Add a download size information on download progressbar

installsystems/progressbar/widgets.py

@@ -140,6 +140,27 @@ class FileTransferSpeed(Widget):
 
         return self.format % (scaled, self.prefixes[power], self.unit)
 
+class FileTransferSize(Widget):
+    'Widget for showing the transfer size (useful for file transfers).'
+
+    format = '%6.2f %s%s'
+    prefixes = ' kMGTPEZY'
+    __slots__ = ('unit', 'format')
+
+    def __init__(self, unit='B'):
+        self.unit = unit
+
+    def update(self, pbar):
+        'Updates the widget with the current SI prefixed speed.'
+
+        if pbar.currval < 2e-6: # =~ 0
+            scaled = power = 0
+        else:
+            power = int(math.log(pbar.currval, 1000))
+            scaled = pbar.currval / 1000.**power
+
+        return self.format % (scaled, self.prefixes[power], self.unit)
+
 
 class AnimatedMarker(Widget):
     '''An animated marker for the progress bar which defaults to appear as if

installsystems/tools.py

@@ -16,7 +16,8 @@ import time
 from subprocess import call, check_call, CalledProcessError
 
 import installsystems
-from installsystems.progressbar import ProgressBar, Percentage, FileTransferSpeed
+from installsystems.progressbar import ProgressBar, Percentage
+from installsystems.progressbar import FileTransferSpeed, FileTransferSize
 from installsystems.progressbar import Bar, BouncingBar, ETA, UnknownLength
 from installsystems.tarball import Tarball
 from installsystems.printer import *
@@ -72,7 +73,7 @@ class PipeFile(object):
         # init progress bar
         # we use 0 because a null file is cannot show a progression during write
         if self.size == 0:
-            widget = [ BouncingBar(), " ", FileTransferSpeed() ]
+            widget = [ FileTransferSize(), " ", BouncingBar(), " ", FileTransferSpeed() ]
             maxval = UnknownLength
         else:
             widget = [ Percentage(), " ", Bar(), " ", FileTransferSpeed(), " ", ETA() ]