1 files changed, 171 insertions, 0 deletions
diff --git a/src/python/grpcio/grpc/_utilities.py b/src/python/grpcio/grpc/_utilities.py
new file mode 100644
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+++ b/src/python/grpcio/grpc/_utilities.py
@@ -0,0 +1,171 @@
+# 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.
+
+"""Internal utilities for gRPC Python."""
+
+import collections
+import threading
+import time
+
+import six
+
+import grpc
+from grpc import _common
+from grpc.framework.foundation import callable_util
+
+_DONE_CALLBACK_EXCEPTION_LOG_MESSAGE = (
+    'Exception calling connectivity future "done" callback!')
+
+
+class RpcMethodHandler(
+    collections.namedtuple(
+        '_RpcMethodHandler',
+        ('request_streaming', 'response_streaming', 'request_deserializer',
+         'response_serializer', 'unary_unary', 'unary_stream', 'stream_unary',
+         'stream_stream',)),
+    grpc.RpcMethodHandler):
+  pass
+
+
+class DictionaryGenericHandler(grpc.GenericRpcHandler):
+
+  def __init__(self, service, method_handlers):
+    self._method_handlers = {
+        _common.fully_qualified_method(service, method): method_handler
+        for method, method_handler in six.iteritems(method_handlers)}
+
+  def service(self, handler_call_details):
+    return self._method_handlers.get(handler_call_details.method)
+
+
+class _ChannelReadyFuture(grpc.Future):
+
+  def __init__(self, channel):
+    self._condition = threading.Condition()
+    self._channel = channel
+
+    self._matured = False
+    self._cancelled = False
+    self._done_callbacks = []
+
+  def _block(self, timeout):
+    until = None if timeout is None else time.time() + timeout
+    with self._condition:
+      while True:
+        if self._cancelled:
+          raise grpc.FutureCancelledError()
+        elif self._matured:
+          return
+        else:
+          if until is None:
+            self._condition.wait()
+          else:
+            remaining = until - time.time()
+            if remaining < 0:
+              raise grpc.FutureTimeoutError()
+            else:
+              self._condition.wait(timeout=remaining)
+
+  def _update(self, connectivity):
+    with self._condition:
+      if (not self._cancelled and
+          connectivity is grpc.ChannelConnectivity.READY):
+        self._matured = True
+        self._channel.unsubscribe(self._update)
+        self._condition.notify_all()
+        done_callbacks = tuple(self._done_callbacks)
+        self._done_callbacks = None
+      else:
+        return
+
+    for done_callback in done_callbacks:
+      callable_util.call_logging_exceptions(
+          done_callback, _DONE_CALLBACK_EXCEPTION_LOG_MESSAGE, self)
+
+  def cancel(self):
+    with self._condition:
+      if not self._matured:
+        self._cancelled = True
+        self._channel.unsubscribe(self._update)
+        self._condition.notify_all()
+        done_callbacks = tuple(self._done_callbacks)
+        self._done_callbacks = None
+      else:
+        return False
+
+    for done_callback in done_callbacks:
+      callable_util.call_logging_exceptions(
+          done_callback, _DONE_CALLBACK_EXCEPTION_LOG_MESSAGE, self)
+
+  def cancelled(self):
+    with self._condition:
+      return self._cancelled
+
+  def running(self):
+    with self._condition:
+      return not self._cancelled and not self._matured
+
+  def done(self):
+    with self._condition:
+      return self._cancelled or self._matured
+
+  def result(self, timeout=None):
+    self._block(timeout)
+    return None
+
+  def exception(self, timeout=None):
+    self._block(timeout)
+    return None
+
+  def traceback(self, timeout=None):
+    self._block(timeout)
+    return None
+
+  def add_done_callback(self, fn):
+    with self._condition:
+      if not self._cancelled and not self._matured:
+        self._done_callbacks.append(fn)
+        return
+
+    fn(self)
+
+  def start(self):
+    with self._condition:
+      self._channel.subscribe(self._update, try_to_connect=True)
+
+  def __del__(self):
+    with self._condition:
+      if not self._cancelled and not self._matured:
+        self._channel.unsubscribe(self._update)
+
+
+def channel_ready_future(channel):
+  ready_future = _ChannelReadyFuture(channel)
+  ready_future.start()
+  return ready_future