buildhistory: add script to check for significant changes

Adds a buildhistory-diff script which can be used to analyse changes in
the buildhistory git repository (as produced by buildhistory.bbclass),
and report significant ones that may need manual checking to ensure they
aren't regressions (e.g. package size changed by more than a certain
percentage, files added/removed/changed in the image, etc.)

The implementation is actually split into a small script and a Python
module, in order to make the logic re-usable in a future web-based
interface.

Implements the first part of [YOCTO #1566].

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

2 files changed, 283 insertions, 0 deletions

diff --git a/meta/lib/oe/buildhistory_analysis.py b/meta/lib/oe/buildhistory_analysis.py
new file mode 100644
index 000000000..9f42fe38a
--- /dev/null
+++ b/meta/lib/oe/buildhistory_analysis.py
@@ -0,0 +1,240 @@
+# Report significant differences in the buildhistory repository since a specific revision
+#
+# Copyright (C) 2012 Intel Corporation
+# Author: Paul Eggleton <paul.eggleton@linux.intel.com>
+#
+# Note: requires GitPython 0.3.1+
+#
+# You can use this from the command line by running scripts/buildhistory-diff
+#
+
+import sys
+import os.path
+import difflib
+import git
+
+
+# How to display fields
+pkg_list_fields = ['DEPENDS', 'RDEPENDS', 'RRECOMMENDS', 'PACKAGES', 'FILES', 'FILELIST']
+pkg_numeric_fields = ['PKGSIZE']
+# Fields to monitor
+pkg_monitor_fields = ['RDEPENDS', 'RRECOMMENDS', 'PACKAGES', 'FILELIST', 'PKGSIZE']
+# Percentage change to alert for numeric fields
+pkg_monitor_numeric_threshold = 20
+# Image files to monitor
+img_monitor_files = ['installed-package-names.txt', 'files-in-image.txt']
+
+
+class ChangeRecord:
+    def __init__(self, path, fieldname, oldvalue, newvalue):
+        self.path = path
+        self.fieldname = fieldname
+        self.oldvalue = oldvalue
+        self.newvalue = newvalue
+        self.filechanges = None
+
+    def __str__(self):
+        if self.fieldname in pkg_list_fields:
+            aitems = self.oldvalue.split(' ')
+            bitems = self.newvalue.split(' ')
+            removed = list(set(aitems) - set(bitems))
+            added = list(set(bitems) - set(aitems))
+            return '%s: %s:%s%s' % (self.path, self.fieldname, ' removed "%s"' % ' '.join(removed) if removed else '', ' added "%s"' % ' '.join(added) if added else '')
+        elif self.fieldname in pkg_numeric_fields:
+            aval = int(self.oldvalue)
+            bval = int(self.newvalue)
+            percentchg = ((bval - aval) / float(aval)) * 100
+            return '%s: %s changed from %d to %d (%s%d%%)' % (self.path, self.fieldname, aval, bval, '+' if percentchg > 0 else '', percentchg)
+        elif self.fieldname in img_monitor_files:
+            out = 'Changes to %s (%s):\n  ' % (self.path, self.fieldname)
+            if self.filechanges:
+                out += '\n  '.join(['%s' % i for i in self.filechanges])
+            else:
+                alines = self.oldvalue.splitlines()
+                blines = self.newvalue.splitlines()
+                diff = difflib.unified_diff(alines, blines, self.fieldname, self.fieldname, lineterm='')
+                out += '\n  '.join(list(diff))
+                out += '\n  --'
+            return out
+        else:
+            return '%s: %s changed from "%s" to "%s"' % (self.path, self.self.fieldname, self.oldvalue, self.newvalue)
+
+
+class FileChange:
+    changetype_add = 'A'
+    changetype_remove = 'R'
+    changetype_type = 'T'
+    changetype_perms = 'P'
+    changetype_ownergroup = 'O'
+    changetype_link = 'L'
+
+    def __init__(self, path, changetype, oldvalue = None, newvalue = None):
+        self.path = path
+        self.changetype = changetype
+        self.oldvalue = oldvalue
+        self.newvalue = newvalue
+
+    def _ftype_str(self, ftype):
+        if ftype == '-':
+            return 'file'
+        elif ftype == 'd':
+            return 'directory'
+        elif ftype == 'l':
