalized_apk_size += native_code_unaligned_size
  # Normalized dex size: Size within the zip + size on disk for Android Go
  # devices running Android O (which ~= uncompressed dex size).
  # Use a constant compression factor to account for fluctuations.
  normalized_apk_size -= java_code.ComputeZippedSize()
  normalized_apk_size += java_code.ComputeUncompressedSize()
  # Don't include zipalign overhead in normalized size, since it effectively
  # causes size changes files that proceed aligned files to be rounded.
  # For APKs where classes.dex directly proceeds libchrome.so (the normal case),
  # this causes small dex size changes to disappear into libchrome.so alignment.
  normalized_apk_size -= zipalign_overhead
  # Don't include the size of the apk's signing block because it can fluctuate
  # by up to 4kb (from my non-scientific observations), presumably based on hash
  # sizes.
  normalized_apk_size -= signing_block_size

  # Unaligned size should be ~= uncompressed size or something is wrong.
  # As of now, padding_fraction ~= .007
  padding_fraction = -_PercentageDifference(
      native_code.ComputeUncompressedSize(), native_code_unaligned_size)
  # Ignore this check for small / no native code
  if native_code.ComputeUncompressedSize() > 1000000:
    assert 0 <= padding_fraction < .02, (
        'Padding was: {} (file_size={}, sections_sum={})'.format(
            padding_fraction, native_code.ComputeUncompressedSize(),
            native_code_unaligned_size))

  if apks_path:
    # Locale normalization not needed when measuring only one locale.
    # E.g. a change that adds 300 chars of unstranslated strings would cause the
    # metric to be off by only 390 bytes (assuming a multiplier of 2.3 for
    # Hindi).
    pass
  else:
    # Avoid noise caused when strings change and translations haven't yet been
    # updated.
    num_translations = translations.GetNumEntries()
    num_stored_translations = stored_translations.GetNumEntries()

    if num_translations > 1:
      # Multipliers found by looking at MonochromePublic.apk and seeing how much
      # smaller en-US.pak is relative to the average locale.pak.
      normalized_apk_size += _NormalizeLanguagePaks(translations, 1.17)
    if num_stored_translations > 1:
      normalized_apk_size += _NormalizeLanguagePaks(stored_translations, 1.43)
    if num_translations + num_stored_translations > 1:
      if num_translations == 0:
        # WebView stores all locale paks uncompressed.
        num_arsc_translations = num_stored_translations
      else:
        # Monochrome has more configurations than Chrome since it includes
        # WebView (which supports more locales), but these should mostly be
        # empty so ignore them here.
        num_arsc_translations = num_translations
      normalized_apk_size += _NormalizeResourcesArsc(apk_path,
                                                     arsc.GetNumEntries(),
                                                     num_arsc_translations,
                                                     out_dir)

  # It will be -Inf for .apk files with multiple .arsc files and no out_dir set.
  if normalized_apk_size < 0:
    sys.stderr.write('Skipping normalized_apk_size (no output directory set)\n')
  else:
    report_func('Specifics', 'normalized apk size', normalized_apk_size,
                'bytes')
  # The "file count" metric cannot be grouped with any other metrics when the
  # end result is going to be uploaded to the perf dashboard in the HistogramSet
  # format due to mixed units (bytes vs. zip entries) causing malformed
  # summaries to be generated.
  # TODO(https://crbug.com/903970): Remove this workaround if unit mixing is
  # ever supported.
  report_func('FileCount', 'file count', len(apk_contents), 'zip entries')

  for info in unknown.AllEntries():
    sys.stderr.write(
        'Unknown entry: %s %d\n' % (info.filename, info.compress_size))
  return normalized_apk_size


def _CalculateCompressedSize(file_path):
  CHUNK_SIZE = 256 * 1024
  compressor = zlib.compressobj()
  total_size = 0
  with open(file_path, 'rb') as f:
    for chunk in iter(lambda: f.read(CHUNK_SIZE), ''):
      total_size += len(compressor.compress(chunk))
  total_size += len(compressor.flush())
  return total_size


