A Flexible and Robust Sys.sleep() Replacement

Provides a near drop-in replacement for base::Sys.sleep() that allows more types of input to produce delays in the execution of code and can silence/prevent typical sources of error.


naptime makes delaying code execution in R more flexible and robust. It makes delaying code execution more flexible by supporting more data types than base::Sys.sleep(). It makes delaying code more robust by allowing errors in the delay specification to throw warnings instead of errors. Most notably, because naptime supports more input data types, you can use package:lubridate functions in conjunction with naptime to yield human readable time delays and intervals.

Consider the case of waiting one hour:

Sys.sleep(3600)

naptime(lubridate::hours(1))

Consider the case of wanting to start processing every hour for a job of an indeterminate duration:

repeat{
  start_time <- lubridate::now()
  # Do processing
  sleep_duration <- 3600 - as.numeric(lubridate::now() - start_time)
  if (sleep_duration > 0) {
    Sys.sleep(sleep_duration)
  }
}

# versus

repeat{
  start_time <- lubridate::now()
  # Do processing
  naptime(start_time + hours(1))
}

Because naptime() has nearly identical arguments and behavior as base::Sys.sleep() in response to numeric inputs, it can be nearly used as a drop-in replacement for base::Sys.sleep().

There are two notable differences in the behavior of Sys.sleep() and naptime():

  • For the input value of Inf base::Sys.sleep() will sleep indefinitely. In contrast, naptime::naptime() will produce an error (or if naptime.permissive = TRUE is set pause the default duration).
  • For a negative input value base::Sys.sleep() will produce an error. In contrast, naptime::naptime() will assume that the period of delay has already elapsed and move forward without further delay.

All options are set via base::options().

  • naptime.default_delay. If left unchanged, the default delay is .1 seconds.
  • naptime.warnings. If left unchanged, the default is TRUE, to show warnings.
  • naptime.permissive. If left unchanged, the default is FALSE, to trigger errors on inputs that couldn't be converted into something sensible. If set TRUE, inputs that couldn't be converted into something sensible will result in a default delay.

naptime() accepts a wide variety of inputs.

Polymorphism for:

  • numeric: time in seconds to nap
naptime(1)
#> NULL
  • POSIXct: time at which the nap should stop (timezone is respected)
naptime(lubridate::now(tzone = "UTC")+lubridate::seconds(1))
#> NULL
  • Period: time from now at which the nap should stop
naptime(lubridate::seconds(1))
#> NULL
  • character: A single character string formatted YYYY-MM-DD HH:MM:SS at which the nap should stop. The time zone is assumed to be device local. The hour, minute, and second do not need to be specified.
naptime(as.character(lubridate::now() + lubridate::seconds(1)))
#> NULL
  • difftime: difference in time to nap
naptime(difftime(lubridate::now() + lubridate::seconds(1), lubridate::now()))
#> NULL
  • logical: nap for default duration if TRUE, skip nap if FALSE
naptime(TRUE)
#> NULL
  • NULL; meaning no delay
naptime(NULL)
#> NULL
  • generic: By default this produces an error, however, you can set naptime.permissive as an option (or argument) that will cause this to nap for default duration instead.
naptime(glm(rnorm(5) ~ runif(5)), permissive = TRUE)
#> Warning: The time paramater was not scalar (length equal to 1)
#> Warning: unhandled input for naptime(): Error in (function (classes, fdef, mtable) : unable to find an inherited method for function 'naptime' for signature '"list"'
#> NULL
options(naptime.permissive = TRUE)
naptime(glm(rnorm(5) ~ runif(5)))
#> Warning: The time paramater was not scalar (length equal to 1)
 
#> Warning: unhandled input for naptime(): Error in (function (classes, fdef, mtable) : unable to find an inherited method for function 'naptime' for signature '"list"'
#> NULL

If you find a reasonable input-type for which naptime::naptime() doesn't have a reasonable response, please file an issue or PR in which you resolve the shortcoming.

The current version is on CRAN, but you can fetch an early release of the upcoming build directly from github:

library(devtools)
install_github("drknexus/naptime")
library(naptime)

The initial draft of this code was written by Timothy Gann under a spec drafted by Russell Pierce. Many improvements and bug fixes to the original code, all packaging, and all tests were written by Russell Pierce. Russell Pierce is the current maintainer and responsible party for this package.

News

naptime 1.2.0

Formatting changes for CRAN deploy. Refer to naptime 1.1.0 NEWS for changes since the last CRAN version.

  • lubridate parse warnings squelched

naptime 1.1.0

  • Per request naptime is now quite a bit more discerning by default. If the argument provided isn't interpretable, naptime will throw as an error. The old permissive behavior that produces warnings and default delays can be more or less restored by setting the option naptime.permissive to TRUE or setting the permissive parameter as TRUE on any given naptime call (parameter overrides the option)
  • Logicals no longer produce a warning. Logical FALSE is interpreted as meaning 'no delay' and TRUE is interpreted as meaning default delay.
  • Calling naptime with a NULL no longer produces a delay or warning as this is interpreted as meaning 'no delay'.
  • naptime can take incompletely specified date times for delays in the future by leveraging lubridate::ymd_hms()'s truncated parameter. We now allow for three truncated formats.
  • naptime actually pauses for the default duration under error conditions rather than returning it as a variable
  • naptime no longer sometimes returns non-NULL values
  • naptime should now delay appropriately for long duration difftimes

naptime 1.0.0

  • Initial CRAN Submission
  • 100% Code Coverage
  • Polymorphism for:
  • numeric
  • NULL
  • POSIXct
  • Period
  • character
  • difftime
  • logical

Reference manual

It appears you don't have a PDF plugin for this browser. You can click here to download the reference manual.

install.packages("naptime")

1.3.0 by Russell S. Pierce, a month ago


URL: https://github.com/drknexus/naptime


Report a bug at https://github.com/drknexus/naptime/issues


Browse source code at https://github.com/cran/naptime


Authors: Russell S. Pierce [aut, cre], Timothy Gann [aut]


Documentation:   PDF Manual  


GPL-2 license


Imports methods, lubridate

Suggests testthat, covr, knitr, rmarkdown


See at CRAN