Add a kernel for a new TensorSummaryOpV2. Add a test for it.

Add a metadata field (type SummaryMetadata) to the Summary::Value proto.
Refactor the static methods in summary.py into a summary_op_util.py file.

Unlike the TensorSummaryOp, TensorSummaryOpV2
- passes a tag to the C++ level. This is more consistent with the rest of the summaries.
- lets the user pass a third argument that is a serialized SummaryMetadata proto. The SummaryMetadata contains plugin-specific data. This lets TensorBoard determine which events are relevant to which plugins.

We must make a new op instead of modifying the TensorSummaryOp because we must be backwards compatible.

PiperOrigin-RevId: 158797579

12 files changed, 413 insertions, 106 deletions

diff --git a/tensorflow/core/framework/summary.proto b/tensorflow/core/framework/summary.proto
index 3560b96dfc..12274d5e13 100644
--- a/tensorflow/core/framework/summary.proto
+++ b/tensorflow/core/framework/summary.proto
@@ -33,6 +33,26 @@ message HistogramProto {
   repeated double bucket = 7 [packed = true];
 };
 
+// A SummaryMetadata encapsulates information on which plugins are able to make
+// use of a certain summary value.
+message SummaryMetadata {
+  message PluginData {
+    // The name of the plugin this data pertains to.
+    string plugin_name = 1;
+
+    // The content to store for the plugin. The best practice is for this JSON
+    // string to be the canonical JSON serialization of a protocol buffer
+    // defined by the plugin. Converting that protobuf to and from JSON is the
+    // responsibility of the plugin code, and is not enforced by
+    // TensorFlow/TensorBoard.
+    string content = 2;
+  }
+
+  // A list of plugin data. A single summary value instance may be used by more
+  // than 1 plugin.
+  repeated PluginData plugin_data = 1;
+};
+
 // A Summary is a set of named values to be displayed by the
 // visualizer.
 //
@@ -71,22 +91,21 @@ message Summary {
   }
 
   message Value {
-    // Name of the node that output this summary; in general, the name of a
-    // TensorSummary node. If the node in question has multiple outputs, then
-    // a ":\d+" suffix will be appended, like "some_op:13".
-    // Might not be set for legacy summaries (i.e. those not using the tensor
-    // value field)
+    // This field is deprecated and will not be set.
     string node_name = 7;
 
-    // Tag name for the data.  Will only be used by legacy summaries
-    // (ie. those not using the tensor value field)
-    // For legacy summaries, will be used as the title of the graph
-    // in the visualizer.
-    //
-    // Tag is usually "op_name:value_name", where "op_name" itself can have
-    // structure to indicate grouping.
+    // Tag name for the data. Used by TensorBoard plugins to organize data. Tags
+    // are often organized by scope (which contains slashes to convey
+    // hierarchy). For example: foo/bar/0
     string tag = 1;
 
+    // Contains metadata on the summary value such as which plugins may use it.
+    // Take note that many summary values may lack a metadata field. This is
+    // because the FileWriter only keeps a metadata object on the first summary
+    // value with a certain tag for each tag. TensorBoard then remembers which
+    // tags are associated with which plugins. This saves space.
+    SummaryMetadata metadata = 9;
+
     // Value associated with the tag.
     oneof value {
       float simple_value = 2;
diff --git a/tensorflow/core/kernels/BUILD b/tensorflow/core/kernels/BUILD
index 8ad345ec72..22a424f3ab 100644
--- a/tensorflow/core/kernels/BUILD
+++ b/tensorflow/core/kernels/BUILD
@@ -2224,6 +2224,7 @@ tf_cc_tests(
         "summary_audio_op_test.cc",
         "summary_image_op_test.cc",
         "summary_op_test.cc",
+        "summary_tensor_op_test.cc",
     ],
     deps = [
         ":logging",
diff --git a/tensorflow/core/kernels/summary_tensor_op.cc b/tensorflow/core/kernels/summary_tensor_op.cc
index e939a58794..c816974378 100644
--- a/tensorflow/core/kernels/summary_tensor_op.cc
+++ b/tensorflow/core/kernels/summary_tensor_op.cc
@@ -17,6 +17,7 @@ limitations under the License.
 #include "tensorflow/core/framework/register_types.h"
 #include "tensorflow/core/framework/resource_mgr.h"
 #include "tensorflow/core/framework/summary.pb.h"
+#include "tensorflow/core/framework/tensor.pb.h"
 #include "tensorflow/core/lib/core/errors.h"
 #include "tensorflow/core/platform/logging.h"
 #include "tensorflow/core/platform/protobuf.h"
@@ -24,6 +25,53 @@ limitations under the License.
 namespace tensorflow {
 
