Re: [Tarantool-patches] [PATCH v5 6/8] lua, datetime: time intervals support

[Safin Timur via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

On 17.08.2021 15:16, Serge Petrenko wrote:
> 
>> diff --git a/src/lua/datetime.lua b/src/lua/datetime.lua
>> index 4d946f194..5fd0565ac 100644
>> --- a/src/lua/datetime.lua
>> +++ b/src/lua/datetime.lua
>> @@ -24,6 +24,17 @@ ffi.cdef [[
>>       int      tnt_dt_rdn          (dt_t dt);
>> +    // dt_arithmetic.h
>> +    typedef enum {
>> +        DT_EXCESS,
>> +        DT_LIMIT,
>> +        DT_SNAP
>> +    } dt_adjust_t;
>> +
>> +    dt_t    tnt_dt_add_years        (dt_t dt, int delta, dt_adjust_t 
>> adjust);
>> +    dt_t    tnt_dt_add_quarters     (dt_t dt, int delta, dt_adjust_t 
>> adjust);
>> +    dt_t    tnt_dt_add_months       (dt_t dt, int delta, dt_adjust_t 
>> adjust);
>> +
> 
> 
> Same about comments inside ffi.cdef. Better avoid them.
> 
> Please, split the cdef into reasonable blocks with
> comments (when you need them)
> between the blocks.

I've split this code into several ffi.cdef blocks, so at the moment the 
header of a module looks like this

-----------------------------------------------------------------
--[[
     `c-dt` library functions handles properly both positive and 
negative `dt`
     values, where `dt` is a number of dates since Rata Die date 
(0001-01-01).

     For better compactness of our typical data in MessagePack stream we 
shift
     root of our time to the Unix Epoch date (1970-01-01), thus our 0 is
     actually dt = 719163.

     So here is a simple formula how convert our epoch-based seconds to 
dt values
         dt = (secs / 86400) + 719163
     Where 719163 is an offset of Unix Epoch (1970-01-01) since Rata Die
     (0001-01-01) in dates.
]]

-- dt_core.h definitions
ffi.cdef [[
     typedef int dt_t;

     dt_t     tnt_dt_from_rdn     (int n);
     dt_t     tnt_dt_from_ymd     (int y, int m, int d);

     int      tnt_dt_rdn          (dt_t dt);
]]

-- dt_arithmetic.h definitions
ffi.cdef [[
     typedef enum {
         DT_EXCESS,
         DT_LIMIT,
         DT_SNAP
     } dt_adjust_t;

     dt_t    tnt_dt_add_years        (dt_t dt, int delta, dt_adjust_t 
adjust);
     dt_t    tnt_dt_add_quarters     (dt_t dt, int delta, dt_adjust_t 
adjust);
     dt_t    tnt_dt_add_months       (dt_t dt, int delta, dt_adjust_t 
adjust);
]]

-- dt_parse_iso.h definitions
ffi.cdef [[
     size_t tnt_dt_parse_iso_date          (const char *str, size_t len, 
dt_t *dt);
     size_t tnt_dt_parse_iso_time          (const char *str, size_t len, 
int *sod, int *nsec);
     size_t tnt_dt_parse_iso_zone_lenient  (const char *str, size_t len, 
int *offset);
]]

-- Tarantool functions - datetime.c
ffi.cdef [[
     int
     datetime_to_string(const struct datetime * date, char *buf, int len);

     char *
     datetime_asctime(const struct datetime *date, char *buf);

     char *
     datetime_ctime(const struct datetime *date, char *buf);

     size_t
     datetime_strftime(const struct datetime *date, const char *fmt, 
char *buf,
                       uint32_t len);

     void
     datetime_now(struct datetime * now);
]]
-----------------------------------------------------------------

> 
> 
>>       // dt_parse_iso.h
>>       size_t tnt_dt_parse_iso_date          (const char *str, size_t 
>> len, dt_t *dt);
>>       size_t tnt_dt_parse_iso_time          (const char *str, size_t 
>> len, int *sod, int *nsec);
>> @@ -50,8 +61,10 @@ ffi.cdef [[
>>   local builtin = ffi.C
>>   local math_modf = math.modf
>> +local math_floor = math.floor
>>   local SECS_PER_DAY     = 86400
>> +local NANOS_PER_SEC    = 1000000000
>>   -- c-dt/dt_config.h
>>
>>
> 
> Everything else looks fine.
> 


Thanks,
Timur