DpkgHistory.__add__() done and small bugfixes.

Adding two DpkgHistory instances combines their operation lists
relying on their chronological relationship to choose what to say
for each package. e.g. x installed and then upgraded -> just say
installed and put latest version number.

Assumes there is no overlap between the two. Normally there won't
be.

Author: jpeg729

TODO

@@ -1,12 +1,14 @@
 Roadmap in order of planned implementation
 
- status command line option
-    -gives date of last snapshot and lists recent package changes
-    
  pickle
-    -in create_snapshot and set_default
+    -in create_snapshot
+    -add function to combine two DpkgHistory objects
+    -set_default
     -testing
 
+ DpkgHistory
+    -change default for since (currently 30d)
+ 
  delete_snapshot 
     -should consolidate package change info, unless there is no parent
 

apt-btrfs-snapshot

@@ -144,7 +144,7 @@ if __name__ == "__main__":
     elif args.command == "list":
         res = apt_btrfs.list(args.how_many)
     elif args.command == "status":
-        res = apt_btrfs.status(args.how_many)
+        res = apt_btrfs.status()
     elif args.command == "set-default":
         res = apt_btrfs.set_default(args.snapshot, args.tag)
     elif args.command == "rollback":

dpkg_history.py

@@ -32,22 +32,52 @@
 
 class DpkgHistory(dict):
     """ Parser for the dpkg history logs """
-    def __init__(self, var_location="/var/", since = None):
+    def __init__(self, var_location="/var/", since = None, do_parse=True):
         super(DpkgHistory, self).__init__()
 
         self["install"] = []
         self["auto-install"] = []
         self["upgrade"] = []
         self["remove"] = []
         self["purge"] = []
-
+        
         self.var_location = var_location
         self.since = self._get_date_from_string(since)
-        self._get_dpkg_history()
-        if len(self['install']) > 0:
-            self.auto = self._find_auto_installs()
-            self._split_installs_by_auto()
-        self._sort_lists()
+        self.auto = []
+
+        if do_parse:
+            self._get_dpkg_history()
+            if len(self['install']) > 0:
+                self.auto = self._find_auto_installs()
+                self._split_installs_by_auto()
+            self._sort_lists()
+
+    def __add__(self, other):
+        if self.since < other.since:
+            order = self, other
+        else:
+            order = other, self
+        
+        ops_by_package = defaultdict(list)
+        versions = defaultdict(list)
+        for history in order:
+            for op in history.keys():
+                for package, version in history[op]:
+                    ops_by_package[package].append(op)
+                    if ", " in version:
+                        version = version.split(", ")
+                    else:
+                        version = [version]
+                    versions[package].append(version)
+                    
+        combined = DpkgHistory(since = order[0].since, do_parse=False)
+        combined._distill_ops(ops_by_package, versions)
+        if len(combined['install']) > 0:
+            combined.auto = order[1].auto
+            combined._split_installs_by_auto()
+        combined._sort_lists()
+        
+        return combined
 
     def _get_date_from_string(self, since):
         if isinstance(since, basestring):
@@ -61,7 +91,8 @@ def _get_dpkg_history(self):
         """ Read dpkg.log's and return dictionary of ops
         """
         logfiles = self._logfiles_to_check()
-        self._parse(logfiles)
+        ops_by_package, versions = self._parse_by_package(logfiles)
+        self._distill_ops(ops_by_package, versions)
 
     def _logfiles_to_check(self):
         """ Return an ordered list of opened logfiles young enough to be 
@@ -99,13 +130,13 @@ def _read_files(self, files):
             for line in f:
                 yield line.strip()
 
-    def _parse(self, logfiles):
+    def _parse_by_package(self, logfiles):
         """ reads in the opened logfiles and makes lists of the ops mentioned.
             Returns a dictionary of lists, each list contains (pkg, version)
             tuples.
         """
         ops_by_package = defaultdict(list)
-        version = defaultdict(list)
+        versions = defaultdict(list)
         # List ops per package
         for line in self._read_files(logfiles):
             if line == "":
@@ -123,15 +154,18 @@ def _parse(self, logfiles):
 
             package = bits[3]
             ops_by_package[package].append(linetype)
-            version[package].append(bits[4:6])
-        
+            versions[package].append(bits[4:6])
+            
+        return ops_by_package, versions
+    
+    def _distill_ops(self, ops_by_package, versions):        
         instup = ("install", "upgrade")
         remurge = ("remove", "purge")
         # Decide which op to remember for each package
         for package, ops in ops_by_package.iteritems():
 
-            oldest_version = version[package][0][0]
-            newest_version = version[package][-1][1]
+            oldest_version = versions[package][0][0]
+            newest_version = versions[package][-1][-1]
             version_change = "%s, %s" % (oldest_version, newest_version)
 
             if ops[0] == "install" and ops[-1] not in remurge:

test/test_dpkg_history.py

@@ -130,6 +130,23 @@ def test_auto_installed_separation(self):
         expected = [(u'lib32asound2', u'1.0.25-1ubuntu10.2'), (u'lib32z1', u'1:1.2.3.4.dfsg-3ubuntu4'), (u'libc6-i386', u'2.15-0ubuntu10.4'), (u'linux-headers-3.8.0-27', u'3.8.0-27.40~precise3'), (u'linux-headers-3.8.0-27-generic', u'3.8.0-27.40~precise3'), (u'lynx-cur', u'2.8.8dev.9-2ubuntu0.12.04.1'), (u'python-gpgme', u'0.2-1')]
         self.assertEqual(log['auto-install'], expected)
 
+    def test_add(self):
+        log1 = DpkgHistory(do_parse=False)
+        log2 = DpkgHistory(do_parse=False)
+        log1['install'] = [('one', '1'), ('two', '2'), ('three', '3')]
+        log1['upgrade'] = [('four', '4, 4.1'), ('five', '5')]
+        log1['remove'] = [('six', '6'), ('seven', '7')]
+        log2['install'] = [('eight', '8'), ('six', '6.1')]
+        log2['remove'] = [('two', '2'), ('five', '5')]
+        log2['upgrade'] = [('one', '1, 1.2'), ('four', '4.1, 4.2')]
+        log3 = log1 + log2
+        self.assertEqual(log3['install'], [('eight', '8'), 
+            ('one', u'1.2'), ('three', '3')])
+        self.assertEqual(log3['upgrade'], [('four', '4, 4.2'), 
+            ('six', '6, 6.1')])
+        self.assertEqual(log3['remove'], [('five', '5'), 
+            ('seven', '7')])
+        self.assertEqual(log3['purge'], log3['auto-install'], [])
 
 if __name__ == "__main__":
     unittest.main()