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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 <cstdint>
#include <memory>
#include "arrow/csv/options.h"
#include "arrow/result.h"
#include "arrow/type_fwd.h"
#include "arrow/util/macros.h"
#include "arrow/util/visibility.h"
namespace arrow {
namespace csv {
class BlockParser;
class ARROW_EXPORT Converter {
public:
Converter(const std::shared_ptr<DataType>& type, const ConvertOptions& options,
MemoryPool* pool);
virtual ~Converter() = default;
virtual Result<std::shared_ptr<Array>> Convert(const BlockParser& parser,
int32_t col_index) = 0;
std::shared_ptr<DataType> type() const { return type_; }
// Create a Converter for the given data type
static Result<std::shared_ptr<Converter>> Make(
const std::shared_ptr<DataType>& type, const ConvertOptions& options,
MemoryPool* pool = default_memory_pool());
protected:
ARROW_DISALLOW_COPY_AND_ASSIGN(Converter);
virtual Status Initialize() = 0;
// CAUTION: ConvertOptions can grow large (if it customizes hundreds or
// thousands of columns), so avoid copying it in each Converter.
const ConvertOptions& options_;
MemoryPool* pool_;
std::shared_ptr<DataType> type_;
};
class ARROW_EXPORT DictionaryConverter : public Converter {
public:
DictionaryConverter(const std::shared_ptr<DataType>& value_type,
const ConvertOptions& options, MemoryPool* pool);
// If the dictionary length goes above this value, conversion will fail
// with Status::IndexError.
virtual void SetMaxCardinality(int32_t max_length) = 0;
// Create a Converter for the given dictionary value type.
// The dictionary index type will always be Int32.
static Result<std::shared_ptr<DictionaryConverter>> Make(
const std::shared_ptr<DataType>& value_type, const ConvertOptions& options,
MemoryPool* pool = default_memory_pool());
protected:
std::shared_ptr<DataType> value_type_;
};
} // namespace csv
} // namespace arrow
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