ceph/src/arrow/csharp/src/Apache.Arrow/Ipc/ArrowStreamReader.cs

   1 // Licensed to the Apache Software Foundation (ASF) under one or more
   2 // contributor license agreements. See the NOTICE file distributed with
   3 // this work for additional information regarding copyright ownership.
   4 // The ASF licenses this file to You under the Apache License, Version 2.0
   5 // (the "License"); you may not use this file except in compliance with
   6 // the License.  You may obtain a copy of the License at
   7 //
   8 //     http://www.apache.org/licenses/LICENSE-2.0
   9 //
  10 // Unless required by applicable law or agreed to in writing, software
  11 // distributed under the License is distributed on an "AS IS" BASIS,
  12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 // See the License for the specific language governing permissions and
  14 // limitations under the License.
  15
  16 using Apache.Arrow.Memory;
  17 using System;
  18 using System.IO;
  19 using System.Threading;
  20 using System.Threading.Tasks;
  21
  22 namespace Apache.Arrow.Ipc
  23 {
  24     /// <summary>
  25     /// Represents a reader that can read Arrow streams.
  26     /// </summary>
  27     public class ArrowStreamReader : IArrowReader, IDisposable
  28     {
  29         private protected readonly ArrowReaderImplementation _implementation;
  30
  31         public Schema Schema => _implementation.Schema;
  32
  33         public ArrowStreamReader(Stream stream)
  34             : this(stream, allocator: null, leaveOpen: false)
  35         {
  36         }
  37
  38         public ArrowStreamReader(Stream stream, MemoryAllocator allocator)
  39             : this(stream, allocator, leaveOpen: false)
  40         {
  41         }
  42
  43         public ArrowStreamReader(Stream stream, bool leaveOpen)
  44             : this(stream, allocator: null, leaveOpen)
  45         {
  46         }
  47
  48         public ArrowStreamReader(Stream stream, MemoryAllocator allocator, bool leaveOpen)
  49         {
  50             if (stream == null)
  51                 throw new ArgumentNullException(nameof(stream));
  52
  53             _implementation = new ArrowStreamReaderImplementation(stream, allocator, leaveOpen);
  54         }
  55
  56         public ArrowStreamReader(ReadOnlyMemory<byte> buffer)
  57         {
  58             _implementation = new ArrowMemoryReaderImplementation(buffer);
  59         }
  60
  61         private protected ArrowStreamReader(ArrowReaderImplementation implementation)
  62         {
  63             _implementation = implementation;
  64         }
  65
  66         public void Dispose()
  67         {
  68             Dispose(true);
  69             GC.SuppressFinalize(this);
  70         }
  71
  72         protected virtual void Dispose(bool disposing)
  73         {
  74             if (disposing)
  75             {
  76                 _implementation.Dispose();
  77             }
  78         }
  79
  80         public ValueTask<RecordBatch> ReadNextRecordBatchAsync(CancellationToken cancellationToken = default)
  81         {
  82             return _implementation.ReadNextRecordBatchAsync(cancellationToken);
  83         }
  84
  85         public RecordBatch ReadNextRecordBatch()
  86         {
  87             return _implementation.ReadNextRecordBatch();
  88         }
  89     }
  90 }