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// Licensed to the Apache Software Foundation (ASF) under one
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// or more contributor license agreements. See the NOTICE file
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// distributed with this work for additional information
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// regarding copyright ownership. The ASF licenses this file
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// to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance
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// with the License. You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing,
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// software distributed under the License is distributed on an
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// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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// KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations
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// under the License.
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#pragma once
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#include <cstdint>
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#include <memory>
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#include "arrow/csv/options.h"
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#include "arrow/result.h"
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#include "arrow/type_fwd.h"
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#include "arrow/util/macros.h"
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#include "arrow/util/visibility.h"
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namespace arrow {
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namespace csv {
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class BlockParser;
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class ARROW_EXPORT Converter {
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public:
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Converter(const std::shared_ptr<DataType>& type, const ConvertOptions& options,
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MemoryPool* pool);
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virtual ~Converter() = default;
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virtual Result<std::shared_ptr<Array>> Convert(const BlockParser& parser,
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int32_t col_index) = 0;
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std::shared_ptr<DataType> type() const { return type_; }
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// Create a Converter for the given data type
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static Result<std::shared_ptr<Converter>> Make(
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const std::shared_ptr<DataType>& type, const ConvertOptions& options,
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MemoryPool* pool = default_memory_pool());
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protected:
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ARROW_DISALLOW_COPY_AND_ASSIGN(Converter);
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virtual Status Initialize() = 0;
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// CAUTION: ConvertOptions can grow large (if it customizes hundreds or
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// thousands of columns), so avoid copying it in each Converter.
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const ConvertOptions& options_;
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MemoryPool* pool_;
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std::shared_ptr<DataType> type_;
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};
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class ARROW_EXPORT DictionaryConverter : public Converter {
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public:
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DictionaryConverter(const std::shared_ptr<DataType>& value_type,
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const ConvertOptions& options, MemoryPool* pool);
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// If the dictionary length goes above this value, conversion will fail
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// with Status::IndexError.
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virtual void SetMaxCardinality(int32_t max_length) = 0;
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// Create a Converter for the given dictionary value type.
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// The dictionary index type will always be Int32.
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static Result<std::shared_ptr<DictionaryConverter>> Make(
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const std::shared_ptr<DataType>& value_type, const ConvertOptions& options,
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MemoryPool* pool = default_memory_pool());
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protected:
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std::shared_ptr<DataType> value_type_;
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};
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} // namespace csv
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} // namespace arrow
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