webkitpy: Remove contents of directory.

third_party/WebKit/Tools/Scripts/merge-layout-test-results

 #!/usr/bin/python
 #
 # Copyright 2017 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.
 
 import argparse
 import json
 import logging
 import os
+import stat
 import shutil
 import sys
 import tempfile
 import time
 
+from webkitpy.common.system.filesystem import FileSystem
 from webkitpy.common.system.log_utils import configure_logging
 from webkitpy.layout_tests import merge_results
 
 # ------------------------------------------------------------------------
+def ensure_empty_dir(fs, directory, allow_existing, remove_existing):
+    """Ensure an empty directory exists.
 
-def rmtree(dirname):
-    # Attempt to remove a directory tree. We try multiple times as on Windows a
-    # process which is currently closing could still have a file open in the
-    # directory.
-    logging.info('Removing %s', dirname)
-    errors = []
-    def onerror(func, path, exc_info):
-        errors.append(path)
-        logging.exception('Failed at %s %s: %r', func, path, exc_info)
-
-    attempts = 0
-    while attempts < 5:
-        del errors[:]
-        shutil.rmtree(dirname, onerror=onerror)
-        if not errors:
-            break
-        attempts += 1
-        time.sleep(1)
-
-    # Check the path is gone.
-    if not os.path.exists(dirname):
+    Args:
+        allow_existing (bool): Allow the empty directory to already exist.
+        remove_existing (bool): Remove the contents if the directory
+            already exists.
+    """
+    if not fs.exists(directory):
+        fs.maybe_make_directory(directory)
         return
 
-    logging.warning('Unable to remove %s', dirname)
-    for dirpath, dirnames, filenames in os.walk(dirname, onerror=onerror, topdown=False):
-        for fname in filenames:
-            logging.warning('File %s still in output dir.', os.path.join(dirpath, fname))
-        for dname in dirnames:
-            logging.warning('Dir %s still in output dir.', os.path.join(dirpath, dname))
+    logging.warning('Output directory exists %r', directory)
+    if not allow_existing:
+        raise IOError(
+            ('Output directory %s exists!\n'
+             'Use --allow-existing-output-directory to continue') % directory)
+
+    if remove_existing and not fs.remove_contents(directory):
+        raise IOError(
+            ('Unable to remove output directory %s contents!\n'
+             'See log output for errors.') % directory)
 
 
 def main(argv):
 
     parser = argparse.ArgumentParser()
     parser.description = """\
 Merges sharded layout test results into a single output directory.
 """
     parser.epilog = """\
 
@@ skipping 89 matching lines @@
 
         if args.results_json_override_with_build_property:
             if not args.build_properties:
                 parser.error(
                     '--results-json-override-with-build-property given'
                     ' but --build-properties was not.')
             build_properties = json.loads(args.build_properties)
             for result_key, build_prop_key in args.results_json_override_with_build_property:
                 results_json_value_overrides[result_key] = build_properties[build_prop_key]
 
-        assert not args.output_directory
-        args.output_directory = os.getcwd()
-        args.remove_existing_output_directory = True
+        if not args.output_directory:
+            args.output_directory = os.getcwd()
+            args.allow_existing_output_directory = True
+            args.remove_existing_output_directory = True
 
         assert not args.input_directories
         args.input_directories = [os.path.dirname(f) for f in args.positional]
         args.positional = []
 
     # Allow skipping the --input-directories bit, for example,
     #   merge-layout-test-results -o outputdir shard0 shard1 shard2
     if args.positional and not args.input_directories:
         args.input_directories = args.positional
 
     if not args.output_directory:
         args.output_directory = tempfile.mkdtemp(suffix='webkit_layout_test_results.')
 
     assert args.output_directory
     assert args.input_directories
 
     for k, v in args.results_json_override_value:
         assert k not in results_json_value_overrides
         try:
             results_json_value_overrides[k] = eval(v)
         except NameError:
             results_json_value_overrides[k] = v
     logging.debug('results_json_value_overrides: %r', results_json_value_overrides)
 
     merger = merge_results.LayoutTestDirMerger(
         results_json_value_overrides=results_json_value_overrides,
         results_json_allow_unknown_if_matching=args.results_json_allow_unknown_if_matching)
-    if os.path.exists(args.output_directory):
-        logging.warning('Output directory exists %r', args.output_directory)
-        if args.remove_existing_output_directory:
-            rmtree(args.output_directory)
-        elif not args.allow_existing_output_directory:
-            raise IOError(
-                ('Output directory %s exists!\n'
-                 'Use --allow-existing-output-directory to continue') % args.output_directory)
+
+    ensure_empty_dir(
+        FileSystem(),
+        args.output_directory,
+        allow_existing=args.allow_existing_output_directory,
+        remove_existing=args.remove_existing_output_directory)
 
     merger.merge(args.output_directory, args.input_directories)
 
     merged_output_json = os.path.join(args.output_directory, 'output.json')
     if os.path.exists(merged_output_json) and args.output_json:
         logging.debug(
             'Copying output.json from %s to %s', merged_output_json, args.output_json)
         shutil.copyfile(merged_output_json, args.output_json)
 
     if args.post_merge_script:
         logging.debug('Changing directory to %s', args.output_directory)
         os.chdir(args.output_directory)
 
         post_script = list(args.post_merge_script)
         post_script.append('--result-dir', args.output_directory)
 
         logging.info('Running post merge script %r', post_script)
         os.execlp(post_script)
 
 main(sys.argv[1:])