 template <typename T>
+class SummaryTensorOpV2 : public OpKernel {
+ public:
+  explicit SummaryTensorOpV2(OpKernelConstruction* context)
+      : OpKernel(context) {}
+
+  void Compute(OpKernelContext* c) override {
+    const Tensor& tag = c->input(0);
+    OP_REQUIRES(c, IsLegacyScalar(tag.shape()),
+                errors::InvalidArgument("tag must be scalar"));
+    const Tensor& tensor = c->input(1);
+    const Tensor& serialized_summary_metadata_tensor = c->input(2);
+
+    Summary s;
+    Summary::Value* v = s.add_value();
+    v->set_tag(tag.scalar<string>()());
+
+    if (tensor.dtype() == DT_STRING) {
+      // tensor_util.makeNdarray doesn't work for strings in tensor_content
+      tensor.AsProtoField(v->mutable_tensor());
+    } else {
+      tensor.AsProtoTensorContent(v->mutable_tensor());
+    }
+
+    v->mutable_metadata()->ParseFromString(
+        serialized_summary_metadata_tensor.scalar<string>()());
+
+    Tensor* summary_tensor = nullptr;
+    OP_REQUIRES_OK(c, c->allocate_output(0, TensorShape({}), &summary_tensor));
+    CHECK(s.SerializeToString(&summary_tensor->scalar<string>()()));
+  }
+};
+
+#define REGISTER(T)                                                      \
+  REGISTER_KERNEL_BUILDER(                                               \
+      Name("TensorSummaryV2").Device(DEVICE_CPU).TypeConstraint<T>("T"), \
+      SummaryTensorOpV2<T>);
+
+TF_CALL_ALL_TYPES(REGISTER)
+
+#undef REGISTER
+
+// NOTE(chizeng): We are phasing out the use of SummaryTensorOp in favor of
+// SummaryTensorOpV2. This is because SummaryTensorOpV2 allows the callers to
+// pass a tag (more consistent with other summaries) as well as serialized
+// summary metadata used by plugins (which lets TensorBoard determine which
+// events are relevant to which plugins).
+template <typename T>
 class SummaryTensorOp : public OpKernel {
  public:
   explicit SummaryTensorOp(OpKernelConstruction* context) : OpKernel(context) {}
diff --git a/tensorflow/core/kernels/summary_tensor_op_test.cc b/tensorflow/core/kernels/summary_tensor_op_test.cc
new file mode 100644
index 0000000000..0006a71bd7
--- /dev/null
+++ b/tensorflow/core/kernels/summary_tensor_op_test.cc
@@ -0,0 +1,101 @@
+/* Copyright 2017 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.
+==============================================================================*/
+
+#include <functional>
+#include <memory>
+
+#include "tensorflow/core/framework/allocator.h"
+#include "tensorflow/core/framework/fake_input.h"
+#include "tensorflow/core/framework/node_def_builder.h"
+#include "tensorflow/core/framework/op_kernel.h"
+#include "tensorflow/core/framework/summary.pb.h"
+#include "tensorflow/core/framework/tensor.h"
+#include "tensorflow/core/framework/types.h"
+#include "tensorflow/core/kernels/ops_testutil.h"
+#include "tensorflow/core/kernels/ops_util.h"
+#include "tensorflow/core/lib/core/status_test_util.h"
+#include "tensorflow/core/lib/histogram/histogram.h"
+#include "tensorflow/core/lib/strings/strcat.h"
+#include "tensorflow/core/platform/env.h"
