sort_order.h

/*
 * 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 <cstdint>
#include <memory>
#include <span>
#include <unordered_set>
#include <vector>
 
#include "iceberg/iceberg_export.h"
#include "iceberg/sort_field.h"
#include "iceberg/type_fwd.h"
#include "iceberg/util/formattable.h"
 
namespace iceberg {
 
class ICEBERG_EXPORT SortOrder : public util::Formattable {
 public:
  static constexpr int32_t kUnsortedOrderId = 0;
  static constexpr int32_t kInitialSortOrderId = 1;
 
  static const std::shared_ptr<SortOrder>& Unsorted();
 
  int32_t order_id() const;
 
  std::span<const SortField> fields() const;
 
  bool is_sorted() const { return !fields_.empty(); }
 
  bool is_unsorted() const { return fields_.empty(); }
 
  bool Satisfies(const SortOrder& other) const;
 
  bool SameOrder(const SortOrder& other) const;
 
  std::string ToString() const override;
 
  friend bool operator==(const SortOrder& lhs, const SortOrder& rhs) {
    return lhs.Equals(rhs);
  }
 
  Status Validate(const Schema& schema) const;
 
  static Result<std::unique_ptr<SortOrder>> Make(const Schema& schema, int32_t sort_id,
                                                 std::vector<SortField> fields);
 
  static Result<std::unique_ptr<SortOrder>> Make(int32_t sort_id,
                                                 std::vector<SortField> fields);
 
  static std::unordered_set<std::string_view> OrderPreservingSortedColumns(
      const Schema& schema, const SortOrder& order);
 
 private:
  SortOrder(int32_t order_id, std::vector<SortField> fields);
 
  bool Equals(const SortOrder& other) const;
 
  int32_t order_id_;
  std::vector<SortField> fields_;
};
 
}  // namespace iceberg