Recipe package system.

recipe_engine/third_party/google/protobuf/descriptor_pool.py

+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Provides DescriptorPool to use as a container for proto2 descriptors.
+
+The DescriptorPool is used in conjection with a DescriptorDatabase to maintain
+a collection of protocol buffer descriptors for use when dynamically creating
+message types at runtime.
+
+For most applications protocol buffers should be used via modules generated by
+the protocol buffer compiler tool. This should only be used when the type of
+protocol buffers used in an application or library cannot be predetermined.
+
+Below is a straightforward example on how to use this class:
+
+  pool = DescriptorPool()
+  file_descriptor_protos = [ ... ]
+  for file_descriptor_proto in file_descriptor_protos:
+    pool.Add(file_descriptor_proto)
+  my_message_descriptor = pool.FindMessageTypeByName('some.package.MessageType')
+
+The message descriptor can be used in conjunction with the message_factory
+module in order to create a protocol buffer class that can be encoded and
+decoded.
+"""
+
+__author__ = 'matthewtoia@google.com (Matt Toia)'
+
+from google.protobuf import descriptor_pb2
+from google.protobuf import descriptor
+from google.protobuf import descriptor_database
+
+
+class DescriptorPool(object):
+  """A collection of protobufs dynamically constructed by descriptor protos."""
+
+  def __init__(self, descriptor_db=None):
+    """Initializes a Pool of proto buffs.
+
+    The descriptor_db argument to the constructor is provided to allow
+    specialized file descriptor proto lookup code to be triggered on demand. An
+    example would be an implementation which will read and compile a file
+    specified in a call to FindFileByName() and not require the call to Add()
+    at all. Results from this database will be cached internally here as well.
+
+    Args:
+      descriptor_db: A secondary source of file descriptors.
+    """
+
+    self._internal_db = descriptor_database.DescriptorDatabase()
+    self._descriptor_db = descriptor_db
+    self._descriptors = {}
+    self._enum_descriptors = {}
+    self._file_descriptors = {}
+
+  def Add(self, file_desc_proto):
+    """Adds the FileDescriptorProto and its types to this pool.
+
+    Args:
+      file_desc_proto: The FileDescriptorProto to add.
+    """
+
+    self._internal_db.Add(file_desc_proto)
+
+  def FindFileByName(self, file_name):
+    """Gets a FileDescriptor by file name.
+
+    Args:
+      file_name: The path to the file to get a descriptor for.
+
+    Returns:
+      A FileDescriptor for the named file.
+
+    Raises:
+      KeyError: if the file can not be found in the pool.
+    """
+
+    try:
+      file_proto = self._internal_db.FindFileByName(file_name)
+    except KeyError as error:
+      if self._descriptor_db:
+        file_proto = self._descriptor_db.FindFileByName(file_name)
+      else:
+        raise error
+    if not file_proto:
+      raise KeyError('Cannot find a file named %s' % file_name)
+    return self._ConvertFileProtoToFileDescriptor(file_proto)
+
+  def FindFileContainingSymbol(self, symbol):
+    """Gets the FileDescriptor for the file containing the specified symbol.
+
+    Args:
+      symbol: The name of the symbol to search for.
+
+    Returns:
+      A FileDescriptor that contains the specified symbol.
+
+    Raises:
+      KeyError: if the file can not be found in the pool.
+    """
+
+    try:
+      file_proto = self._internal_db.FindFileContainingSymbol(symbol)
+    except KeyError as error:
+      if self._descriptor_db:
+        file_proto = self._descriptor_db.FindFileContainingSymbol(symbol)
+      else:
+        raise error
+    if not file_proto:
+      raise KeyError('Cannot find a file containing %s' % symbol)
+    return self._ConvertFileProtoToFileDescriptor(file_proto)
+
+  def FindMessageTypeByName(self, full_name):
+    """Loads the named descriptor from the pool.
+
+    Args:
+      full_name: The full name of the descriptor to load.
+
+    Returns:
+      The descriptor for the named type.
+    """
+
+    full_name = full_name.lstrip('.')  # fix inconsistent qualified name formats
+    if full_name not in self._descriptors:
+      self.FindFileContainingSymbol(full_name)
+    return self._descriptors[full_name]
+
+  def FindEnumTypeByName(self, full_name):
+    """Loads the named enum descriptor from the pool.
