Re: [pbs-devel] [PATCH proxmox-backup 1/3] tools/systemd/time: implement some Traits for TimeSpan

[Dominik Csapak <d.csapak@proxmox.com>]

On 3/17/21 20:35, Thomas Lamprecht wrote:
> On 16.03.21 12:56, Dominik Csapak wrote:
>> namely
>> * From<Duration> (to convert easily from duration to timespan)
>> * Display (for better formatting)
>>
>> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
>> ---
>> if wanted, we can optimize the display trait a bit further, e.g.
>> only showing the biggest two units instead
>>
>>   src/tools/systemd/time.rs | 84 +++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 84 insertions(+)
>>
>> diff --git a/src/tools/systemd/time.rs b/src/tools/systemd/time.rs
>> index 7cc42415..75fb0ea2 100644
>> --- a/src/tools/systemd/time.rs
>> +++ b/src/tools/systemd/time.rs
>> @@ -141,6 +141,90 @@ impl From<TimeSpan> for f64 {
>>       }
>>   }
>>   
>> +impl From<std::time::Duration> for TimeSpan {
>> +    fn from(duration: std::time::Duration) -> Self {
>> +        let mut duration = duration.as_nanos();
>> +        let nsec = (duration % 1000) as u64;
>> +        duration /= 1000;
>> +        let usec = (duration % 1000) as u64;
>> +        duration /= 1000;
>> +        let msec = (duration % 1000) as u64;
>> +        duration /= 1000;
>> +        let seconds = (duration % 60) as u64;
>> +        duration /= 60;
>> +        let minutes = (duration % 60) as u64;
>> +        duration /= 60;
>> +        let hours = (duration % 24) as u64;
>> +        duration /= 24;
>> +        let years = (duration as f64 / 365.25) as u64;
>> +        let ydays = (duration as f64 % 365.25) as u64;
>> +        let months = (ydays as f64 / 30.44) as u64;
>> +        let mdays = (ydays as f64 % 30.44) as u64;
>> +        let weeks = mdays / 7;
>> +        let days = mdays % 7;
>> +        Self {
>> +            nsec,
>> +            msec,
>> +            usec,
> 
> nit:
> nano -> milli -> micro? While it works correct, that order above seems just wrong...

yeah sorry...


> 
>> +            seconds,
>> +            minutes,
>> +            hours,
>> +            days,
>> +            weeks,
>> +            months,
>> +            years,
>> +        }
>> +    }
>> +}
>> +
>> +impl std::fmt::Display for TimeSpan {
>> +    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
>> +        let mut single = true;
>> +        if self.years > 0 {
>> +            write!(f, "{}y", self.years)?;
>> +            single = false;
>> +        }
>> +        let write_space = |single: bool, f: &mut std::fmt::Formatter| -> Result<bool, std::fmt::Error> {
>> +            if !single {
>> +                write!(f, " ")?;
>> +            }
>> +            Ok(false)
>> +        };
> 
> No sure if something like (untested):
> 
> let mut first = true;
> let mut do_write = |v: u64, unit: &str| -> Result<(), std::fmt::Error> {
>      if !first {
>          write!(f, " ")?;
>          first = false;
>      }
>      write!(f, "{}{}", v, unit)
> }
> 
> if self.months > 0 {
>      do_write(self.months, "m")?;
> }
> 
> ...
> 
> would be nicer IMO, especially as the "single" handling reads a bit weird.
> Maybe the seconds field makes this not really feasible though...

mhm.. i can try to improve that a bit

> 
>> +        if self.months > 0 {
>> +            single = write_space(single, f)?;
>> +            write!(f, "{}m", self.months)?;
>> +        }
>> +        if self.weeks > 0 {
>> +            single = write_space(single, f)?;
>> +            write!(f, "{}w", self.weeks)?;
>> +        }
>> +        if self.days > 0 {
>> +            single = write_space(single, f)?;
>> +            write!(f, "{}d", self.days)?;
>> +        }
>> +        if self.hours > 0 {
>> +            single = write_space(single, f)?;
>> +            write!(f, "{}h", self.hours)?;
>> +        }
>> +        if self.minutes > 0 {
>> +            single = write_space(single, f)?;
>> +            write!(f, "{}min", self.minutes)?;
>> +        }
>> +        let seconds = self.seconds as f64 + (self.msec as f64 / 1000.0);
>> +        if seconds >= 0.1 {
>> +            write_space(single, f)?;
>> +            if seconds >= 1.0 || !single {
>> +                write!(f, "{:.0}s", seconds)?;
>> +            } else {
>> +                write!(f, "{:.1}s", seconds)?;
>> +            }
>> +        } else if single {
>> +            write_space(single, f)?;
>> +            write!(f, "<0.1s")?;
>> +        }
>> +        Ok(())
>> +    }
>> +}
>>   
>>   pub fn verify_time_span(i: &str) -> Result<(), Error> {
>>       parse_time_span(i)?;
>>
>