diff --git a/import-layers/yocto-poky/scripts/buildstats-diff b/import-layers/yocto-poky/scripts/buildstats-diff
index adeba44..a128dd3 100755
--- a/import-layers/yocto-poky/scripts/buildstats-diff
+++ b/import-layers/yocto-poky/scripts/buildstats-diff
@@ -15,15 +15,18 @@
 #
 import argparse
 import glob
-import json
 import logging
 import math
 import os
-import re
 import sys
-from collections import namedtuple
 from operator import attrgetter
 
+# Import oe libs
+scripts_path = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(scripts_path, 'lib'))
+from buildstats import BuildStats, diff_buildstats, taskdiff_fields, BSVerDiff
+
+
 # Setup logging
 logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
 log = logging.getLogger()
@@ -34,180 +37,16 @@
     pass
 
 
-taskdiff_fields = ('pkg', 'pkg_op', 'task', 'task_op', 'value1', 'value2',
-                   'absdiff', 'reldiff')
-TaskDiff = namedtuple('TaskDiff', ' '.join(taskdiff_fields))
-
-
-class BSTask(dict):
-    def __init__(self, *args, **kwargs):
-        self['start_time'] = None
-        self['elapsed_time'] = None
-        self['status'] = None
-        self['iostat'] = {}
-        self['rusage'] = {}
-        self['child_rusage'] = {}
-        super(BSTask, self).__init__(*args, **kwargs)
-
-    @property
-    def cputime(self):
-        """Sum of user and system time taken by the task"""
-        return self['rusage']['ru_stime'] + self['rusage']['ru_utime'] + \
-               self['child_rusage']['ru_stime'] + self['child_rusage']['ru_utime']
-
-    @property
-    def walltime(self):
-        """Elapsed wall clock time"""
-        return self['elapsed_time']
-
-    @property
-    def read_bytes(self):
-        """Bytes read from the block layer"""
-        return self['iostat']['read_bytes']
-
-    @property
-    def write_bytes(self):
-        """Bytes written to the block layer"""
-        return self['iostat']['write_bytes']
-
-    @property
-    def read_ops(self):
-        """Number of read operations on the block layer"""
-        return self['rusage']['ru_inblock'] + self['child_rusage']['ru_inblock']
-
-    @property
-    def write_ops(self):
-        """Number of write operations on the block layer"""
-        return self['rusage']['ru_oublock'] + self['child_rusage']['ru_oublock']
-
-
-def read_buildstats_file(buildstat_file):
-    """Convert buildstat text file into dict/json"""
-    bs_task = BSTask()
-    log.debug("Reading task buildstats from %s", buildstat_file)
-    with open(buildstat_file) as fobj:
-        for line in fobj.readlines():
-            key, val = line.split(':', 1)
-            val = val.strip()
-            if key == 'Started':
-                start_time = float(val)
-                bs_task['start_time'] = start_time
-            elif key == 'Ended':
-                end_time = float(val)
-            elif key.startswith('IO '):
-                split = key.split()
-                bs_task['iostat'][split[1]] = int(val)
-            elif key.find('rusage') >= 0:
-                split = key.split()
-                ru_key = split[-1]
-                if ru_key in ('ru_stime', 'ru_utime'):
-                    val = float(val)
-                else:
-                    val = int(val)
-                ru_type = 'rusage' if split[0] == 'rusage' else \
-                                                  'child_rusage'
-                bs_task[ru_type][ru_key] = val
-            elif key == 'Status':
-                bs_task['status'] = val
-    bs_task['elapsed_time'] = end_time - start_time
-    return bs_task
-
-
-def read_buildstats_dir(bs_dir):
-    """Read buildstats directory"""
-    def split_nevr(nevr):
-        """Split name and version information from recipe "nevr" string"""
-        n_e_v, revision = nevr.rsplit('-', 1)
