Hi,
You can use g_object_set():
g_object_set(G_OBJECT(properties),
"compression", GARROW_COMPRESSION_TYPE_ZSTD,
NULL);
See also:
* g_object_set()'s reference manual:
https://developer.gnome.org/gobject/stable/gobject-The-Base-Object-Type.html#g-object-set
* "compression" property's reference manual:
https://arrow.apache.org/docs/c_glib/arrow-glib/GArrowTable.html#GArrowFeatherWriteProperties--compression
Thanks,
--
kou
In <kfucul49.22787f08-ade1-4e26-b589-9d94482f7...@we.are.superhuman.com>
"Defining Compression Type in Arrow GLib?" on Sun, 04 Oct 2020 00:51:48 +0000,
"Xander Dunn" <[email protected]> wrote:
> I am writing a Swift language interface to the Apache Arrow GLib C bindings.
>
> I am currently successfully putting Swift arrays into GArrays into GTables
> into feather files on disk:
>
> func saveGTableToFeather(_ gTable: UnsafeMutablePointer<GArrowTable>,
> outputPath: String) throws {
> var error: UnsafeMutablePointer<GError>? = nil
> // TODO: How do I turn on compression?
> let properties = garrow_feather_write_properties_new()
> let path = outputPath.cString(using: .utf8)
> let output = garrow_file_output_stream_new(path, 0, &error)
> if let error = error {
> let errorString: String = String(cString: error.pointee.message)
> g_error_free(error)
> g_object_unref(output)
> g_object_unref(properties)
> throw ArrowError.invalidTableCreation(errorString)
> }
> let result: gboolean = garrow_table_write_as_feather(gTable,
> GARROW_OUTPUT_STREAM(output), properties, &error)
> if result == 0 {
> let errorString: String = error != nil ? String(cString:
> error!.pointee.message) : ""
> g_error_free(error)
> g_object_unref(output)
> g_object_unref(properties)
> throw ArrowError.invalidTableCreation(errorString)
> }
> g_object_unref(output)
> g_object_unref(properties)
> }
>
> When I run file myData.feather on Ubuntu 18.04, it doesn’t indicate any kind
> of compression, so the files I’m saving may not be compressed at all.
>
> You can see I’ve created a new GArrowFeatherWriteProperties with
> garrow_feather_write_properties_new , but how do I set the compression level?
> I see it is meant to have a compression property based on the docs here (
> https://arrow.apache.org/docs/c_glib/arrow-glib/GArrowTable.html#GArrowFeatherWriteProperties--compression
> ). When I attempt to set properties.compression (In Swift this is likely
> properties.pointee.compression ), I get a compiler error that it has no such
> property. Do I need to make a cast? Is there any example code of setting the
> compression on a GArrowFeatherWriteProperties ?
>
> Thank you,
>
> Xander
>
>
