move to django 1.4 and django-pipeline,
[wolnelektury.git] / apps / catalogue / models.py
index 9a1e71a..29106b1 100644 (file)
@@ -5,10 +5,9 @@
 from collections import namedtuple
 
 from django.db import models
 from collections import namedtuple
 
 from django.db import models
-from django.db.models import permalink, Q
+from django.db.models import permalink
 import django.dispatch
 import django.dispatch
-from django.core.cache import cache
-from django.core.files.storage import DefaultStorage
+from django.core.cache import get_cache
 from django.utils.translation import ugettext_lazy as _
 from django.contrib.auth.models import User
 from django.template.loader import render_to_string
 from django.utils.translation import ugettext_lazy as _
 from django.contrib.auth.models import User
 from django.template.loader import render_to_string
@@ -16,23 +15,19 @@ from django.utils.datastructures import SortedDict
 from django.utils.safestring import mark_safe
 from django.utils.translation import get_language
 from django.core.urlresolvers import reverse
 from django.utils.safestring import mark_safe
 from django.utils.translation import get_language
 from django.core.urlresolvers import reverse
-from django.db.models.signals import post_save, m2m_changed, pre_delete
+from django.db.models.signals import post_save, pre_delete, post_delete
+import jsonfield
 
 from django.conf import settings
 
 from newtagging.models import TagBase, tags_updated
 from newtagging import managers
 
 from django.conf import settings
 
 from newtagging.models import TagBase, tags_updated
 from newtagging import managers
-from catalogue.fields import JSONField, OverwritingFileField
-from catalogue.utils import create_zip, split_tags
-from catalogue.tasks import touch_tag, index_book
-from shutil import copy
-from glob import glob
+from catalogue.fields import OverwritingFileField
+from catalogue.utils import create_zip, split_tags, truncate_html_words
+from catalogue import tasks
 import re
 import re
-from os import path
 
 
 
 
-import search
-
 # Those are hard-coded here so that makemessages sees them.
 TAG_CATEGORIES = (
     ('author', _('author')),
 # Those are hard-coded here so that makemessages sees them.
 TAG_CATEGORIES = (
     ('author', _('author')),
@@ -44,8 +39,8 @@ TAG_CATEGORIES = (
     ('book', _('book')),
 )
 
     ('book', _('book')),
 )
 
-# not quite, but Django wants you to set a timeout
-CACHE_FOREVER = 2419200  # 28 days
+
+permanent_cache = get_cache('permanent')
 
 
 class TagSubcategoryManager(models.Manager):
 
 
 class TagSubcategoryManager(models.Manager):
@@ -58,6 +53,10 @@ class TagSubcategoryManager(models.Manager):
 
 
 class Tag(TagBase):
 
 
 class Tag(TagBase):
+    """A tag attachable to books and fragments (and possibly anything).
+    
+    Used to represent searchable metadata (authors, epochs, genres, kinds),
+    fragment themes (motifs) and some book hierarchy related kludges."""
     name = models.CharField(_('name'), max_length=50, db_index=True)
     slug = models.SlugField(_('slug'), max_length=120, db_index=True)
     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True)
     name = models.CharField(_('name'), max_length=50, db_index=True)
     slug = models.SlugField(_('slug'), max_length=120, db_index=True)
     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True)
@@ -119,8 +118,8 @@ class Tag(TagBase):
             objects = Book.tagged.with_all((self,)).order_by()
             if self.category != 'set':
                 # eliminate descendants
             objects = Book.tagged.with_all((self,)).order_by()
             if self.category != 'set':
                 # eliminate descendants
-                l_tags = Tag.objects.filter(slug__in=[book.book_tag_slug() for book in objects])
-                descendants_keys = [book.pk for book in Book.tagged.with_any(l_tags)]
+                l_tags = Tag.objects.filter(slug__in=[book.book_tag_slug() for book in objects.iterator()])
+                descendants_keys = [book.pk for book in Book.tagged.with_any(l_tags).iterator()]
                 if descendants_keys:
                     objects = objects.exclude(pk__in=descendants_keys)
         return objects.count()
                 if descendants_keys:
                     objects = objects.exclude(pk__in=descendants_keys)
         return objects.count()
@@ -216,30 +215,8 @@ def book_upload_path(ext=None, maxlen=100):
     return lambda *args: get_dynamic_path(*args, ext=ext, maxlen=maxlen)
 
 
     return lambda *args: get_dynamic_path(*args, ext=ext, maxlen=maxlen)
 
