X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/5a605e04abaa18a80e391c5cc26c48e0125d6f3c..8e658aa5dc4613d7789e8b37adb066c10b601166:/apps/catalogue/utils.py

diff --git a/apps/catalogue/utils.py b/apps/catalogue/utils.py
index 3ffe9c0f6..a48ec0370 100644
--- a/apps/catalogue/utils.py
+++ b/apps/catalogue/utils.py
@@ -20,7 +20,6 @@ from errno import EEXIST, ENOENT
 from fcntl import flock, LOCK_EX
 from zipfile import ZipFile
 
-from librarian import DocProvider
 from reporting.utils import read_chunks
 from celery.task import task
 import catalogue.models
@@ -60,19 +59,6 @@ class ExistingFile(UploadedFile):
         pass
 
 
-class ORMDocProvider(DocProvider):
-    """Used for getting books' children."""
-
-    def __init__(self, book):
-        self.book = book
-
-    def by_slug(self, slug):
-        if slug == self.book.slug:
-            return self.book.xml_file
-        else:
-            return type(self.book).objects.get(slug=slug).xml_file
-
-
 class LockFile(object):
     """
     A file lock monitor class; createas an ${objname}.lock
@@ -163,3 +149,37 @@ def async_build_pdf(book_id, customizations, file_name):
     if not DefaultStorage().exists(file_name):
         book.build_pdf(customizations=customizations, file_name=file_name)
     print "done."
+
+
+class MultiQuerySet(object):
+    def __init__(self, *args, **kwargs):
+        self.querysets = args
+        self._count = None
+    
+    def count(self):
+        if not self._count:
+            self._count = sum(len(qs) for qs in self.querysets)
+        return self._count
+    
+    def __len__(self):
+        return self.count()
+        
+    def __getitem__(self, item):
+        try:
+            indices = (offset, stop, step) = item.indices(self.count())
+        except AttributeError:
+            # it's not a slice - make it one
+            return self[item : item + 1][0]
+        items = []
+        total_len = stop - offset
+        for qs in self.querysets:
+            if len(qs) < offset:
+                offset -= len(qs)
+            else:
+                items += list(qs[offset:stop])
+                if len(items) >= total_len:
+                    return items
+                else:
+                    offset = 0
+                    stop = total_len - len(items)
+                    continue
\ No newline at end of file