| // Copyright 2020 Google LLC |
| // |
| // 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 |
| // |
| // https://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_UTILS_GRAMMAR_SEMANTICS_VALUE_H_ |
| #define LIBTEXTCLASSIFIER_UTILS_GRAMMAR_SEMANTICS_VALUE_H_ |
| |
| #include "utils/base/arena.h" |
| #include "utils/base/logging.h" |
| #include "utils/flatbuffers/mutable.h" |
| #include "utils/flatbuffers/reflection.h" |
| #include "utils/strings/stringpiece.h" |
| #include "utils/utf8/unicodetext.h" |
| #include "flatbuffers/base.h" |
| #include "flatbuffers/reflection.h" |
| |
| namespace libtextclassifier3::grammar { |
| |
| // A semantic value as a typed, arena-allocated flatbuffer. |
| // This denotes the possible results of the evaluation of a semantic expression. |
| class SemanticValue { |
| public: |
| // Creates an arena allocated semantic value. |
| template <typename T> |
| static const SemanticValue* Create(const T value, UnsafeArena* arena) { |
| static_assert(!std::is_pointer<T>() && std::is_scalar<T>()); |
| if (char* buffer = reinterpret_cast<char*>( |
| arena->AllocAligned(sizeof(T), alignof(T)))) { |
| flatbuffers::WriteScalar<T>(buffer, value); |
| return arena->AllocAndInit<SemanticValue>( |
| libtextclassifier3::flatbuffers_base_type<T>::value, |
| StringPiece(buffer, sizeof(T))); |
| } |
| return nullptr; |
| } |
| |
| template <> |
| const SemanticValue* Create(const StringPiece value, UnsafeArena* arena) { |
| return arena->AllocAndInit<SemanticValue>(reflection::BaseType::String, |
| value); |
| } |
| |
| template <> |
| const SemanticValue* Create(const UnicodeText value, UnsafeArena* arena) { |
| return arena->AllocAndInit<SemanticValue>( |
| reflection::BaseType::String, |
| StringPiece(value.data(), value.size_bytes())); |
| } |
| |
| template <> |
| const SemanticValue* Create(const MutableFlatbuffer* value, |
| UnsafeArena* arena) { |
| const std::string buffer = value->Serialize(); |
| return Create( |
| value->type(), |
| StringPiece(arena->Memdup(buffer.data(), buffer.size()), buffer.size()), |
| arena); |
| } |
| |
| static const SemanticValue* Create(const reflection::Object* type, |
| const StringPiece data, |
| UnsafeArena* arena) { |
| return arena->AllocAndInit<SemanticValue>(type, data); |
| } |
| |
| static const SemanticValue* Create(const reflection::BaseType base_type, |
| const StringPiece data, |
| UnsafeArena* arena) { |
| return arena->AllocAndInit<SemanticValue>(base_type, data); |
| } |
| |
| template <typename T> |
| static const SemanticValue* Create(const reflection::BaseType base_type, |
| const T value, UnsafeArena* arena) { |
| switch (base_type) { |
| case reflection::BaseType::Bool: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::Bool>::value>(value), |
| arena); |
| case reflection::BaseType::Byte: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::Byte>::value>(value), |
| arena); |
| case reflection::BaseType::UByte: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::UByte>::value>( |
| value), |
| arena); |
| case reflection::BaseType::Short: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::Short>::value>( |
| value), |
| arena); |
| case reflection::BaseType::UShort: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::UShort>::value>( |
| value), |
| arena); |
| case reflection::BaseType::Int: |
| return Create( |
| static_cast<flatbuffers_cpp_type<reflection::BaseType::Int>::value>( |
| value), |
| arena); |
| case reflection::BaseType::UInt: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::UInt>::value>(value), |
| arena); |
| case reflection::BaseType::Long: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::Long>::value>(value), |
| arena); |
| case reflection::BaseType::ULong: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::ULong>::value>( |
| value), |
| arena); |
| case reflection::BaseType::Float: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::Float>::value>( |
| value), |
| arena); |
| case reflection::BaseType::Double: |
| return Create( |
| static_cast< |
| flatbuffers_cpp_type<reflection::BaseType::Double>::value>( |
| value), |
| arena); |
| default: { |
| TC3_LOG(ERROR) << "Unhandled type: " << base_type; |
| return nullptr; |
| } |
| } |
| } |
| |
| explicit SemanticValue(const reflection::BaseType base_type, |
| const StringPiece data) |
| : base_type_(base_type), type_(nullptr), data_(data) {} |
| explicit SemanticValue(const reflection::Object* type, const StringPiece data) |
| : base_type_(reflection::BaseType::Obj), type_(type), data_(data) {} |
| |
| template <typename T> |
| bool Has() const { |
| return base_type_ == libtextclassifier3::flatbuffers_base_type<T>::value; |
| } |
| |
| template <> |
| bool Has<flatbuffers::Table>() const { |
| return base_type_ == reflection::BaseType::Obj; |
| } |
| |
| template <typename T = flatbuffers::Table> |
| const T* Table() const { |
| TC3_CHECK(Has<flatbuffers::Table>()); |
| return flatbuffers::GetRoot<T>( |
| reinterpret_cast<const unsigned char*>(data_.data())); |
| } |
| |
| template <typename T> |
| const T Value() const { |
| TC3_CHECK(Has<T>()); |
| return flatbuffers::ReadScalar<T>(data_.data()); |
| } |
| |
| template <> |
| const StringPiece Value<StringPiece>() const { |
| TC3_CHECK(Has<StringPiece>()); |
| return data_; |
| } |
| |
| template <> |
| const std::string Value<std::string>() const { |
| TC3_CHECK(Has<StringPiece>()); |
| return data_.ToString(); |
| } |
| |
| template <> |
| const UnicodeText Value<UnicodeText>() const { |
| TC3_CHECK(Has<StringPiece>()); |
| return UTF8ToUnicodeText(data_, /*do_copy=*/false); |
| } |
| |
| const reflection::BaseType base_type() const { return base_type_; } |
| const reflection::Object* type() const { return type_; } |
| |
| private: |
| // The base type. |
| const reflection::BaseType base_type_; |
| |
| // The object type of the value. |
| const reflection::Object* type_; |
| |
| StringPiece data_; |
| }; |
| |
| } // namespace libtextclassifier3::grammar |
| |
| #endif // LIBTEXTCLASSIFIER_UTILS_GRAMMAR_SEMANTICS_VALUE_H_ |