How to implement Multiple Progress Bars??? about pb

[cheggaaa]

Hi!
I made commit with experimental support
It's based on ANSI Escape Sequences
Checkout this branch https://github.com/cheggaaa/pb/tree/multiple

Example

package main

import (
    "math/rand"
    "pb"
    "sync"
    "time"
)

func main() {
    pool := &pb.Pool{}
    first := pb.New(1000).Prefix("First ")
    second := pb.New(1000).Prefix("Second ")
    third := pb.New(1000).Prefix("Third ")
    pool.Add(first, second, third)
    pool.Start()
    wg := new(sync.WaitGroup)
    for _, bar := range []*pb.ProgressBar{first, second, third} {
        wg.Add(1)
        go func(cb *pb.ProgressBar) {
            for n := 0; n < 1000; n++ {
                cb.Increment()
                time.Sleep(time.Millisecond * time.Duration(rand.Intn(100)))
            }
            cb.Finish()
            wg.Done()
        }(bar)
    }
    wg.Wait()
}

now have some problems, but i'm working on it

[marcellodesales]

Hi @cheggaaa...

Thanks a lot for making this!!! The example works... Other suggestions to improve it:

• Block any terminal key to be ENTERED other than Ctrl+C
• Add this as an example in the examples directory

This is a very valuable component! Let me know how I can help... I will work on integrating the example for multiple files uploads... Let me know when you integrate this!

thanks!

[cheggaaa]

Block any terminal key to be ENTERED other than Ctrl+C

This not easy.. want to do this without heavy dependencies like ncurses.
If we'll know absolute cursor position, we can change only necessary rows without locking normal input and output. Until i can't found solution of this problem.

[marcellodesales]

@cheggaaa That's alright! That's definitely a stretch...

I will try to create an example for the Multiple IO downloads, which is what I need... I tried last night but I might have missed something...

Thanks a lot for this!!! Easier than the others...

[cheggaaa]

Good news!
Now we have locked input - b2aef60

Bad news - windows is not yet supported

[cheggaaa]

Needs to be done:

• win support
• sortable bars
• test on BSD and Solaris systems (i have only mac and linux)

[marcellodesales]

@cheggaaa I was able to implement the IO-based Progress Bars with the sample you have (this is a real app)...

I can contribute with the code sample code based on https://github.com/thbar/golang-playground/blob/master/download-files.go.

Wow, the locked input will definitely be great!!! :D I still have to test this on CI/CD environment (Travis and Jenkins for that matter)...

Other than that, I'm glad my team is not on Windows :D sorry for the windows users... Hopefully someone will tackle that... In addition, I like your TODOs... I can't test neither on BSD nor Solaris (same situation)...

Awesome! I'm so happy I got this working... I will work on the example code after tonight!!!

[marcellodesales]

Hi @cheggaaa... Here's a feedback with the use of the Terminal: It helps with blocking the console, but it creates TOO MANY scrolls!!! That was NOT the plan :(

It is re-writing all the lines upon an update... I'd love to go back to square one, and be able to quit the process before... I had to close the window in order to stop the download of too many files and the experience was annoying...

Anyway, this is just my 2cs...

[marcellodesales]

Not sure, I first thought that the commit 9ba607e worked... And I did not introduce any change to the library during my pull request...

Your initial support worked as expected, where there's no buffer in the terminal nor the scroll grows over the updated values. However, I was tagging the commits, merging to my local fork, and the same scrolling behavior showed up again...

Do you know why? The screenshot below shows the behavior of the terminal scrolling down instead of updating the status in-place, when compared to the first screenshot above.

[marcellodesales]

Reason for the problem

if the number of PBs is greater than the number of lines in the current terminal window, then the scrolls will be engaged because of reprinting... Maximizing the terminal window to accommodate all my entries worked...

Possible Workaround

If there's no way to solve this, Is there a way to get the total number of lines of the terminal? That way, the PB API could expose the dimensions of the terminal and enqueue only the maximum number of PBs to be running. Further, it would be a matter of enqueuing the remainder while PBs are finished...

[cheggaaa]

About ctrl+c. We need copy some code from this package https://github.com/golang/crypto/tree/master/ssh/terminal and write method 'lockInput' (like this https://github.com/golang/crypto/blob/master/ssh/terminal/util.go#L87 , but without reading from stdin).
I'm doing it now.

About many bars. I think user has no need more than 5-6 bars) and problems like queues should solve user.

[cheggaaa]

Can you check last version? Under linux signals works fine

[marcellodesales]

Well, the number of bars is up to the API Client to decide... What I'm suggesting is that if there are more bars than the terminal's current size can accommodate, then the PB API should give that information to the user's API... That way, users can use "Tickle" http://www.tecmint.com/manage-and-limit-downloadupload-bandwidth-with-trickle-in-linux/ to control the download bandwidth, or control the number of bars.

I will verify the last version in a few hours...

[uetchy]

Any updates?
I guess that it looks good to merge multiple branch into master.

[cheggaaa]

So far it's alpha.. We have not windows support and have some problems with catching os signals

[uetchy]

Did you checked out go-keybind ? This library can catch user inputs and supports windows.

[GideonRed-zz]

Any chance you can merge some minimal support for multiple progress bars into master? Doesn't have to satisfy every requirement set in this issue. Just something to give a few progress bars.

I can create the PR for you if you wish.

[cheggaaa]

Merged!
Code was cleaned and added some safety changes.
But anyway do not work at windows.

[Quentin-M]

Merged just in time!
We planned to start using it today on the experimental branch.
Thanks!

👍

[mnvx]

@cheggaaa Thanks for great feature and example. Would be great to add pbPool.Stop() into end of example:

package main

import (
    "math/rand"
    "pb"
    "sync"
    "time"
)

func main() {
    pool := &pb.Pool{}
    first := pb.New(1000).Prefix("First ")
    second := pb.New(1000).Prefix("Second ")
    third := pb.New(1000).Prefix("Third ")
    pool.Add(first, second, third)
    pool.Start()
    wg := new(sync.WaitGroup)
    for _, bar := range []*pb.ProgressBar{first, second, third} {
        wg.Add(1)
        go func(cb *pb.ProgressBar) {
            for n := 0; n < 1000; n++ {
                cb.Increment()
                time.Sleep(time.Millisecond * time.Duration(rand.Intn(100)))
            }
            cb.Finish()
            wg.Done()
        }(bar)
    }
    wg.Wait()

    // Stop pool, else keyboard will be locked after execution (as minimum in Ubuntu)
    pbPool.Stop()
}