GH-49252: [GLib] Deprecate Feather features

[kou]

Rationale for this change

We'll deprecate Feather V1 reader/writer. See also the discussion at https://lists.apache.org/thread/1npvnhjb1xwz09zh8vnd079zt2q4o08l .

We can use IPC file reader/writer for Feather V2.

What changes are included in this PR?

• Add deprecation warnings to Feather features.
• Use GARROW_DEPRECATED()/GARROW_DEPRECATED_FOR() instead of G_GNUC_DEPRECATED()/G_GNUC_DEPRECATED_FOR().

Are these changes tested?

Yes.

Are there any user-facing changes?

Yes.

• GitHub Issue: [GLib] Deprecate Feather reader and writer #49252

[github-actions]

⚠️ GitHub issue #49252 has been automatically assigned in GitHub to PR creator.

[Copilot]

Pull request overview

This PR deprecates Apache Arrow GLib’s Feather APIs (notably Feather V1 reader/writer surfaces) and standardizes deprecation annotations by switching to GARROW_DEPRECATED* macros.

Changes:

• Add GARROW_DEPRECATED_IN_24_0 / GARROW_DEPRECATED_IN_24_0_FOR(...) annotations to Feather-related APIs.
• Replace direct GLib deprecation attributes (G_GNUC_DEPRECATED*) with Arrow-GLib wrappers (GARROW_DEPRECATED*).
• Deprecate raw GIO*Stream accessors via GARROW_DEPRECATED.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
c_glib/arrow-glib/table.h	Deprecates Feather write properties + table Feather writer API.
c_glib/arrow-glib/reader.h	Switches deprecated annotations and deprecates Feather file reader APIs.
c_glib/arrow-glib/output-stream.h	Uses GARROW_DEPRECATED for deprecated raw GIO output stream accessor.
c_glib/arrow-glib/input-stream.h	Uses GARROW_DEPRECATED for deprecated raw GIO input stream accessor.

Comments suppressed due to low confidence (1)

c_glib/arrow-glib/table.h:176

• GARROW_DEPRECATED_IN_24_0_FOR(garrow_record_batch_file_writer_new) suggests a direct replacement, but garrow_table_write_as_feather() writes a whole table in Feather format whereas garrow_record_batch_file_writer_new() only constructs a writer and requires additional steps (schema, write_table, close) and produces IPC file format rather than Feather. Consider dropping _FOR (use GARROW_DEPRECATED_IN_24_0) or pointing at the most appropriate entry point for the migration (for example the writer creation + garrow_record_batch_writer_write_table/garrow_record_batch_writer_close).

GARROW_AVAILABLE_IN_0_17
GARROW_DEPRECATED_IN_24_0_FOR(garrow_record_batch_file_writer_new)
gboolean
garrow_table_write_as_feather(GArrowTable *table,
                              GArrowOutputStream *sink,
                              GArrowFeatherWriteProperties *properties,
                              GError **error);

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[Copilot]

GARROW_DEPRECATED_IN_24_0_FOR(garrow_write_options_new) is likely misleading here: GArrowFeatherWriteProperties configures Feather write behavior, while GArrowWriteOptions is for Arrow IPC serialization. If there isn’t a 1:1 replacement API, prefer using GARROW_DEPRECATED_IN_24_0 (without _FOR) or point to a closer replacement specific to the intended migration path (e.g., IPC file writer + options).

Suggested change

	GARROW_DEPRECATED_IN_24_0_FOR(garrow_write_options_new)
	GARROW_DEPRECATED_IN_24_0

[Copilot]

GARROW_DEPRECATED_IN_24_0_FOR(garrow_record_batch_reader_read_all) doesn’t look like a valid replacement: garrow_record_batch_reader_read_all() takes a GArrowRecordBatchReader*, but this API works on GArrowFeatherFileReader*, and GArrowRecordBatchFileReader is not a GArrowRecordBatchReader. If there’s no single drop-in replacement, use GARROW_DEPRECATED_IN_24_0 (no _FOR) or reference a concrete, correct alternative flow (e.g., garrow_record_batch_file_reader_new() + reading record batches).

Suggested change

	GARROW_DEPRECATED_IN_24_0_FOR(garrow_record_batch_reader_read_all)
	GARROW_DEPRECATED_IN_24_0

[kou]

@raulcd Can we merge this for 24.0.0? This just adds deprecation warnings to Feature related features.

[raulcd]

I don't think the comments from copilot are relevant as we want to direct users to ipc from feather. Will merge for 24.0.0. @kou is there anything else here to be done or shall we just merge?

[kou]

No! We can merge this as-is for 24.0.0!

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit 1f94910.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 13 possible false positives for unstable benchmarks that are known to sometimes produce them.