[catapult] - Copy Telemetry's gsutilz over to third_party.

third_party/gsutil/third_party/protorpc/protorpc/generate.py

Index: third_party/gsutil/third_party/protorpc/protorpc/generate.py
diff --git a/third_party/gsutil/third_party/protorpc/protorpc/generate.py b/third_party/gsutil/third_party/protorpc/protorpc/generate.py
new file mode 100755
index 0000000000000000000000000000000000000000..9a2630b32381f1568ec14fede089188daa86fee6
--- /dev/null
+++ b/third_party/gsutil/third_party/protorpc/protorpc/generate.py
@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+__author__ = 'rafek@google.com (Rafe Kaplan)'
+
+import contextlib
+
+from . import messages
+from . import util
+
+__all__ = ['IndentationError',
+           'IndentWriter',
+          ]
+
+
+class IndentationError(messages.Error):
+  """Raised when end_indent is called too many times."""
+
+
+class IndentWriter(object):  
+  """Utility class to make it easy to write formatted indented text.
+
+  IndentWriter delegates to a file-like object and is able to keep track of the
+  level of indentation.  Each call to write_line will write a line terminated
+  by a new line proceeded by a number of spaces indicated by the current level
+  of indentation.
+
+  IndexWriter overloads the << operator to make line writing operations clearer.
+
+  The indent method returns a context manager that can be used by the Python
+  with statement that makes generating python code easier to use.  For example:
+
+    index_writer << 'def factorial(n):'
+    with index_writer.indent():
+      index_writer << 'if n <= 1:'
+      with index_writer.indent():
+        index_writer << 'return 1'
+      index_writer << 'else:'
+      with index_writer.indent():
+        index_writer << 'return factorial(n - 1)'
+
+  This would generate:
+
+  def factorial(n):
+    if n <= 1:
+      return 1
+    else:
+      return factorial(n - 1)
+  """
+
+  @util.positional(2)
+  def __init__(self, output, indent_space=2):
+    """Constructor.
+
+    Args:
+      output: File-like object to wrap.
+      indent_space: Number of spaces each level of indentation will be.
+    """
+    # Private attributes:
+    #
+    #   __output: The wrapped file-like object.
+    #   __indent_space: String to append for each level of indentation.
+    #   __indentation: The current full indentation string.
+    self.__output = output
+    self.__indent_space = indent_space * ' '
+    self.__indentation = 0
+
+  @property
+  def indent_level(self):
+    """Current level of indentation for IndentWriter."""
+    return self.__indentation
+
+  def write_line(self, line):
+    """Write line to wrapped file-like object using correct indentation.
+
+    The line is written with the current level of indentation printed before it
+    and terminated by a new line.
+
+    Args:
+      line: Line to write to wrapped file-like object.
+    """
+    if line != '':
+      self.__output.write(self.__indentation * self.__indent_space)
+      self.__output.write(line)
+    self.__output.write('\n')
+
+  def begin_indent(self):
+    """Begin a level of indentation."""
+    self.__indentation += 1
+
+  def end_indent(self):
+    """Undo the most recent level of indentation.
+
+    Raises:
+      IndentationError when called with no indentation levels.
+    """
+    if not self.__indentation:
+      raise IndentationError('Unable to un-indent further')
+    self.__indentation -= 1
+
+  @contextlib.contextmanager
+  def indent(self):
+    """Create indentation level compatible with the Python 'with' keyword."""
+    self.begin_indent()
+    yield
+    self.end_indent()
+
+  def __lshift__(self, line):
+    """Syntactic sugar for write_line method.
+
+    Args:
+      line: Line to write to wrapped file-like object.
+    """
+    self.write_line(line)