 
-def get_customized_pdf_path(book, customizations):
-    """
-    Returns a MEDIA_ROOT relative path for a customized pdf. The name will contain a hash of customization options.
-    """
-    customizations.sort()
-    h = hash(tuple(customizations))
-
-    pdf_name = '%s-custom-%s' % (book.slug, h)
-    pdf_file = get_dynamic_path(None, pdf_name, ext='pdf')
-
-    return pdf_file
-
-
-def get_existing_customized_pdf(book):
-    """
-    Returns a list of paths to generated customized pdf of a book
-    """
-    pdf_glob = '%s-custom-' % (book.slug,)
-    pdf_glob = get_dynamic_path(None, pdf_glob, ext='pdf')
-    pdf_glob = re.sub(r"[.]([a-z0-9]+)$", "*.\\1", pdf_glob)
-    return glob(path.join(settings.MEDIA_ROOT, pdf_glob))
-
-
 class BookMedia(models.Model):
 class BookMedia(models.Model):
+    """Represents media attached to a book."""
     FileFormat = namedtuple("FileFormat", "name ext")
     formats = SortedDict([
         ('mp3', FileFormat(name='MP3', ext='mp3')),
     FileFormat = namedtuple("FileFormat", "name ext")
     formats = SortedDict([
         ('mp3', FileFormat(name='MP3', ext='mp3')),
@@ -253,7 +230,7 @@ class BookMedia(models.Model):
     name        = models.CharField(_('name'), max_length="100")
     file        = OverwritingFileField(_('file'), upload_to=book_upload_path())
     uploaded_at = models.DateTimeField(_('creation date'), auto_now_add=True, editable=False)
     name        = models.CharField(_('name'), max_length="100")
     file        = OverwritingFileField(_('file'), upload_to=book_upload_path())
     uploaded_at = models.DateTimeField(_('creation date'), auto_now_add=True, editable=False)
-    extra_info  = JSONField(_('extra information'), default='{}', editable=False)
+    extra_info  = jsonfield.JSONField(_('extra information'), default='{}', editable=False)
     book = models.ForeignKey('Book', related_name='media')
     source_sha1 = models.CharField(null=True, blank=True, max_length=40, editable=False)
 
     book = models.ForeignKey('Book', related_name='media')
     source_sha1 = models.CharField(null=True, blank=True, max_length=40, editable=False)
 
@@ -271,7 +248,7 @@ class BookMedia(models.Model):
 
         try:
             old = BookMedia.objects.get(pk=self.pk)
 
         try:
             old = BookMedia.objects.get(pk=self.pk)
-        except BookMedia.DoesNotExist, e:
+        except BookMedia.DoesNotExist:
             old = None
         else:
             # if name changed, change the file name, too
             old = None
         else:
             # if name changed, change the file name, too
@@ -285,9 +262,9 @@ class BookMedia(models.Model):
             remove_zip("%s_%s" % (old.book.slug, old.type))
         remove_zip("%s_%s" % (self.book.slug, self.type))
 
             remove_zip("%s_%s" % (old.book.slug, old.type))
         remove_zip("%s_%s" % (self.book.slug, self.type))
 
-        extra_info = self.get_extra_info_value()
+        extra_info = self.extra_info
         extra_info.update(self.read_meta())
         extra_info.update(self.read_meta())
-        self.set_extra_info_value(extra_info)
+        self.extra_info = extra_info
         self.source_sha1 = self.read_source_sha1(self.file.path, self.type)
         return super(BookMedia, self).save(*args, **kwargs)
 
         self.source_sha1 = self.read_source_sha1(self.file.path, self.type)
         return super(BookMedia, self).save(*args, **kwargs)
 
@@ -350,6 +327,7 @@ class BookMedia(models.Model):
 
 
 class Book(models.Model):
 
