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, 34 insertions, 0 deletions

diff --git a/lib/bb/build.py b/lib/bb/build.py
index 2ebe67306..4fb2a77cf 100644
--- a/lib/bb/build.py
+++ b/lib/bb/build.py
@@ -35,6 +35,7 @@ import stat
 import bb
 import bb.msg
 import bb.process
+import bb.progress
 from bb import data, event, utils
 
 bblogger = logging.getLogger('BitBake')
@@ -137,6 +138,25 @@ class TaskInvalid(TaskBase):
         super(TaskInvalid, self).__init__(task, None, metadata)
         self._message = "No such task '%s'" % task
 
+class TaskProgress(event.Event):
+    """
+    Task made some progress that could be reported to the user, usually in
+    the form of a progress bar or similar.
+    NOTE: this class does not inherit from TaskBase since it doesn't need
+    to - it's fired within the task context itself, so we don't have any of
+    the context information that you do in the case of the other events.
+    The event PID can be used to determine which task it came from.
+    The progress value is normally 0-100, but can also be negative
+    indicating that progress has been made but we aren't able to determine
+    how much.
+    The rate is optional, this is simply an extra string to display to the
+    user if specified.
+    """
+    def __init__(self, progress, rate=None):
+        self.progress = progress
+        self.rate = rate
+        event.Event.__init__(self)
+
 
 class LogTee(object):
     def __init__(self, logger, outfile):
@@ -340,6 +360,20 @@ exit $ret
     else:
         logfile = sys.stdout
 
+    progress = d.getVarFlag(func, 'progress', True)
+    if progress:
+        if progress == 'percent':
+            # Use default regex
+            logfile = bb.progress.BasicProgressHandler(d, outfile=logfile)
+        elif progress.startswith('percent:'):
+            # Use specified regex
+            logfile = bb.progress.BasicProgressHandler(d, regex=progress.split(':', 1)[1], outfile=logfile)
+        elif progress.startswith('outof:'):
+            # Use specified regex
+            logfile = bb.progress.OutOfProgressHandler(d, regex=progress.split(':', 1)[1], outfile=logfile)
+        else:
+            bb.warn('%s: invalid task progress varflag value "%s", ignoring' % (func, progress))
+
     def readfifo(data):
         lines = data.split(b'\0')
         for line in lines: