diff --git a/ox/cache.py b/ox/cache.py
index 2dbc0e2..b8264de 100644
--- a/ox/cache.py
+++ b/ox/cache.py
@@ -144,6 +144,17 @@ class Cache:
     def set(self, url, post_data, data, headers):
         pass
 
+    def get_domain(self, url):
+        return ".".join(urllib.parse.urlparse(url)[1].split('.')[-2:])
+
+    def get_url_hash(self, url, data=None):
+        if data:
+            url_hash = hashlib.sha1((url + '?' + data).encode('utf-8')).hexdigest()
+        else:
+            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
+        return url_hash
+
+
 class SQLiteCache(Cache):
     def __init__(self):
         path = cache_path()
@@ -171,7 +182,7 @@ class SQLiteCache(Cache):
             self.set_setting(c, 'version', 1)
             c.execute('''ALTER TABLE cache ADD compressed INT DEFAULT 0''')
             conn.commit()
-    
+
     def get_setting(self, c, key, default=None):
         c.execute('SELECT value FROM setting WHERE key = ?', (key, ))
         for row in c:
@@ -185,10 +196,7 @@ class SQLiteCache(Cache):
         r = None
         if timeout == 0:
             return r
-        if data:
-            url_hash = hashlib.sha1((url + '?' + data).encode('utf-8')).hexdigest()
-        else:
-            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
+        url_hash = self.get_url_hash(url, data)
 
         conn = self.connect()
         c = conn.cursor()
@@ -218,23 +226,19 @@ class SQLiteCache(Cache):
         return r
 
     def delete(self, url, data=None, headers=DEFAULT_HEADERS):
-        if data:
-            url_hash = hashlib.sha1((url + '?' + data).encode('utf-8')).hexdigest()
-        else:
-            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
+        url_hash = self.get_url_hash(url, data)
         conn = self.connect()
         c = conn.cursor()
         sql = 'DELETE FROM cache WHERE url_hash=?'
         t = (url_hash, )
         c.execute(sql, t)
+        conn.commit()
+        c.close()
+        conn.close()
 
     def set(self, url, post_data, data, headers):
-        if post_data:
-            url_hash = hashlib.sha1((url + '?' + post_data).encode('utf-8')).hexdigest()
-        else:
-            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
-
-        domain = ".".join(urllib.parse.urlparse(url)[1].split('.')[-2:])
+        url_hash = self.get_url_hash(url, post_data)
+        domain = self.get_domain(url)
 
         conn = self.connect()
         c = conn.cursor()
@@ -279,18 +283,15 @@ class FileCache(Cache):
         i = os.path.join(prefix, '%s.json'%h)
         f = os.path.join(prefix, '%s.dat'%h)
         return prefix, i, f
- 
+
     def get(self, url, data={}, headers=DEFAULT_HEADERS, timeout=-1, value="data"):
         r = None
         if timeout == 0:
             return r
 
-        if data:
-            url_hash = hashlib.sha1((url + '?' + data).encode('utf-8')).hexdigest()
-        else:
-            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
+        url_hash = self.get_url_hash(url, data)
+        domain = self.get_domain(url)
 
-        domain = ".".join(urllib.parse.urlparse(url)[1].split('.')[-2:])
         prefix, i, f = self.files(domain, url_hash)
         if os.path.exists(i):
             with open(i) as _i:
@@ -314,22 +315,17 @@ class FileCache(Cache):
         return r
 
     def delete(self, url, data=None, headers=DEFAULT_HEADERS):
-        if data:
-            url_hash = hashlib.sha1((url + '?' + data).encode('utf-8')).hexdigest()
-        else:
-            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
-        domain = ".".join(urllib.parse.urlparse(url)[1].split('.')[-2:])
+        url_hash = self.get_url_hash(url, data)
+        domain = self.get_domain(url)
+
         prefix, i, f = self.files(domain, url_hash)
         if os.path.exists(i):
             os.unlink(i)
 
     def set(self, url, post_data, data, headers):
-        if post_data:
-            url_hash = hashlib.sha1((url + '?' + post_data).encode('utf-8')).hexdigest()
-        else:
-            url_hash = hashlib.sha1(url.encode('utf-8')).hexdigest()
+        url_hash = self.get_url_hash(url, post_data)
+        domain = self.get_domain(url)
 
-        domain = ".".join(urllib.parse.urlparse(url)[1].split('.')[-2:])
         prefix, i, f = self.files(domain, url_hash)
         makedirs(prefix)