arrow/json/chunked_builder.h

0001 // Licensed to the Apache Software Foundation (ASF) under one
0002 // or more contributor license agreements.  See the NOTICE file
0003 // distributed with this work for additional information
0004 // regarding copyright ownership.  The ASF licenses this file
0005 // to you under the Apache License, Version 2.0 (the
0006 // "License"); you may not use this file except in compliance
0007 // with the License.  You may obtain a copy of the License at
0008 //
0009 //   http://www.apache.org/licenses/LICENSE-2.0
0010 //
0011 // Unless required by applicable law or agreed to in writing,
0012 // software distributed under the License is distributed on an
0013 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
0014 // KIND, either express or implied.  See the License for the
0015 // specific language governing permissions and limitations
0016 // under the License.
0017
0018 #pragma once
0019
0020 #include <memory>
0021 #include <vector>
0022
0023 #include "arrow/status.h"
0024 #include "arrow/type_fwd.h"
0025 #include "arrow/util/type_fwd.h"
0026 #include "arrow/util/visibility.h"
0027
0028 namespace arrow {
0029 namespace json {
0030
0031 class PromotionGraph;
0032
0033 class ARROW_EXPORT ChunkedArrayBuilder {
0034  public:
0035   virtual ~ChunkedArrayBuilder() = default;
0036
0037   /// Spawn a task that will try to convert and insert the given JSON block
0038   virtual void Insert(int64_t block_index,
0039                       const std::shared_ptr<Field>& unconverted_field,
0040                       const std::shared_ptr<Array>& unconverted) = 0;
0041
0042   /// Return the final chunked array.
0043   /// Every chunk must be inserted before this is called!
0044   virtual Status Finish(std::shared_ptr<ChunkedArray>* out) = 0;
0045
0046   /// Finish current task group and substitute a new one
0047   virtual Status ReplaceTaskGroup(
0048       const std::shared_ptr<arrow::internal::TaskGroup>& task_group) = 0;
0049
0050  protected:
0051   explicit ChunkedArrayBuilder(
0052       const std::shared_ptr<arrow::internal::TaskGroup>& task_group)
0053       : task_group_(task_group) {}
0054
0055   std::shared_ptr<arrow::internal::TaskGroup> task_group_;
0056 };
0057
0058 /// create a chunked builder
0059 ///
0060 /// if unexpected fields and promotion need to be handled, promotion_graph must be
0061 /// non-null
0062 ARROW_EXPORT Status MakeChunkedArrayBuilder(
0063     const std::shared_ptr<arrow::internal::TaskGroup>& task_group, MemoryPool* pool,
0064     const PromotionGraph* promotion_graph, const std::shared_ptr<DataType>& type,
0065     std::shared_ptr<ChunkedArrayBuilder>* out);
0066
0067 }  // namespace json
0068 }  // namespace arrow