-        match = re.match(r'^(?P<name>\S+)-((?P<epoch>[0-9]{1,5})_)?(?P<version>[0-9]\S*)$',
-                         n_e_v)
-        if not match:
-            # If we're not able to parse a version starting with a number, just
-            # take the part after last dash
-            match = re.match(r'^(?P<name>\S+)-((?P<epoch>[0-9]{1,5})_)?(?P<version>[^-]+)$',
-                             n_e_v)
-        name = match.group('name')
-        version = match.group('version')
-        epoch = match.group('epoch')
-        return name, epoch, version, revision
-
-    if not os.path.isfile(os.path.join(bs_dir, 'build_stats')):
-        raise ScriptError("{} does not look like a buildstats directory".format(bs_dir))
-
-    log.debug("Reading buildstats directory %s", bs_dir)
-
-    buildstats = {}
-    subdirs = os.listdir(bs_dir)
-    for dirname in subdirs:
-        recipe_dir = os.path.join(bs_dir, dirname)
-        if not os.path.isdir(recipe_dir):
-            continue
-        name, epoch, version, revision = split_nevr(dirname)
-        recipe_bs = {'nevr': dirname,
-                     'name': name,
-                     'epoch': epoch,
-                     'version': version,
-                     'revision': revision,
-                     'tasks': {}}
-        for task in os.listdir(recipe_dir):
-            recipe_bs['tasks'][task] = [read_buildstats_file(
-                    os.path.join(recipe_dir, task))]
-        if name in buildstats:
-            raise ScriptError("Cannot handle multiple versions of the same "
-                              "package ({})".format(name))
-        buildstats[name] = recipe_bs
-
-    return buildstats
-
-
-def bs_append(dst, src):
-    """Append data from another buildstats"""
-    if set(dst.keys()) != set(src.keys()):
-        raise ScriptError("Refusing to join buildstats, set of packages is "
-                          "different")
-    for pkg, data in dst.items():
-        if data['nevr'] != src[pkg]['nevr']:
-            raise ScriptError("Refusing to join buildstats, package version "
-                              "differs: {} vs. {}".format(data['nevr'], src[pkg]['nevr']))
-        if set(data['tasks'].keys()) != set(src[pkg]['tasks'].keys()):
-            raise ScriptError("Refusing to join buildstats, set of tasks "
-                              "in {} differ".format(pkg))
-        for taskname, taskdata in data['tasks'].items():
-            taskdata.extend(src[pkg]['tasks'][taskname])
-
-
-def read_buildstats_json(path):
-    """Read buildstats from JSON file"""
-    buildstats = {}
-    with open(path) as fobj:
-        bs_json = json.load(fobj)
-    for recipe_bs in bs_json:
-        if recipe_bs['name'] in buildstats:
-            raise ScriptError("Cannot handle multiple versions of the same "
-                              "package ({})".format(recipe_bs['name']))
-
-        if recipe_bs['epoch'] is None:
-            recipe_bs['nevr'] = "{}-{}-{}".format(recipe_bs['name'], recipe_bs['version'], recipe_bs['revision'])
-        else:
-            recipe_bs['nevr'] = "{}-{}_{}-{}".format(recipe_bs['name'], recipe_bs['epoch'], recipe_bs['version'], recipe_bs['revision'])
-
-        for task, data in recipe_bs['tasks'].copy().items():
-            recipe_bs['tasks'][task] = [BSTask(data)]
-
-        buildstats[recipe_bs['name']] = recipe_bs
-
-    return buildstats
-
-
 def read_buildstats(path, multi):
     """Read buildstats"""
     if not os.path.exists(path):
         raise ScriptError("No such file or directory: {}".format(path))
 
     if os.path.isfile(path):
-        return read_buildstats_json(path)
+        return BuildStats.from_file_json(path)
 
     if os.path.isfile(os.path.join(path, 'build_stats')):
-        return read_buildstats_dir(path)
+        return BuildStats.from_dir(path)
 
