[ARROW-11066] [Java] Is there a bug in flight AddWritableBuffer

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Fix Version/s: 4.0.0
• Component/s: FlightRPC, Java
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/26980
• Assignee: David Li
• Reporter: Kangping Huang
• Created: 29/Dec/20 15:27
• Updated: 11/Jan/23 08:17
• Resolved: 17/Mar/21 18:57

Description

https://github.com/apache/arrow/blob/9bab12f03ac486bb8270f031b83f0a0411766b3e/java/flight/flight-core/src/main/java/org/apache/arrow/flight/grpc/AddWritableBuffer.java#L94

buf.readBytes(stream, buf.readableBytes());

is this line redundant
In my perf.svg, this will copy the data from buf to OutputStream, which can not realize zero-copy.

Issue Links

• links to: GitHub Pull Request #9354
• links to: GitHub Pull Request #9385
• links to: GitHub Pull Request #9387
• links to: GitHub Pull Request #9418
• links to: GitHub Pull Request #9421