main-restOfMain.go

// import this awesome package : github.com/cheggaaa/pb

// Create a new bar with int64 content corresponding to the total file size.
bar := pb.New64(head.ContentLength)
// Refresh rate - Nanosecond is too much... Just for fun...
bar.RefreshRate = time.Nanosecond
// Show the download speed.
bar.ShowSpeed = true
// Units : B/s (autmatically switches to MB/s kB/s etc.,)
bar.Units = pb.U_BYTES
// Start displaying the bar.
bar.Start()
// variable for storing total bytes completed downloading.
w := int64(0)
// Loop till the total is full or 100%
for w < head.ContentLength {
  w += (<-written) // Get the amount written from the channel passed to various goroutines.
  bar.Set64(w) // set the amount finished to the progressbar...
}
// Done?? Display this and stop updating.
bar.FinishPrint("Appending Files...")
// This is the WaitGroup waiting till the Job count is 0
// Almost like `for jobCount == 0 {}`
// I know that above loop `for w < head.ContentLength ` does the same.
// Still to make sure.
c.Wait()
// Append all the files...
addParts(outfile, files)
// Remove the temporary directory corresponding to the download....
os.RemoveAll(filepath.Join("/tmp/", outfile))
// END OF MAIN.... DONE.