grouped object creations in a transaction, use a cache for retrieving tags and templates

django_journal/__init__.py

@@ -1,7 +1,8 @@
 from exceptions import JournalException
-from models import (Journal, Tag, Template, ObjectData, StringData)
+from models import (Journal, Tag, Template)
 
-from django.db import models
+
+from django.db import models, transaction
 from django.conf import settings
 
 __all__ = ('record', 'error_record', 'Journal')
@@ -12,7 +13,28 @@ def unicode_truncate(s, length, encoding='utf-8'):
     encoded = s.encode(encoding)[:length]
     return encoded.decode(encoding, 'ignore')
 
-def record(tag, tpl, using='default', **kwargs):
+
+__TAG_CACHE = dict()
+
+
+def get_tag(name, using=None):
+    if name not in __TAG_CACHE:
+        __TAG_CACHE[name], created = \
+                Tag.objects.using(using).get_or_create(name=name)
+    return __TAG_CACHE[name]
+
+
+__TEMPLATE_CACHE = dict()
+
+
+def get_template(content, using=None):
+    if content not in __TEMPLATE_CACHE:
+        __TEMPLATE_CACHE[content], created = \
+                Template.objects.using(using).get_or_create(content=content)
+    return __TEMPLATE_CACHE[content]
+
+
+def record(tag, template, using=None, **kwargs):
     '''Record an event in the journal. The modification is done inside the
        current transaction.
 
@@ -23,22 +45,23 @@ def record(tag, tpl, using='default', **kwargs):
        kwargs:
            a mapping of object or data to interpolate in the format string
     '''
-    tag, created = Tag.objects.using(using).get_or_create(name=tag)
-    template, created = Template.objects.using(using).get_or_create(content=tpl)
-    try:
-        message = tpl.format(**kwargs)
-    except (KeyError, IndexError), e:
-        raise JournalException(
-                'Missing variable for the template message', tpl, e)
-    journal = Journal.objects.using(using).create(tag=tag, template=template,
-            message=unicode_truncate(message, 128))
-    for tag, value in kwargs.iteritems():
-        tag, created = Tag.objects.using(using).get_or_create(name=tag)
-        if isinstance(value, models.Model):
-            journal.objectdata_set.create(tag=tag, content_object=value)
-        else:
-            journal.stringdata_set.create(tag=tag, content=unicode(value))
-    return journal
+    with transaction.commit_on_success(using=using):
+        tag = get_tag(tag, using=using)
+        template = get_template(template, using=using)
+        try:
+            message = template.content.format(**kwargs)
+        except (KeyError, IndexError), e:
+            raise JournalException(
+                    'Missing variable for the template message', template, e)
+        journal = Journal.objects.using(using).create(tag=tag, template=template,
+                message=unicode_truncate(message, 128))
+        for tag, value in kwargs.iteritems():
+            tag = get_tag(tag, using=using)
+            if isinstance(value, models.Model):
+                journal.objectdata_set.create(tag=tag, content_object=value)
+            else:
+                journal.stringdata_set.create(tag=tag, content=unicode(value))
+        return journal
 
 def error_record(tag, tpl, **kwargs):
     '''Records error events.