Create a function that can generate ApexInfo using target-files

If an OTA contains compressed APEX inside it, then the device will need
to allocate space on /data partition for their decompression. In order
to calculate how much space the OTA process needs to allocate, the
process needs more information about the APEX contained inside the OTA.

In this CL, we are adding functionality to the OTA generation script
that allows us to gather information about the APEX stored inside the
target-file zip. However, we did not integrate the new functionality
with the ota_from_target_files.py scrip yet. That will be done on follow
up CL.

Bug: 172911822
Test: atest releasetools_py3_test
Change-Id: I2ac42018f628c2c21527b3e086be1f4e7e7247ad

tools/releasetools/apex_utils.py

@@ -21,7 +21,12 @@ import shlex
 import shutil
 import zipfile
 
+import apex_manifest
 import common
+from common import UnzipTemp, RunAndCheckOutput, MakeTempFile, OPTIONS
+
+import ota_metadata_pb2
+
 
 logger = logging.getLogger(__name__)
 
@@ -69,7 +74,7 @@ class ApexApkSigner(object):
     if not os.path.exists(self.debugfs_path):
       raise ApexSigningError(
           "Couldn't find location of debugfs_static: " +
-          "Path {} does not exist. ".format(debugfs_path) +
+          "Path {} does not exist. ".format(self.debugfs_path) +
           "Make sure bin/debugfs_static can be found in -p <path>")
     list_cmd = ['deapexer', '--debugfs_path',
                 self.debugfs_path, 'list', self.apex_path]
@@ -105,7 +110,7 @@ class ApexApkSigner(object):
     if not os.path.exists(self.debugfs_path):
       raise ApexSigningError(
           "Couldn't find location of debugfs_static: " +
-          "Path {} does not exist. ".format(debugfs_path) +
+          "Path {} does not exist. ".format(self.debugfs_path) +
           "Make sure bin/debugfs_static can be found in -p <path>")
     payload_dir = common.MakeTempDir()
     extract_cmd = ['deapexer', '--debugfs_path',
@@ -127,8 +132,9 @@ class ApexApkSigner(object):
       # signed apk file.
       unsigned_apk = common.MakeTempFile()
       os.rename(apk_path, unsigned_apk)
-      common.SignFile(unsigned_apk, apk_path, key_name, self.key_passwords.get(key_name),
-                      codename_to_api_level_map=self.codename_to_api_level_map)
+      common.SignFile(
+          unsigned_apk, apk_path, key_name, self.key_passwords.get(key_name),
+          codename_to_api_level_map=self.codename_to_api_level_map)
       has_signed_apk = True
     return payload_dir, has_signed_apk
 
@@ -427,4 +433,71 @@ def SignApex(avbtool, apex_data, payload_key, container_key, container_pw,
 
   except common.ExternalError as e:
     raise ApexInfoError(
-        'Failed to get type for {}:\n{}'.format(apex_file))
+        'Failed to get type for {}:\n{}'.format(apex_file, e))
+
+def GetApexInfoFromTargetFiles(input_file):
+  """
+  Get information about system APEX stored in the input_file zip
+
+  Args:
+    input_file: The filename of the target build target-files zip or directory.
+
+  Return:
+    A list of ota_metadata_pb2.ApexInfo() populated using the APEX stored in
+    /system partition of the input_file
+  """
+
+  # Extract the apex files so that we can run checks on them
+  if not isinstance(input_file, str):
+    raise RuntimeError("must pass filepath to target-files zip or directory")
+
+  if os.path.isdir(input_file):
+    tmp_dir = input_file
+  else:
+    tmp_dir = UnzipTemp(input_file, ["SYSTEM/apex/*"])
+  target_dir = os.path.join(tmp_dir, "SYSTEM/apex/")
+
+  apex_infos = []
+  for apex_filename in os.listdir(target_dir):
+    apex_filepath = os.path.join(target_dir, apex_filename)
+    if not os.path.isfile(apex_filepath) or \
+        not zipfile.is_zipfile(apex_filepath):
+      logger.info("Skipping %s because it's not a zipfile", apex_filepath)
+      continue
+    apex_info = ota_metadata_pb2.ApexInfo()
+    # Open the apex file to retrieve information
+    manifest = apex_manifest.fromApex(apex_filepath)
+    apex_info.package_name = manifest.name
+    apex_info.version = manifest.version
+    # Check if the file is compressed or not
+    debugfs_path = "debugfs"
+    if OPTIONS.search_path:
+      debugfs_path = os.path.join(OPTIONS.search_path, "bin", "debugfs_static")
+    deapexer = 'deapexer'
+    if OPTIONS.search_path:
+      deapexer_path = os.path.join(OPTIONS.search_path, "deapexer")
+      if os.path.isfile(deapexer_path):
+        deapexer = deapexer_path
+    apex_type = RunAndCheckOutput([
+        deapexer, "--debugfs_path", debugfs_path,
+        'info', '--print-type', apex_filepath]).rstrip()
+    if apex_type == 'COMPRESSED':
+      apex_info.is_compressed = True
+    elif apex_type == 'UNCOMPRESSED':
+      apex_info.is_compressed = False
+    else:
+      raise RuntimeError('Not an APEX file: ' + apex_type)
+
+    # Decompress compressed APEX to determine its size
+    if apex_info.is_compressed:
+      decompressed_file_path = MakeTempFile(prefix="decompressed-",
+                                            suffix=".apex")
+      # Decompression target path should not exist
+      os.remove(decompressed_file_path)
+      RunAndCheckOutput([deapexer, 'decompress', '--input', apex_filepath,
+                         '--output', decompressed_file_path])
+      apex_info.decompressed_size = os.path.getsize(decompressed_file_path)
+
+    apex_infos.append(apex_info)
+
+  return apex_infos