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].

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

1 files changed, 86 insertions, 0 deletions

diff --git a/lib/bb/progress.py b/lib/bb/progress.py
new file mode 100644
index 000000000..bab8e9465
--- /dev/null
+++ b/lib/bb/progress.py
@@ -0,0 +1,86 @@
+"""
+BitBake progress handling code
+"""
+
+# Copyright (C) 2016 Intel Corporation
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import sys
+import re
+import time
+import bb.event
+import bb.build
+
+class ProgressHandler(object):
+    """
+    Base class that can pretend to be a file object well enough to be
+    used to build objects to intercept console output and determine the
+    progress of some operation.
+    """
+    def __init__(self, d, outfile=None):
+        self._progress = 0
+        self._data = d
+        self._lastevent = 0
+        if outfile:
+            self._outfile = outfile
+        else:
+            self._outfile = sys.stdout
+
+    def _fire_progress(self, taskprogress, rate=None):
+        """Internal function to fire the progress event"""
+        bb.event.fire(bb.build.TaskProgress(taskprogress, rate), self._data)
+
+    def write(self, string):
+        self._outfile.write(string)
+
+    def flush(self):
+        self._outfile.flush()
+
+    def update(self, progress, rate=None):
+        ts = time.time()
+        if progress > 100:
+            progress = 100
+        if progress != self._progress or self._lastevent + 1 < ts:
+            self._fire_progress(progress, rate)
+            self._lastevent = ts
+            self._progress = progress
+
+class BasicProgressHandler(ProgressHandler):
+    def __init__(self, d, regex=r'(\d+)%', outfile=None):
+        super(BasicProgressHandler, self).__init__(d, outfile)
+        self._regex = re.compile(regex)
+        # Send an initial progress event so the bar gets shown
+        self._fire_progress(0)
+
+    def write(self, string):
+        percs = self._regex.findall(string)
+        if percs:
+            progress = int(percs[-1])
+            self.update(progress)
+        super(BasicProgressHandler, self).write(string)
+
+class OutOfProgressHandler(ProgressHandler):
+    def __init__(self, d, regex, outfile=None):
+        super(OutOfProgressHandler, self).__init__(d, outfile)
+        self._regex = re.compile(regex)
+        # Send an initial progress event so the bar gets shown
+        self._fire_progress(0)
+
+    def write(self, string):
+        nums = self._regex.findall(string)
+        if nums:
+            progress = (float(nums[-1][0]) / float(nums[-1][1])) * 100
+            self.update(progress)
+        super(OutOfProgressHandler, self).write(string)