Support units in progress messages

This allows our progress meter to be used for bytes transferred, by
setting the units to KB or MB to let the user know the size.

Change-Id: Ie8653d4a40d79439026c18bd51915845b2c5bba9
Signed-off-by: Shawn O. Pearce <sop@google.com>

progress.py

@@ -21,13 +21,14 @@ from trace import IsTrace
 _NOT_TTY = not os.isatty(2)
 
 class Progress(object):
-  def __init__(self, title, total=0):
+  def __init__(self, title, total=0, units=''):
     self._title = title
     self._total = total
     self._done = 0
     self._lastp = -1
     self._start = time()
     self._show = False
+    self._units = units
 
   def update(self, inc=1):
     self._done += inc
@@ -51,11 +52,11 @@ class Progress(object):
 
       if self._lastp != p:
         self._lastp = p
-        sys.stderr.write('\r%s: %3d%% (%d/%d)  ' % (
+        sys.stderr.write('\r%s: %3d%% (%d%s/%d%s)  ' % (
           self._title,
           p,
-          self._done,
-          self._total))
+          self._done, self._units,
+          self._total, self._units))
         sys.stderr.flush()
 
   def end(self):
@@ -69,9 +70,9 @@ class Progress(object):
       sys.stderr.flush()
     else:
       p = (100 * self._done) / self._total
-      sys.stderr.write('\r%s: %3d%% (%d/%d), done.  \n' % (
+      sys.stderr.write('\r%s: %3d%% (%d%s/%d%s), done.  \n' % (
         self._title,
         p,
-        self._done,
-        self._total))
+        self._done, self._units,
+        self._total, self._units))
       sys.stderr.flush()