Add FileOutputCache to avoid disk reading generated posts if not necessary

Always write post on edit (don't try to hash)

dynastie/generators/generator.py

@@ -90,19 +90,35 @@ class DynastieGenerator:
         return int(res)
 
     def writeIfNotTheSame(self, filename, node):
+        from dynastie.models import FileOutputCache
+
         writer = StrictUTF8Writer()
         node.writexml(writer)
         content = writer.getvalue().encode('utf-8')
-        if os.path.exists(filename):
-            src_md5 = hashlib.md5()
-            f = open(filename,'rb') 
-            src_md5.update(f.read())
-            f.close()
 
-            dst_md5 = hashlib.md5()
-            dst_md5.update(content)
+        dst_md5 = hashlib.md5()
+        dst_md5.update(content)
 
-            if src_md5.digest() == dst_md5.digest():
+        cache_objs = FileOutputCache.objects.filter(name=filename)
+        if cache_objs.count() == 0:
+            cache_obj = None
+        else:
+            cache_obj = cache_objs[0]
+
+        if not cache_obj is None or os.path.exists(filename):
+            if cache_obj is None:
+                src_md5 = hashlib.md5()
+                f = open(filename,'rb') 
+                src_md5.update(f.read())
+                f.close()
+                src_md5 = src_md5.hexdigest()
+            else:
+                src_md5 = cache_obj.hash
+
+            if src_md5 == dst_md5.hexdigest():
+                if cache_obj is None:
+                    cache_obj = FileOutputCache(name=filename, hash=src_md5)
+                    cache_obj.save()
                 filename = filename + '.gz'
                 if not os.path.exists(filename):
                     f = gzip.open(filename, 'wb')
@@ -111,6 +127,11 @@ class DynastieGenerator:
                 return
             os.unlink(filename)
 
+        if cache_obj is None:
+            cache_obj = FileOutputCache(name=filename, hash=dst_md5.hexdigest())
+        else:
+            cache_obj.hash = dst_md5.hexdigest()
+
         self.addReport('Write (and compress) ' + filename)
         f = open(filename,'wb') 
         f.write(content)
@@ -122,6 +143,8 @@ class DynastieGenerator:
         f.write(content)
         f.close()
         
+        cache_obj.save()
+
         self.somethingWrote = True
 
     def createLinkElem(self, dom, path, title):

dynastie/models.py

@@ -305,38 +305,20 @@ class Post(models.Model):
                     self.tags.remove(t)
 
     def createPost(self, content, tags):
-        b = self.blog
-        output = b.src_path
+        output = self.blog.src_path
         if not os.path.exists(output + '/_post'):
             os.mkdir(output + '/_post')
 
         filename = output + '/_post/' + str(self.pk)
         content = unicode(content)
         content = content.encode('utf-8')
-        modif = True
 
-        if os.path.exists(filename):
-            f = open(filename, 'rb')
-            src_md5 = hashlib.md5()
-            src_md5.update(f.read())
-            f.close()
-
-            dst_md5 = hashlib.md5()
-            dst_md5.update(content)
-
-            if src_md5.digest() == dst_md5.digest():
-                modif = False
-            else:
-                os.unlink(filename)
-
-        if modif:
-            f = open(filename, 'wb')
-            f.write(content)
-            f.close()
-            self.modification_date=datetime.now()
+        f = open(filename, 'wb')
+        f.write(content)
+        f.close()
+        self.modification_date=datetime.now()
 
         self.manageTags(tags)
-        self.save()
 
     def remove(self):
         b = self.blog
@@ -432,6 +414,10 @@ class Comment(models.Model):
     def _remove_br(self):
         self.the_comment = self.the_comment.replace('<br />', '\n')
 
+class FileOutputCache(models.Model):
+    name = models.CharField(max_length=512)
+    hash = models.CharField(max_length=512)
+
 @receiver(post_init, sender=Blog)
 def init_blog_signal(sender, **kwargs):
     kwargs['instance'].create_paths()

dynastie/sites/blog.soutade.fr/_ljdc.xml

@@ -1,5 +1,23 @@
 <?xml version="1.0" encoding="utf-8"?>
 <ljdc>
+    <entry>
+        <id>87094581962</id>
+        <address>http://thecodinglove.com/post/87094581962/when-caffeine-is-no-longer-effective</address>
+        <title>when caffeine is no longer effective</title>
+        <img>http://i.imgur.com/ocjPFJL.gif</img>
+    </entry>
+    <entry>
+        <id>85721632915</id>
+        <address>http://lesjoiesducode.fr/post/85721632915/quand-je-suggere-lusage-de-nouvelles-technos</address>
+        <title>quand je suggère l'usage de nouvelles technos</title>
+        <img>http://i.imgur.com/BezORLq.gif</img>
+    </entry>
+    <entry>
+        <id>85709017865</id>
+        <address>http://lesjoiesducode.fr/post/85709017865/quand-un-collegue-me-refile-un-ticket-facile-a</address>
+        <title>quand un collègue me refile un ticket "facile à traiter"</title>
+        <img>http://ljdchost.com/XyeioZc.gif</img>
+    </entry>
     <entry>
         <id>85704348740</id>
         <address>http://lesjoiesducode.fr/post/85704348740/quand-le-client-reclame-une-feature-hors-cahier-des</address>