+            return 'symlink'
+        elif ftype == 'c':
+            return 'char device'
+        elif ftype == 'b':
+            return 'block device'
+        elif ftype == 'p':
+            return 'fifo'
+        elif ftype == 's':
+            return 'socket'
+        else:
+            return 'unknown (%s)' % ftype
+
+    def __str__(self):
+        if self.changetype == self.changetype_add:
+            return '%s was added' % self.path
+        elif self.changetype == self.changetype_remove:
+            return '%s was removed' % self.path
+        elif self.changetype == self.changetype_type:
+            return '%s changed type from %s to %s' % (self.path, self._ftype_str(self.oldvalue), self._ftype_str(self.newvalue))
+        elif self.changetype == self.changetype_perms:
+            return '%s changed permissions from %s to %s' % (self.path, self.oldvalue, self.newvalue)
+        elif self.changetype == self.changetype_ownergroup:
+            return '%s changed owner/group from %s to %s' % (self.path, self.oldvalue, self.newvalue)
+        elif self.changetype == self.changetype_link:
+            return '%s changed symlink target from %s to %s' % (self.path, self.oldvalue, self.newvalue)
+        else:
+            return '%s changed (unknown)' % self.path
+
+
+def blob_to_dict(blob):
+    alines = blob.data_stream.read().splitlines()
+    adict = {}
+    for line in alines:
+        splitv = [i.strip() for i in line.split('=',1)]
+        if splitv.count > 1:
+            adict[splitv[0]] = splitv[1]
+    return adict
+
+
+def file_list_to_dict(lines):
+    adict = {}
+    for line in lines:
+        # Leave the last few fields intact so we handle file names containing spaces
+        splitv = line.split(None,4)
+        # Grab the path and remove the leading .
+        path = splitv[4][1:].strip()
+        # Handle symlinks
+        if(' -> ' in path):
+            target = path.split(' -> ')[1]
+            path = path.split(' -> ')[0]
+            adict[path] = splitv[0:3] + [target]
+        else:
+            adict[path] = splitv[0:3]
+    return adict
+
+
+def compare_file_lists(alines, blines):
+    adict = file_list_to_dict(alines)
+    bdict = file_list_to_dict(blines)
+    filechanges = []
+    for path, splitv in adict.iteritems():
+        newsplitv = bdict.pop(path, None)
+        if newsplitv:
+            # Check type
+            oldvalue = splitv[0][0]
+            newvalue = newsplitv[0][0]
+            if oldvalue != newvalue:
+                filechanges.append(FileChange(path, FileChange.changetype_type, oldvalue, newvalue))
+            # Check permissions
+            oldvalue = splitv[0][1:]
+            newvalue = newsplitv[0][1:]
+            if oldvalue != newvalue:
+                filechanges.append(FileChange(path, FileChange.changetype_perms, oldvalue, newvalue))
+            # Check owner/group
+            oldvalue = '%s/%s' % (splitv[1], splitv[2])
+            newvalue = '%s/%s' % (newsplitv[1], newsplitv[2])
+            if oldvalue != newvalue:
+                filechanges.append(FileChange(path, FileChange.changetype_ownergroup, oldvalue, newvalue))
+            # Check symlink target
+            if newsplitv[0][0] == 'l':
+                if splitv.count > 3:
+                    oldvalue = splitv[3]
+                else:
+                    oldvalue = None
+                newvalue = newsplitv[3]
+                if oldvalue != newvalue:
+                    filechanges.append(FileChange(path, FileChange.changetype_link, oldvalue, newvalue))
+        else:
+            filechanges.append(FileChange(path, FileChange.changetype_remove))
+
+    # Whatever is left over has been added
+    for path in bdict:
+        filechanges.append(FileChange(path, FileChange.changetype_add))
+
+    return filechanges
+
+
+def compare_lists(alines, blines):
+    removed = list(set(alines) - set(blines))
+    added = list(set(blines) - set(alines))
+
+    filechanges = []
+    for pkg in removed:
+        filechanges.append(FileChange(pkg, FileChange.changetype_remove))