+#include "tensorflow/core/platform/logging.h"
+#include "tensorflow/core/platform/protobuf.h"
+#include "tensorflow/core/platform/test.h"
+
+namespace tensorflow {
+namespace {
+
+static void EXPECT_SummaryMatches(const Summary& actual,
+                                  const string& expected_str) {
+  Summary expected;
+  CHECK(protobuf::TextFormat::ParseFromString(expected_str, &expected));
+  EXPECT_EQ(expected.DebugString(), actual.DebugString());
+}
+
+// --------------------------------------------------------------------------
+// SummaryTensorOpV2
+// --------------------------------------------------------------------------
+class SummaryTensorOpV2Test : public OpsTestBase {
+ protected:
+  void MakeOp() {
+    TF_ASSERT_OK(NodeDefBuilder("myop", "TensorSummaryV2")
+                     .Input(FakeInput(DT_STRING))
+                     .Input(FakeInput(DT_STRING))
+                     .Input(FakeInput(DT_STRING))
+                     .Finalize(node_def()));
+    TF_ASSERT_OK(InitOp());
+  }
+};
+
+TEST_F(SummaryTensorOpV2Test, BasicPluginData) {
+  MakeOp();
+
+  // Feed and run
+  AddInputFromArray<string>(TensorShape({}), {"tag_foo"});
+  AddInputFromArray<string>(TensorShape({}), {"some string tensor content"});
+
+  // Create a SummaryMetadata that stores data for 2 plugins.
+  SummaryMetadata summary_metadata;
+  SummaryMetadata::PluginData* plugin_data_0 =
+      summary_metadata.add_plugin_data();
+  plugin_data_0->set_plugin_name("foo");
+  plugin_data_0->set_content("content_for_plugin_foo");
+  SummaryMetadata::PluginData* plugin_data_1 =
+      summary_metadata.add_plugin_data();
+  plugin_data_1->set_plugin_name("bar");
+  plugin_data_1->set_content("content_for_plugin_bar");
+  AddInputFromArray<string>(TensorShape({}),
+                            {summary_metadata.SerializeAsString()});
+
+  TF_ASSERT_OK(RunOpKernel());
+
+  // Check the output size.
+  Tensor* out_tensor = GetOutput(0);
+  ASSERT_EQ(0, out_tensor->dims());
+  Summary summary;
+  ParseProtoUnlimited(&summary, out_tensor->scalar<string>()());
+
+  ASSERT_EQ(1, summary.value_size());
+  ASSERT_EQ("tag_foo", summary.value(0).tag());
+  ASSERT_EQ(2, summary.value(0).metadata().plugin_data_size());
+  ASSERT_EQ("foo", summary.value(0).metadata().plugin_data(0).plugin_name());
+  ASSERT_EQ("content_for_plugin_foo",
+            summary.value(0).metadata().plugin_data(0).content());
+  ASSERT_EQ("bar", summary.value(0).metadata().plugin_data(1).plugin_name());
+  ASSERT_EQ("content_for_plugin_bar",
+            summary.value(0).metadata().plugin_data(1).content());
+}
+
+}  // namespace
+}  // namespace tensorflow
diff --git a/tensorflow/core/ops/logging_ops.cc b/tensorflow/core/ops/logging_ops.cc
index 42bd12a5b3..4f5191f9f5 100644
--- a/tensorflow/core/ops/logging_ops.cc
+++ b/tensorflow/core/ops/logging_ops.cc
@@ -65,6 +65,24 @@ summarize: Only print this many entries of each tensor.
 // Operators that deal with SummaryProtos (encoded as DT_STRING tensors) as
 // inputs or outputs in various ways.
 
