[HDFS-4046] ChecksumTypeProto use NULL as enum value which is illegal in C/C++

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.0.3-alpha
• Component/s: datanode, namenode
• Target Version/s: 2.0.3-alpha, 0.23.5
• Hadoop Flags: Reviewed
• Assignee: Binglin Chang
• Reporter: Binglin Chang
• Created: 12/Oct/12 16:27
• Updated: 03/Sep/14 23:09
• Resolved: 05/Nov/12 23:56

Description

I tried to write a native hdfs client using protobuf based protocol, when I generate c++ code using hdfs.proto, the generated file can not compile, because NULL is an already defined macro.
I am thinking two solutions:
1. refactor all DataChecksum.Type.NULL references to NONE, which should be fine for all languages, but this may breaking compatibility.
2. only change protobuf definition ChecksumTypeProto.NULL to NONE, and use enum integer value(DataChecksum.Type.id) to convert between ChecksumTypeProto and DataChecksum.Type, and make sure enum integer values are match(currently already match).
I can make a patch for solution 2.

Issue Links

• is related to: HADOOP-8985 Add namespace declarations in .proto files for languages other than java
• is related to: HDFS-4121 Add namespace declarations in hdfs .proto files for languages other than java