[Java/Python] in-process vector sharing from Java to Python
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Beschreibung
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.*
Beitragsleitfaden
Rechercherichtung
Beginnen Sie mit den vorgeschlagenen Einstiegspunkten pyarrow.Array.from_jvm und pyarrow.RecordBatch.from_jvm und prüfen Sie anschließend das zugehörige Issue zur Unterstützung von pyarrow.Array, Field und jvm_buffer. Sehen Sie sich die Migrationsdokumentation und das blockierte Buffer-Issue an, bevor Sie eine Teilaufgabe auswählen. Als abgeschlossen gilt die Aufgabe erst, wenn ein definierter Konvertierungspfad von Java nach Python mit Zero-Copy-Speicherlebensdauerverwaltung vorhanden ist.
Vom Indexierungsmodell aus dem Issue-Text verfasst.
Bewertung
- Tech-Stack
- java, python
- Bereich
- data, distributed-systems
- Issue-Typ
- Feature
- Schwierigkeit
- 5/5
- Geschätzter Aufwand
- Über eine Woche
- Aktivitätsstatus
- Veraltet
- Klarheit
- Muss geklärt werden
- Anfängerfreundlichkeit
- 25/100