Add file.filesizes to recipe engine core modules.

recipe_modules/file/api.py

 # Copyright 2017 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """File manipulation (read/write/delete/glob) methods."""
 
 from recipe_engine import recipe_api
 
 
 import os
@@ skipping 206 matching lines @@
         does not ensure the mode if the directory already exists (if you need
         that behaviour, file a bug).
 
     Raises file.Error if the path exists but is not a directory.
     """
     self.m.path.assert_absolute(dest)
     self._run(
       name, ['ensure-directory', '--mode', oct(mode), dest])
     self.m.path.mock_add_paths(dest)
 
+  def filesizes(self, name, files, **kwargs):

[iannucci, 2017/08/07 19:27:30]

No kwargs; we're trying to stamp this out everywhere. Look at the other methods
here to see how to do test data.

+    """Returns list of filesizes for the given files.
+
+    Args:
+      * name (str) - The name of the step.
+      * files (list[Path]) - Paths to files.
+
+    Returns list[int], size of each file in bytes.
+    """
+    test_data = kwargs.pop('test_data', [111 * (i+1) + (i % 3 - 2) * i
+                                         for i, _ in enumerate(files)])
+    assert not kwargs, 'only test_data kwarg allowed'
+    for f in files:
+      self.m.path.assert_absolute(f)
+    result = self._run(
+      name, ['filesizes'] + list(files),
+      lambda: self.test_api.filesizes(test_data),
+      self.m.raw_io.output_text())
+    ret = map(int, result.stdout.strip().splitlines())
+    result.presentation.logs['filesizes'] = ['%s: \t%d' % fs
+                                             for fs in zip(files, ret)]
+    return ret
+
   def rmtree(self, name, source):
     """Recursively removes a directory.
 
     This uses a native python on Linux/Mac, and uses `rd` on Windows to avoid
     issues w.r.t. path lengths and read-only attributes. If the directory is
     gone already, this returns without error.
 
     Args:
       * name (str) - The name of the step.
       * source (Path) - The directory to remove.
@@ skipping 35 matching lines @@
     Raises file.Error.
     """
     self.m.path.assert_absolute(source)
     self._run(name, ['rmglob', source, pattern])
 
     src = str(source)
     def filt(p):
       assert p.startswith(src), (src, p)
       return fnmatch.fnmatch(p[len(src)+1:].split(os.path.sep)[0], pattern)
     self.m.path.mock_remove_paths(str(source), filt)