+
+    Args:
+      full_name: The full name of the enum descriptor to load.
+
+    Returns:
+      The enum descriptor for the named type.
+    """
+
+    full_name = full_name.lstrip('.')  # fix inconsistent qualified name formats
+    if full_name not in self._enum_descriptors:
+      self.FindFileContainingSymbol(full_name)
+    return self._enum_descriptors[full_name]
+
+  def _ConvertFileProtoToFileDescriptor(self, file_proto):
+    """Creates a FileDescriptor from a proto or returns a cached copy.
+
+    This method also has the side effect of loading all the symbols found in
+    the file into the appropriate dictionaries in the pool.
+
+    Args:
+      file_proto: The proto to convert.
+
+    Returns:
+      A FileDescriptor matching the passed in proto.
+    """
+
+    if file_proto.name not in self._file_descriptors:
+      file_descriptor = descriptor.FileDescriptor(
+          name=file_proto.name,
+          package=file_proto.package,
+          options=file_proto.options,
+          serialized_pb=file_proto.SerializeToString())
+      scope = {}
+      dependencies = list(self._GetDeps(file_proto))
+
+      for dependency in dependencies:
+        dep_desc = self.FindFileByName(dependency.name)
+        dep_proto = descriptor_pb2.FileDescriptorProto.FromString(
+            dep_desc.serialized_pb)
+        package = '.' + dep_proto.package
+        package_prefix = package + '.'
+
+        def _strip_package(symbol):
+          if symbol.startswith(package_prefix):
+            return symbol[len(package_prefix):]
+          return symbol
+
+        symbols = list(self._ExtractSymbols(dep_proto.message_type, package))
+        scope.update(symbols)
+        scope.update((_strip_package(k), v) for k, v in symbols)
+
+        symbols = list(self._ExtractEnums(dep_proto.enum_type, package))
+        scope.update(symbols)
+        scope.update((_strip_package(k), v) for k, v in symbols)
+
+      for message_type in file_proto.message_type:
+        message_desc = self._ConvertMessageDescriptor(
+            message_type, file_proto.package, file_descriptor, scope)
+        file_descriptor.message_types_by_name[message_desc.name] = message_desc
+      for enum_type in file_proto.enum_type:
+        self._ConvertEnumDescriptor(enum_type, file_proto.package,
+                                    file_descriptor, None, scope)
+      for desc_proto in self._ExtractMessages(file_proto.message_type):
+        self._SetFieldTypes(desc_proto, scope)
+
+      for desc_proto in file_proto.message_type:
+        desc = scope[desc_proto.name]
+        file_descriptor.message_types_by_name[desc_proto.name] = desc
+      self.Add(file_proto)
+      self._file_descriptors[file_proto.name] = file_descriptor
+
+    return self._file_descriptors[file_proto.name]
+
+  def _ConvertMessageDescriptor(self, desc_proto, package=None, file_desc=None,
+                                scope=None):
+    """Adds the proto to the pool in the specified package.
+
+    Args:
+      desc_proto: The descriptor_pb2.DescriptorProto protobuf message.
+      package: The package the proto should be located in.
+      file_desc: The file containing this message.
+      scope: Dict mapping short and full symbols to message and enum types.
+
+    Returns:
+      The added descriptor.
+    """
+
+    if package:
+      desc_name = '.'.join((package, desc_proto.name))
+    else:
+      desc_name = desc_proto.name
+
+    if file_desc is None:
+      file_name = None
+    else:
+      file_name = file_desc.name
+
+    if scope is None:
+      scope = {}
+
+    nested = [
+        self._ConvertMessageDescriptor(nested, desc_name, file_desc, scope)
+        for nested in desc_proto.nested_type]
+    enums = [
+        self._ConvertEnumDescriptor(enum, desc_name, file_desc, None, scope)
+        for enum in desc_proto.enum_type]
+    fields = [self._MakeFieldDescriptor(field, desc_name, index)
+              for index, field in enumerate(desc_proto.field)]
+    extensions = [self._MakeFieldDescriptor(extension, desc_name, True)
+                  for index, extension in enumerate(desc_proto.extension)]
+    extension_ranges = [(r.start, r.end) for r in desc_proto.extension_range]
+    if extension_ranges:
+      is_extendable = True
+    else:
+      is_extendable = False
+    desc = descriptor.Descriptor(
+        name=desc_proto.name,
+        full_name=desc_name,
+        filename=file_name,
+        containing_type=None,
+        fields=fields,
+        nested_types=nested,
+        enum_types=enums,
+        extensions=extensions,
+        options=desc_proto.options,
+        is_extendable=is_extendable,
+        extension_ranges=extension_ranges,
+        file=file_desc,
+        serialized_start=None,
+        serialized_end=None)
+    for nested in desc.nested_types:
+      nested.containing_type = desc
+    for enum in desc.enum_types:
+      enum.containing_type = desc
+    scope[desc_proto.name] = desc
+    scope['.' + desc_name] = desc
+    self._descriptors[desc_name] = desc
+    return desc
+
+  def _ConvertEnumDescriptor(self, enum_proto, package=None, file_desc=None,
+                             containing_type=None, scope=None):
+    """Make a protobuf EnumDescriptor given an EnumDescriptorProto protobuf.
