F consolidation

Summary

Insert a meaningful description for this merge request here.  What is the
new/changed behavior? Which bug has been fixed? Are there related Issues?

Focus

Point the reviewer to the core of the code change. Where should they start
reading? What should they focus on (e.g. security, performance,
maintainability, user-friendliness, compliance with the specs, finding more
corner cases, concrete questions)?

Test Environment

How to set up a test environment for manual testing?

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

include/caosdb/data_type.h

+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * DataTypes have 2 dimensions: They may be atomic or reference typed, and they
+ * may be scalar or list valued.  If they are atomic, they have an
+ * AtomicDataType.  If they are reference typed, the reference name can be
+ * obtained with GetName().
+ */
+
+#ifndef CAOSDB_DATA_TYPE_H
+#define CAOSDB_DATA_TYPE_H
+#include "caosdb/protobuf_helper.h"         // for ProtoMessageWrapper
+#include "caosdb/entity/v1alpha1/main.pb.h" // for RepeatedPtrField, Message
+#include <memory>                           // for unique_ptr
+#include <string>                           // for string
+namespace caosdb::entity {
+using ProtoAtomicDataType = caosdb::entity::v1alpha1::AtomicDataType;
+using ProtoDataType = caosdb::entity::v1alpha1::DataType;
+using ProtoListDataType = caosdb::entity::v1alpha1::ListDataType;
+using ProtoReferenceDataType = caosdb::entity::v1alpha1::ReferenceDataType;
+using DataTypeCase = caosdb::entity::v1alpha1::DataType::DataTypeCase;
+using ListDataTypeCase = caosdb::entity::v1alpha1::ListDataType::ListDataTypeCase;
+using caosdb::utility::ProtoMessageWrapper;
+
+class Entity;
+class Property;
+
+// Atomic data types.
+enum class AtomicDataType {
+  // The data type is unset/unknown.
+  UNSPECIFIED = ProtoAtomicDataType::ATOMIC_DATA_TYPE_UNSPECIFIED,
+  // TEXT data type.
+  TEXT = ProtoAtomicDataType::ATOMIC_DATA_TYPE_TEXT,
+  // DOUBLE data type.
+  DOUBLE = ProtoAtomicDataType::ATOMIC_DATA_TYPE_DOUBLE,
+  // DATETIME data type.
+  DATETIME = ProtoAtomicDataType::ATOMIC_DATA_TYPE_DATETIME,
+  // INTEGER data type.
+  INTEGER = ProtoAtomicDataType::ATOMIC_DATA_TYPE_INTEGER,
+  // BOOLEAN data type.
+  BOOLEAN = ProtoAtomicDataType::ATOMIC_DATA_TYPE_BOOLEAN,
+};
+
+const std::map<AtomicDataType, std::string> atomicdatatype_names = {
+  {AtomicDataType::UNSPECIFIED, "UNSPECIFIED"}, {AtomicDataType::TEXT, "TEXT"},
+  {AtomicDataType::DOUBLE, "DOUBLE"},           {AtomicDataType::DATETIME, "DATETIME"},
+  {AtomicDataType::INTEGER, "INTEGER"},         {AtomicDataType::BOOLEAN, "BOOLEAN"}};
+
+class DataType;
+class ListDataType;
+
+class ReferenceDataType : public ProtoMessageWrapper<ProtoDataType> {
+public:
+  [[nodiscard]] inline auto GetName() const noexcept -> const std::string & {
+    // is list of reference?
+    if (this->wrapped->data_type_case() == DataTypeCase::kListDataType) {
+      return this->wrapped->list_data_type().reference_data_type().name();
+    }
+    return this->wrapped->reference_data_type().name();
+  }
+
+  friend class DataType;
+  friend class ListDataType;
+
+  inline auto GetWrapped() const -> const ProtoDataType * { return wrapped; }
+
+protected:
+  static auto GetEmptyInstance() -> const ReferenceDataType & {
+    static ReferenceDataType instance;
+    return instance;
+  }
+  inline static auto Create(ProtoDataType *wrapped) -> std::unique_ptr<ReferenceDataType> {
+    return std::unique_ptr<ReferenceDataType>(new ReferenceDataType(wrapped));
+  }
+  ReferenceDataType() : ProtoMessageWrapper<ProtoDataType>() {}
+  ReferenceDataType(ProtoDataType *wrapped) : ProtoMessageWrapper<ProtoDataType>(wrapped) {}
+};
+
+class ListDataType : public ProtoMessageWrapper<ProtoDataType> {
+public:
+  [[nodiscard]] inline auto IsListOfReference() const noexcept -> bool {
+    return this->wrapped->list_data_type().list_data_type_case() ==
+           ListDataTypeCase::kReferenceDataType;
+  }
+  [[nodiscard]] inline auto GetReferenceDataType() const -> const ReferenceDataType & {
+    if (!IsListOfReference()) {
+      return ReferenceDataType::GetEmptyInstance();
+    }
+    if (reference_data_type == nullptr) {
+      this->reference_data_type =
+        std::unique_ptr<ReferenceDataType>(ReferenceDataType::Create(this->wrapped).release());