 
 class Book(models.Model):
+    """Represents a book imported from WL-XML."""
     title         = models.CharField(_('title'), max_length=120)
     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True, editable=False)
     slug = models.SlugField(_('slug'), max_length=120, db_index=True,
     title         = models.CharField(_('title'), max_length=120)
     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True, editable=False)
     slug = models.SlugField(_('slug'), max_length=120, db_index=True,
@@ -361,7 +339,7 @@ class Book(models.Model):
     created_at    = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True)
     changed_at    = models.DateTimeField(_('creation date'), auto_now=True, db_index=True)
     parent_number = models.IntegerField(_('parent number'), default=0)
     created_at    = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True)
     changed_at    = models.DateTimeField(_('creation date'), auto_now=True, db_index=True)
     parent_number = models.IntegerField(_('parent number'), default=0)
-    extra_info    = JSONField(_('extra information'), default='{}')
+    extra_info    = jsonfield.JSONField(_('extra information'), default='{}')
     gazeta_link   = models.CharField(blank=True, max_length=240)
     wiki_link     = models.CharField(blank=True, max_length=240)
     # files generated during publication
     gazeta_link   = models.CharField(blank=True, max_length=240)
     wiki_link     = models.CharField(blank=True, max_length=240)
     # files generated during publication
@@ -372,6 +350,9 @@ class Book(models.Model):
     formats = ebook_formats + ['html', 'xml']
 
     parent        = models.ForeignKey('self', blank=True, null=True, related_name='children')
     formats = ebook_formats + ['html', 'xml']
 
     parent        = models.ForeignKey('self', blank=True, null=True, related_name='children')
+
+    _related_info = jsonfield.JSONField(blank=True, null=True, editable=False)
+
     objects  = models.Manager()
     tagged   = managers.ModelTaggedItemManager(Tag)
     tags     = managers.TagDescriptor(Tag)
     objects  = models.Manager()
     tagged   = managers.ModelTaggedItemManager(Tag)
     tags     = managers.TagDescriptor(Tag)
@@ -422,18 +403,18 @@ class Book(models.Model):
             book_tag.save()
         return book_tag
 
             book_tag.save()
         return book_tag
 
-    def has_media(self, type):
-        if type in Book.formats:
-            return bool(getattr(self, "%s_file" % type))
+    def has_media(self, type_):
+        if type_ in Book.formats:
+            return bool(getattr(self, "%s_file" % type_))
         else:
         else:
-            return self.media.filter(type=type).exists()
+            return self.media.filter(type=type_).exists()
 
 
-    def get_media(self, type):
-        if self.has_media(type):
-            if type in Book.formats:
-                return getattr(self, "%s_file" % type)
+    def get_media(self, type_):
+        if self.has_media(type_):
+            if type_ in Book.formats:
+                return getattr(self, "%s_file" % type_)
             else:                                             
             else:                                             
-                return self.media.filter(type=type)
+                return self.media.filter(type=type_)
         else:
             return None
 
         else:
             return None
 
@@ -450,58 +431,11 @@ class Book(models.Model):
         if self.id is None:
             return
 
         if self.id is None:
             return
 
-        cache_key = "Book.short_html/%d/%s"
-        for lang, langname in settings.LANGUAGES:
-            cache.delete(cache_key % (self.id, lang))
-        cache.delete("Book.mini_box/%d" % (self.id, ))
+        type(self).objects.filter(pk=self.pk).update(_related_info=None)
         # Fragment.short_html relies on book's tags, so reset it here too
         # Fragment.short_html relies on book's tags, so reset it here too
-        for fragm in self.fragments.all():
+        for fragm in self.fragments.all().iterator():
             fragm.reset_short_html()
 
             fragm.reset_short_html()
 
-    def short_html(self):
-        if self.id:
-            cache_key = "Book.short_html/%d/%s" % (self.id, get_language())
-            short_html = cache.get(cache_key)
-        else:
-            short_html = None
-
-        if short_html is not None:
-            return mark_safe(short_html)
-        else:
-            tags = self.tags.filter(category__in=('author', 'kind', 'genre', 'epoch'))
-            tags = split_tags(tags)
-
-            formats = {}
-            # files generated during publication
-            for ebook_format in self.ebook_formats:
-                if self.has_media(ebook_format):
-                    formats[ebook_format] = self.get_media(ebook_format)
-
-
-            short_html = unicode(render_to_string('catalogue/book_short.html',
-                {'book': self, 'tags': tags, 'formats': formats}))
-
-            if self.id:
-                cache.set(cache_key, short_html, CACHE_FOREVER)
-            return mark_safe(short_html)
-
-    def mini_box(self):
-        if self.id:
-            cache_key = "Book.mini_box/%d" % (self.id, )
-            short_html = cache.get(cache_key)
-        else:
-            short_html = None
-
-        if short_html is None:
-            authors = self.tags.filter(category='author')
-
-            short_html = unicode(render_to_string('catalogue/book_mini_box.html',
-                {'book': self, 'authors': authors, 'STATIC_URL': settings.STATIC_URL}))
-
-            if self.id:
-                cache.set(cache_key, short_html, CACHE_FOREVER)
-        return mark_safe(short_html)
-
     def has_description(self):
         return len(self.description) > 0
     has_description.short_description = _('description')
     def has_description(self):
         return len(self.description) > 0
     has_description.short_description = _('description')
@@ -545,71 +479,7 @@ class Book(models.Model):
         cover.save(imgstr, 'png')
         self.cover.save(None, ContentFile(imgstr.getvalue()))
 