+REGISTER_OP("TensorSummaryV2")
+    .Input("tag: string")
+    .Input("tensor: T")
+    // This serialized summary metadata field describes a summary value,
+    // specifically which plugins may use that summary.
+    .Input("serialized_summary_metadata: string")
+    .Output("summary: string")
+    .Attr("T: type")
+    .SetShapeFn(shape_inference::ScalarShape)
+    .Doc(R"doc(
+Outputs a `Summary` protocol buffer with a tensor and per-plugin data.
+
+tag: A string attached to this summary. Used for organization in TensorBoard.
+tensor: A tensor to serialize.
+serialized_summary_metadata: A serialized SummaryMetadata proto. Contains plugin
+  data.
+)doc");
+
 REGISTER_OP("TensorSummary")
     .Input("tensor: T")
     .Output("summary: string")
@@ -76,6 +94,10 @@ REGISTER_OP("TensorSummary")
     .Doc(R"doc(
 Outputs a `Summary` protocol buffer with a tensor.
 
+This op is being phased out in favor of TensorSummaryV2, which lets callers pass
+a tag as well as a serialized SummaryMetadata proto string that contains
+plugin-specific data. We will keep this op to maintain backwards compatibility.
+
 tensor: A tensor to serialize.
 description: A json-encoded SummaryDescription proto.
 labels: An unused list of strings.
diff --git a/tensorflow/python/BUILD b/tensorflow/python/BUILD
index 8cb7c5d0df..2027eaf977 100644
--- a/tensorflow/python/BUILD
+++ b/tensorflow/python/BUILD
@@ -2028,6 +2028,7 @@ py_library(
     deps = [
         ":framework_for_generated_wrappers",
         ":logging_ops_gen",
+        ":summary_op_util",
     ],
 )
 
@@ -3404,6 +3405,18 @@ tf_py_test(
 )
 
 py_library(
+    name = "summary_op_util",
+    srcs = ["ops/summary_op_util.py"],
+    srcs_version = "PY2AND3",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":framework",
+        ":framework_for_generated_wrappers",
+        ":platform",
+    ],
+)
+
+py_library(
     name = "summary",
     srcs = glob(
         ["summary/**/*.py"],
@@ -3420,6 +3433,7 @@ py_library(
         ":platform",
         ":protos_all_py",
         ":pywrap_tensorflow",
+        ":summary_op_util",
         ":summary_ops",
         ":util",
         "//third_party/py/numpy",
diff --git a/tensorflow/python/ops/hidden_ops.txt b/tensorflow/python/ops/hidden_ops.txt
index 553e0dc135..9aef6bffde 100644
--- a/tensorflow/python/ops/hidden_ops.txt
+++ b/tensorflow/python/ops/hidden_ops.txt
@@ -219,6 +219,7 @@ MergeSummary
 Print
 ScalarSummary
 TensorSummary
+TensorSummaryV2
 
