Re: [Tarantool-patches] [PATCH v3 0/2] Encapsulate MEM type changing and checking

[Vladislav Shpilevoy via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Hi! Thanks for the patchset!

On 20.02.2021 17:59, Mergen Imeev via Tarantool-patches wrote:
> This patch-set is part of issue #5818. It changes the way to check and change
> MEM from outside. However, there is almost no changes in functions that work
> with internal structure of MEM, most of which located in vdbemem.c. This will be
> done in another patch-set.
> 
> https://github.com/tarantool/tarantool/issues/5818
> https://github.com/tarantool/tarantool/tree/imeevma/gh-5818-encapsulate-mem-type-checking-and-changing
> 
> Changes in v3:
>   - Inlined most of the introduced functions to improve performance.
>   - Some other fixes in code to improve performance.

How is this patch related to performance? Isn't it called 'encapsulate'? Not
'optimize'.

Or did the non-inlined approach make the performance worse than it is on the
master branch? I see that on the master branch things like mem_set_... are
not inlined and all is fine.

I have no issues with optimizing it a bit, as long as it does not involve
doing extra actions and does not complicate the code even more. And is not
motivated by introduction of a perf issue in a different place.

My main concern to the patchset is why do we still have Mem in that scattered
all over the other source files? Can it be extracted into a new file sql/mem.h
and .c? With proper API, separated into public and private.

> Changes in v2:
>   - Squashed almost all patches.
>   - Review fixes.
> 
> Mergen Imeev (2):
>   sql: Initialize MEM in sqlVdbeAllocUnpackedRecord()
>   sql: Encapsulate MEM type changing and checking
> 
>  src/box/sql/func.c      |  14 +-
>  src/box/sql/sqlInt.h    |   1 -
>  src/box/sql/vdbe.c      | 513 ++++++++++++++++++----------------------
>  src/box/sql/vdbeInt.h   | 465 +++++++++++++++++++++++++++++++++---
>  src/box/sql/vdbeapi.c   |  57 ++---
>  src/box/sql/vdbeaux.c   | 360 ++++++++++++++--------------
>  src/box/sql/vdbemem.c   | 146 +-----------
>  src/box/sql/vdbesort.c  |   9 +-
>  src/box/sql/vdbetrace.c |  12 +-
>  9 files changed, 874 insertions(+), 703 deletions(-)
>