[AVRO-2944] DataFileReader has incorrect logic reading magic header

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.9.2
• Fix Version/s: 1.10.1, 1.10.2
• Component/s: java
• Assignee: Mick Jermsurawong
• Reporter: Mick Jermsurawong
• Created: 24/Oct/20 19:36
• Updated: 15/Feb/21 13:47
• Resolved: 03/Feb/21 16:56

Description

When creating reader using static method which includes checking for magic header, we currently read 4 bytes but the pointer is not correctly updated.

https://github.com/apache/avro/blob/328c539afc77da347ec52be1e112a6a7c371143b/lang/java/avro/src/main/java/org/apache/avro/file/DataFileReader.java#L61-L62

When inputstream reads less byte than expected, this will get stuck in the loop until the end of file. Or if inputstream returns -1, for EOF like S3AInpustream, read hangs in this loop.

Issue Links

• relates to: CRUNCH-698 Avro DataFileReader creation can hang
• links to: GitHub Pull Request #969
• links to: GitHub Pull Request #1080