1/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
2
3Licensed under the Apache License, Version 2.0 (the "License");
4you may not use this file except in compliance with the License.
5You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9Unless required by applicable law or agreed to in writing, software
10distributed under the License is distributed on an "AS IS" BASIS,
11WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12See the License for the specific language governing permissions and
13limitations under the License.
14==============================================================================*/
15
16#include <iostream>
17#include "absl/strings/str_split.h"
18#include "tensorflow/core/framework/op_kernel.h"
19#include "tensorflow/core/lib/core/status.h"
20#include "tensorflow/core/lib/strings/str_util.h"
21#include "tensorflow/core/platform/logging.h"
22
23namespace tensorflow {
24
25class StringFormatOp : public OpKernel {
26 public:
27 explicit StringFormatOp(OpKernelConstruction* ctx) : OpKernel(ctx) {
28 string template_;
29 OP_REQUIRES_OK(ctx, ctx->GetAttr("template", &template_));
30 OP_REQUIRES_OK(ctx, ctx->GetAttr("placeholder", &placeholder_));
31 OP_REQUIRES_OK(ctx, ctx->GetAttr("summarize", &summarize_));
32
33 split_template_ = absl::StrSplit(template_, placeholder_);
34 int64_t num_placeholders = split_template_.size() - 1;
35 OP_REQUIRES(ctx, ctx->num_inputs() == num_placeholders,
36 errors::InvalidArgument(strings::StrCat(
37 "num placeholders in template and num inputs must match: ",
38 num_placeholders, " vs. ", ctx->num_inputs())));
39 }
40
41 void Compute(OpKernelContext* ctx) override {
42 Tensor* formatted_string = nullptr;
43 OP_REQUIRES_OK(ctx,
44 ctx->allocate_output(0, TensorShape({}), &formatted_string));
45
46 string msg;
47 strings::StrAppend(&msg, split_template_[0].c_str());
48 for (int i = 0; i < ctx->num_inputs(); ++i) {
49 strings::StrAppend(&msg, ctx->input(i).SummarizeValue(summarize_, true));
50 strings::StrAppend(&msg, split_template_[i + 1].c_str());
51 }
52
53 formatted_string->scalar<tstring>()() = std::move(msg);
54 }
55
56 private:
57 int32 summarize_ = 0;
58 string placeholder_;
59 std::vector<std::string> split_template_;
60};
61
62REGISTER_KERNEL_BUILDER(Name("StringFormat").Device(DEVICE_CPU),
63 StringFormatOp);
64
65} // end namespace tensorflow
66