Antonin Houska <a...@cybertec.at> writes:
> Tom Lane <t...@sss.pgh.pa.us> wrote:
>> At one time, I think, readLen told how much data in readBuf was
>> actually valid. It seems not to be used for that anymore, but
>> I don't much like the idea that readBuf is only partially filled
>> but there is *no* persistent state indicating how much is valid.
>> The existing coding guarantees that the answer is "XLOG_BLCKSZ",
>> so that's fine, but this change would remove the guarantee.
Oh, I withdraw that complaint --- readBuf isn't a persistent data
structure anymore, so there's no need for readLen to be persistent
either.
> XLogPageRead() is a callback of the XLOG reader and that passes reqLen telling
> how much data of the page is actually needed in readBuf at the moment. And the
> function checks that readLen is high enough:
> Assert(reqLen <= readLen);
Hm. Sure would be nice if there were any mention of reqLen in the
function's specification.
regards, tom lane