         cover.save(imgstr, 'png')
         self.cover.save(None, ContentFile(imgstr.getvalue()))
 
-    def build_pdf(self, customizations=None, file_name=None):
-        """ (Re)builds the pdf file.
-        customizations - customizations which are passed to LaTeX class file.
-        file_name - save the pdf file under a different name and DO NOT save it in db.
-        """
-        from os import unlink
-        from django.core.files import File
-        from catalogue.utils import remove_zip
-
-        pdf = self.wldocument().as_pdf(customizations=customizations)
-
-        if file_name is None:
-            # we'd like to be sure not to overwrite changes happening while
-            # (timely) pdf generation is taking place (async celery scenario)
-            current_self = Book.objects.get(id=self.id)
-            current_self.pdf_file.save('%s.pdf' % self.slug,
-                    File(open(pdf.get_filename())))
-            self.pdf_file = current_self.pdf_file
-
-            # remove cached downloadables
-            remove_zip(settings.ALL_PDF_ZIP)
-
-            for customized_pdf in get_existing_customized_pdf(self):
-                unlink(customized_pdf)
-        else:
-            print "saving %s" % file_name
-            print "to: %s" % DefaultStorage().path(file_name)
-            DefaultStorage().save(file_name, File(open(pdf.get_filename())))
-
-    def build_mobi(self):
-        """ (Re)builds the MOBI file.
-
-        """
-        from django.core.files import File
-        from catalogue.utils import remove_zip
-
-        mobi = self.wldocument().as_mobi()
-
-        self.mobi_file.save('%s.mobi' % self.slug, File(open(mobi.get_filename())))
-
-        # remove zip with all mobi files
-        remove_zip(settings.ALL_MOBI_ZIP)
-
-    def build_epub(self):
-        """(Re)builds the epub file."""
-        from django.core.files import File
-        from catalogue.utils import remove_zip
-
-        epub = self.wldocument().as_epub()
-
-        self.epub_file.save('%s.epub' % self.slug,
-                File(open(epub.get_filename())))
-
-        # remove zip package with all epub files
-        remove_zip(settings.ALL_EPUB_ZIP)
-
-    def build_txt(self):
-        from django.core.files.base import ContentFile
-
-        text = self.wldocument().as_text()
-        self.txt_file.save('%s.txt' % self.slug, ContentFile(text.get_string()))
-
-
     def build_html(self):
     def build_html(self):
-        from markupstring import MarkupString
         from django.core.files.base import ContentFile
         from slughifi import slughifi
         from librarian import html
         from django.core.files.base import ContentFile
         from slughifi import slughifi
         from librarian import html
@@ -653,9 +523,9 @@ class Book(models.Model):
                     continue
 
                 text = fragment.to_string()
                     continue
 
                 text = fragment.to_string()
-                short_text = ''
-                if (len(MarkupString(text)) > 240):
-                    short_text = unicode(MarkupString(text)[:160])
+                short_text = truncate_html_words(text, 15)
+                if text == short_text:
+                    short_text = ''
                 new_fragment = Fragment.objects.create(anchor=fragment.id, book=self,
                     text=text, short_text=short_text)
 
                 new_fragment = Fragment.objects.create(anchor=fragment.id, book=self,
                     text=text, short_text=short_text)
 
