[tf.data] Move all C++ code inside the `tensorflow::data` namespace.

PiperOrigin-RevId: 211733735

67 files changed, 168 insertions, 87 deletions

diff --git a/tensorflow/core/kernels/data/batch_dataset_op.cc b/tensorflow/core/kernels/data/batch_dataset_op.cc
index f9b5353724..a25f78c6f1 100644
--- a/tensorflow/core/kernels/data/batch_dataset_op.cc
+++ b/tensorflow/core/kernels/data/batch_dataset_op.cc
@@ -18,7 +18,7 @@ limitations under the License.
 #include "tensorflow/core/util/batch_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -241,5 +241,5 @@ REGISTER_KERNEL_BUILDER(Name("BatchDatasetV2").Device(DEVICE_CPU),
                         BatchDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/cache_dataset_ops.cc b/tensorflow/core/kernels/data/cache_dataset_ops.cc
index 6ca0bcd37d..221b5ad835 100644
--- a/tensorflow/core/kernels/data/cache_dataset_ops.cc
+++ b/tensorflow/core/kernels/data/cache_dataset_ops.cc
@@ -20,7 +20,7 @@ limitations under the License.
 #include "tensorflow/core/util/tensor_bundle/tensor_bundle.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level description of
@@ -891,5 +891,5 @@ REGISTER_KERNEL_BUILDER(Name("CacheDataset").Device(DEVICE_CPU),
                         CacheDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/captured_function.cc b/tensorflow/core/kernels/data/captured_function.cc
index 186740c2ac..ad2365b25b 100644
--- a/tensorflow/core/kernels/data/captured_function.cc
+++ b/tensorflow/core/kernels/data/captured_function.cc
@@ -23,6 +23,7 @@ limitations under the License.
 #include "tensorflow/core/platform/notification.h"
 
 namespace tensorflow {
+namespace data {
 
 /* static */
 Status CapturedFunction::Create(
@@ -418,4 +419,5 @@ CapturedFunction::CapturedFunction(const NameAttrList& func,
       captured_inputs_(std::move(captured_inputs)),
       use_inter_op_parallelism_(use_inter_op_parallelism) {}
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/captured_function.h b/tensorflow/core/kernels/data/captured_function.h
index 9526da22d1..e44bc78b1c 100644
--- a/tensorflow/core/kernels/data/captured_function.h
+++ b/tensorflow/core/kernels/data/captured_function.h
@@ -32,6 +32,8 @@ class Device;
 class OpKernelContext;
 class ResourceMgr;
 
+namespace data {
+
 // A `CapturedFunction` encapsulates a TensorFlow function and all of
 // the runtime support required to execute it.
 //
@@ -141,6 +143,12 @@ class CapturedFunction {
   TF_DISALLOW_COPY_AND_ASSIGN(CapturedFunction);
 };
 
+}  // namespace data
+
+// TODO(b/114112161): Remove these aliases when all users have moved over to the
+// `tensorflow::data` namespace.
+using data::CapturedFunction;
+
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_CAPTURED_FUNCTION_H_
diff --git a/tensorflow/core/kernels/data/concatenate_dataset_op.cc b/tensorflow/core/kernels/data/concatenate_dataset_op.cc
index c361a9adcb..a04f150e71 100644
--- a/tensorflow/core/kernels/data/concatenate_dataset_op.cc
+++ b/tensorflow/core/kernels/data/concatenate_dataset_op.cc
@@ -17,7 +17,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -195,5 +195,5 @@ REGISTER_KERNEL_BUILDER(Name("ConcatenateDataset").Device(DEVICE_CPU),
                         ConcatenateDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/dataset_ops.cc b/tensorflow/core/kernels/data/dataset_ops.cc
index c71d027f23..bd1ccd5b5d 100644
--- a/tensorflow/core/kernels/data/dataset_ops.cc
+++ b/tensorflow/core/kernels/data/dataset_ops.cc
@@ -19,6 +19,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
+namespace data {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
 // description of the following op.
@@ -48,4 +49,5 @@ class DatasetToGraphOp : public OpKernel {
 REGISTER_KERNEL_BUILDER(Name("DatasetToGraph").Device(DEVICE_CPU),
                         DatasetToGraphOp);
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/dataset_utils.cc b/tensorflow/core/kernels/data/dataset_utils.cc
index d85ef1cbab..e7ac368ae3 100644
--- a/tensorflow/core/kernels/data/dataset_utils.cc
+++ b/tensorflow/core/kernels/data/dataset_utils.cc
@@ -17,8 +17,7 @@ limitations under the License.
 #include "tensorflow/core/common_runtime/device.h"
 
 namespace tensorflow {
-
-namespace dataset {
+namespace data {
 
 Status MakeIteratorFromInputElement(
     IteratorContext* ctx, const std::vector<Tensor>& input_element,
@@ -45,6 +44,5 @@ Status MakeIteratorFromInputElement(
       ctx, strings::StrCat(prefix, "[", thread_index, "]"), out_iterator);
 }
 
-}  // namespace dataset
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/dataset_utils.h b/tensorflow/core/kernels/data/dataset_utils.h
index 6c4191c2be..234856ea39 100644
--- a/tensorflow/core/kernels/data/dataset_utils.h
+++ b/tensorflow/core/kernels/data/dataset_utils.h
@@ -20,16 +20,14 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
-namespace dataset {
+namespace data {
 
 Status MakeIteratorFromInputElement(
     IteratorContext* ctx, const std::vector<Tensor>& input_element,
     int64 thread_index, CapturedFunction* captured_func, StringPiece prefix,
     std::unique_ptr<IteratorBase>* out_iterator);
 