     # Handle a non-buildstat directory
     subpaths = sorted(glob.glob(path + '/*'))
@@ -222,88 +61,63 @@
     bs = None
     for subpath in subpaths:
         if os.path.isfile(subpath):
-            tmpbs = read_buildstats_json(subpath)
+            _bs = BuildStats.from_file_json(subpath)
         else:
-            tmpbs = read_buildstats_dir(subpath)
-        if not bs:
-            bs = tmpbs
+            _bs = BuildStats.from_dir(subpath)
+        if bs is None:
+            bs = _bs
         else:
-            log.debug("Joining buildstats")
-            bs_append(bs, tmpbs)
-
+            bs.aggregate(_bs)
     if not bs:
         raise ScriptError("No buildstats found under {}".format(path))
+
     return bs
 
 
 def print_ver_diff(bs1, bs2):
     """Print package version differences"""
-    pkgs1 = set(bs1.keys())
-    pkgs2 = set(bs2.keys())
-    new_pkgs = pkgs2 - pkgs1
-    deleted_pkgs = pkgs1 - pkgs2
 
-    echanged = []
-    vchanged = []
-    rchanged = []
-    unchanged = []
-    common_pkgs = pkgs2.intersection(pkgs1)
-    if common_pkgs:
-        for pkg in common_pkgs:
-            if bs1[pkg]['epoch'] != bs2[pkg]['epoch']:
-                echanged.append(pkg)
-            elif bs1[pkg]['version'] != bs2[pkg]['version']:
-                vchanged.append(pkg)
-            elif bs1[pkg]['revision'] != bs2[pkg]['revision']:
-                rchanged.append(pkg)
-            else:
-                unchanged.append(pkg)
+    diff = BSVerDiff(bs1, bs2)
 
-    maxlen = max([len(pkg) for pkg in pkgs1.union(pkgs2)])
+    maxlen = max([len(r) for r in set(bs1.keys()).union(set(bs2.keys()))])
     fmt_str = "  {:{maxlen}} ({})"
-#    if unchanged:
-#        print("\nUNCHANGED PACKAGES:")
-#        print("-------------------")
-#        maxlen = max([len(pkg) for pkg in unchanged])
-#        for pkg in sorted(unchanged):
-#            print(fmt_str.format(pkg, bs2[pkg]['nevr'], maxlen=maxlen))
 
-    if new_pkgs:
-        print("\nNEW PACKAGES:")
-        print("-------------")
-        for pkg in sorted(new_pkgs):
-            print(fmt_str.format(pkg, bs2[pkg]['nevr'], maxlen=maxlen))
+    if diff.new:
+        print("\nNEW RECIPES:")
+        print("------------")
+        for name, val in sorted(diff.new.items()):
+            print(fmt_str.format(name, val.nevr, maxlen=maxlen))
 
-    if deleted_pkgs:
-        print("\nDELETED PACKAGES:")
-        print("-----------------")
-        for pkg in sorted(deleted_pkgs):
-            print(fmt_str.format(pkg, bs1[pkg]['nevr'], maxlen=maxlen))
+    if diff.dropped:
+        print("\nDROPPED RECIPES:")
+        print("----------------")
+        for name, val in sorted(diff.dropped.items()):
+            print(fmt_str.format(name, val.nevr, maxlen=maxlen))
 
     fmt_str = "  {0:{maxlen}} {1:<20}    ({2})"
-    if rchanged:
+    if diff.rchanged:
         print("\nREVISION CHANGED:")
         print("-----------------")
-        for pkg in sorted(rchanged):
-            field1 = "{} -> {}".format(pkg, bs1[pkg]['revision'], bs2[pkg]['revision'])
-            field2 = "{} -> {}".format(bs1[pkg]['nevr'], bs2[pkg]['nevr'])
-            print(fmt_str.format(pkg, field1, field2, maxlen=maxlen))
+        for name, val in sorted(diff.rchanged.items()):
+            field1 = "{} -> {}".format(val.left.revision, val.right.revision)
+            field2 = "{} -> {}".format(val.left.nevr, val.right.nevr)
+            print(fmt_str.format(name, field1, field2, maxlen=maxlen))
 
