[Tarantool-patches] [PATCH 4/5] qsync: implement direct write of confirm/rollback into a journal

[Cyrill Gorcunov]

On Wed, Jul 22, 2020 at 06:33:58PM +0300, Cyrill Gorcunov wrote:
> When we need to write CONFIRM or ROLLBACK message (which is just
> a binary record in msgpack format) into a journal we use txn code
> to allocate a new transaction, encode there a message and pass it
> to walk the long txn path before it hit the journal. This is not
> only resource wasting but also somehow strange from arhitectural
> point of view.
> 
> Instead lets encode a record on the stack and write it
> directly to the journal.
> 
> Closes #5129
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>

It might be hard to review the diff, so the final result is
https://github.com/tarantool/tarantool/blob/gorcunov/gh-5129-journal/src/box/txn_limbo.c#L264