On 2021/09/02 16:26, Kyotaro Horiguchi wrote:
I believe errmsg_buf is an interface to emit error messages dedicated to xlogreader that doesn't have an access to elog facility, and xlogreader doesn't (or ought not to or expect to) suppose non-xlogreader callback functions set the variable. In that sense I don't think theoriginally proposed patch is proper for the reason that the non-xlogreader callback function may set errmsg_buf. This is what I meant by the word "modularity". For that reason I avoided in my second proposal to call XLogReaderValidatePageHeader() at all while not in standby mode, because calling the validator function while in non-standby mode results in the non-xlogreader function return errmsg_buf. Of course we can instead always consume errmsg_buf in the function but I don't like to shadow the caller's task.
Understood. Thanks for clarifying this!
Does that makes sense?
Yes, I'm fine with your latest patch. Regards, -- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION
