Export lib3 to AOSP (external/libtextclassifier part)
1. Include both annotator (existing one) and actions(new one for smart
reply and actions)
2. One more model file. actions_suggestions.model is dropped to
/etc/textclassifier./ It is around 7.5mb for now, we will slim down
it later.
3. The Java counterpart of the JNI is now moved from frameworks/base
to here.
Test: atest android.view.textclassifier.TextClassificationManagerTest
Change-Id: Icb2458967ef51efa2952b3eaddefbf1f7b359930
diff --git a/annotator/token-feature-extractor.h b/annotator/token-feature-extractor.h
new file mode 100644
index 0000000..7dc19fe
--- /dev/null
+++ b/annotator/token-feature-extractor.h
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LIBTEXTCLASSIFIER_ANNOTATOR_TOKEN_FEATURE_EXTRACTOR_H_
+#define LIBTEXTCLASSIFIER_ANNOTATOR_TOKEN_FEATURE_EXTRACTOR_H_
+
+#include <memory>
+#include <unordered_set>
+#include <vector>
+
+#include "annotator/types.h"
+#include "utils/strings/stringpiece.h"
+#include "utils/utf8/unilib.h"
+
+namespace libtextclassifier3 {
+
+struct TokenFeatureExtractorOptions {
+ // Number of buckets used for hashing charactergrams.
+ int num_buckets = 0;
+
+ // Orders of charactergrams to extract. E.g., 2 means character bigrams, 3
+ // character trigrams etc.
+ std::vector<int> chargram_orders;
+
+ // Whether to extract the token case feature.
+ bool extract_case_feature = false;
+
+ // If true, will use the unicode-aware functionality for extracting features.
+ bool unicode_aware_features = false;
+
+ // Whether to extract the selection mask feature.
+ bool extract_selection_mask_feature = false;
+
+ // Regexp features to extract.
+ std::vector<std::string> regexp_features;
+
+ // Whether to remap digits to a single number.
+ bool remap_digits = false;
+
+ // Whether to lowercase all tokens.
+ bool lowercase_tokens = false;
+
+ // Maximum length of a word.
+ int max_word_length = 20;
+
+ // List of allowed charactergrams. The extracted charactergrams are filtered
+ // using this list, and charactergrams that are not present are interpreted as
+ // out-of-vocabulary.
+ // If no allowed_chargrams are specified, all charactergrams are allowed.
+ std::unordered_set<std::string> allowed_chargrams;
+};
+
+class TokenFeatureExtractor {
+ public:
+ TokenFeatureExtractor(const TokenFeatureExtractorOptions& options,
+ const UniLib& unilib);
+
+ // Extracts both the sparse (charactergram) and the dense features from a
+ // token. is_in_span is a bool indicator whether the token is a part of the
+ // selection span (true) or not (false).
+ // The sparse_features output is optional. Fails and returns false if
+ // dense_fatures in a nullptr.
+ bool Extract(const Token& token, bool is_in_span,
+ std::vector<int>* sparse_features,
+ std::vector<float>* dense_features) const;
+
+ // Extracts the sparse (charactergram) features from the token.
+ std::vector<int> ExtractCharactergramFeatures(const Token& token) const;
+
+ // Extracts the dense features from the token. is_in_span is a bool indicator
+ // whether the token is a part of the selection span (true) or not (false).
+ std::vector<float> ExtractDenseFeatures(const Token& token,
+ bool is_in_span) const;
+
+ int DenseFeaturesCount() const {
+ int feature_count =
+ options_.extract_case_feature + options_.extract_selection_mask_feature;
+ feature_count += regex_patterns_.size();
+ return feature_count;
+ }
+
+ protected:
+ // Hashes given token to given number of buckets.
+ int HashToken(StringPiece token) const;
+
+ // Extracts the charactergram features from the token in a non-unicode-aware
+ // way.
+ std::vector<int> ExtractCharactergramFeaturesAscii(const Token& token) const;
+
+ // Extracts the charactergram features from the token in a unicode-aware way.
+ std::vector<int> ExtractCharactergramFeaturesUnicode(
+ const Token& token) const;
+
+ private:
+ TokenFeatureExtractorOptions options_;
+ std::vector<std::unique_ptr<UniLib::RegexPattern>> regex_patterns_;
+ const UniLib& unilib_;
+};
+
+} // namespace libtextclassifier3
+
+#endif // LIBTEXTCLASSIFIER_ANNOTATOR_TOKEN_FEATURE_EXTRACTOR_H_