+    }
+    return *this->reference_data_type;
+  }
+
+  [[nodiscard]] inline auto IsListOfAtomic() const noexcept -> bool {
+    return this->wrapped->list_data_type().list_data_type_case() ==
+           ListDataTypeCase::kAtomicDataType;
+  }
+  [[nodiscard]] inline auto GetAtomicDataType() const -> AtomicDataType {
+    return static_cast<AtomicDataType>(this->wrapped->list_data_type().atomic_data_type());
+  }
+
+  friend class DataType;
+
+protected:
+  static auto GetEmptyInstance() -> const ListDataType & {
+    static auto empty_instance = ListDataType();
+    return empty_instance;
+  }
+  inline static auto Create(ProtoDataType *wrapped) -> std::unique_ptr<ListDataType> {
+    return std::unique_ptr<ListDataType>(new ListDataType(wrapped));
+  }
+  ListDataType() : ProtoMessageWrapper<ProtoDataType>() {}
+
+  ListDataType(ProtoDataType *wrapped) : ProtoMessageWrapper<ProtoDataType>(wrapped) {}
+
+  mutable std::unique_ptr<ReferenceDataType> reference_data_type;
+};
+
+class DataType : public ProtoMessageWrapper<ProtoDataType> {
+public:
+  DataType(ProtoDataType *wrapped) : ProtoMessageWrapper<ProtoDataType>(wrapped) {}
+  DataType() : ProtoMessageWrapper<ProtoDataType>() {}
+  /**
+   * Create an AtomicDataType typed DataType.  For references, use the std::string constructor.
+   */
+  DataType(AtomicDataType data_type, bool list_type = false) : DataType() {
+    if (list_type) {
+      this->wrapped->mutable_list_data_type()->set_atomic_data_type(
+        static_cast<ProtoAtomicDataType>(data_type));
+    } else {
+      this->wrapped->set_atomic_data_type(static_cast<ProtoAtomicDataType>(data_type));
+    }
+  }
+  /**
+   * Create a reference typed DataType.
+   */
+  DataType(const std::string &data_type, bool list_type = false) : DataType() {
+    if (list_type) {
+      this->wrapped->mutable_list_data_type()->mutable_reference_data_type()->set_name(data_type);
+    } else {
+      this->wrapped->mutable_reference_data_type()->set_name(data_type);
+    }
+  }
+
+  inline static auto ListOf(const AtomicDataType &atomic_data_type) -> DataType {
+    DataType result;
+    result.wrapped->mutable_list_data_type()->set_atomic_data_type(
+      static_cast<ProtoAtomicDataType>(atomic_data_type));
+    return result;
+  }
+  inline static auto ListOf(const std::string reference_data_type) -> DataType {
+    DataType result;
+    result.wrapped->mutable_list_data_type()->mutable_reference_data_type()->set_name(
+      reference_data_type);
+    return result;
+  }
+
+  [[nodiscard]] inline auto IsAtomic() const noexcept -> bool {
+    return this->wrapped->data_type_case() == DataTypeCase::kAtomicDataType;
+  }
+  [[nodiscard]] inline auto AsAtomic() const noexcept -> AtomicDataType {
+    return static_cast<AtomicDataType>(this->wrapped->atomic_data_type());
+  }
+
+  [[nodiscard]] inline auto IsReference() const noexcept -> bool {
+    return this->wrapped->data_type_case() == DataTypeCase::kReferenceDataType;
+  }
+  [[nodiscard]] inline auto AsReference() const noexcept -> const ReferenceDataType & {
+    if (!IsReference()) {
+      return ReferenceDataType::GetEmptyInstance();
+    } else if (reference_data_type == nullptr) {
+      reference_data_type =
+        std::unique_ptr<ReferenceDataType>(ReferenceDataType::Create(this->wrapped).release());
+    }
+    return *reference_data_type;
+  }
+
+  [[nodiscard]] inline auto IsList() const noexcept -> bool {
+    return this->wrapped->data_type_case() == DataTypeCase::kListDataType;
+  }
+
+  [[nodiscard]] inline auto AsList() const noexcept -> const ListDataType & {
+    if (!IsList()) {
+      return ListDataType::GetEmptyInstance();
+    } else if (list_data_type == nullptr) {
+      list_data_type = std::unique_ptr<ListDataType>(ListDataType::Create(this->wrapped).release());
+    }
+    return *list_data_type;
+  }
+
+  inline auto operator==(const DataType &other) const noexcept -> bool {
+    // TODO(tf) Is this safe?
+    return this->wrapped->SerializeAsString() == other.wrapped->SerializeAsString();
+  }
+
+  friend class Entity;
+  friend class Property;
+
+protected:
+  mutable std::unique_ptr<ReferenceDataType> reference_data_type;
+  mutable std::unique_ptr<ListDataType> list_data_type;
+};
+
+} // namespace caosdb::entity
+
+#endif