+
+    Args:
+      enum_proto: The descriptor_pb2.EnumDescriptorProto protobuf message.
+      package: Optional package name for the new message EnumDescriptor.
+      file_desc: The file containing the enum descriptor.
+      containing_type: The type containing this enum.
+      scope: Scope containing available types.
+
+    Returns:
+      The added descriptor
+    """
+
+    if package:
+      enum_name = '.'.join((package, enum_proto.name))
+    else:
+      enum_name = enum_proto.name
+
+    if file_desc is None:
+      file_name = None
+    else:
+      file_name = file_desc.name
+
+    values = [self._MakeEnumValueDescriptor(value, index)
+              for index, value in enumerate(enum_proto.value)]
+    desc = descriptor.EnumDescriptor(name=enum_proto.name,
+                                     full_name=enum_name,
+                                     filename=file_name,
+                                     file=file_desc,
+                                     values=values,
+                                     containing_type=containing_type,
+                                     options=enum_proto.options)
+    scope[enum_proto.name] = desc
+    scope['.%s' % enum_name] = desc
+    self._enum_descriptors[enum_name] = desc
+    return desc
+
+  def _MakeFieldDescriptor(self, field_proto, message_name, index,
+                           is_extension=False):
+    """Creates a field descriptor from a FieldDescriptorProto.
+
+    For message and enum type fields, this method will do a look up
+    in the pool for the appropriate descriptor for that type. If it
+    is unavailable, it will fall back to the _source function to
+    create it. If this type is still unavailable, construction will
+    fail.
+
+    Args:
+      field_proto: The proto describing the field.
+      message_name: The name of the containing message.
+      index: Index of the field
+      is_extension: Indication that this field is for an extension.
+
+    Returns:
+      An initialized FieldDescriptor object
+    """
+
+    if message_name:
+      full_name = '.'.join((message_name, field_proto.name))
+    else:
+      full_name = field_proto.name
+
+    return descriptor.FieldDescriptor(
+        name=field_proto.name,
+        full_name=full_name,
+        index=index,
+        number=field_proto.number,
+        type=field_proto.type,
+        cpp_type=None,
+        message_type=None,
+        enum_type=None,
+        containing_type=None,
+        label=field_proto.label,
+        has_default_value=False,
+        default_value=None,
+        is_extension=is_extension,
+        extension_scope=None,
+        options=field_proto.options)
+
+  def _SetFieldTypes(self, desc_proto, scope):
+    """Sets the field's type, cpp_type, message_type and enum_type.
+
+    Args:
+      desc_proto: The message descriptor to update.
+      scope: Enclosing scope of available types.
