1 /* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #include "tensorflow/contrib/bigtable/kernels/bigtable_lib.h"
17 #include "tensorflow/core/framework/op_kernel.h"
18 
19 namespace tensorflow {
20 namespace data {
21 namespace {
22 
23 class BigtablePrefixKeyDatasetOp : public DatasetOpKernel {
24  public:
25   using DatasetOpKernel::DatasetOpKernel;
26 
MakeDataset(OpKernelContext * ctx,DatasetBase ** output)27   void MakeDataset(OpKernelContext* ctx, DatasetBase** output) override {
28     string prefix;
29     OP_REQUIRES_OK(ctx, ParseScalarArgument<string>(ctx, "prefix", &prefix));
30 
31     BigtableTableResource* resource;
32     OP_REQUIRES_OK(ctx,
33                    LookupResource(ctx, HandleFromInput(ctx, 0), &resource));
34     core::ScopedUnref scoped_unref(resource);
35 
36     *output = new Dataset(ctx, resource, std::move(prefix));
37   }
38 
39  private:
40   class Dataset : public DatasetBase {
41    public:
Dataset(OpKernelContext * ctx,BigtableTableResource * table,string prefix)42     explicit Dataset(OpKernelContext* ctx, BigtableTableResource* table,
43                      string prefix)
44         : DatasetBase(DatasetContext(ctx)),
45           table_(table),
46           prefix_(std::move(prefix)) {
47       table_->Ref();
48     }
49 
~Dataset()50     ~Dataset() override { table_->Unref(); }
51 
MakeIteratorInternal(const string & prefix) const52     std::unique_ptr<IteratorBase> MakeIteratorInternal(
53         const string& prefix) const override {
54       return std::unique_ptr<IteratorBase>(
55           new Iterator({this, strings::StrCat(prefix, "::BigtablePrefixKey")}));
56     }
57 
output_dtypes() const58     const DataTypeVector& output_dtypes() const override {
59       static DataTypeVector* dtypes = new DataTypeVector({DT_STRING});
60       return *dtypes;
61     }
62 
output_shapes() const63     const std::vector<PartialTensorShape>& output_shapes() const override {
64       static std::vector<PartialTensorShape>* shapes =
65           new std::vector<PartialTensorShape>({{}});
66       return *shapes;
67     }
68 
DebugString() const69     string DebugString() const override {
70       return "BigtablePrefixKeyDatasetOp::Dataset";
71     }
72 
table() const73     BigtableTableResource* table() const { return table_; }
74 
75    protected:
AsGraphDefInternal(SerializationContext * ctx,DatasetGraphDefBuilder * b,Node ** output) const76     Status AsGraphDefInternal(SerializationContext* ctx,
77                               DatasetGraphDefBuilder* b,
78                               Node** output) const override {
79       return errors::Unimplemented("%s does not support serialization",
80                                    DebugString());
81     }
82 
83    private:
84     class Iterator : public BigtableReaderDatasetIterator<Dataset> {
85      public:
Iterator(const Params & params)86       explicit Iterator(const Params& params)
87           : BigtableReaderDatasetIterator<Dataset>(params) {}
88 
MakeRowRange()89       ::google::cloud::bigtable::RowRange MakeRowRange() override {
90         return ::google::cloud::bigtable::RowRange::Prefix(dataset()->prefix_);
91       }
MakeFilter()92       ::google::cloud::bigtable::Filter MakeFilter() override {
93         return ::google::cloud::bigtable::Filter::Chain(
94             ::google::cloud::bigtable::Filter::CellsRowLimit(1),
95             ::google::cloud::bigtable::Filter::StripValueTransformer());
96       }
ParseRow(IteratorContext * ctx,const::google::cloud::bigtable::Row & row,std::vector<Tensor> * out_tensors)97       Status ParseRow(IteratorContext* ctx,
98                       const ::google::cloud::bigtable::Row& row,
99                       std::vector<Tensor>* out_tensors) override {
100         Tensor output_tensor(ctx->allocator({}), DT_STRING, {});
101         output_tensor.scalar<string>()() = string(row.row_key());
102         out_tensors->emplace_back(std::move(output_tensor));
103         return Status::OK();
104       }
105     };
106 
107     BigtableTableResource* const table_;
108     const string prefix_;
109   };
110 };
111 
112 REGISTER_KERNEL_BUILDER(Name("BigtablePrefixKeyDataset").Device(DEVICE_CPU),
113                         BigtablePrefixKeyDatasetOp);
114 
115 }  // namespace
116 }  // namespace data
117 }  // namespace tensorflow
118