Initial checkin of gRPC to third_party/

third_party/grpc/src/python/grpcio/grpc/beta/_stub.py

Index: third_party/grpc/src/python/grpcio/grpc/beta/_stub.py
diff --git a/third_party/grpc/src/python/grpcio/grpc/beta/_stub.py b/third_party/grpc/src/python/grpcio/grpc/beta/_stub.py
new file mode 100644
index 0000000000000000000000000000000000000000..2af019309afc412077089c21986f3397e690218c
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+++ b/third_party/grpc/src/python/grpcio/grpc/beta/_stub.py
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+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# 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.
+
+"""Beta API stub implementation."""
+
+import threading
+
+from grpc._links import invocation
+from grpc.framework.core import implementations as _core_implementations
+from grpc.framework.crust import implementations as _crust_implementations
+from grpc.framework.foundation import logging_pool
+from grpc.framework.interfaces.links import utilities
+
+_DEFAULT_POOL_SIZE = 6
+
+
+class _AutoIntermediary(object):
+
+  def __init__(self, up, down, delegate):
+    self._lock = threading.Lock()
+    self._up = up
+    self._down = down
+    self._in_context = False
+    self._delegate = delegate
+
+  def __getattr__(self, attr):
+    with self._lock:
+      if self._delegate is None:
+        raise AttributeError('No useful attributes out of context!')
+      else:
+        return getattr(self._delegate, attr)
+
+  def __enter__(self):
+    with self._lock:
+      if self._in_context:
+        raise ValueError('Already in context!')
+      elif self._delegate is None:
+        self._delegate = self._up()
+      self._in_context = True
+      return self
+
+  def __exit__(self, exc_type, exc_val, exc_tb):
+    with self._lock:
+      if not self._in_context:
+        raise ValueError('Not in context!')
+      self._down()
+      self._in_context = False
+      self._delegate = None
+      return False
+
+  def __del__(self):
+    with self._lock:
+      if self._delegate is not None:
+        self._down()
+        self._delegate = None
+
+
+class _StubAssemblyManager(object):
+
+  def __init__(
+      self, thread_pool, thread_pool_size, end_link, grpc_link, stub_creator):
+    self._thread_pool = thread_pool
+    self._pool_size = thread_pool_size
+    self._end_link = end_link
+    self._grpc_link = grpc_link
+    self._stub_creator = stub_creator
+    self._own_pool = None
+
+  def up(self):
+    if self._thread_pool is None:
+      self._own_pool = logging_pool.pool(
+          _DEFAULT_POOL_SIZE if self._pool_size is None else self._pool_size)
+      assembly_pool = self._own_pool
+    else:
+      assembly_pool = self._thread_pool
+    self._end_link.join_link(self._grpc_link)
+    self._grpc_link.join_link(self._end_link)
+    self._end_link.start()
+    self._grpc_link.start()
+    return self._stub_creator(self._end_link, assembly_pool)
+
+  def down(self):
+    self._end_link.stop(0).wait()
+    self._grpc_link.stop()
+    self._end_link.join_link(utilities.NULL_LINK)
+    self._grpc_link.join_link(utilities.NULL_LINK)
+    if self._own_pool is not None:
+      self._own_pool.shutdown(wait=True)
+      self._own_pool = None
+
+
+def _assemble(
+    channel, host, metadata_transformer, request_serializers,
+    response_deserializers, thread_pool, thread_pool_size, stub_creator):
+  end_link = _core_implementations.invocation_end_link()
+  grpc_link = invocation.invocation_link(
+      channel, host, metadata_transformer, request_serializers,
+      response_deserializers)
+  stub_assembly_manager = _StubAssemblyManager(
+      thread_pool, thread_pool_size, end_link, grpc_link, stub_creator)
+  stub = stub_assembly_manager.up()
+  return _AutoIntermediary(
+      stub_assembly_manager.up, stub_assembly_manager.down, stub)
+
+
+def _dynamic_stub_creator(service, cardinalities):
+  def create_dynamic_stub(end_link, invocation_pool):
+    return _crust_implementations.dynamic_stub(
+        end_link, service, cardinalities, invocation_pool)
+  return create_dynamic_stub
+
+
+def generic_stub(
+    channel, host, metadata_transformer, request_serializers,
+    response_deserializers, thread_pool, thread_pool_size):
+  return _assemble(
+      channel, host, metadata_transformer, request_serializers,
+      response_deserializers, thread_pool, thread_pool_size,
+      _crust_implementations.generic_stub)
+
+
+def dynamic_stub(
+    channel, host, service, cardinalities, metadata_transformer,
+    request_serializers, response_deserializers, thread_pool,
+    thread_pool_size):
+  return _assemble(
+      channel, host, metadata_transformer, request_serializers,
+      response_deserializers, thread_pool, thread_pool_size,
+      _dynamic_stub_creator(service, cardinalities))