+    """
+
+    desc = scope[desc_proto.name]
+    for field_proto, field_desc in zip(desc_proto.field, desc.fields):
+      if field_proto.type_name:
+        type_name = field_proto.type_name
+        if type_name not in scope:
+          type_name = '.' + type_name
+        desc = scope[type_name]
+      else:
+        desc = None
+
+      if not field_proto.HasField('type'):
+        if isinstance(desc, descriptor.Descriptor):
+          field_proto.type = descriptor.FieldDescriptor.TYPE_MESSAGE
+        else:
+          field_proto.type = descriptor.FieldDescriptor.TYPE_ENUM
+
+      field_desc.cpp_type = descriptor.FieldDescriptor.ProtoTypeToCppProtoType(
+          field_proto.type)
+
+      if (field_proto.type == descriptor.FieldDescriptor.TYPE_MESSAGE
+          or field_proto.type == descriptor.FieldDescriptor.TYPE_GROUP):
+        field_desc.message_type = desc
+
+      if field_proto.type == descriptor.FieldDescriptor.TYPE_ENUM:
+        field_desc.enum_type = desc
+
+      if field_proto.label == descriptor.FieldDescriptor.LABEL_REPEATED:
+        field_desc.has_default = False
+        field_desc.default_value = []
+      elif field_proto.HasField('default_value'):
+        field_desc.has_default = True
+        if (field_proto.type == descriptor.FieldDescriptor.TYPE_DOUBLE or
+            field_proto.type == descriptor.FieldDescriptor.TYPE_FLOAT):
+          field_desc.default_value = float(field_proto.default_value)
+        elif field_proto.type == descriptor.FieldDescriptor.TYPE_STRING:
+          field_desc.default_value = field_proto.default_value
+        elif field_proto.type == descriptor.FieldDescriptor.TYPE_BOOL:
+          field_desc.default_value = field_proto.default_value.lower() == 'true'
+        elif field_proto.type == descriptor.FieldDescriptor.TYPE_ENUM:
+          field_desc.default_value = field_desc.enum_type.values_by_name[
+              field_proto.default_value].index
+        else:
+          field_desc.default_value = int(field_proto.default_value)
+      else:
+        field_desc.has_default = False
+        field_desc.default_value = None
+
+      field_desc.type = field_proto.type
+
+    for nested_type in desc_proto.nested_type:
+      self._SetFieldTypes(nested_type, scope)
+
+  def _MakeEnumValueDescriptor(self, value_proto, index):
+    """Creates a enum value descriptor object from a enum value proto.
+
+    Args:
+      value_proto: The proto describing the enum value.
+      index: The index of the enum value.
+
+    Returns:
+      An initialized EnumValueDescriptor object.
+    """
+
+    return descriptor.EnumValueDescriptor(
+        name=value_proto.name,
+        index=index,
+        number=value_proto.number,
+        options=value_proto.options,
+        type=None)
+
+  def _ExtractSymbols(self, desc_protos, package):
+    """Pulls out all the symbols from descriptor protos.
+
+    Args:
+      desc_protos: The protos to extract symbols from.
+      package: The package containing the descriptor type.
+    Yields:
+      A two element tuple of the type name and descriptor object.
+    """
+
+    for desc_proto in desc_protos:
+      if package:
+        message_name = '.'.join((package, desc_proto.name))
+      else:
+        message_name = desc_proto.name
+      message_desc = self.FindMessageTypeByName(message_name)
+      yield (message_name, message_desc)
+      for symbol in self._ExtractSymbols(desc_proto.nested_type, message_name):
+        yield symbol
+      for symbol in self._ExtractEnums(desc_proto.enum_type, message_name):
+        yield symbol
+
+  def _ExtractEnums(self, enum_protos, package):
+    """Pulls out all the symbols from enum protos.
+
+    Args:
+      enum_protos: The protos to extract symbols from.
+      package: The package containing the enum type.
+
+    Yields:
+      A two element tuple of the type name and enum descriptor object.
+    """
+
+    for enum_proto in enum_protos:
+      if package:
+        enum_name = '.'.join((package, enum_proto.name))
+      else:
+        enum_name = enum_proto.name
+      enum_desc = self.FindEnumTypeByName(enum_name)
+      yield (enum_name, enum_desc)
+
+  def _ExtractMessages(self, desc_protos):
+    """Pulls out all the message protos from descriptos.
+
+    Args:
+      desc_protos: The protos to extract symbols from.
+
+    Yields:
+      Descriptor protos.
+    """
+
+    for desc_proto in desc_protos:
+      yield desc_proto
+      for message in self._ExtractMessages(desc_proto.nested_type):
+        yield message
+
+  def _GetDeps(self, file_proto):
+    """Recursively finds dependencies for file protos.
+
+    Args:
+      file_proto: The proto to get dependencies from.
+
+    Yields:
+      Each direct and indirect dependency.
+    """
+
+    for dependency in file_proto.dependency:
+      dep_desc = self.FindFileByName(dependency)
+      dep_proto = descriptor_pb2.FileDescriptorProto.FromString(
+          dep_desc.serialized_pb)
+      yield dep_proto
+      for parent_dep in self._GetDeps(dep_proto):
+        yield parent_dep