 # math_ops
 Abs
diff --git a/tensorflow/python/ops/summary_op_util.py b/tensorflow/python/ops/summary_op_util.py
new file mode 100644
index 0000000000..a3f6616902
--- /dev/null
+++ b/tensorflow/python/ops/summary_op_util.py
@@ -0,0 +1,107 @@
+# Copyright 2017 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.
+#==============================================================================
+"""Contains utility functions used by summary ops."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import contextlib
+import re
+
+from tensorflow.python.framework import ops
+from tensorflow.python.platform import tf_logging
+
+
+def collect(val, collections, default_collections):
+  """Adds keys to a collection.
+
+  Args:
+    val: The value to add per each key.
+    collections: A collection of keys to add.
+    default_collections: Used if collections is None.
+  """
+  if collections is None:
+    collections = default_collections
+  for key in collections:
+    ops.add_to_collection(key, val)
+
+
+_INVALID_TAG_CHARACTERS = re.compile(r'[^-/\w\.]')
+
+
+def clean_tag(name):
+  """Cleans a tag. Removes illegal characters for instance.
+
+  Args:
+    name: The original tag name to be processed.
+
+  Returns:
+    The cleaned tag name.
+  """
+  # In the past, the first argument to summary ops was a tag, which allowed
+  # arbitrary characters. Now we are changing the first argument to be the node
+  # name. This has a number of advantages (users of summary ops now can
+  # take advantage of the tf name scope system) but risks breaking existing
+  # usage, because a much smaller set of characters are allowed in node names.
+  # This function replaces all illegal characters with _s, and logs a warning.
+  # It also strips leading slashes from the name.
+  if name is not None:
+    new_name = _INVALID_TAG_CHARACTERS.sub('_', name)
+    new_name = new_name.lstrip('/')  # Remove leading slashes
+    if new_name != name:
+      tf_logging.info('Summary name %s is illegal; using %s instead.' %
+                      (name, new_name))
+      name = new_name
+  return name
+
+
+@contextlib.contextmanager
+def summary_scope(name, family=None, default_name=None, values=None):
+  """Enters a scope used for the summary and yields both the name and tag.
+
+  To ensure that the summary tag name is always unique, we create a name scope
+  based on `name` and use the full scope name in the tag.
+
+  If `family` is set, then the tag name will be '<family>/<scope_name>', where
+  `scope_name` is `<outer_scope>/<family>/<name>`. This ensures that `family`
+  is always the prefix of the tag (and unmodified), while ensuring the scope
+  respects the outer scope from this this summary was created.
+
+  Args:
+    name: A name for the generated summary node.
+    family: Optional; if provided, used as the prefix of the summary tag name.
+    default_name: Optional; if provided, used as default name of the summary.
+    values: Optional; passed as `values` parameter to name_scope.
+
+  Yields:
+    A tuple `(tag, scope)`, both of which are unique and should be used for the
+    tag and the scope for the summary to output.
+  """
+  name = clean_tag(name)
+  family = clean_tag(family)
+  # Use family name in the scope to ensure uniqueness of scope/tag.
+  scope_base_name = name if family is None else '{}/{}'.format(family, name)
+  with ops.name_scope(scope_base_name, default_name, values=values) as scope:
+    if family is None:
+      tag = scope.rstrip('/')
+    else:
+      # Prefix our scope with family again so it displays in the right tab.
+      tag = '{}/{}'.format(family, scope.rstrip('/'))
+      # Note: tag is not 100% unique if the user explicitly enters a scope with
+      # the same name as family, then later enter it again before summaries.
+      # This is very contrived though, and we opt here to let it be a runtime
+      # exception if tags do indeed collide.
+    yield (tag, scope)
diff --git a/tensorflow/python/ops/summary_ops.py b/tensorflow/python/ops/summary_ops.py
index 005f17dc45..4ad0862dcc 100644
--- a/tensorflow/python/ops/summary_ops.py
+++ b/tensorflow/python/ops/summary_ops.py
@@ -22,19 +22,13 @@ from google.protobuf import json_format
 from tensorflow.core.framework import summary_pb2
 from tensorflow.python.framework import ops
 from tensorflow.python.ops import gen_logging_ops
+from tensorflow.python.ops import summary_op_util
 # go/tf-wildcard-import
 # pylint: disable=wildcard-import
 from tensorflow.python.ops.gen_logging_ops import *
 # pylint: enable=wildcard-import
 
 
-def _Collect(val, collections, default_collections):
-  if collections is None:
-    collections = default_collections
-  for key in collections:
-    ops.add_to_collection(key, val)
-
-
 # TODO(dandelion): As currently implemented, this op has several problems.
 # The 'summary_description' field is passed but not used by the kernel.
 # The 'name' field is used to creat a scope and passed down via name=scope,
@@ -78,8 +72,67 @@ def tensor_summary(  # pylint: disable=invalid-name
         tensor=tensor,
         description=description,
         name=scope)
-    _Collect(val, collections, [ops.GraphKeys.SUMMARIES])
+    summary_op_util.collect(val, collections, [ops.GraphKeys.SUMMARIES])
   return val
 