@contextmanager
def Unzip(zip_file, filename=None):
  """Utility for temporary use of a single file in a zip archive."""
  with build_utils.TempDir() as unzipped_dir:
    unzipped_files = build_utils.ExtractAll(
        zip_file, unzipped_dir, True, pattern=filename)
    if len(unzipped_files) == 0:
      raise Exception(
          '%s not found in %s' % (filename, zip_file))
    yield unzipped_files[0]


def _ConfigOutDirAndToolsPrefix(out_dir):
  if out_dir:
    constants.SetOutputDirectory(out_dir)
  else:
    try:
      # Triggers auto-detection when CWD == output directory.
      constants.CheckOutputDirectory()
      out_dir = constants.GetOutDirectory()
    except Exception:  # pylint: disable=broad-except
      return out_dir, ''
  build_vars = gn_helpers.ReadBuildVars(out_dir)
  tool_prefix = os.path.join(out_dir, build_vars['android_tool_prefix'])
  return out_dir, tool_prefix


def _IterSplits(namelist):
  for subpath in namelist:
    # Looks for paths like splits/vr-master.apk, splits/vr-hi.apk.
    name_parts = subpath.split('/')
    if name_parts[0] == 'splits' and len(name_parts) == 2:
      name_parts = name_parts[1].split('-')
      if len(name_parts) == 2:
        split_name, config_name = name_parts
        if config_name == 'master.apk':
          yield subpath, split_name


def _ExtractToTempFile(zip_obj, subpath, temp_file):
  temp_file.seek(0)
  temp_file.truncate()
  temp_file.write(zip_obj.read(subpath))
  temp_file.flush()


def _AnalyzeApkOrApks(report_func, apk_path, args):
  # Create DexStatsCollector here to track unique methods across base & chrome
  # modules.
  dex_stats_collector = method_count.DexStatsCollector()
  out_dir, tool_prefix = _ConfigOutDirAndToolsPrefix(args.out_dir)

  if apk_path.endswith('.apk'):
    sdk_version, _, _ = _ParseManifestAttributes(apk_path)
    _AnalyzeInternal(apk_path, sdk_version, report_func, dex_stats_collector,
                     out_dir, tool_prefix)
  elif apk_path.endswith('.apks'):
    with tempfile.NamedTemporaryFile(suffix='.apk') as f:
      with zipfile.ZipFile(apk_path) as z:
        # Currently bundletool is creating two apks when .apks is created
        # without specifying an sdkVersion. Always measure the one with an
        # uncompressed shared library.
        try:
          info = z.getinfo('splits/base-master_2.apk')
        except KeyError:
          info = z.getinfo('splits/base-master.apk')
        _ExtractToTempFile(z, info.filename, f)
        sdk_version, _, _ = _ParseManifestAttributes(f.name)

        orig_report_func = report_func
        report_func = _AccumulatingReporter()

        def do_measure(split_name, on_demand):
          logging.info('Measuring %s on_demand=%s', split_name, on_demand)
          # Use no-op reporting functions to get normalized size for DFMs.
          inner_report_func = report_func
          inner_dex_stats_collector = dex_stats_collector
          if on_demand:
            inner_report_func = lambda *_: None
            inner_dex_stats_collector = method_count.DexStatsCollector()

          size = _AnalyzeInternal(f.name,
                                  sdk_version,
                                  inner_report_func,
                                  inner_dex_stats_collector,
                                  out_dir,
                                  tool_prefix,
                                  apks_path=apk_path,
                                  split_name=split_name)
          report_func('DFM_' + split_name, 'Size with hindi', size, 'bytes')

        # Measure base outside of the loop since we've already extracted it.
        do_measure('base', on_demand=False)

        for subpath, split_name in _IterSplits(z.namelist()):
          if split_name != 'base':
            _ExtractToTempFile(z, subpath, f)
            _, _, on_demand = _ParseManifestAttributes(f.name)
            do_measure(split_name, on_demand=on_demand)

        report_func.DumpReports(orig_report_func)
        report_func = orig_report_func
  else:
    raise Exception('Unknown file type: ' + apk_path)

  # Report dex stats outside of _AnalyzeInternal() so that the "unique methods"
  # metric is not just the sum of the base and chrome modules.
  for metric, count in dex_stats_collector.GetTotalCounts().items():
    report_func('Dex', metric, count, 'entries')
  report_func('Dex', 'unique methods',
              dex_stats_collector.GetUniqueMethodCount(), 'entries')
  report_func('DexCache', 'DexCache',
              dex_stats_collector.GetDexCacheSize(pre_oreo=sdk_version < 26),
              'bytes')

  return dex_stats_collector


def _ResourceSizes(args):
  chartjson = _BASE_CHART.copy() if args.output_format else None
  reporter = _ChartJsonReporter(chartjson)
  # Create DexStatsCollector here to track unique methods across trichrome APKs.
  dex_stats_collector = method_count.DexStatsCollector()

  specs = [
      ('Chrome_', args.trichrome_chrome),
      ('WebView_', args.trichrome_webview),
      ('Library_', args.trichrome_library),
  ]
  for prefix, path in specs:
    if path:
      reporter.trace_title_prefix = prefix
      child_dex_stats_collector = _AnalyzeApkOrApks(reporter, path, args)
      dex_stats_collector.MergeFrom(prefix, child_dex_stats_collector)

