PUT command should work with OutputStreams rather than InputStreams

[markslater]

SnowflakeConnection.uploadStream facilitates "transfer[ring] data directly from a stream to an internal (i.e. Snowflake) stage as a file".

The signature is:

public void uploadStream(String stageName,
                         String destPrefix,
                         InputStream inputStream,
                         String destFileName,
                         boolean compressData)
    throws SQLException

An InputStream seems to be the wrong paradigm for writing to a stage - surely it should work with an OutputStream?

In fact, the use of InputStream causes practical problems. In the normal case where I have a data generator that expects to write to an OuputStream, in order to make it write to a Snowflake stage, I have to use PipedInputStream and PipedOutputStream, which in turn means I need to deal with threads.

Note that making the API work with OutputStreams doesn't cause friction for clients that have data coming from an InputStream, because InputStream offers the transferTo​(OutputStream out) method.

[sfc-gh-mknister]

Hi @markslater , changing the function signature from inputstream to outputstream could break existing customers. But do you want to submit a feature request to have another uploadStream() function that uses outputstream instead?

[markslater]

Hi @sfc-gh-mknister, my take on it is that using an InputStream for writing data is a bug in the API. It's possible to work around the issue, but a workaround that involves threading is fairly onerous.

I appreciate that the fix would be a breaking change. My preference would be to grasp the nettle and fix the API, but it's your call. Let me know if you'd rather leave it as is, and I will submit a feature request for a new operation that uses an OutputStream.

[sfc-gh-igarish]

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