On 01/31/2017 01:51 AM, Peter Geoghegan wrote:
* If you're writing out any old bit pattern, I suggest using 0x7F
bytes rather than nul bytes (I do agree that it does seem worth making
this some particular bit pattern, so as to not have to bother with
Valgrind suppressions and so on). That pattern
On Mon, Jan 30, 2017 at 10:01 AM, Peter Geoghegan wrote:
> Let me take another look at this later today before proceeding. I want
> to run it against a custom test suite I've developed.
I've done so. Some more thoughts:
* I don't think that this is really any less efficient than my patch.
It's j
On Mon, Jan 30, 2017 at 9:55 AM, Heikki Linnakangas wrote:
> It won't make any difference for correctness what bit pattern you write to
> "fill the hole", but you have to write something, and zeros seems like a
> natural choice.
Ah, okay. That's probably fine, then.
Let me take another look at t
On 01/30/2017 07:45 PM, Peter Geoghegan wrote:
On Mon, Jan 30, 2017 at 4:04 AM, Heikki Linnakangas wrote:
Alternatively, we could fix this with a small change in ltsWriteBlock(), see
attached patch. When we're about to create a hole in the file, write
all-zero blocks to avoid the creating hole,
On Mon, Jan 30, 2017 at 4:04 AM, Heikki Linnakangas wrote:
> Hmm. The LogicalTapeEndWriting() function is very similar to the
> LogicalTapePause() function I had in the pause/resume patch. They both flush
> the last block to disk. The difference is that LogicalTapePause() also
> free'd the buffer,
On 01/07/2017 12:33 AM, Peter Geoghegan wrote:
Previously, all calls to ltsGetFreeBlock() were immediately followed
by a corresponding call to ltsWriteBlock(); we wrote out the
newly-allocated-in-first-pass block there and then. It's a good idea
for a corresponding ltsWriteBlock() call to happen
It seems that commit 01ec2563 has a subtle bug, which stems from the
fact that logtape.c no longer follows the rule described above
ltsGetFreeBlock():
/*
* Select a currently unused block for writing to.
*
* NB: should only be called when writer is ready to write immediately,
* to ensure that