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      1 /*
      2  * Copyright (C) 2018 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "actions/feature-processor.h"
     18 
     19 namespace libtextclassifier3 {
     20 namespace {
     21 TokenFeatureExtractorOptions BuildTokenFeatureExtractorOptions(
     22     const ActionsTokenFeatureProcessorOptions* const options) {
     23   TokenFeatureExtractorOptions extractor_options;
     24   extractor_options.num_buckets = options->num_buckets();
     25   if (options->chargram_orders() != nullptr) {
     26     for (int order : *options->chargram_orders()) {
     27       extractor_options.chargram_orders.push_back(order);
     28     }
     29   }
     30   extractor_options.max_word_length = options->max_token_length();
     31   extractor_options.extract_case_feature = options->extract_case_feature();
     32   extractor_options.unicode_aware_features = options->unicode_aware_features();
     33   extractor_options.extract_selection_mask_feature = false;
     34   if (options->regexp_features() != nullptr) {
     35     for (const auto& regexp_feauture : *options->regexp_features()) {
     36       extractor_options.regexp_features.push_back(regexp_feauture->str());
     37     }
     38   }
     39   extractor_options.remap_digits = options->remap_digits();
     40   extractor_options.lowercase_tokens = options->lowercase_tokens();
     41   return extractor_options;
     42 }
     43 }  // namespace
     44 
     45 std::unique_ptr<Tokenizer> CreateTokenizer(
     46     const ActionsTokenizerOptions* options, const UniLib* unilib) {
     47   std::vector<const TokenizationCodepointRange*> codepoint_config;
     48   if (options->tokenization_codepoint_config() != nullptr) {
     49     codepoint_config.insert(codepoint_config.end(),
     50                             options->tokenization_codepoint_config()->begin(),
     51                             options->tokenization_codepoint_config()->end());
     52   }
     53   std::vector<const CodepointRange*> internal_codepoint_config;
     54   if (options->internal_tokenizer_codepoint_ranges() != nullptr) {
     55     internal_codepoint_config.insert(
     56         internal_codepoint_config.end(),
     57         options->internal_tokenizer_codepoint_ranges()->begin(),
     58         options->internal_tokenizer_codepoint_ranges()->end());
     59   }
     60   const bool tokenize_on_script_change =
     61       options->tokenization_codepoint_config() != nullptr &&
     62       options->tokenize_on_script_change();
     63   return std::unique_ptr<Tokenizer>(new Tokenizer(
     64       options->type(), unilib, codepoint_config, internal_codepoint_config,
     65       tokenize_on_script_change, options->icu_preserve_whitespace_tokens()));
     66 }
     67 
     68 ActionsFeatureProcessor::ActionsFeatureProcessor(
     69     const ActionsTokenFeatureProcessorOptions* options, const UniLib* unilib)
     70     : options_(options),
     71       tokenizer_(CreateTokenizer(options->tokenizer_options(), unilib)),
     72       token_feature_extractor_(BuildTokenFeatureExtractorOptions(options),
     73                                *unilib) {}
     74 
     75 int ActionsFeatureProcessor::GetTokenEmbeddingSize() const {
     76   return options_->embedding_size() +
     77          token_feature_extractor_.DenseFeaturesCount();
     78 }
     79 
     80 bool ActionsFeatureProcessor::AppendFeatures(
     81     const std::vector<int>& sparse_features,
     82     const std::vector<float>& dense_features,
     83     const EmbeddingExecutor* embedding_executor,
     84     std::vector<float>* output_features) const {
     85   // Embed the sparse features, appending them directly to the output.
     86   const int embedding_size = options_->embedding_size();
     87   output_features->resize(output_features->size() + embedding_size);
     88   float* output_features_end =
     89       output_features->data() + output_features->size();
     90   if (!embedding_executor->AddEmbedding(
     91           TensorView<int>(sparse_features.data(),
     92                           {static_cast<int>(sparse_features.size())}),
     93           /*dest=*/output_features_end - embedding_size,
     94           /*dest_size=*/embedding_size)) {
     95     TC3_LOG(ERROR) << "Could not embed token's sparse features.";
     96     return false;
     97   }
     98 
     99   // Append the dense features to the output.
    100   output_features->insert(output_features->end(), dense_features.begin(),
    101                           dense_features.end());
    102   return true;
    103 }
    104 
    105 bool ActionsFeatureProcessor::AppendTokenFeatures(
    106     const Token& token, const EmbeddingExecutor* embedding_executor,
    107     std::vector<float>* output_features) const {
    108   // Extract the sparse and dense features.
    109   std::vector<int> sparse_features;
    110   std::vector<float> dense_features;
    111   if (!token_feature_extractor_.Extract(token, /*(unused) is_in_span=*/false,
    112                                         &sparse_features, &dense_features)) {
    113     TC3_LOG(ERROR) << "Could not extract token's features.";
    114     return false;
    115   }
    116   return AppendFeatures(sparse_features, dense_features, embedding_executor,
    117                         output_features);
    118 }
    119 
    120 bool ActionsFeatureProcessor::AppendTokenFeatures(
    121     const std::vector<Token>& tokens,
    122     const EmbeddingExecutor* embedding_executor,
    123     std::vector<float>* output_features) const {
    124   for (const Token& token : tokens) {
    125     if (!AppendTokenFeatures(token, embedding_executor, output_features)) {
    126       return false;
    127     }
    128   }
    129   return true;
    130 }
    131 
    132 }  // namespace libtextclassifier3
    133