bitbake: lib: implement basic task progress support

For long-running tasks where we have some output from the task that
gives us some idea of the progress of the task (such as a percentage
complete), provide the means to scrape the output for that progress
information and show it to the user in the default knotty terminal
output in the form of a progress bar. This is implemented using a new
TaskProgress event as well as some code we can insert to do output
scanning/filtering.

Any task can fire TaskProgress events; however, if you have a shell task
whose output you wish to scan for progress information, you just need to
set the "progress" varflag on the task. This can be set to:
 * "percent" to just look for a number followed by a % sign
 * "percent:<regex>" to specify your own regex matching a percentage
   value (must have a single group which matches the percentage number)
 * "outof:<regex>" to look for the specified regex matching x out of y
   items completed (must have two groups - first group needs to be x,
   second y).
We can potentially extend this in future but this should be a good
start.

Part of the implementation for [YOCTO #5383].

(Bitbake rev: 0d275fc5b6531957a6189069b04074065bb718a0)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/bitbake/lib/progressbar/widgets.py b/bitbake/lib/progressbar/widgets.py
index 6434ad5591..77285ca7a3 100644
--- a/bitbake/lib/progressbar/widgets.py
+++ b/bitbake/lib/progressbar/widgets.py
@@ -353,3 +353,39 @@ class BouncingBar(Bar):
         if not self.fill_left: rpad, lpad = lpad, rpad
 
         return '%s%s%s%s%s' % (left, lpad, marker, rpad, right)
+
+
+class BouncingSlider(Bar):
+    """
+    A slider that bounces back and forth in response to update() calls
+    without reference to the actual value. Based on a combination of
+    BouncingBar from a newer version of this module and RotatingMarker.
+    """
+    def __init__(self, marker='<=>'):
+        self.curmark = -1
+        self.forward = True
+        Bar.__init__(self, marker=marker)
+    def update(self, pbar, width):
+        left, marker, right = (format_updatable(i, pbar) for i in
+                               (self.left, self.marker, self.right))
+
+        width -= len(left) + len(right)
+        if width < 0:
+            return ''
+
+        if pbar.finished: return '%s%s%s' % (left, width * '=', right)
+
+        self.curmark = self.curmark + 1
+        position = int(self.curmark % (width * 2 - 1))
+        if position + len(marker) > width:
+            self.forward = not self.forward
+            self.curmark = 1
+            position = 1
+        lpad = ' ' * (position - 1)
+        rpad = ' ' * (width - len(marker) - len(lpad))
+
+        if not self.forward:
+            temp = lpad
+            lpad = rpad
+            rpad = temp
+        return '%s%s%s%s%s' % (left, lpad, marker, rpad, right)