first cut at tree-building API and synchronous implementation

lithoxyl/context.py

@@ -59,6 +59,37 @@ def note(self, name, message, *a, **kw):
             nh(name, message)
         return
 
+    def _sync_parent_getter(self, record):
+        import weakref
+
+        logger = record.logger
+
+        try:
+            rec_tree = self._record_tree[logger]
+        except AttributeError:
+            self._record_tree = {}
+            rec_tree = self._record_tree[logger] = weakref.WeakKeyDictionary()
+            self._last_logged = weakref.WeakKeyDictionary({logger: None})
+        except KeyError:
+            rec_tree = self._record_tree[logger] = weakref.WeakKeyDictionary()
+
+        try:
+            ret = rec_tree[record]
+        except KeyError:
+            # haven't seen this one before
+            if self._last_logged.get(logger):
+                ret = self._last_logged[logger]
+                # TODO: might be belt and braces
+                if ret.record_id < record.record_id:
+                    self._last_logged[logger] = record
+            else:
+                # nothing logged yet
+                ret = None
+                self._last_logged[logger] = record
+
+            rec_tree[record] = ret
+        return ret
+
     def enable_async(self, **kwargs):
         update_loggers = kwargs.pop('update_loggers', True)
         update_sigterm = kwargs.pop('update_sigterm', True)
@@ -134,6 +165,23 @@ def remove_logger(self, logger):
             pass
 
 
+class SyncTreeTracker(object):
+    def __init__(self):
+        self.tree = {}
+
+    def get_parent(self, logger, record):
+        try:
+            stack = self.tree[logger]
+        except KeyError:
+            self.tree[logger] = []
+        try:
+            ret = stack[-1]
+        except IndexError:
+            ret = None
+        stack.append(self)
+        return ret
+
+
 def signal_sysexit(signum, frame):
     # return code ends up being 143 for sigterm, See page 544 Kerrisk
     # for more see atexit_reissue_sigterm docstring for more details

lithoxyl/record.py

@@ -90,6 +90,8 @@ def __init__(self, logger, level, name,
         # these can go internal and be lazily created through properties
         self.warn_events = []
         self.exc_events = []
+
+        self.parent_record = self.logger.context._sync_parent_getter(self)
         return
 
     def __repr__(self):

playground.py

@@ -39,8 +39,9 @@
 
 log = Logger('test', sinks=[stderr_sink])
 
-with log.critical('first'):
-    print 'did some work'
+with log.critical('first') as lr1:
+    with log.critical('second') as lr2:
+        print 'did some work'
 
 import os
 print os.getpid()