Revert of Cross-repo recipe package system.

third_party/recipe_engine/util.py

+# Copyright 2013-2015 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 functools
+import os
+
+from cStringIO import StringIO
+
+class RecipeAbort(Exception):
+  pass
+
+
+class ModuleInjectionError(AttributeError):
+  pass
+
+
+class ModuleInjectionSite(object):
+  def __init__(self, owner_module=None):
+    self.owner_module = owner_module
+
+  def __getattr__(self, key):
+    if self.owner_module is None:
+      raise ModuleInjectionError(
+        "RecipeApi has no dependency %r. (Add it to DEPS?)" % (key,))
+    else:
+      raise ModuleInjectionError(
+        "Recipe Module %r has no dependency %r. (Add it to __init__.py:DEPS?)"
+        % (self.owner_module.name, key))
+
+
+class Placeholder(object):
+  """Base class for json placeholders. Do not use directly."""
+  def __init__(self):
+    self.name_pieces = None
+
+  @property
+  def backing_file(self):  # pragma: no cover
+    """Return path to a temp file that holds or receives the data.
+
+    Valid only after 'render' has been called.
+    """
+    raise NotImplementedError
+
+  def render(self, test):  # pragma: no cover
+    """Return [cmd items]*"""
+    raise NotImplementedError
+
+  def result(self, presentation, test):
+    """Called after step completion.
+
+    Args:
+      presentation (StepPresentation) - for the current step.
+      test (PlaceholderTestData) - test data for this placeholder.
+
+    Returns value to add to step result.
+
+    May optionally modify presentation as a side-effect.
+    """
+    pass
+
+  @property
+  def name(self):
+    assert self.name_pieces
+    return "%s.%s" % self.name_pieces
+
+
+def static_wraps(func):
+  wrapped_fn = func
+  if isinstance(func, staticmethod):
+    # __get__(obj) is the way to get the function contained in the staticmethod.
+    # python 2.7+ has a __func__ member, but previous to this the attribute
+    # doesn't exist. It doesn't matter what the obj is, as long as it's not
+    # None.
+    wrapped_fn = func.__get__(object)
+  return functools.wraps(wrapped_fn)
+
+
+def static_call(obj, func, *args, **kwargs):
+  if isinstance(func, staticmethod):
+    return func.__get__(obj)(*args, **kwargs)
+  else:
+    return func(obj, *args, **kwargs)
+
+
+def static_name(obj, func):
+  if isinstance(func, staticmethod):
+    return func.__get__(obj).__name__
+  else:
+    return func.__name__
+
+
+def returns_placeholder(func):
+  @static_wraps(func)
+  def inner(self, *args, **kwargs):
+    ret = static_call(self, func, *args, **kwargs)
+    assert isinstance(ret, Placeholder)
+    ret.name_pieces = (self.name, static_name(self, func))
+    return ret
+  # prevent this placeholder-returning function from becoming a composite_step.
+  inner._non_step = True # pylint: disable=protected-access
+  return inner
+
+
+def cached_unary(f):
+  """Decorator that caches/memoizes an unary function result.
+
+  If the function throws an exception, the cache table will not be updated.
+  """
+  cache = {}
+  empty = object()
+
+  @functools.wraps(f)
+  def cached_f(inp):
+    cache_entry = cache.get(inp, empty)
+    if cache_entry is empty:
+      cache_entry = f(inp)
+      cache[inp] = cache_entry
+    return cache_entry
+  return cached_f
+
+
+def scan_directory(path, predicate):
+  """Recursively scans a directory and yields paths that match predicate."""
+  for root, _dirs, files in os.walk(path):
+    for file_name in (f for f in files if predicate(f)):
+      file_path = os.path.join(root, file_name)
+      yield file_path
+
+
+class StringListIO(object):
+  def __init__(self):
+    self.lines = [StringIO()]
+
+  def write(self, s):
+    while s:
+      i = s.find('\n')
+      if i == -1:
+        self.lines[-1].write(s)
+        break
+      self.lines[-1].write(s[:i])
+      self.lines[-1] = self.lines[-1].getvalue()
+      self.lines.append(StringIO())
+      s = s[i+1:]
+
+  def close(self):
+    if not isinstance(self.lines[-1], basestring):
+      self.lines[-1] = self.lines[-1].getvalue()