Re: [Tarantool-patches] [PATCH v3 07/13] txm: save does_require_old_tuple flag in txn_stmt

[Nikita Pettik <korablev@tarantool.org>]

On 15 Jul 16:55, Aleksandr Lyapunov wrote:
> That flag is needed for transactional conflict manager - if any
> other transaction replaces old_tuple before current one and the flag
> is set - the current transaction will be aborted.
> For example REPLACE just replaces a key, no matter what tuple
> lays in the index and thus does_require_old_tuple = false.
> In contrast, UPDATE makes new tuple using old_tuple and thus
> the statement will require old_tuple (does_require_old_tuple = true).
> INSERT also does_require_old_tuple = true because it requires
> old_tuple to be NULL.
> 
> Part of #4897
> ---
>  src/box/memtx_space.c | 17 +++++++++++++++++
>  src/box/txn.c         |  3 +++
>  src/box/txn.h         | 13 +++++++++++++
>  3 files changed, 33 insertions(+)
> 
> diff --git a/src/box/memtx_space.c b/src/box/memtx_space.c
> index 8452ab4..e48ed3a 100644
> --- a/src/box/memtx_space.c
> +++ b/src/box/memtx_space.c
> @@ -316,6 +316,10 @@ memtx_space_execute_replace(struct space *space, struct txn *txn,
>  	if (stmt->new_tuple == NULL)
>  		return -1;
>  	tuple_ref(stmt->new_tuple);
> +
> +	if (mode == DUP_INSERT)
> +		stmt->does_require_old_tuple = true;

I'd prefer is_old_tuple_required name, but it's up to you.

LGTM