Use short uuids.

paste/tools.py

@@ -2,24 +2,15 @@ import string
 import shortuuid
 import os
 from webtools import settings
+from .models import Paste
 
-
-def next_slug(slug):
-    """Returns the shortest next slug alphabetically."""
-    slug = list(slug[::-1])
-    for i in range(len(slug)):
-        pos = string.ascii_letters.find(slug[i]) + 1
-        slug[i] = string.ascii_letters[pos % 52]
-        if slug[i] != 'a':
-            break
-    if slug[i] == 'a':
-        slug.append('a')
-    return "".join(slug)[::-1]
-
-
-def random_id():
-    """Returns an id."""
-    return shortuuid.uuid()
+def random_id(model):
+    """Returns a short uuid for the slug of the given model."""
+    uuid = shortuuid.uuid()
+    for i in range(3, len(uuid)):
+        if not model.objects.filter(slug=uuid[:i]):
+            return uuid[:i]
+    return uuid
 
 
 def cache_get_filepath(key):

paste/views.py

@@ -13,7 +13,7 @@ def index(request):
     data = {'menu': 'index',
             'max_characters': settings.MAX_CHARACTERS}
     if request.method == 'POST':
-        paste = Paste(slug=random_id(),
+        paste = Paste(slug=random_id(Paste),
                       paste_ip=request.META['REMOTE_ADDR'],
                       paste_agent=request.META['HTTP_USER_AGENT'])
         form = PasteForm(request.POST, instance=paste)