@@ -666,29 +536,42 @@ class Book(models.Model):
             return True
         return False
 
             return True
         return False
 
+    # Thin wrappers for builder tasks
+    def build_pdf(self, *args, **kwargs):
+        """(Re)builds PDF."""
+        return tasks.build_pdf.delay(self.pk, *args, **kwargs)
+    def build_epub(self, *args, **kwargs):
+        """(Re)builds EPUB."""
+        return tasks.build_epub.delay(self.pk, *args, **kwargs)
+    def build_mobi(self, *args, **kwargs):
+        """(Re)builds MOBI."""
+        return tasks.build_mobi.delay(self.pk, *args, **kwargs)
+    def build_txt(self, *args, **kwargs):
+        """(Re)builds TXT."""
+        return tasks.build_txt.delay(self.pk, *args, **kwargs)
+
     @staticmethod
     def zip_format(format_):
         def pretty_file_name(book):
             return "%s/%s.%s" % (
     @staticmethod
     def zip_format(format_):
         def pretty_file_name(book):
             return "%s/%s.%s" % (
-                b.get_extra_info_value()['author'],
+                b.extra_info['author'],
                 b.slug,
                 format_)
 
         field_name = "%s_file" % format_
         books = Book.objects.filter(parent=None).exclude(**{field_name: ""})
         paths = [(pretty_file_name(b), getattr(b, field_name).path)
                 b.slug,
                 format_)
 
         field_name = "%s_file" % format_
         books = Book.objects.filter(parent=None).exclude(**{field_name: ""})
         paths = [(pretty_file_name(b), getattr(b, field_name).path)
-                    for b in books]
-        result = create_zip.delay(paths,
+                    for b in books.iterator()]
+        return create_zip(paths,
                     getattr(settings, "ALL_%s_ZIP" % format_.upper()))
                     getattr(settings, "ALL_%s_ZIP" % format_.upper()))
-        return result.wait()
 
     def zip_audiobooks(self, format_):
         bm = BookMedia.objects.filter(book=self, type=format_)
         paths = map(lambda bm: (None, bm.file.path), bm)
 
     def zip_audiobooks(self, format_):
         bm = BookMedia.objects.filter(book=self, type=format_)
         paths = map(lambda bm: (None, bm.file.path), bm)
-        result = create_zip.delay(paths, "%s_%s" % (self.slug, format_))
-        return result.wait()
+        return create_zip(paths, "%s_%s" % (self.slug, format_))
 
 
-    def search_index(self, book_info=None, reuse_index=False):
+    def search_index(self, book_info=None, reuse_index=False, index_tags=True):
+        import search
         if reuse_index:
             idx = search.ReusableIndex()
         else:
         if reuse_index:
             idx = search.ReusableIndex()
         else:
@@ -697,7 +580,8 @@ class Book(models.Model):
         idx.open()
         try:
             idx.index_book(self, book_info)
         idx.open()
         try:
             idx.index_book(self, book_info)
-            idx.index_tags()
+            if index_tags:
+                idx.index_tags()
         finally:
             idx.close()
 
         finally:
             idx.close()
 
@@ -720,9 +604,7 @@ class Book(models.Model):
     @classmethod
     def from_text_and_meta(cls, raw_file, book_info, overwrite=False,
             build_epub=True, build_txt=True, build_pdf=True, build_mobi=True,
     @classmethod
     def from_text_and_meta(cls, raw_file, book_info, overwrite=False,
             build_epub=True, build_txt=True, build_pdf=True, build_mobi=True,
-            search_index=True):
-        import re
-        from sortify import sortify
+            search_index=True, search_index_tags=True, search_index_reuse=False):
 
         # check for parts before we do anything
         children = []
 
         # check for parts before we do anything
         children = []
@@ -730,7 +612,7 @@ class Book(models.Model):
             for part_url in book_info.parts:
                 try:
                     children.append(Book.objects.get(slug=part_url.slug))
             for part_url in book_info.parts:
                 try:
                     children.append(Book.objects.get(slug=part_url.slug))
-                except Book.DoesNotExist, e:
+                except Book.DoesNotExist:
                     raise Book.DoesNotExist(_('Book "%s" does not exist.') %
                             part_url.slug)
 
                     raise Book.DoesNotExist(_('Book "%s" does not exist.') %
                             part_url.slug)
 
@@ -756,7 +638,7 @@ class Book(models.Model):
             book.common_slug = book_info.variant_of.slug
         else:
             book.common_slug = book.slug
             book.common_slug = book_info.variant_of.slug
         else:
             book.common_slug = book.slug
-        book.set_extra_info_value(book_info.to_dict())
+        book.extra_info = book_info.to_dict()
         book.save()
 
         meta_tags = Tag.tags_from_info(book_info)
         book.save()
 
         meta_tags = Tag.tags_from_info(book_info)
@@ -792,7 +674,8 @@ class Book(models.Model):
             book.build_mobi()
 
         if not settings.NO_SEARCH_INDEX and search_index:
             book.build_mobi()
 