+    for pkg in added:
+        filechanges.append(FileChange(pkg, FileChange.changetype_add))
+
+    return filechanges
+
+
+def process_changes(repopath, revision1, revision2 = 'HEAD', report_all = False):
+    repo = git.Repo(repopath)
+    assert repo.bare == False
+    commit = repo.commit(revision1)
+    diff = commit.diff(revision2)
+
+    changes = []
+    for d in diff.iter_change_type('M'):
+        path = os.path.dirname(d.a_blob.path)
+        if path.startswith('packages/'):
+            adict = blob_to_dict(d.a_blob)
+            bdict = blob_to_dict(d.b_blob)
+
+            for key in adict:
+                if report_all or key in pkg_monitor_fields:
+                    if adict[key] != bdict[key]:
+                        if (not report_all) and key in pkg_numeric_fields:
+                            aval = int(adict[key])
+                            bval = int(bdict[key])
+                            percentchg = ((bval - aval) / float(aval)) * 100
+                            if percentchg < pkg_monitor_numeric_threshold:
+                                continue
+                        chg = ChangeRecord(path, key, adict[key], bdict[key])
+                        changes.append(chg)
+        elif path.startswith('images/'):
+            filename = os.path.basename(d.a_blob.path)
+            if filename in img_monitor_files:
+                if filename == 'files-in-image.txt':
+                    alines = d.a_blob.data_stream.read().splitlines()
+                    blines = d.b_blob.data_stream.read().splitlines()
+                    filechanges = compare_file_lists(alines,blines)
+                    if filechanges:
+                        chg = ChangeRecord(path, filename, None, None)
+                        chg.filechanges = filechanges
+                        changes.append(chg)
+                elif filename == 'installed-package-names.txt':
+                    alines = d.a_blob.data_stream.read().splitlines()
+                    blines = d.b_blob.data_stream.read().splitlines()
+                    filechanges = compare_lists(alines,blines)
+                    if filechanges:
+                        chg = ChangeRecord(path, filename, None, None)
+                        chg.filechanges = filechanges
+                        changes.append(chg)
+                else:
+                    chg = ChangeRecord(path, filename, d.a_blob.data_stream.read(), d.b_blob.data_stream.read())
+                    changes.append(chg)
+
+    return changes
diff --git a/scripts/buildhistory-diff b/scripts/buildhistory-diff
new file mode 100755
index 000000000..6b344ebfa
--- /dev/null
+++ b/scripts/buildhistory-diff
@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+
+# Report significant differences in the buildhistory repository since a specific revision
+#
+# Copyright (C) 2012 Intel Corporation
+# Author: Paul Eggleton <paul.eggleton@linux.intel.com>
+
+import sys
+import os.path
+
+# Ensure PythonGit is installed (buildhistory_analysis needs it)
+try:
+    import git
+except ImportError:
+    print("Please install PythonGit 0.3.1 or later in order to use this script")
+    sys.exit(1)
+
+
+def main():
+    if (len(sys.argv) < 3):
+        print("Report significant differences in the buildhistory repository")
+        print("Syntax: %s <buildhistory-path> <since-revision> [to-revision]" % os.path.basename(sys.argv[0]))
+        print("If to-revision is not specified, it defaults to HEAD")
+        sys.exit(1)
+
+    # Set path to OE lib dir so we can import the buildhistory_analysis module
+    newpath = os.path.abspath(os.path.dirname(os.path.abspath(sys.argv[0])) + '/../meta/lib')
+    sys.path = sys.path + [newpath]
+    import oe.buildhistory_analysis
+
+    if len(sys.argv) > 3:
+        torev = sys.argv[3]
+    else:
+        torev = 'HEAD'
+    changes = oe.buildhistory_analysis.process_changes(sys.argv[1], sys.argv[2], torev)
+    for chg in changes:
+        print('%s' % chg)
+
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()