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From: Timur Safin via Tarantool-patches <tarantool-patches@dev.tarantool.org>
To: "'Oleg Babin'" <olegrok@tarantool.org>, <v.shpilevoy@tarantool.org>
Cc: <tarantool-patches@dev.tarantool.org>
Subject: Re: [Tarantool-patches] [PATCH resend v2 10/11] lua, datetime: unixtime, timestamp setters in datetime.lua
Date: Sat, 31 Jul 2021 12:54:19 +0300
Message-ID: <04bc01d785f2$08ac04f0$1a040ed0$@tarantool.org> (raw)
In-Reply-To: <b99586b5-4e88-43eb-7965-8ebe78771455@tarantool.org>

: From: Oleg Babin <olegrok@tarantool.org>
: Subject: Re: [Tarantool-patches] [PATCH resend v2 10/11] lua, datetime:
: unixtime, timestamp setters in datetime.lua
: 
: 
: On 31.07.2021 02:11, Timur Safin wrote:
: > Hello Oleg,
: >
: > :
: > :
: > : Unixtime and timestamp is great but they loss precision. I think it
: > : should be possible
: > :
: > : go get timestamp with nanoseconds precision since datetime has
: > : nanoseconds precision.
: >
: > I'm not quite get it. Do you want to have nanoseconds exported via
: newindex?
: > For direct assignments? It's not useful because of available .nsec field.
: > Or may be you meant something else?
: >
: > :
: > :
: > : Also still it's hard how to convert timestamp to datetime value back.
: >
: > Timestamp is something secs.nsec, what looks complicated? I'm confused.
: > Could you please elaborate?
: 
: I expected something like.
: 
: tarantool> clock.time64()
: ---
: - 1627712632369020000
: ...
: 
: 
: This timestamp is in nanoseconds. It's unsigned long long value.
: 
: I tried to do something for datetime...
: 
: sec * 1e9 + nsec, but sec is null while nsec is not:
: 
: ```
: 
: tarantool> dt.sec
: ---
: - null
: ...
: 
: ```
: 
: 
: timestamp + nsec works in quite strage way:
: 
: ```
: 
: tarantool> dt.timestamp * (1e9 * 1ULL) + dt.nsec
: ---
: - 1627712485108074000
: ...
: 
: ```
: 
: (I need to cast to ULL here to avoid precision lost).
: 
: But maybe my question is not relevant. There is a way to get nanoseconds
: timestamp.
: 
: I just need to write some simple helper for my app. It's ok.

There are nanoseconds / microseconds / milliseconds getters in datetime
object, which operate on the original uint64_t. Do you want them to make
read-write, not read-only?

tarantool> T = date '1970-01-01'
---
...

tarantool> T.timestamp
---
- 0
...

tarantool> T.nanoseconds
---
- 0
...

tarantool> T2000 = date '2000-01-01'
---
...

tarantool> T.nanoseconds
---
- 0
...

tarantool> T2000.timestamp
---
- 946684800
...

tarantool> T2000.nanoseconds
---
- 946684800000000000
...

tarantool> T2000.secs
---
- 946684800
...

tarantool> ffi = require 'ffi'
---
...

tarantool> ffi.typeof(T2000.nanoseconds)
---
- ctype<int64_t>
...

Regards,
Timur


  reply	other threads:[~2021-07-31  9:54 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-28 10:34 [Tarantool-patches] [PATCH resend v2 00/11] Initial datetime support Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 01/11] build: add Christian Hansen c-dt to the build Timur Safin via Tarantool-patches
2021-07-29 23:40   ` Vladislav Shpilevoy via Tarantool-patches
2021-07-31  9:22     ` Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 02/11] lua: built-in module datetime Timur Safin via Tarantool-patches
2021-07-29 18:55   ` Oleg Babin via Tarantool-patches
2021-07-30 19:00     ` Timur Safin via Tarantool-patches
2021-07-31  6:29       ` Oleg Babin via Tarantool-patches
2021-07-31 16:51         ` Timur Safin via Tarantool-patches
2021-07-29 23:36   ` Vladislav Shpilevoy via Tarantool-patches
2021-07-30 15:39     ` Timur Safin via Tarantool-patches
2021-08-01 17:01       ` Vladislav Shpilevoy via Tarantool-patches
2021-08-01 20:23         ` Timur Safin via Tarantool-patches
2021-08-04 23:57           ` Vladislav Shpilevoy via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 03/11] lua, datetime: datetime tests Timur Safin via Tarantool-patches
2021-07-29 18:55   ` Oleg Babin via Tarantool-patches
2021-07-30 20:45     ` Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 04/11] lua, datetime: display datetime Timur Safin via Tarantool-patches
2021-07-29 18:55   ` Oleg Babin via Tarantool-patches
2021-07-30 21:48     ` Timur Safin via Tarantool-patches
2021-07-31  6:29       ` Oleg Babin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 05/11] box, datetime: add messagepack support for datetime Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 06/11] box, datetime: datetime comparison for indices Timur Safin via Tarantool-patches
2021-07-29 18:56   ` Oleg Babin via Tarantool-patches
2021-07-30 22:18     ` Timur Safin via Tarantool-patches
2021-07-31  6:30       ` Oleg Babin via Tarantool-patches
2021-07-31  9:31         ` Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 07/11] lua, datetime: proper datetime encoding Timur Safin via Tarantool-patches
2021-07-29 18:57   ` Oleg Babin via Tarantool-patches
2021-07-30 22:20     ` Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 08/11] lua, datetime: calculated attributes for datetimes Timur Safin via Tarantool-patches
2021-07-29 18:57   ` Oleg Babin via Tarantool-patches
2021-07-30 22:30     ` Timur Safin via Tarantool-patches
2021-07-31  6:31       ` Oleg Babin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 09/11] lua, datetime: time intervals support Timur Safin via Tarantool-patches
2021-07-29 18:58   ` Oleg Babin via Tarantool-patches
2021-07-30 22:58     ` Timur Safin via Tarantool-patches
2021-07-31  6:31       ` Oleg Babin via Tarantool-patches
2021-07-31  9:20         ` Timur Safin via Tarantool-patches
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 10/11] lua, datetime: unixtime, timestamp setters in datetime.lua Timur Safin via Tarantool-patches
2021-07-29 18:58   ` Oleg Babin via Tarantool-patches
2021-07-30 23:11     ` Timur Safin via Tarantool-patches
2021-07-31  6:31       ` Oleg Babin via Tarantool-patches
2021-07-31  9:54         ` Timur Safin via Tarantool-patches [this message]
2021-07-28 10:34 ` [Tarantool-patches] [PATCH resend v2 11/11] datetime: changelog for datetime module Timur Safin via Tarantool-patches
2021-07-29 18:55 ` [Tarantool-patches] [PATCH resend v2 00/11] Initial datetime support Oleg Babin via Tarantool-patches

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