[Tarantool-patches] [PATCH resend v2 00/11] Initial datetime support

Oleg Babin olegrok at tarantool.org
Thu Jul 29 21:55:28 MSK 2021


Thanks for your patch.


I can't say that it will be complete review but it's brief feedback.

I left comments for some patches. Currently it is not complete series,

in fact it looks like as one-two commits with portion of fixups on the 
top of them.


I believe this module should be implemented in pure C. I don't think 
that arithmetic will

work fast enough in C.


Probably datetime and interval should be logically splitted into 2 parts.

```

tarantool> require('datetime')
---
- weeks: 'function: 0x010ca0aa48'
   minutes: 'function: 0x010ca694d8'
   new: 'function: 0x010ca5e098'
   strftime: 'function: 0x010caa8fb0'
   tostring: 'function: 0x010ca2f700'
   hours: 'function: 0x010ca671c0'
   parse_date: 'function: 0x010ca96f80'
   seconds: 'function: 0x010ca63b78'
   parse_time: 'function: 0x010ca22208'
   is_interval: 'function: 0x010caa6d20'
   months: 'function: 0x010ca61130'
   is_datetime: 'function: 0x010ca5d3a0'
   asctime: 'function: 0x010caa8e28'
   ctime: 'function: 0x010ca88260'
   parse_zone: 'function: 0x010ca02eb0'
   now: 'function: 0x010ca86e70'
   days: 'function: 0x010ca81980'
   years: 'function: 0x010ca61438'
   parse: 'function: 0x010ca9ad38'
   interval: 'function: 0x010c9feb60'
...

```


It's not clear that part is about intervals and datetime.

```

-- Currently

datetime.now() + datetime.week(1)


-- Possible version

datetime.now() + interval.week(1)

```


Interface is better than in previous time. Thanks for working on this 
series.


On 28.07.2021 13:34, Timur Safin via Tarantool-patches wrote:
> * Version #2:
>
>    - fixed problem with overloaded '-' and '+' operations for datetime
>      arguments;
>    - fixed messagepack serialization problems;
>    - heavily documented MessagePack serialization schema in the code;
>    - introduced working implementation of datetime hints for storage engines;
>    - made interval related names be more consistent, renamed durations and period
>      to intervals, i.e. t_datetime_duration to datetime_interval_t,
>      duration_* to interval_*, period to interval;
>    - properly implemented all reasonable cases of datetime+interval
>      arithmetic;
>    - moved all initialization code to utils.c;
>    - renamed core/mp_datetime.c to core/datetime.c because it makes more
>      sense now;
>
> * Version #1 - initial RFC series
>
> In brief
> --------
> This patchset implements datetime lua support in box, with serialization
> to messagepack, yaml, json and lua mode. Also it contains storage
> engines' indices implementation for datetime type introduced.
>
> * Current implementation is heavily influenced by Sci-Lua lua-time module
>    https://github.com/stepelu/lua-time  
>    e.g. you could find very similar approach for handling of operations
>    with year or month long intervals (which should be handled differently than
>    usual intervals of seconds, or days).
>
> * But internally we actually use Christian Hanson' c-dt module
>    https://github.com/chansen/c-dt  
>    (though it has been modified slightly for cleaner integration
>    into cmake build process)
>
>
> Datetime Module API
> -------------------
>
> We used to have here draft documentation of datetime module api, but
> for a convenience it has been extracted to the discussion topic there -
> https://github.com/tarantool/tarantool/discussions/6244#discussioncomment-1043988
>
> Messagepack serialization schema
> --------------------------------
>
> In short it looks like:
> - now we introduce new MP_EXT extension type #4;
> - we may save 1 required and 2 optional fields for datetime field;
>
> In details it's explained in MessagePack serialization schema depicted here:
> https://github.com/tarantool/tarantool/discussions/6244#discussioncomment-1043990
>
>
> https://github.com/tarantool/tarantool/issues/5941
> https://github.com/tarantool/tarantool/issues/5946
>
> https://github.com/tarantool/tarantool/tree/tsafin/gh-5941-datetime-v3
>
> Timur Safin (11):
>    build: add Christian Hansen c-dt to the build
>    lua: built-in module datetime
>    lua, datetime: datetime tests
>    lua, datetime: display datetime
>    box, datetime: add messagepack support for datetime
>    box, datetime: datetime comparison for indices
>    lua, datetime: proper datetime encoding
>    lua, datetime: calculated attributes for datetimes
>    lua, datetime: time intervals support
>    lua, datetime: unixtime, timestamp setters in datetime.lua
>    datetime: changelog for datetime module
>
>   .gitmodules                                   |    3 +
>   CMakeLists.txt                                |    8 +
>   .../gh-5941-datetime-type-support.md          |    4 +
>   cmake/BuildCDT.cmake                          |    6 +
>   src/CMakeLists.txt                            |    3 +
>   src/box/field_def.c                           |   52 +-
>   src/box/field_def.h                           |    4 +
>   src/box/lua/serialize_lua.c                   |    7 +-
>   src/box/memtx_space.c                         |    3 +-
>   src/box/msgpack.c                             |    7 +-
>   src/box/tuple_compare.cc                      |   50 +
>   src/box/vinyl.c                               |    3 +-
>   src/exports.h                                 |   29 +
>   src/lib/core/CMakeLists.txt                   |    4 +-
>   src/lib/core/datetime.c                       |  251 ++++
>   src/lib/core/datetime.h                       |  114 ++
>   src/lib/core/mp_extension_types.h             |    1 +
>   src/lib/mpstream/mpstream.c                   |   11 +
>   src/lib/mpstream/mpstream.h                   |    4 +
>   src/lua/datetime.lua                          | 1016 +++++++++++++++++
>   src/lua/init.c                                |    4 +-
>   src/lua/msgpack.c                             |   12 +
>   src/lua/msgpackffi.lua                        |   18 +
>   src/lua/serializer.c                          |    4 +
>   src/lua/serializer.h                          |    2 +
>   src/lua/utils.c                               |   28 +-
>   src/lua/utils.h                               |   12 +
>   test/app-tap/datetime.test.lua                |  367 ++++++
>   test/engine/datetime.result                   |   77 ++
>   test/engine/datetime.test.lua                 |   35 +
>   test/unit/CMakeLists.txt                      |    2 +
>   test/unit/datetime.c                          |  220 ++++
>   test/unit/datetime.result                     |  358 ++++++
>   third_party/c-dt                              |    1 +
>   third_party/lua-cjson/lua_cjson.c             |    8 +
>   third_party/lua-yaml/lyaml.cc                 |    6 +-
>   36 files changed, 2709 insertions(+), 25 deletions(-)
>   create mode 100644 changelogs/unreleased/gh-5941-datetime-type-support.md
>   create mode 100644 cmake/BuildCDT.cmake
>   create mode 100755 src/lib/core/datetime.c
>   create mode 100644 src/lib/core/datetime.h
>   create mode 100644 src/lua/datetime.lua
>   create mode 100755 test/app-tap/datetime.test.lua
>   create mode 100644 test/engine/datetime.result
>   create mode 100644 test/engine/datetime.test.lua
>   create mode 100644 test/unit/datetime.c
>   create mode 100644 test/unit/datetime.result
>   create mode 160000 third_party/c-dt
>


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