  if any(path for _, path in specs):
    reporter.SynthesizeTotals(dex_stats_collector.GetUniqueMethodCount())
  else:
    _AnalyzeApkOrApks(reporter, args.input, args)

  if chartjson:
    _DumpChartJson(args, chartjson)


def _DumpChartJson(args, chartjson):
  if args.output_file == '-':
    json_file = sys.stdout
  elif args.output_file:
    json_file = open(args.output_file, 'w')
  else:
    results_path = os.path.join(args.output_dir, 'results-chart.json')
    logging.critical('Dumping chartjson to %s', results_path)
    json_file = open(results_path, 'w')

  json.dump(chartjson, json_file, indent=2)

  if json_file is not sys.stdout:
    json_file.close()

  # We would ideally generate a histogram set directly instead of generating
  # chartjson then converting. However, perf_tests_results_helper is in
  # //build, which doesn't seem to have any precedent for depending on
  # anything in Catapult. This can probably be fixed, but since this doesn't
  # need to be super fast or anything, converting is a good enough solution
  # for the time being.
  if args.output_format == 'histograms':
    histogram_result = convert_chart_json.ConvertChartJson(results_path)
    if histogram_result.returncode != 0:
      raise Exception('chartjson conversion failed with error: ' +
                      histogram_result.stdout)

    histogram_path = os.path.join(args.output_dir, 'perf_results.json')
    logging.critical('Dumping histograms to %s', histogram_path)
    with open(histogram_path, 'w') as json_file:
      json_file.write(histogram_result.stdout)


def main():
  argparser = argparse.ArgumentParser(description='Print APK size metrics.')
  argparser.add_argument(
      '--min-pak-resource-size',
      type=int,
      default=20 * 1024,
      help='Minimum byte size of displayed pak resources.')
  argparser.add_argument(
      '--chromium-output-directory',
      dest='out_dir',
      type=os.path.realpath,
      help='Location of the build artifacts.')
  argparser.add_argument(
      '--chartjson',
      action='store_true',
      help='DEPRECATED. Use --output-format=chartjson '
      'instead.')
  argparser.add_argument(
      '--output-format',
      choices=['chartjson', 'histograms'],
      help='Output the results to a file in the given '
      'format instead of printing the results.')
  argparser.add_argument('--loadable_module', help='Obsolete (ignored).')

  # Accepted to conform to the isolated script interface, but ignored.
  argparser.add_argument(
      '--isolated-script-test-filter', help=argparse.SUPPRESS)
  argparser.add_argument(
      '--isolated-script-test-perf-output',
      type=os.path.realpath,
      help=argparse.SUPPRESS)

  output_group = argparser.add_mutually_exclusive_group()

  output_group.add_argument(
      '--output-dir', default='.', help='Directory to save chartjson to.')
  output_group.add_argument(
      '--output-file',
      help='Path to output .json (replaces --output-dir). Works only for '
      '--output-format=chartjson')
  output_group.add_argument(
      '--isolated-script-test-output',
      type=os.path.realpath,
      help='File to which results will be written in the '
      'simplified JSON output format.')

  argparser.add_argument('input', help='Path to .apk or .apks file to measure.')
  trichrome_group = argparser.add_argument_group(
      'Trichrome inputs',
      description='When specified, |input| is used only as Test suite name.')
  trichrome_group.add_argument(
      '--trichrome-chrome', help='Path to Trichrome Chrome .apks')
  trichrome_group.add_argument(
      '--trichrome-webview', help='Path to Trichrome WebView .apk(s)')
  trichrome_group.add_argument(
      '--trichrome-library', help='Path to Trichrome Library .apk')
  args = argparser.parse_args()

  devil_chromium.Initialize(output_directory=args.out_dir)

  # TODO(bsheedy): Remove this once uses of --chartjson have been removed.
  if args.chartjson:
    args.output_format = 'chartjson'

  isolated_script_output = {'valid': False, 'failures': []}

  test_name = 'resource_sizes (%s)' % os.path.basename(args.input)

  if args.isolated_script_test_output:
    args.output_dir = os.path.join(
        os.path.dirname(args.isolated_script_test_output), test_name)
    if not os.path.exists(args.output_dir):
      os.makedirs(args.output_dir)

  try:
    _ResourceSizes(args)
    isolated_script_output = {
        'valid': True,
        'failures': [],
    }
  finally:
    if args.isolated_script_test_output:
      results_path = os.path.join(args.output_dir, 'test_results.json')
      with open(results_path, 'w') as output_file:
        json.dump(isolated_script_output, output_file)
      with open(args.isolated_script_test_output, 'w') as output_file:
        json.dump(isolated_script_output, output_file)


if __name__ == '__main__':
  main()