-}  // namespace dataset
-
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_DATASET_UTILS_H_
diff --git a/tensorflow/core/kernels/data/dense_to_sparse_batch_dataset_op.cc b/tensorflow/core/kernels/data/dense_to_sparse_batch_dataset_op.cc
index 9770bc025d..237511a07d 100644
--- a/tensorflow/core/kernels/data/dense_to_sparse_batch_dataset_op.cc
+++ b/tensorflow/core/kernels/data/dense_to_sparse_batch_dataset_op.cc
@@ -18,7 +18,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -301,5 +301,5 @@ REGISTER_KERNEL_BUILDER(Name("DenseToSparseBatchDataset").Device(DEVICE_CPU),
                         DenseToSparseBatchDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/filter_by_component_dataset_op.cc b/tensorflow/core/kernels/data/filter_by_component_dataset_op.cc
index ce577397c5..a7e3a56727 100644
--- a/tensorflow/core/kernels/data/filter_by_component_dataset_op.cc
+++ b/tensorflow/core/kernels/data/filter_by_component_dataset_op.cc
@@ -21,7 +21,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -166,5 +166,5 @@ REGISTER_KERNEL_BUILDER(Name("FilterByLastComponentDataset").Device(DEVICE_CPU),
                         FilterByLastComponentDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/filter_dataset_op.cc b/tensorflow/core/kernels/data/filter_dataset_op.cc
index bbce001eaf..bf0aecaf3c 100644
--- a/tensorflow/core/kernels/data/filter_dataset_op.cc
+++ b/tensorflow/core/kernels/data/filter_dataset_op.cc
@@ -21,7 +21,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -280,5 +280,5 @@ REGISTER_KERNEL_BUILDER(Name("FilterDataset").Device(DEVICE_CPU),
                         FilterDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/flat_map_dataset_op.cc b/tensorflow/core/kernels/data/flat_map_dataset_op.cc
index b1eb2fd849..e3c45ef86c 100644
--- a/tensorflow/core/kernels/data/flat_map_dataset_op.cc
+++ b/tensorflow/core/kernels/data/flat_map_dataset_op.cc
@@ -21,7 +21,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -245,7 +245,7 @@ class FlatMapDatasetOp : public UnaryDatasetOpKernel {
      private:
       Status BuildCurrentElementIteratorLocked(IteratorContext* ctx)
           EXCLUSIVE_LOCKS_REQUIRED(mu_) {
-        return dataset::MakeIteratorFromInputElement(
+        return MakeIteratorFromInputElement(
             ctx, captured_func_inputs_, element_index_++,
             dataset()->captured_func_.get(), prefix(),
             &current_element_iterator_);
@@ -285,5 +285,5 @@ REGISTER_KERNEL_BUILDER(Name("FlatMapDataset").Device(DEVICE_CPU),
                         FlatMapDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/generator_dataset_op.cc b/tensorflow/core/kernels/data/generator_dataset_op.cc
index ccee690d7e..ac5cc1b2c1 100644
--- a/tensorflow/core/kernels/data/generator_dataset_op.cc
+++ b/tensorflow/core/kernels/data/generator_dataset_op.cc
@@ -23,6 +23,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
+namespace data {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
 // description of the following op.
@@ -188,10 +189,13 @@ void GeneratorDatasetOp::MakeDataset(OpKernelContext* ctx,
                   std::move(finalize_func), output_types_, output_shapes_);
 }
 
+namespace {
 REGISTER_KERNEL_BUILDER(Name("GeneratorDataset").Device(DEVICE_CPU),
                         GeneratorDatasetOp);
 REGISTER_KERNEL_BUILDER(
     Name("GeneratorDataset").Device(DEVICE_GPU).HostMemory("handle"),
     GeneratorDatasetOp);
+}  // namespace
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/generator_dataset_op.h b/tensorflow/core/kernels/data/generator_dataset_op.h
index 8407543136..d23ed97ec3 100644
--- a/tensorflow/core/kernels/data/generator_dataset_op.h
+++ b/tensorflow/core/kernels/data/generator_dataset_op.h
@@ -19,6 +19,7 @@ limitations under the License.
 #include "tensorflow/core/framework/dataset.h"
 
 namespace tensorflow {
+namespace data {
 
 class GeneratorDatasetOp : public DatasetOpKernel {
  public:
@@ -36,5 +37,6 @@ class GeneratorDatasetOp : public DatasetOpKernel {
   NameAttrList finalize_func_;
 };
 
+}  // namespace data
 }  // namespace tensorflow
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_GENERATOR_DATASET_OP_H_
diff --git a/tensorflow/core/kernels/data/group_by_reducer_dataset_op.cc b/tensorflow/core/kernels/data/group_by_reducer_dataset_op.cc
index 130f04da3e..d6ee42a7c6 100644
--- a/tensorflow/core/kernels/data/group_by_reducer_dataset_op.cc
+++ b/tensorflow/core/kernels/data/group_by_reducer_dataset_op.cc
@@ -22,6 +22,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -433,4 +434,5 @@ REGISTER_KERNEL_BUILDER(Name("GroupByReducerDataset").Device(DEVICE_CPU),
                         GroupByReducerDatasetOp);
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/group_by_window_dataset_op.cc b/tensorflow/core/kernels/data/group_by_window_dataset_op.cc
index 46a3185b49..e4fa557598 100644
--- a/tensorflow/core/kernels/data/group_by_window_dataset_op.cc
+++ b/tensorflow/core/kernels/data/group_by_window_dataset_op.cc
@@ -23,6 +23,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -549,4 +550,5 @@ REGISTER_KERNEL_BUILDER(Name("GroupByWindowDataset").Device(DEVICE_CPU),
                         GroupByWindowDatasetOp);
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/interleave_dataset_op.cc b/tensorflow/core/kernels/data/interleave_dataset_op.cc
index 716e040277..0768f46665 100644
--- a/tensorflow/core/kernels/data/interleave_dataset_op.cc
+++ b/tensorflow/core/kernels/data/interleave_dataset_op.cc
@@ -21,7 +21,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -201,7 +201,7 @@ class InterleaveDatasetOp : public UnaryDatasetOpKernel {
             TF_RETURN_IF_ERROR(input_impl_->GetNext(
                 ctx, &args_list_[cycle_index_], &end_of_input_));
             if (!end_of_input_) {
-              TF_RETURN_IF_ERROR(dataset::MakeIteratorFromInputElement(
+              TF_RETURN_IF_ERROR(MakeIteratorFromInputElement(
                   ctx, args_list_[cycle_index_], cycle_index_,
                   dataset()->captured_func_.get(), prefix(),
                   &current_elements_[cycle_index_]));
@@ -288,7 +288,7 @@ class InterleaveDatasetOp : public UnaryDatasetOpKernel {
                   full_name(strings::StrCat("args_list_[", idx, "][", i, "]")),
                   &args_list_[idx][i]));
             }
-            TF_RETURN_IF_ERROR(dataset::MakeIteratorFromInputElement(
+            TF_RETURN_IF_ERROR(MakeIteratorFromInputElement(
                 ctx, args_list_[idx], idx, dataset()->captured_func_.get(),
                 prefix(), &current_elements_[idx]));
             TF_RETURN_IF_ERROR(
@@ -330,5 +330,5 @@ REGISTER_KERNEL_BUILDER(Name("InterleaveDataset").Device(DEVICE_CPU),
                         InterleaveDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/iterator_ops.cc b/tensorflow/core/kernels/data/iterator_ops.cc
index 4e9b280968..fe6d705eab 100644
--- a/tensorflow/core/kernels/data/iterator_ops.cc
+++ b/tensorflow/core/kernels/data/iterator_ops.cc
@@ -36,7 +36,7 @@ limitations under the License.
 #include "tensorflow/core/public/session_options.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -236,6 +236,8 @@ class IteratorResource : public ResourceBase {
   const std::vector<PartialTensorShape> output_shapes_;
 };
 
