type_util.h

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */
 
#pragma once
 
#include <functional>
#include <memory>
#include <string>
#include <string_view>
#include <unordered_map>
#include <unordered_set>
#include <vector>
 
#include "iceberg/iceberg_export.h"
#include "iceberg/result.h"
#include "iceberg/schema_field.h"
#include "iceberg/type_fwd.h"
#include "iceberg/util/string_util.h"
 
 
namespace iceberg {
 
class IdToFieldVisitor {
 public:
  explicit IdToFieldVisitor(
      std::unordered_map<int32_t, std::reference_wrapper<const SchemaField>>&
          id_to_field);
  Status Visit(const PrimitiveType& type);
  Status Visit(const NestedType& type);
 
 private:
  std::unordered_map<int32_t, std::reference_wrapper<const SchemaField>>& id_to_field_;
};
 
class NameToIdVisitor {
 public:
  explicit NameToIdVisitor(
      std::unordered_map<std::string, int32_t, StringHash, std::equal_to<>>& name_to_id,
      std::unordered_map<int32_t, std::string>* id_to_name, bool case_sensitive = true,
      std::function<std::string(std::string_view)> quoting_func = {});
  Status Visit(const ListType& type, const std::string& path,
               const std::string& short_path);
  Status Visit(const MapType& type, const std::string& path,
               const std::string& short_path);
  Status Visit(const StructType& type, const std::string& path,
               const std::string& short_path);
  Status Visit(const PrimitiveType& type, const std::string& path,
               const std::string& short_path);
  void Finish();
 
 private:
  std::string BuildPath(std::string_view prefix, std::string_view field_name,
                        bool case_sensitive);
 
 private:
  bool case_sensitive_;
  std::unordered_map<std::string, int32_t, StringHash, std::equal_to<>>& name_to_id_;
  std::unordered_map<int32_t, std::string>* id_to_name_;
  std::unordered_map<std::string, int32_t, StringHash, std::equal_to<>> short_name_to_id_;
  std::function<std::string(std::string_view)> quoting_func_;
};
 
class PositionPathVisitor {
 public:
  Status Visit(const PrimitiveType& type);
  Status Visit(const StructType& type);
  Status Visit(const ListType& type);
  Status Visit(const MapType& type);
  std::unordered_map<int32_t, std::vector<size_t>> Finish();
 
 private:
  constexpr static int32_t kUnassignedFieldId = -1;
  int32_t current_field_id_ = kUnassignedFieldId;
  std::vector<size_t> current_path_;
  std::unordered_map<int32_t, std::vector<size_t>> position_path_;
};
 
class PruneColumnVisitor {
 public:
  PruneColumnVisitor(const std::unordered_set<int32_t>& selected_ids,
                     bool select_full_types);
 
  Result<std::shared_ptr<Type>> Visit(const std::shared_ptr<Type>& type) const;
  Result<std::shared_ptr<Type>> Visit(const SchemaField& field) const;
  static SchemaField MakeField(const SchemaField& field, std::shared_ptr<Type> type);
  Result<std::shared_ptr<Type>> Visit(const std::shared_ptr<StructType>& type) const;
  Result<std::shared_ptr<Type>> Visit(const std::shared_ptr<ListType>& type) const;
  Result<std::shared_ptr<Type>> Visit(const std::shared_ptr<MapType>& type) const;
 
 private:
  const std::unordered_set<int32_t>& selected_ids_;
  const bool select_full_types_;
};
 
class GetProjectedIdsVisitor {
 public:
  explicit GetProjectedIdsVisitor(bool include_struct_ids = false);
 
  Status Visit(const Type& type);
  Status VisitNested(const NestedType& type);
  Status VisitPrimitive(const PrimitiveType& type);
  std::unordered_set<int32_t> Finish() const;
 
  static Result<std::unordered_set<int32_t>> GetProjectedIds(
      const Type& type, bool include_struct_ids = false);
 
 private:
  const bool include_struct_ids_;
  std::unordered_set<int32_t> ids_;
};
 
ICEBERG_EXPORT std::unordered_map<int32_t, int32_t> IndexParents(
    const StructType& root_struct);
 
class AssignFreshIdVisitor {
 public:
  explicit AssignFreshIdVisitor(std::function<int32_t()> next_id);
 
  std::shared_ptr<Type> Visit(const std::shared_ptr<Type>& type) const;
  std::shared_ptr<StructType> Visit(const StructType& type) const;
  std::shared_ptr<ListType> Visit(const ListType& type) const;
  std::shared_ptr<MapType> Visit(const MapType& type) const;
 
 private:
  std::function<int32_t()> next_id_;
};
 
ICEBERG_EXPORT Result<std::shared_ptr<Schema>> AssignFreshIds(
    int32_t schema_id, const Schema& schema, std::function<int32_t()> next_id);
 
ICEBERG_EXPORT bool IsPromotionAllowed(const std::shared_ptr<Type>& from_type,
                                       const std::shared_ptr<Type>& to_type);
 
}  // namespace iceberg