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 "lang_id/common/fel/feature-extractor.h"
18
19 #include "lang_id/common/fel/feature-types.h"
20 #include "lang_id/common/fel/fel-parser.h"
21 #include "lang_id/common/lite_base/logging.h"
22 #include "lang_id/common/lite_strings/numbers.h"
23
24 namespace libtextclassifier3 {
25 namespace mobile {
26
27 constexpr FeatureValue GenericFeatureFunction::kNone;
28
GenericFeatureExtractor()29 GenericFeatureExtractor::GenericFeatureExtractor() {}
30
~GenericFeatureExtractor()31 GenericFeatureExtractor::~GenericFeatureExtractor() {}
32
Parse(const string & source)33 bool GenericFeatureExtractor::Parse(const string &source) {
34 // Parse feature specification into descriptor.
35 FELParser parser;
36
37 if (!parser.Parse(source, mutable_descriptor())) {
38 SAFTM_LOG(ERROR) << "Error parsing the FEL spec " << source;
39 return false;
40 }
41
42 // Initialize feature extractor from descriptor.
43 return InitializeFeatureFunctions();
44 }
45
InitializeFeatureTypes()46 bool GenericFeatureExtractor::InitializeFeatureTypes() {
47 // Register all feature types.
48 GetFeatureTypes(&feature_types_);
49 for (size_t i = 0; i < feature_types_.size(); ++i) {
50 FeatureType *ft = feature_types_[i];
51 ft->set_base(i);
52
53 // Check for feature space overflow.
54 double domain_size = ft->GetDomainSize();
55 if (domain_size < 0) {
56 SAFTM_LOG(ERROR) << "Illegal domain size for feature " << ft->name()
57 << ": " << domain_size;
58 return false;
59 }
60 }
61 return true;
62 }
63
GetParameter(const string & name,const string & default_value) const64 string GenericFeatureFunction::GetParameter(const string &name,
65 const string &default_value) const {
66 // Find named parameter in feature descriptor.
67 for (int i = 0; i < descriptor_->parameter_size(); ++i) {
68 if (name == descriptor_->parameter(i).name()) {
69 return descriptor_->parameter(i).value();
70 }
71 }
72 return default_value;
73 }
74
GenericFeatureFunction()75 GenericFeatureFunction::GenericFeatureFunction() {}
76
~GenericFeatureFunction()77 GenericFeatureFunction::~GenericFeatureFunction() { delete feature_type_; }
78
GetIntParameter(const string & name,int default_value) const79 int GenericFeatureFunction::GetIntParameter(const string &name,
80 int default_value) const {
81 string value_str = GetParameter(name, "");
82 if (value_str.empty()) {
83 // Parameter not specified, use default value for it.
84 return default_value;
85 }
86 int value = 0;
87 if (!LiteAtoi(value_str, &value)) {
88 SAFTM_LOG(DFATAL) << "Unable to parse '" << value_str
89 << "' as int for parameter " << name;
90 return default_value;
91 }
92 return value;
93 }
94
GetBoolParameter(const string & name,bool default_value) const95 bool GenericFeatureFunction::GetBoolParameter(const string &name,
96 bool default_value) const {
97 string value = GetParameter(name, "");
98 if (value.empty()) return default_value;
99 if (value == "true") return true;
100 if (value == "false") return false;
101 SAFTM_LOG(DFATAL) << "Illegal value '" << value << "' for bool parameter "
102 << name;
103 return default_value;
104 }
105
GetFeatureTypes(std::vector<FeatureType * > * types) const106 void GenericFeatureFunction::GetFeatureTypes(
107 std::vector<FeatureType *> *types) const {
108 if (feature_type_ != nullptr) types->push_back(feature_type_);
109 }
110
GetFeatureType() const111 FeatureType *GenericFeatureFunction::GetFeatureType() const {
112 // If a single feature type has been registered return it.
113 if (feature_type_ != nullptr) return feature_type_;
114
115 // Get feature types for function.
116 std::vector<FeatureType *> types;
117 GetFeatureTypes(&types);
118
119 // If there is exactly one feature type return this, else return null.
120 if (types.size() == 1) return types[0];
121 return nullptr;
122 }
123
name() const124 string GenericFeatureFunction::name() const {
125 string output;
126 if (descriptor_->name().empty()) {
127 if (!prefix_.empty()) {
128 output.append(prefix_);
129 output.append(".");
130 }
131 ToFEL(*descriptor_, &output);
132 } else {
133 output = descriptor_->name();
134 }
135 return output;
136 }
137
138 } // namespace mobile
139 } // namespace nlp_saft
140