+namespace {
+
 // Helper class for reading data from a VariantTensorData object.
 class VariantTensorDataReader : public IteratorStateReader {
  public:
@@ -443,6 +445,8 @@ class IteratorStateVariant {
 REGISTER_UNARY_VARIANT_DECODE_FUNCTION(IteratorStateVariant,
                                        kIteratorVariantTypeName);
 
+}  // namespace
+
 // Note that IteratorHandleOp holds a reference to the resource it creates. If
 // cleaning up resources with DestroyResourceOp is important, consider creating
 // resource containers with AnonymousIteratorHandleOp instead.
@@ -622,6 +626,8 @@ void MakeIteratorOp::Compute(OpKernelContext* ctx) {
   OP_REQUIRES_OK(ctx, iterator_resource->set_iterator(std::move(iterator)));
 }
 
+namespace {
+
 class ToSingleElementOp : public AsyncOpKernel {
  public:
   explicit ToSingleElementOp(OpKernelConstruction* ctx)
@@ -887,6 +893,8 @@ class OneShotIteratorOp : public AsyncOpKernel {
   const int graph_def_version_;
 };
 
+}  // namespace
+
 void IteratorGetNextOp::ComputeAsync(OpKernelContext* ctx, DoneCallback done) {
   IteratorResource* iterator;
   OP_REQUIRES_OK_ASYNC(
@@ -957,6 +965,8 @@ void IteratorGetNextSyncOp::Compute(OpKernelContext* ctx) {
   }
 }
 
+namespace {
+
 class IteratorGetNextAsOptionalOp : public AsyncOpKernel {
  public:
   explicit IteratorGetNextAsOptionalOp(OpKernelConstruction* ctx)
@@ -1037,6 +1047,8 @@ class IteratorGetNextAsOptionalOp : public AsyncOpKernel {
   std::vector<PartialTensorShape> output_shapes_;
 };
 
+}  // namespace
+
 void IteratorToStringHandleOp::Compute(OpKernelContext* ctx) {
   const Tensor& resource_handle_t = ctx->input(0);
   OP_REQUIRES(ctx, TensorShapeUtils::IsScalar(resource_handle_t.shape()),
@@ -1108,6 +1120,8 @@ void IteratorFromStringHandleOp::Compute(OpKernelContext* ctx) {
   resource_handle_t->scalar<ResourceHandle>()() = resource_handle;
 }
 
+namespace {
+
 class SerializeIteratorOp : public OpKernel {
  public:
   explicit SerializeIteratorOp(OpKernelConstruction* ctx) : OpKernel(ctx) {}
@@ -1202,4 +1216,7 @@ REGISTER_KERNEL_BUILDER(Name("SerializeIterator").Device(DEVICE_CPU),
 REGISTER_KERNEL_BUILDER(Name("DeserializeIterator").Device(DEVICE_CPU),
                         DeserializeIteratorOp);
 
+}  // namespace
+
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/iterator_ops.h b/tensorflow/core/kernels/data/iterator_ops.h
index 723564286c..8a2b2639a7 100644
--- a/tensorflow/core/kernels/data/iterator_ops.h
+++ b/tensorflow/core/kernels/data/iterator_ops.h
@@ -22,6 +22,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/ops_util.h"
 
 namespace tensorflow {
+namespace data {
 
 class IteratorResource;
 
@@ -142,6 +143,7 @@ class IteratorFromStringHandleOp : public OpKernel {
   std::vector<PartialTensorShape> output_shapes_;
 };
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_ITERATOR_OPS_H_
diff --git a/tensorflow/core/kernels/data/map_and_batch_dataset_op.cc b/tensorflow/core/kernels/data/map_and_batch_dataset_op.cc
index 8b0c9ad6b2..27c89b3661 100644
--- a/tensorflow/core/kernels/data/map_and_batch_dataset_op.cc
+++ b/tensorflow/core/kernels/data/map_and_batch_dataset_op.cc
@@ -29,7 +29,7 @@ limitations under the License.
 #include "tensorflow/core/platform/tracing.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -675,5 +675,5 @@ REGISTER_KERNEL_BUILDER(Name("MapAndBatchDatasetV2").Device(DEVICE_CPU),
                         MapAndBatchDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/map_dataset_op.cc b/tensorflow/core/kernels/data/map_dataset_op.cc
index 6c45fcafcc..306486b96a 100644
--- a/tensorflow/core/kernels/data/map_dataset_op.cc
+++ b/tensorflow/core/kernels/data/map_dataset_op.cc
@@ -20,7 +20,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -196,5 +196,5 @@ class MapDatasetOp : public UnaryDatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("MapDataset").Device(DEVICE_CPU), MapDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/map_defun_op.cc b/tensorflow/core/kernels/data/map_defun_op.cc
index cc4d7976f8..3c562fc7f3 100644
--- a/tensorflow/core/kernels/data/map_defun_op.cc
+++ b/tensorflow/core/kernels/data/map_defun_op.cc
@@ -23,6 +23,7 @@ limitations under the License.
 #include "tensorflow/core/util/reffed_status_callback.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 void SetRunOptions(OpKernelContext* ctx, FunctionLibraryRuntime::Options* opts,
@@ -191,8 +192,9 @@ class MapDefunOp : public AsyncOpKernel {
     const OpKernel* kernel_;
     const size_t iter_;
   };
-};  // namespace
+};
 
