Add Python API functions to query kernels

This is part of the work to make available kernels easier to query at runtime.

PiperOrigin-RevId: 205802663

tensorflow/python/BUILD

@@ -96,6 +96,7 @@ py_library(
         ":image_ops",
         ":initializers_ns",
         ":io_ops",
+        ":kernels",
         ":layers",
         ":lib",
         ":list_ops",
@@ -789,6 +790,19 @@ py_library(
     ],
 )
 
+py_library(
+    name = "kernels",
+    srcs = [
+        "framework/kernels.py",
+    ],
+    srcs_version = "PY2AND3",
+    deps = [
+        ":pywrap_tensorflow",
+        ":util",
+        "//tensorflow/core:protos_all_py",
+    ],
+)
+
 py_library(
     name = "op_def_library",
     srcs = ["framework/op_def_library.py"],
@@ -1482,6 +1496,20 @@ py_test(
     ],
 )
 
+py_test(
+    name = "framework_kernels_test",
+    size = "small",
+    srcs = ["framework/kernels_test.py"],
+    main = "framework/kernels_test.py",
+    srcs_version = "PY2AND3",
+    deps = [
+        ":framework_test_lib",
+        ":kernels",
+        ":platform_test",
+        ":test_ops",
+    ],
+)
+
 tf_gen_op_wrapper_private_py(
     name = "array_ops_gen",
     visibility = [

tensorflow/python/framework/kernels.py

@@ -0,0 +1,46 @@
+# Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+#
+# 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.
+# ==============================================================================
+"""Functions for querying registered kernels."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from tensorflow.core.framework import kernel_def_pb2
+from tensorflow.python import pywrap_tensorflow as c_api
+from tensorflow.python.util import compat
+
+
+def get_all_registered_kernels():
+  """Returns a KernelList proto of all registered kernels.
+  """
+  buf = c_api.TF_GetAllRegisteredKernels()
+  data = c_api.TF_GetBuffer(buf)
+  kernel_list = kernel_def_pb2.KernelList()
+  kernel_list.ParseFromString(compat.as_bytes(data))
+  return kernel_list
+
+
+def get_registered_kernels_for_op(name):
+  """Returns a KernelList proto of registered kernels for a given op.
+
+  Args:
+    name: A string representing the name of the op whose kernels to retrieve.
+  """
+  buf = c_api.TF_GetRegisteredKernelsForOp(name)
+  data = c_api.TF_GetBuffer(buf)
+  kernel_list = kernel_def_pb2.KernelList()
+  kernel_list.ParseFromString(compat.as_bytes(data))
+  return kernel_list

tensorflow/python/framework/kernels_test.py

@@ -0,0 +1,41 @@
+# Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+#
+# 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.
+# ==============================================================================
+"""Tests for querying registered kernels."""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from tensorflow.python.framework import kernels
+from tensorflow.python.framework import test_util
+from tensorflow.python.platform import googletest
+
+
+class GetAllRegisteredKernelsTest(test_util.TensorFlowTestCase):
+
+  def testFindsAtLeastOneKernel(self):
+    kernel_list = kernels.get_all_registered_kernels()
+    self.assertGreater(len(kernel_list.kernel), 0)
+
+
+class GetRegisteredKernelsForOp(test_util.TensorFlowTestCase):
+
+  def testFindsAtLeastOneKernel(self):
+    kernel_list = kernels.get_registered_kernels_for_op("KernelLabel")
+    self.assertGreater(len(kernel_list.kernel), 0)
+    self.assertEqual(kernel_list.kernel[0].op, "KernelLabel")
+
+
+if __name__ == "__main__":
+  googletest.main()