[FIX] cache: ormcache logger

The adaptation to Python 3 was done with two mistakes: the iteration on the lru
cache does not return keys, and functions are not sortable.

closes odoo/odoo#28870

odoo/tools/cache.py

@@ -201,16 +201,22 @@ def log_ormcache_stats(sig=None, frame=None):
 
     me = threading.currentThread()
     me_dbname = getattr(me, 'dbname', 'n/a')
-    entries = defaultdict(int)
-    for dbname, reg in Registry.registries.items():
-        for key in reg.cache:
-            entries[(dbname,) + key[:2]] += 1
-    for key, count in sorted(entries.items()):
-        dbname, model_name, method = key
+
+    for dbname, reg in sorted(Registry.registries.items()):
+        # set logger prefix to dbname
         me.dbname = dbname
-        stat = STAT[key]
-        _logger.info("%6d entries, %6d hit, %6d miss, %6d err, %4.1f%% ratio, for %s.%s",
-                     count, stat.hit, stat.miss, stat.err, stat.ratio, model_name, method.__name__)
+        entries = defaultdict(int)
+        # beware: we use .keys() on purpose here (reg.cache is not a real dict)
+        for key in reg.cache.keys():
+            entries[key[:2]] += 1
+        # show entries sorted by model name, method name
+        for key in sorted(entries, key=lambda key: (key[0], key[1].__name__)):
+            model, method = key
+            stat = STAT[(dbname, model, method)]
+            _logger.info(
+                "%6d entries, %6d hit, %6d miss, %6d err, %4.1f%% ratio, for %s.%s",
+                entries[key], stat.hit, stat.miss, stat.err, stat.ratio, model, method.__name__,
+            )
 
     me.dbname = me_dbname