 REGISTER_KERNEL_BUILDER(Name("MapDefun").Device(DEVICE_CPU), MapDefunOp);
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/optimize_dataset_op.cc b/tensorflow/core/kernels/data/optimize_dataset_op.cc
index 6263dc3cf8..d5b725eac9 100644
--- a/tensorflow/core/kernels/data/optimize_dataset_op.cc
+++ b/tensorflow/core/kernels/data/optimize_dataset_op.cc
@@ -33,6 +33,7 @@ limitations under the License.
 #include "tensorflow/core/protobuf/rewriter_config.pb.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -270,4 +271,5 @@ REGISTER_KERNEL_BUILDER(Name("OptimizeDataset").Device(DEVICE_CPU),
                         OptimizeDatasetOp);
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/optional_ops.cc b/tensorflow/core/kernels/data/optional_ops.cc
index cfac45dbc7..b372d31a93 100644
--- a/tensorflow/core/kernels/data/optional_ops.cc
+++ b/tensorflow/core/kernels/data/optional_ops.cc
@@ -20,6 +20,7 @@ limitations under the License.
 #include "tensorflow/core/framework/variant_op_registry.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 const char kOptionalVariantTypeName[] = "tensorflow::data::Optional";
 
@@ -267,4 +268,5 @@ Status WriteOptionalNoneToOutput(OpKernelContext* ctx, int output_index) {
   return Status::OK();
 }
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/optional_ops.h b/tensorflow/core/kernels/data/optional_ops.h
index 6f25567678..2cbf2933f5 100644
--- a/tensorflow/core/kernels/data/optional_ops.h
+++ b/tensorflow/core/kernels/data/optional_ops.h
@@ -21,6 +21,7 @@ limitations under the License.
 #include "tensorflow/core/framework/variant_tensor_data.h"
 
 namespace tensorflow {
+namespace data {
 
 // Stores a DT_VARIANT value representing an Optional with the given value
 // in the `output_index`^th output of the given kernel execution context.
@@ -31,6 +32,7 @@ Status WriteOptionalWithValueToOutput(OpKernelContext* ctx, int output_index,
 // in the `output_index`^th output of the given kernel execution context.
 Status WriteOptionalNoneToOutput(OpKernelContext* ctx, int output_index);
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_OPTIONAL_OPS_H_
diff --git a/tensorflow/core/kernels/data/padded_batch_dataset_op.cc b/tensorflow/core/kernels/data/padded_batch_dataset_op.cc
index be45eac46e..fd0e6c4cd0 100644
--- a/tensorflow/core/kernels/data/padded_batch_dataset_op.cc
+++ b/tensorflow/core/kernels/data/padded_batch_dataset_op.cc
@@ -19,7 +19,7 @@ limitations under the License.
 #include "tensorflow/core/util/batch_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -382,5 +382,5 @@ REGISTER_KERNEL_BUILDER(Name("PaddedBatchDatasetV2").Device(DEVICE_CPU),
                         PaddedBatchDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/parallel_interleave_dataset_op.cc b/tensorflow/core/kernels/data/parallel_interleave_dataset_op.cc
index f6b3fd97e3..f8287cf0e3 100644
--- a/tensorflow/core/kernels/data/parallel_interleave_dataset_op.cc
+++ b/tensorflow/core/kernels/data/parallel_interleave_dataset_op.cc
@@ -25,7 +25,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -684,7 +684,7 @@ class ParallelInterleaveDatasetOp : public UnaryDatasetOpKernel {
             {
               tf_shared_lock l(ckpt_mu_);
               worker_thread_states_[thread_index].iterator_creation_status =
-                  dataset::MakeIteratorFromInputElement(
+                  MakeIteratorFromInputElement(
                       ctx.get(), worker_thread_states_[thread_index].input,
                       thread_index, dataset()->captured_func_.get(), prefix(),
                       &worker_thread_states_[thread_index].iterator);
@@ -914,7 +914,7 @@ class ParallelInterleaveDatasetOp : public UnaryDatasetOpKernel {
           worker_thread_states_[index].iterator.reset();
         } else {
           std::unique_ptr<IteratorBase> iterator;
-          Status s = dataset::MakeIteratorFromInputElement(
+          Status s = MakeIteratorFromInputElement(
               ctx, worker_thread_states_[index].input, index,
               dataset()->captured_func_.get(), prefix(), &iterator);
           TF_RETURN_IF_ERROR(RestoreInput(ctx, reader, iterator));
@@ -1068,5 +1068,5 @@ REGISTER_KERNEL_BUILDER(Name("ParallelInterleaveDataset").Device(DEVICE_CPU),
                         ParallelInterleaveDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/parallel_map_dataset_op.cc b/tensorflow/core/kernels/data/parallel_map_dataset_op.cc
index bff54813d6..ac5ed286ee 100644
--- a/tensorflow/core/kernels/data/parallel_map_dataset_op.cc
+++ b/tensorflow/core/kernels/data/parallel_map_dataset_op.cc
@@ -24,7 +24,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -180,5 +180,5 @@ REGISTER_KERNEL_BUILDER(Name("ParallelMapDataset").Device(DEVICE_CPU),
                         ParallelMapDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/parallel_map_iterator.cc b/tensorflow/core/kernels/data/parallel_map_iterator.cc
index 61f8139b9e..4ae742aaaf 100644
--- a/tensorflow/core/kernels/data/parallel_map_iterator.cc
+++ b/tensorflow/core/kernels/data/parallel_map_iterator.cc
@@ -20,6 +20,7 @@ limitations under the License.
 #include <vector>
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 class ParallelMapIterator : public DatasetBaseIterator {
@@ -333,4 +334,5 @@ std::unique_ptr<IteratorBase> NewParallelMapIterator(
                               std::move(map_func), num_parallel_calls));
 }
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/parallel_map_iterator.h b/tensorflow/core/kernels/data/parallel_map_iterator.h
index 7e6cc586f3..dc26c5cf25 100644
--- a/tensorflow/core/kernels/data/parallel_map_iterator.h
+++ b/tensorflow/core/kernels/data/parallel_map_iterator.h
@@ -20,6 +20,7 @@ limitations under the License.
 #include "tensorflow/core/framework/dataset.h"
 
