Initial checkin of gRPC to third_party/

third_party/grpc/src/python/grpcio_health_checking/grpc/health/v1/health.py

Index: third_party/grpc/src/python/grpcio_health_checking/grpc/health/v1/health.py
diff --git a/third_party/grpc/src/python/grpcio_health_checking/grpc/health/v1/health.py b/third_party/grpc/src/python/grpcio_health_checking/grpc/health/v1/health.py
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@@ -0,0 +1,129 @@
+# Copyright 2015-2016, 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.
+
+"""Reference implementation for health checking in gRPC Python."""
+
+import abc
+import enum
+import threading
+
+from grpc.health.v1 import health_pb2
+
+
+@enum.unique
+class HealthStatus(enum.Enum):
+  """Statuses for a service mirroring the reference health.proto's values."""
+  UNKNOWN = health_pb2.HealthCheckResponse.UNKNOWN
+  SERVING = health_pb2.HealthCheckResponse.SERVING
+  NOT_SERVING = health_pb2.HealthCheckResponse.NOT_SERVING
+
+
+class _HealthServicer(health_pb2.EarlyAdopterHealthServicer):
+  """Servicer handling RPCs for service statuses."""
+
+  def __init__(self):
+    self._server_status_lock = threading.Lock()
+    self._server_status = {}
+
+  def Check(self, request, context):
+    with self._server_status_lock:
+      if request.service not in self._server_status:
+        # TODO(atash): once the Python API has a way of setting the server
+        # status, bring us into conformance with the health check spec by
+        # returning the NOT_FOUND status here.
+        raise NotImplementedError()
+      else:
+        return health_pb2.HealthCheckResponse(
+            status=self._server_status[request.service].value)
+
+  def set(service, status):
+    if not isinstance(status, HealthStatus):
+      raise TypeError('expected grpc.health.v1.health.HealthStatus '
+                      'for argument `status` but got {}'.format(status))
+    with self._server_status_lock:
+      self._server_status[service] = status
+
+
+class HealthServer(health_pb2.EarlyAdopterHealthServer):
+  """Interface for the reference gRPC Python health server."""
+  __metaclass__ = abc.ABCMeta
+
+  @abc.abstractmethod
+  def start(self):
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def stop(self):
+    raise NotImplementedError()
+
+  @abc.abstractmethod
+  def set(self, service, status):
+    """Set the status of the given service.
+
+    Args:
+      service (str): service name of the service to set the reported status of
+      status (HealthStatus): status to set for the specified service
+    """
+    raise NotImplementedError()
+
+
+class _HealthServerImplementation(HealthServer):
+  """Implementation for the reference gRPC Python health server."""
+
+  def __init__(self, server, servicer):
+    self._server = server
+    self._servicer = servicer
+
+  def start(self):
+    self._server.start()
+
+  def stop(self):
+    self._server.stop()
+
+  def set(self, service, status):
+    self._servicer.set(service, status)
+
+
+def create_Health_server(port, private_key=None, certificate_chain=None):
+  """Get a HealthServer instance.
+
+  Args:
+    port (int): port number passed through to health_pb2 server creation
+      routine.
+    private_key (str): to-be-created server's desired private key
+    certificate_chain (str): to-be-created server's desired certificate chain
+
+  Returns:
+    An instance of HealthServer (conforming thus to
+    EarlyAdopterHealthServer and providing a method to set server status)."""
+  servicer = _HealthServicer()
+  server = health_pb2.early_adopter_create_Health_server(
+      servicer, port=port, private_key=private_key,
+      certificate_chain=certificate_chain)
+  return _HealthServerImplementation(server, servicer)