-    if vchanged:
+    if diff.vchanged:
         print("\nVERSION CHANGED:")
         print("----------------")
-        for pkg in sorted(vchanged):
-            field1 = "{} -> {}".format(bs1[pkg]['version'], bs2[pkg]['version'])
-            field2 = "{} -> {}".format(bs1[pkg]['nevr'], bs2[pkg]['nevr'])
-            print(fmt_str.format(pkg, field1, field2, maxlen=maxlen))
+        for name, val in sorted(diff.vchanged.items()):
+            field1 = "{} -> {}".format(val.left.version, val.right.version)
+            field2 = "{} -> {}".format(val.left.nevr, val.right.nevr)
+            print(fmt_str.format(name, field1, field2, maxlen=maxlen))
 
-    if echanged:
+    if diff.echanged:
         print("\nEPOCH CHANGED:")
         print("--------------")
-        for pkg in sorted(echanged):
-            field1 = "{} -> {}".format(bs1[pkg]['epoch'], bs2[pkg]['epoch'])
-            field2 = "{} -> {}".format(bs1[pkg]['nevr'], bs2[pkg]['nevr'])
-            print(fmt_str.format(pkg, field1, field2, maxlen=maxlen))
+        for name, val in sorted(diff.echanged.items()):
+            field1 = "{} -> {}".format(val.left.epoch, val.right.epoch)
+            field2 = "{} -> {}".format(val.left.nevr, val.right.nevr)
+            print(fmt_str.format(name, field1, field2, maxlen=maxlen))
 
 
 def print_task_diff(bs1, bs2, val_type, min_val=0, min_absdiff=0, sort_by=('absdiff',)):
@@ -343,12 +157,10 @@
         """Get cumulative sum of all tasks"""
         total = 0.0
         for recipe_data in buildstats.values():
-            for bs_task in recipe_data['tasks'].values():
-                total += sum([getattr(b, val_type) for b in bs_task]) / len(bs_task)
+            for bs_task in recipe_data.tasks.values():
+                total += getattr(bs_task, val_type)
         return total
 
-    tasks_diff = []
-
     if min_val:
         print("Ignoring tasks less than {} ({})".format(
                 val_to_str(min_val, True), val_to_str(min_val)))
@@ -357,49 +169,7 @@
                 val_to_str(min_absdiff, True), val_to_str(min_absdiff)))
 
     # Prepare the data
-    pkgs = set(bs1.keys()).union(set(bs2.keys()))
-    for pkg in pkgs:
-        tasks1 = bs1[pkg]['tasks'] if pkg in bs1 else {}
-        tasks2 = bs2[pkg]['tasks'] if pkg in bs2 else {}
-        if not tasks1:
-            pkg_op = '+ '
-        elif not tasks2:
-            pkg_op = '- '
-        else:
-            pkg_op = '  '
-
-        for task in set(tasks1.keys()).union(set(tasks2.keys())):
-            task_op = '  '
-            if task in tasks1:
-                # Average over all values
-                val1 = [getattr(b, val_type) for b in bs1[pkg]['tasks'][task]]
-                val1 = sum(val1) / len(val1)
-            else:
-                task_op = '+ '
-                val1 = 0
-            if task in tasks2:
-                # Average over all values
-                val2 = [getattr(b, val_type) for b in bs2[pkg]['tasks'][task]]
-                val2 = sum(val2) / len(val2)
-            else:
-                val2 = 0
-                task_op = '- '
-
-            if val1 == 0:
-                reldiff = float('inf')
-            else:
-                reldiff = 100 * (val2 - val1) / val1
-
-            if max(val1, val2) < min_val:
-                log.debug("Filtering out %s:%s (%s)", pkg, task,
-                          val_to_str(max(val1, val2)))
-                continue
-            if abs(val2 - val1) < min_absdiff:
-                log.debug("Filtering out %s:%s (difference of %s)", pkg, task,
-                          val_to_str(val2-val1))
-                continue
-            tasks_diff.append(TaskDiff(pkg, pkg_op, task, task_op, val1, val2,
-                                       val2-val1, reldiff))
+    tasks_diff = diff_buildstats(bs1, bs2, val_type, min_val, min_absdiff)
 
     # Sort our list
     for field in reversed(sort_by):