 namespace tensorflow {
+namespace data {
 
 // A function that transforms elements of one dataset into another
 // asynchronously. The arguments are:
@@ -47,6 +48,7 @@ std::unique_ptr<IteratorBase> NewParallelMapIterator(
     const DatasetBase* input_dataset, ParallelMapIteratorFunction map_func,
     int32 num_parallel_calls);
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_PARALLEL_MAP_ITERATOR_H_
diff --git a/tensorflow/core/kernels/data/parse_example_dataset_op.cc b/tensorflow/core/kernels/data/parse_example_dataset_op.cc
index 9057800d94..0cf5db017b 100644
--- a/tensorflow/core/kernels/data/parse_example_dataset_op.cc
+++ b/tensorflow/core/kernels/data/parse_example_dataset_op.cc
@@ -20,7 +20,7 @@ limitations under the License.
 #include "tensorflow/core/util/example_proto_fast_parsing.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -368,5 +368,5 @@ REGISTER_KERNEL_BUILDER(Name("ParseExampleDataset").Device(DEVICE_CPU),
                         ParseExampleDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/prefetch_autotuner.cc b/tensorflow/core/kernels/data/prefetch_autotuner.cc
index b3272f6bcd..533d0bd5d2 100644
--- a/tensorflow/core/kernels/data/prefetch_autotuner.cc
+++ b/tensorflow/core/kernels/data/prefetch_autotuner.cc
@@ -16,6 +16,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/prefetch_autotuner.h"
 
 namespace tensorflow {
+namespace data {
 
 PrefetchAutotuner::PrefetchAutotuner(int64 initial_buffer_size)
     : buffer_limit_(initial_buffer_size) {
@@ -43,4 +44,5 @@ void PrefetchAutotuner::RecordConsumption(size_t current_buffer_size) {
   }
 }
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/prefetch_autotuner.h b/tensorflow/core/kernels/data/prefetch_autotuner.h
index fa8a184072..8693205512 100644
--- a/tensorflow/core/kernels/data/prefetch_autotuner.h
+++ b/tensorflow/core/kernels/data/prefetch_autotuner.h
@@ -19,6 +19,7 @@ limitations under the License.
 #include "tensorflow/core/platform/types.h"
 
 namespace tensorflow {
+namespace data {
 
 // PrefetchAutotuner dynamically adjusts the buffer size of a prefetch iterator.
 //
@@ -66,6 +67,7 @@ class PrefetchAutotuner {
   Mode mode_ = Mode::kDisabled;
 };
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_PREFETCH_AUTOTUNER_H_
diff --git a/tensorflow/core/kernels/data/prefetch_autotuner_test.cc b/tensorflow/core/kernels/data/prefetch_autotuner_test.cc
index 29a8cc50cd..cfc324fc7e 100644
--- a/tensorflow/core/kernels/data/prefetch_autotuner_test.cc
+++ b/tensorflow/core/kernels/data/prefetch_autotuner_test.cc
@@ -18,6 +18,7 @@ limitations under the License.
 #include "tensorflow/core/platform/test.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 TEST(PrefetchAutotuner, Disabled) {
@@ -79,4 +80,5 @@ TEST(PrefetchAutotuner, EnabledSteady) {
 }
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/prefetch_dataset_op.cc b/tensorflow/core/kernels/data/prefetch_dataset_op.cc
index 50efbcbe2a..a7a2935195 100644
--- a/tensorflow/core/kernels/data/prefetch_dataset_op.cc
+++ b/tensorflow/core/kernels/data/prefetch_dataset_op.cc
@@ -21,6 +21,7 @@ limitations under the License.
 #include "tensorflow/core/lib/core/error_codes.pb.h"
 
 namespace tensorflow {
+namespace data {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
 // description of the following op.
@@ -346,6 +347,7 @@ void PrefetchDatasetOp::MakeDataset(OpKernelContext* ctx, DatasetBase* input,
   *output = new Dataset(ctx, input, buffer_size);
 }
 
+namespace {
 REGISTER_KERNEL_BUILDER(Name("PrefetchDataset").Device(DEVICE_CPU),
                         PrefetchDatasetOp);
 REGISTER_KERNEL_BUILDER(Name("PrefetchDataset")
@@ -354,4 +356,7 @@ REGISTER_KERNEL_BUILDER(Name("PrefetchDataset")
                             .HostMemory("input_dataset")
                             .HostMemory("handle"),
                         PrefetchDatasetOp);
+}  // namespace
+
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/prefetch_dataset_op.h b/tensorflow/core/kernels/data/prefetch_dataset_op.h
index c40c4b00da..588fb25a06 100644
--- a/tensorflow/core/kernels/data/prefetch_dataset_op.h
+++ b/tensorflow/core/kernels/data/prefetch_dataset_op.h
@@ -20,6 +20,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/prefetch_autotuner.h"
 
