Stephen Toub created ARROW-4718:
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Summary: Add ArrowStreamWriter/Reader ctors that leave open the
underlying Stream
Key: ARROW-4718
URL: https://issues.apache.org/jira/browse/ARROW-4718
Project: Apache Arrow
Issue Type: Improvement
Components: C#
Reporter: Stephen Toub
It's often the case that data being read/written in arrow format is part of
some larger protocol. However, ArrowStreamWriter and ArrowStreamReader close
the provided stream when they're disposed. This means that if you need to, for
example, write a footer after the arrow data is written, you need to actually
construct the ArrowStreamWriter around some temporary stream, write to that,
then copy the data from that stream to the actual one that you then write the
footer to; otherwise, ArrowStreamWriter will end up disposing of the stream
before you have the opportunity to write the footer.
Throughout .NET, this approach is generally codified as a ctor that takes a
"leaveOpen" Boolean parameter, e.g. as on System.IO.StreamWriter
(https://docs.microsoft.com/en-us/dotnet/api/system.io.streamwriter.-ctor?view=netframework-4.7.2#System_IO_StreamWriter__ctor_System_IO_Stream_System_Text_Encoding_System_Int32_System_Boolean_)
or System.IO.DeflateStream
(https://docs.microsoft.com/en-us/dotnet/api/system.io.compression.deflatestream.-ctor?view=netframework-4.7.2#System_IO_Compression_DeflateStream__ctor_System_IO_Stream_System_IO_Compression_CompressionLevel_System_Boolean_).
ArrowStreamReader and ArrowStreamWriter should do the same:
public ArrowStreamReader(Stream stream, bool leaveOpen);
public ArrowStreamWriter(Stream baseStream, Schema schema, bool leaveOpen);
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