Disable progress bar but keep sticky messages

[john-ioannides]

I am running a lengthy process (~5 hours) in parallel using furrr::future_walk and want to display a real-time message of the progress at each iteration.
I have all outputs redirected to a logfile so keeping the progress bar clutters the output.
The parallel workers are opened using future::multisession if it makes any difference.

Sample code:

steps = 10
progressr::with_progress({
  p <- progressr::progressor(steps=steps)
  
  furrr::future_walk(1:steps, ~{
    
    if(.x/2==0){
      Sys.sleep(2)
    } else {
      Sys.sleep(8)
    }
    
    p(paste0("progress print for ", .x), class = "sticky")

  })
  
}, enable = T)

Is there a way to keep displaying the sticky messages in real-time while hiding the progress bar?

[HenrikBengtsson]

There's currently no "non-visual" progress handler. It could be implemented, but I don't think you need the progressr package to achieve what you want. Instead, all that is needed is to send a message condition, which message() do, while making sure the condition also inherits from the special class immediateCondition. The future framework recognizes immediateCondition conditions as special and will relay them back up to the parent R process as soon as possible. This is essentially how and why progressr works. Now, if we do this for a regular message, then it will be relayed up asap, and there it'll be handled as usual, i.e. be displayed.

Here's an example:

#' Send a message that also inherits from immediateCondition.
immediateMessage <- function (..., domain = NULL, appendLF = TRUE)  {
  msg <- .makeMessage(..., domain = domain, appendLF = appendLF)
  call <- sys.call()
  cond <- simpleMessage(msg, call)
  class(cond) <- c(class(cond), "immediateCondition")
  message(cond)
}

Demonstration that this will display the message equally fast as "sticky" progress messages:

library(furrr)
plan(multisession, workers = 4)

y <- furrr::future_map(1:100, function(i) {
  immediateMessage(paste("Step ", i))
  Sys.sleep(8)
  i^2
})

Let me know if this does what you need.

[john-ioannides]

@HenrikBengtsson This worked perfectly!!! Thank you so much!