 namespace tensorflow {
+namespace data {
 
 class PrefetchDatasetOp : public UnaryDatasetOpKernel {
  public:
@@ -34,6 +35,7 @@ class PrefetchDatasetOp : public UnaryDatasetOpKernel {
   class Dataset;
 };
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_PREFETCH_DATASET_OP_H_
diff --git a/tensorflow/core/kernels/data/random_dataset_op.cc b/tensorflow/core/kernels/data/random_dataset_op.cc
index 7817170e73..044a791a3f 100644
--- a/tensorflow/core/kernels/data/random_dataset_op.cc
+++ b/tensorflow/core/kernels/data/random_dataset_op.cc
@@ -21,7 +21,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random_distributions.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -151,5 +151,5 @@ REGISTER_KERNEL_BUILDER(Name("RandomDataset").Device(DEVICE_CPU),
                         RandomDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/range_dataset_op.cc b/tensorflow/core/kernels/data/range_dataset_op.cc
index aa38775125..89fbaae369 100644
--- a/tensorflow/core/kernels/data/range_dataset_op.cc
+++ b/tensorflow/core/kernels/data/range_dataset_op.cc
@@ -17,7 +17,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -142,5 +142,5 @@ REGISTER_KERNEL_BUILDER(Name("RangeDataset").Device(DEVICE_CPU),
                         RangeDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/reader_dataset_ops.cc b/tensorflow/core/kernels/data/reader_dataset_ops.cc
index 086b552936..c474cb4773 100644
--- a/tensorflow/core/kernels/data/reader_dataset_ops.cc
+++ b/tensorflow/core/kernels/data/reader_dataset_ops.cc
@@ -23,7 +23,7 @@ limitations under the License.
 #include "tensorflow/core/lib/io/zlib_inputstream.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -691,5 +691,5 @@ REGISTER_KERNEL_BUILDER(Name("TFRecordDataset").Device(DEVICE_CPU),
                         TFRecordDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/repeat_dataset_op.cc b/tensorflow/core/kernels/data/repeat_dataset_op.cc
index 299949b99f..94e96635ab 100644
--- a/tensorflow/core/kernels/data/repeat_dataset_op.cc
+++ b/tensorflow/core/kernels/data/repeat_dataset_op.cc
@@ -17,7 +17,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -250,5 +250,5 @@ REGISTER_KERNEL_BUILDER(Name("RepeatDataset").Device(DEVICE_CPU),
                         RepeatDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/scan_dataset_op.cc b/tensorflow/core/kernels/data/scan_dataset_op.cc
index fccad933d0..6e515d6cc8 100644
--- a/tensorflow/core/kernels/data/scan_dataset_op.cc
+++ b/tensorflow/core/kernels/data/scan_dataset_op.cc
@@ -23,7 +23,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -279,5 +279,5 @@ class ScanDatasetOp : public UnaryDatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("ScanDataset").Device(DEVICE_CPU), ScanDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/shuffle_dataset_op.cc b/tensorflow/core/kernels/data/shuffle_dataset_op.cc
index 93a4376836..66466d6a36 100644
--- a/tensorflow/core/kernels/data/shuffle_dataset_op.cc
+++ b/tensorflow/core/kernels/data/shuffle_dataset_op.cc
@@ -25,7 +25,7 @@ limitations under the License.
 #include "tensorflow/core/util/ptr_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 const int64 kLogIntervalMicros = 10 * 1000000;  // 10 seconds.
@@ -620,5 +620,5 @@ REGISTER_KERNEL_BUILDER(Name("ShuffleAndRepeatDataset").Device(DEVICE_CPU),
                         ShuffleAndRepeatDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/single_threaded_executor.cc b/tensorflow/core/kernels/data/single_threaded_executor.cc
index e785b8b4d5..5b084a16f0 100644
--- a/tensorflow/core/kernels/data/single_threaded_executor.cc
+++ b/tensorflow/core/kernels/data/single_threaded_executor.cc
@@ -22,6 +22,7 @@ limitations under the License.
 #include "tensorflow/core/lib/core/status.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 typedef gtl::InlinedVector<TensorValue, 4> TensorValueVec;
@@ -375,4 +376,5 @@ Status NewSingleThreadedExecutor(const LocalExecutorParams& params,
   return Status::OK();
 }
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/single_threaded_executor.h b/tensorflow/core/kernels/data/single_threaded_executor.h
index 15836b24c9..e934352a1d 100644
--- a/tensorflow/core/kernels/data/single_threaded_executor.h
+++ b/tensorflow/core/kernels/data/single_threaded_executor.h
@@ -19,6 +19,7 @@ limitations under the License.
 #include "tensorflow/core/common_runtime/executor.h"
 
 namespace tensorflow {
+namespace data {
 
 // Creates a new `Executor` for executing `graph` synchronously on the caller
 // thread.
@@ -55,6 +56,7 @@ Status NewSingleThreadedExecutor(const LocalExecutorParams& params,
                                  std::unique_ptr<const Graph> graph,
                                  Executor** executor);
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_SINGLE_THREADED_EXECUTOR_H_
diff --git a/tensorflow/core/kernels/data/single_threaded_executor_test.cc b/tensorflow/core/kernels/data/single_threaded_executor_test.cc
index f8b5769197..6244e287bb 100644
--- a/tensorflow/core/kernels/data/single_threaded_executor_test.cc
+++ b/tensorflow/core/kernels/data/single_threaded_executor_test.cc
@@ -37,6 +37,7 @@ limitations under the License.
 #include "tensorflow/core/public/session_options.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 class ExecutorTest : public ::testing::Test {
@@ -327,4 +328,5 @@ BENCHMARK(BM_FeedInputFetchOutput);
 #endif
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/skip_dataset_op.cc b/tensorflow/core/kernels/data/skip_dataset_op.cc
index fe7ef38d5f..b8c7fb15f4 100644
--- a/tensorflow/core/kernels/data/skip_dataset_op.cc
+++ b/tensorflow/core/kernels/data/skip_dataset_op.cc
@@ -17,7 +17,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -187,5 +187,5 @@ class SkipDatasetOp : public UnaryDatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("SkipDataset").Device(DEVICE_CPU), SkipDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/slide_dataset_op.cc b/tensorflow/core/kernels/data/slide_dataset_op.cc
index 14df3a6801..1e73cfc753 100644
--- a/tensorflow/core/kernels/data/slide_dataset_op.cc
+++ b/tensorflow/core/kernels/data/slide_dataset_op.cc
@@ -23,7 +23,7 @@ limitations under the License.
 #include "tensorflow/core/util/batch_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -293,5 +293,5 @@ REGISTER_KERNEL_BUILDER(Name("SlideDataset").Device(DEVICE_CPU),
                         SlideDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/sparse_tensor_slice_dataset_op.cc b/tensorflow/core/kernels/data/sparse_tensor_slice_dataset_op.cc
index e526578701..85b1e50695 100644
--- a/tensorflow/core/kernels/data/sparse_tensor_slice_dataset_op.cc
+++ b/tensorflow/core/kernels/data/sparse_tensor_slice_dataset_op.cc
@@ -21,7 +21,7 @@ limitations under the License.
 #include "tensorflow/core/util/sparse/sparse_tensor.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -274,5 +274,5 @@ TF_CALL_DATASET_TYPES(REGISTER_DATASET_KERNEL);
 #undef REGISTER_DATASET_KERNEL
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/sql/driver_manager.cc b/tensorflow/core/kernels/data/sql/driver_manager.cc
index ffabda1a8a..783d1e6cb2 100644
--- a/tensorflow/core/kernels/data/sql/driver_manager.cc
+++ b/tensorflow/core/kernels/data/sql/driver_manager.cc
@@ -16,7 +16,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/sql/sqlite_query_connection.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace sql {
 
 std::unique_ptr<QueryConnection> DriverManager::CreateQueryConnection(
@@ -30,5 +30,5 @@ std::unique_ptr<QueryConnection> DriverManager::CreateQueryConnection(
 }
 
