apache / apache/arrow-java

[Java/Python] in-process vector sharing from Java to Python

オープン
#420 コメント 3 件 リアクション 0 件 担当者 0 名 GitHub で見る
Type: enhancement
主要言語
Java
スター
94
フォーク
152
平均マージ
3日 16時間
マージ済み PR(30日)
11

説明

Currently we seem to use in all applications of Arrow the IPC capabilities to move data between a Java process and a Python process. While this is 0-serialization, it is not zero-copy. By taking the address and offset, we can already create Python buffers from Java buffers: https://github.com/apache/arrow/pull/1693. This is still a very low-level interface and we should provide the user with:

- A guide on how to load Apache Arrow java libraries in Python (either through a fat-jar that was shipped with Arrow or how he should integrate it into its Java packaging)
- `pyarrow.Array.from_jvm`, `pyarrow.RecordBatch.from_jvm`, … functions that take the respective Java objects and emit Python objects. These Python objects should also ensure that the underlying memory regions are kept alive as long as the Python objects exist.

This issue can also be used as a tracker for the various sub-tasks that will need to be done to complete this rather large milestone.

**Reporter**: [Uwe Korn](https://issues.apache.org/jira/browse/ARROW-2249) / @xhochy
#### Related issues:
- [[Python] Create buffer from address, size and base](https://github.com/apache/arrow/issues/18211) (is blocked by)
- [[Java/Python] Add unit test for pyarrow.timeX types in Array.from_jvm](https://github.com/apache/arrow/issues/44875) (is a parent of)
- [[Java/Python]  Add unit test for pyarrow.decimal128 in Array.from_jvm](https://github.com/apache/arrow/issues/44874) (is a parent of)
- [[Java/Python] Support VarCharVector / StringArray in pyarrow.Array.from_jvm](https://github.com/apache/arrow/issues/44873) (is a parent of)
- [[Java/Python] Complex type conversion in pyarrow.Field.from_jvm](https://github.com/apache/arrow/issues/19009) (is a parent of)
- [[Java/Python] Add support for dictionary type to pyarrow.Field.from_jvm](https://github.com/apache/arrow/issues/15719) (is a parent of)
- [[Java/Python] Add pyarrow.{Array,Field}.from_jvm / jvm_buffer](https://github.com/apache/arrow/issues/19008) (is a parent of)
- [[Java] Add method overload for VarCharVector.set(int,String)](https://github.com/apache/arrow/issues/19004) (is related to)
- [[Java] Java implementation of Arrow C data interface](https://github.com/apache/arrow/issues/28685) (is related to)

**Note**: *This issue was originally created as [ARROW-2249](https://issues.apache.org/jira/browse/ARROW-2249). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*

コントリビューションガイド

コントリビューションガイドを開く

調査の方向性

提案されているエントリーポイント pyarrow.Array.from_jvm と pyarrow.RecordBatch.from_jvm から始め、pyarrow.Array、Field、jvm_buffer のサポートに関する関連 issue を確認してください。サブタスクを選択する前に、移行ドキュメントとブロックされているバッファ issue を確認してください。完了の条件は、メモリのライフタイムを zero-copy で処理する、Java から Python への定義済みの変換経路があることです。

索引モデルが issue の本文から書いたものです。

評価

技術スタック
java, python
領域
data, distributed-systems
issue の種類
機能追加
難易度
5/5
見積もり時間
1週間以上
活発さ
停滞
明瞭さ
説明が足りない
初心者へのやさしさ
25/100

新しい issue をメールで受け取る

初心者向けの GitHub issue を短くまとめたダイジェスト。