-
 ops.NotDifferentiable("TensorSummary")
+
+
+def _tensor_summary_v2(  # pylint: disable=invalid-name
+    name,
+    tensor,
+    summary_description=None,
+    collections=None,
+    summary_metadata=None,
+    family=None):
+  # pylint: disable=line-too-long
+  """Outputs a `Summary` protocol buffer with a serialized tensor.proto.
+
+  NOTE(chizeng): This method is temporary. It should never make it into
+  TensorFlow 1.3, and nothing should depend on it. This method should be deleted
+  before August 2017 (ideally, earlier). This method exists to unblock the
+  TensorBoard plugin refactoring effort. We will later modify the tensor_summary
+  method to directly make use of the TensorSummaryV2 op. There must be a 3-week
+  difference between adding a new op (C++) and changing a python interface to
+  use it.
+
+  The generated
+  [`Summary`](https://www.tensorflow.org/code/tensorflow/core/framework/summary.proto)
+  has one summary value containing the input tensor.
+
+  Args:
+    name: A name for the generated node. Will also serve as the series name in
+      TensorBoard.
+    tensor: A tensor of any type and shape to serialize.
+    summary_description: This is currently un-used but must be kept for
+      backwards compatibility.
+    collections: Optional list of graph collections keys. The new summary op is
+      added to these collections. Defaults to `[GraphKeys.SUMMARIES]`.
+    summary_metadata: Optional SummaryMetadata proto (which describes which
+      plugins may use the summary value).
+    family: Optional; if provided, used as the prefix of the summary tag name,
+      which controls the tab name used for display on Tensorboard.
+
+  Returns:
+    A scalar `Tensor` of type `string`. The serialized `Summary` protocol
+    buffer.
+  """
+  # pylint: enable=line-too-long
+
+  # The summary description is unused now.
+  del summary_description
+
+  serialized_summary_metadata = ""
+  if summary_metadata:
+    serialized_summary_metadata = summary_metadata.SerializeToString()
+
+  with summary_op_util.summary_scope(
+      name, family, values=[tensor]) as (tag, scope):
+    val = gen_logging_ops._tensor_summary_v2(
+        tensor=tensor,
+        tag=tag,
+        description="",
+        name=scope,
+        serialized_summary_metadata=serialized_summary_metadata)
+    summary_op_util.collect(val, collections, [ops.GraphKeys.SUMMARIES])
+  return val
diff --git a/tensorflow/python/summary/summary.py b/tensorflow/python/summary/summary.py
index cb8778be28..7ff01a51f3 100644
--- a/tensorflow/python/summary/summary.py
+++ b/tensorflow/python/summary/summary.py
@@ -36,9 +36,6 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
-import contextlib as _contextlib
-import re as _re
-
 from google.protobuf import json_format as _json_format
 
 # exports Summary, SummaryDescription, Event, TaggedRunMetadata, SessionLog
@@ -53,14 +50,14 @@ from tensorflow.core.util.event_pb2 import TaggedRunMetadata
 from tensorflow.python.framework import dtypes as _dtypes
 from tensorflow.python.framework import ops as _ops
 from tensorflow.python.ops import gen_logging_ops as _gen_logging_ops
+from tensorflow.python.ops import summary_op_util as _summary_op_util
 
-# exports tensor_summary
+# exports tensor-related summaries
 # pylint: disable=unused-import
+from tensorflow.python.ops.summary_ops import _tensor_summary_v2
 from tensorflow.python.ops.summary_ops import tensor_summary
 # pylint: enable=unused-import
 
-from tensorflow.python.platform import tf_logging as _logging
-
 # exports text
 # pylint: disable=unused-import
 from tensorflow.python.summary.text_summary import text_summary as text
@@ -76,74 +73,6 @@ from tensorflow.python.util import compat as _compat
 from tensorflow.python.util.all_util import remove_undocumented
 