 }  // namespace sql
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/sql/driver_manager.h b/tensorflow/core/kernels/data/sql/driver_manager.h
index a34691b5a2..c5428f396b 100644
--- a/tensorflow/core/kernels/data/sql/driver_manager.h
+++ b/tensorflow/core/kernels/data/sql/driver_manager.h
@@ -18,7 +18,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/sql/query_connection.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace sql {
 
 // A factory class for creating `QueryConnection` instances.
@@ -35,7 +35,7 @@ class DriverManager {
 };
 
 }  // namespace sql
-
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_SQL_DRIVER_MANAGER_H_
diff --git a/tensorflow/core/kernels/data/sql/query_connection.h b/tensorflow/core/kernels/data/sql/query_connection.h
index e9ffca202f..2fd229a9bf 100644
--- a/tensorflow/core/kernels/data/sql/query_connection.h
+++ b/tensorflow/core/kernels/data/sql/query_connection.h
@@ -18,6 +18,7 @@ limitations under the License.
 #include "tensorflow/core/framework/tensor.h"
 
 namespace tensorflow {
+namespace data {
 
 class IteratorContext;
 
@@ -63,7 +64,7 @@ class QueryConnection {
 };
 
 }  // namespace sql
-
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_SQL_QUERY_CONNECTION_H_
diff --git a/tensorflow/core/kernels/data/sql/sqlite_query_connection.cc b/tensorflow/core/kernels/data/sql/sqlite_query_connection.cc
index 7cd07bd8ec..5108e83976 100644
--- a/tensorflow/core/kernels/data/sql/sqlite_query_connection.cc
+++ b/tensorflow/core/kernels/data/sql/sqlite_query_connection.cc
@@ -19,7 +19,7 @@ limitations under the License.
 #include "tensorflow/core/lib/strings/stringprintf.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace sql {
 
 SqliteQueryConnection::SqliteQueryConnection() {}
@@ -115,5 +115,5 @@ void SqliteQueryConnection::FillTensorWithResultSetEntry(
 }
 
 }  // namespace sql
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/sql/sqlite_query_connection.h b/tensorflow/core/kernels/data/sql/sqlite_query_connection.h
index 81b19530b7..175492c49d 100644
--- a/tensorflow/core/kernels/data/sql/sqlite_query_connection.h
+++ b/tensorflow/core/kernels/data/sql/sqlite_query_connection.h
@@ -22,7 +22,7 @@ limitations under the License.
 #include "tensorflow/core/platform/types.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace sql {
 
 class SqliteQueryConnection : public QueryConnection {
@@ -50,7 +50,7 @@ class SqliteQueryConnection : public QueryConnection {
 };
 
 }  // namespace sql
-
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_SQL_SQLITE_QUERY_CONNECTION_H_
diff --git a/tensorflow/core/kernels/data/sql_dataset_ops.cc b/tensorflow/core/kernels/data/sql_dataset_ops.cc
index 2aa153fcfa..6bbe459332 100644
--- a/tensorflow/core/kernels/data/sql_dataset_ops.cc
+++ b/tensorflow/core/kernels/data/sql_dataset_ops.cc
@@ -24,8 +24,9 @@ limitations under the License.
 #include "tensorflow/core/lib/strings/stringprintf.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
+
 // See documentation in ../ops/dataset_ops.cc for a high-level
 // description of the following ops.
 
@@ -211,5 +212,5 @@ class SqlDatasetOp : public DatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("SqlDataset").Device(DEVICE_CPU), SqlDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/stats_aggregator_dataset_op.cc b/tensorflow/core/kernels/data/stats_aggregator_dataset_op.cc
index 75af73df54..f5314f7a75 100644
--- a/tensorflow/core/kernels/data/stats_aggregator_dataset_op.cc
+++ b/tensorflow/core/kernels/data/stats_aggregator_dataset_op.cc
@@ -19,6 +19,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 class SetStatsAggregatorDatasetOp : public UnaryDatasetOpKernel {
@@ -135,4 +136,5 @@ class SetStatsAggregatorDatasetOp : public UnaryDatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("SetStatsAggregatorDataset").Device(DEVICE_CPU),
                         SetStatsAggregatorDatasetOp);
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/stats_aggregator_ops.cc b/tensorflow/core/kernels/data/stats_aggregator_ops.cc
index b133cfab54..a7ded67876 100644
--- a/tensorflow/core/kernels/data/stats_aggregator_ops.cc
+++ b/tensorflow/core/kernels/data/stats_aggregator_ops.cc
@@ -26,6 +26,7 @@ limitations under the License.
 #include "tensorflow/core/platform/macros.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 static mutex* get_counters_map_lock() {
@@ -145,4 +146,5 @@ REGISTER_KERNEL_BUILDER(Name("StatsAggregatorSummary").Device(DEVICE_CPU),
                         StatsAggregatorSummaryOp);
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/stats_dataset_ops.cc b/tensorflow/core/kernels/data/stats_dataset_ops.cc
index 8957f5d997..e9e42f05a1 100644
--- a/tensorflow/core/kernels/data/stats_dataset_ops.cc
+++ b/tensorflow/core/kernels/data/stats_dataset_ops.cc
@@ -22,6 +22,7 @@ limitations under the License.
 #include "tensorflow/core/lib/random/random.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 // This op defines a `Dataset` that passes through its input elements and
@@ -248,4 +249,5 @@ REGISTER_KERNEL_BUILDER(Name("BytesProducedStatsDataset").Device(DEVICE_CPU),
                         BytesProducedStatsDatasetOp);
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/take_dataset_op.cc b/tensorflow/core/kernels/data/take_dataset_op.cc
index e5c237dfaa..e5cdfdd732 100644
--- a/tensorflow/core/kernels/data/take_dataset_op.cc
+++ b/tensorflow/core/kernels/data/take_dataset_op.cc
@@ -17,7 +17,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -174,5 +174,5 @@ class TakeDatasetOp : public UnaryDatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("TakeDataset").Device(DEVICE_CPU), TakeDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/tensor_dataset_op.cc b/tensorflow/core/kernels/data/tensor_dataset_op.cc
index 1192fafc4c..e1cefd23d8 100644
--- a/tensorflow/core/kernels/data/tensor_dataset_op.cc
+++ b/tensorflow/core/kernels/data/tensor_dataset_op.cc
@@ -18,7 +18,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -140,5 +140,5 @@ REGISTER_KERNEL_BUILDER(Name("TensorDataset").Device(DEVICE_CPU),
                         TensorDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/tensor_queue_dataset_op.cc b/tensorflow/core/kernels/data/tensor_queue_dataset_op.cc
index ccd5e60acc..2ed636a400 100644
--- a/tensorflow/core/kernels/data/tensor_queue_dataset_op.cc
+++ b/tensorflow/core/kernels/data/tensor_queue_dataset_op.cc
@@ -24,7 +24,7 @@ limitations under the License.
 #include "tensorflow/core/util/batch_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 bool IsGreaterEqualToOrCompatibleWith(const PartialTensorShape& a,
@@ -648,5 +648,5 @@ REGISTER_KERNEL_BUILDER(Name("EnqueueInQueueDataset").Device(DEVICE_CPU),
                         EnqueueInQueueDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/tensor_slice_dataset_op.cc b/tensorflow/core/kernels/data/tensor_slice_dataset_op.cc
index dc32cd23e5..7dc64b0a75 100644
--- a/tensorflow/core/kernels/data/tensor_slice_dataset_op.cc
+++ b/tensorflow/core/kernels/data/tensor_slice_dataset_op.cc
@@ -19,7 +19,7 @@ limitations under the License.
 #include "tensorflow/core/util/batch_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -168,5 +168,5 @@ REGISTER_KERNEL_BUILDER(Name("TensorSliceDataset").Device(DEVICE_CPU),
                         TensorSliceDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/unbatch_dataset_op.cc b/tensorflow/core/kernels/data/unbatch_dataset_op.cc
index 1a79f72b28..81c432b938 100644
--- a/tensorflow/core/kernels/data/unbatch_dataset_op.cc
+++ b/tensorflow/core/kernels/data/unbatch_dataset_op.cc
@@ -18,7 +18,7 @@ limitations under the License.
 #include "tensorflow/core/util/batch_util.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -204,5 +204,5 @@ REGISTER_KERNEL_BUILDER(Name("UnbatchDataset").Device(DEVICE_CPU),
                         UnbatchDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/window_dataset.cc b/tensorflow/core/kernels/data/window_dataset.cc
index 0ab6beabfc..2ad4711aab 100644
--- a/tensorflow/core/kernels/data/window_dataset.cc
+++ b/tensorflow/core/kernels/data/window_dataset.cc
@@ -16,6 +16,7 @@ limitations under the License.
 #include "tensorflow/core/lib/core/errors.h"
 
 namespace tensorflow {
+namespace data {
 namespace {
 
 class WindowDataset : public DatasetBase {
@@ -107,4 +108,5 @@ Status NewWindowDataset(std::vector<std::vector<Tensor>> elements,
   return Status::OK();
 }
 
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/window_dataset.h b/tensorflow/core/kernels/data/window_dataset.h
index 7bd31a0bc7..84cb3c7860 100644
--- a/tensorflow/core/kernels/data/window_dataset.h
+++ b/tensorflow/core/kernels/data/window_dataset.h
@@ -23,6 +23,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
+namespace data {
 
 // Creates a dataset representing an eagerly-collected window of elements.
 //
@@ -43,6 +44,7 @@ Status NewWindowDataset(std::vector<std::vector<Tensor>> elements,
                         std::vector<PartialTensorShape> output_shapes,
                         DatasetBase** out_dataset);
 
+}  // namespace data
 }  // namespace tensorflow
 
 #endif  // TENSORFLOW_CORE_KERNELS_DATA_WINDOW_DATASET_H_
diff --git a/tensorflow/core/kernels/data/window_dataset_op.cc b/tensorflow/core/kernels/data/window_dataset_op.cc
index 41bf9d43fe..3975086841 100644
--- a/tensorflow/core/kernels/data/window_dataset_op.cc
+++ b/tensorflow/core/kernels/data/window_dataset_op.cc
@@ -19,7 +19,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/window_dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -195,5 +195,5 @@ REGISTER_KERNEL_BUILDER(Name("WindowDataset").Device(DEVICE_CPU),
                         WindowDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/writer_ops.cc b/tensorflow/core/kernels/data/writer_ops.cc
index 1c49874a6a..3f76695bb1 100644
--- a/tensorflow/core/kernels/data/writer_ops.cc
+++ b/tensorflow/core/kernels/data/writer_ops.cc
@@ -22,7 +22,7 @@ limitations under the License.
 #include "tensorflow/core/platform/file_system.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 class ToTFRecordOp : public AsyncOpKernel {
@@ -104,4 +104,5 @@ REGISTER_KERNEL_BUILDER(Name("DatasetToTFRecord").Device(DEVICE_CPU),
                         ToTFRecordOp);
 
 }  // namespace
+}  // namespace data
 }  // namespace tensorflow
diff --git a/tensorflow/core/kernels/data/zip_dataset_op.cc b/tensorflow/core/kernels/data/zip_dataset_op.cc
index e4306579ed..61a2078f46 100644
--- a/tensorflow/core/kernels/data/zip_dataset_op.cc
+++ b/tensorflow/core/kernels/data/zip_dataset_op.cc
@@ -17,7 +17,7 @@ limitations under the License.
 #include "tensorflow/core/kernels/data/dataset.h"
 
 namespace tensorflow {
-
+namespace data {
 namespace {
 
 // See documentation in ../ops/dataset_ops.cc for a high-level
@@ -175,5 +175,5 @@ class ZipDatasetOp : public DatasetOpKernel {
 REGISTER_KERNEL_BUILDER(Name("ZipDataset").Device(DEVICE_CPU), ZipDatasetOp);
 
 }  // namespace
-
+}  // namespace data
 }  // namespace tensorflow