 
-def _collect(val, collections, default_collections):
-  if collections is None:
-    collections = default_collections
-  for key in collections:
-    _ops.add_to_collection(key, val)
-
-
-_INVALID_TAG_CHARACTERS = _re.compile(r'[^-/\w\.]')
-
-
-def _clean_tag(name):
-  # In the past, the first argument to summary ops was a tag, which allowed
-  # arbitrary characters. Now we are changing the first argument to be the node
-  # name. This has a number of advantages (users of summary ops now can
-  # take advantage of the tf name scope system) but risks breaking existing
-  # usage, because a much smaller set of characters are allowed in node names.
-  # This function replaces all illegal characters with _s, and logs a warning.
-  # It also strips leading slashes from the name.
-  if name is not None:
-    new_name = _INVALID_TAG_CHARACTERS.sub('_', name)
-    new_name = new_name.lstrip('/')  # Remove leading slashes
-    if new_name != name:
-      _logging.info(
-          'Summary name %s is illegal; using %s instead.' %
-          (name, new_name))
-      name = new_name
-  return name
-
-
-@_contextlib.contextmanager
-def _summary_scope(name, family=None, default_name=None, values=None):
-  """Enters a scope used for the summary and yields both the name and tag.
-
-  To ensure that the summary tag name is always unique, we create a name scope
-  based on `name` and use the full scope name in the tag.
-
-  If `family` is set, then the tag name will be '<family>/<scope_name>', where
-  `scope_name` is `<outer_scope>/<family>/<name>`. This ensures that `family`
-  is always the prefix of the tag (and unmodified), while ensuring the scope
-  respects the outer scope from this this summary was created.
-
-  Args:
-    name: A name for the generated summary node.
-    family: Optional; if provided, used as the prefix of the summary tag name.
-    default_name: Optional; if provided, used as default name of the summary.
-    values: Optional; passed as `values` parameter to name_scope.
-
-  Yields:
-    A tuple `(tag, scope)`, both of which are unique and should be used for the
-    tag and the scope for the summary to output.
-  """
-  name = _clean_tag(name)
-  family = _clean_tag(family)
-  # Use family name in the scope to ensure uniqueness of scope/tag.
-  scope_base_name = name if family is None else '{}/{}'.format(family, name)
-  with _ops.name_scope(scope_base_name, default_name, values=values) as scope:
-    if family is None:
-      tag = scope.rstrip('/')
-    else:
-      # Prefix our scope with family again so it displays in the right tab.
-      tag = '{}/{}'.format(family, scope.rstrip('/'))
-      # Note: tag is not 100% unique if the user explicitly enters a scope with
-      # the same name as family, then later enter it again before summaries.
-      # This is very contrived though, and we opt here to let it be a runtime
-      # exception if tags do indeed collide.
-    yield (tag, scope)
-
-
 def scalar(name, tensor, collections=None, family=None):
   """Outputs a `Summary` protocol buffer containing a single scalar value.
 
@@ -164,10 +93,11 @@ def scalar(name, tensor, collections=None, family=None):
   Raises:
     ValueError: If tensor has the wrong shape or type.
   """
-  with _summary_scope(name, family, values=[tensor]) as (tag, scope):
+  with _summary_op_util.summary_scope(
+      name, family, values=[tensor]) as (tag, scope):
     # pylint: disable=protected-access
     val = _gen_logging_ops._scalar_summary(tags=tag, values=tensor, name=scope)
-    _collect(val, collections, [_ops.GraphKeys.SUMMARIES])
+    _summary_op_util.collect(val, collections, [_ops.GraphKeys.SUMMARIES])
   return val
 
 
@@ -216,11 +146,12 @@ def image(name, tensor, max_outputs=3, collections=None, family=None):
     A scalar `Tensor` of type `string`. The serialized `Summary` protocol
     buffer.
   """
-  with _summary_scope(name, family, values=[tensor]) as (tag, scope):
+  with _summary_op_util.summary_scope(
+      name, family, values=[tensor]) as (tag, scope):
     # pylint: disable=protected-access
     val = _gen_logging_ops._image_summary(
         tag=tag, tensor=tensor, max_images=max_outputs, name=scope)
-    _collect(val, collections, [_ops.GraphKeys.SUMMARIES])
+    _summary_op_util.collect(val, collections, [_ops.GraphKeys.SUMMARIES])
   return val
 
 
@@ -253,12 +184,13 @@ def histogram(name, values, collections=None, family=None):
     A scalar `Tensor` of type `string`. The serialized `Summary` protocol
     buffer.
   """
-  with _summary_scope(name, family, values=[values],
-                      default_name='HistogramSummary') as (tag, scope):
+  with _summary_op_util.summary_scope(
+      name, family, values=[values],
+      default_name='HistogramSummary') as (tag, scope):
     # pylint: disable=protected-access
     val = _gen_logging_ops._histogram_summary(
         tag=tag, values=values, name=scope)
-    _collect(val, collections, [_ops.GraphKeys.SUMMARIES])
+    _summary_op_util.collect(val, collections, [_ops.GraphKeys.SUMMARIES])
   return val
 
 
@@ -297,14 +229,15 @@ def audio(name, tensor, sample_rate, max_outputs=3, collections=None,
     A scalar `Tensor` of type `string`. The serialized `Summary` protocol
     buffer.
   """
-  with _summary_scope(name, family=family, values=[tensor]) as (tag, scope):
+  with _summary_op_util.summary_scope(
+      name, family=family, values=[tensor]) as (tag, scope):
     # pylint: disable=protected-access
     sample_rate = _ops.convert_to_tensor(
         sample_rate, dtype=_dtypes.float32, name='sample_rate')
     val = _gen_logging_ops._audio_summary_v2(
         tag=tag, tensor=tensor, max_outputs=max_outputs,
         sample_rate=sample_rate, name=scope)
-    _collect(val, collections, [_ops.GraphKeys.SUMMARIES])
+    _summary_op_util.collect(val, collections, [_ops.GraphKeys.SUMMARIES])
   return val
 
 
@@ -332,11 +265,11 @@ def merge(inputs, collections=None, name=None):
     buffer resulting from the merging.
   """
   # pylint: enable=line-too-long
-  name = _clean_tag(name)
+  name = _summary_op_util.clean_tag(name)
   with _ops.name_scope(name, 'Merge', inputs):
     # pylint: disable=protected-access
     val = _gen_logging_ops._merge_summary(inputs=inputs, name=name)
-    _collect(val, collections, [])
+    _summary_op_util.collect(val, collections, [])
   return val
 
 
diff --git a/tensorflow/tools/api/golden/tensorflow.-summary.-value.pbtxt b/tensorflow/tools/api/golden/tensorflow.-summary.-value.pbtxt
index d02fb9ecd4..ffb4f45fc5 100644
--- a/tensorflow/tools/api/golden/tensorflow.-summary.-value.pbtxt
+++ b/tensorflow/tools/api/golden/tensorflow.-summary.-value.pbtxt
@@ -23,6 +23,10 @@ tf_class {
     mtype: "<type \'int\'>"
   }
   member {
+    name: "METADATA_FIELD_NUMBER"
+    mtype: "<type \'int\'>"
+  }
+  member {
     name: "NODE_NAME_FIELD_NUMBER"
     mtype: "<type \'int\'>"
   }
diff --git a/tensorflow/tools/api/golden/tensorflow.summary.-summary.-value.pbtxt b/tensorflow/tools/api/golden/tensorflow.summary.-summary.-value.pbtxt
index 5294b37f57..b319cd03d9 100644
--- a/tensorflow/tools/api/golden/tensorflow.summary.-summary.-value.pbtxt
+++ b/tensorflow/tools/api/golden/tensorflow.summary.-summary.-value.pbtxt
@@ -23,6 +23,10 @@ tf_class {
     mtype: "<type \'int\'>"
   }
   member {
+    name: "METADATA_FIELD_NUMBER"
+    mtype: "<type \'int\'>"
+  }
+  member {
     name: "NODE_NAME_FIELD_NUMBER"
     mtype: "<type \'int\'>"
   }