         if not settings.NO_SEARCH_INDEX and search_index:
-            index_book.delay(book.id, book_info)
+            book.search_index(index_tags=search_index_tags, reuse_index=search_index_reuse)
+            #index_book.delay(book.id, book_info)
 
         book_descendants = list(book.children.all())
         descendants_tags = set()
 
         book_descendants = list(book.children.all())
         descendants_tags = set()
@@ -802,12 +685,12 @@ class Book(models.Model):
             descendants_tags.update(child_book.tags)
             child_book.tags = list(child_book.tags) + [book_tag]
             child_book.save()
             descendants_tags.update(child_book.tags)
             child_book.tags = list(child_book.tags) + [book_tag]
             child_book.save()
-            for fragment in child_book.fragments.all():
+            for fragment in child_book.fragments.all().iterator():
                 fragment.tags = set(list(fragment.tags) + [book_tag])
             book_descendants += list(child_book.children.all())
 
         for tag in descendants_tags:
                 fragment.tags = set(list(fragment.tags) + [book_tag])
             book_descendants += list(child_book.children.all())
 
         for tag in descendants_tags:
-            touch_tag.delay(tag)
+            tasks.touch_tag(tag)
 
         book.save()
 
 
         book.save()
 
@@ -818,12 +701,49 @@ class Book(models.Model):
         cls.published.send(sender=book)
         return book
 
         cls.published.send(sender=book)
         return book
 
+    def related_info(self):
+        """Keeps info about related objects (tags, media) in cache field."""
+        if self._related_info is not None:
+            return self._related_info
+        else:
+            rel = {'tags': {}, 'media': {}}
+
+            tags = self.tags.filter(category__in=(
+                    'author', 'kind', 'genre', 'epoch'))
+            tags = split_tags(tags)
+            for category in tags:
+                rel['tags'][category] = [
+                        (t.name, t.slug) for t in tags[category]]
+
+            for media_format in BookMedia.formats:
+                rel['media'][media_format] = self.has_media(media_format)
+
+            book = self
+            parents = []
+            while book.parent:
+                parents.append((book.parent.title, book.parent.slug))
+                book = book.parent
+            parents = parents[::-1]
+            if parents:
+                rel['parents'] = parents
+
+            if self.pk:
+                type(self).objects.filter(pk=self.pk).update(_related_info=rel)
+            return rel
+
+    def related_themes(self):
+        theme_counter = self.theme_counter
+        book_themes = list(Tag.objects.filter(pk__in=theme_counter.keys()))
+        for tag in book_themes:
+            tag.count = theme_counter[tag.pk]
+        return book_themes
+
     def reset_tag_counter(self):
         if self.id is None:
             return
 
         cache_key = "Book.tag_counter/%d" % self.id
     def reset_tag_counter(self):
         if self.id is None:
             return
 
         cache_key = "Book.tag_counter/%d" % self.id
-        cache.delete(cache_key)
+        permanent_cache.delete(cache_key)
         if self.parent:
             self.parent.reset_tag_counter()
 
         if self.parent:
             self.parent.reset_tag_counter()
 
@@ -831,20 +751,20 @@ class Book(models.Model):
     def tag_counter(self):
         if self.id:
             cache_key = "Book.tag_counter/%d" % self.id
     def tag_counter(self):
         if self.id:
             cache_key = "Book.tag_counter/%d" % self.id
-            tags = cache.get(cache_key)
+            tags = permanent_cache.get(cache_key)
         else:
             tags = None
 
         if tags is None:
             tags = {}
         else:
             tags = None
 
         if tags is None:
             tags = {}
-            for child in self.children.all().order_by():
+            for child in self.children.all().order_by().iterator():
                 for tag_pk, value in child.tag_counter.iteritems():
                     tags[tag_pk] = tags.get(tag_pk, 0) + value
                 for tag_pk, value in child.tag_counter.iteritems():
                     tags[tag_pk] = tags.get(tag_pk, 0) + value
-            for tag in self.tags.exclude(category__in=('book', 'theme', 'set')).order_by():
+            for tag in self.tags.exclude(category__in=('book', 'theme', 'set')).order_by().iterator():
                 tags[tag.pk] = 1
 
             if self.id:
                 tags[tag.pk] = 1
 
             if self.id:
-                cache.set(cache_key, tags, CACHE_FOREVER)
+                permanent_cache.set(cache_key, tags)
         return tags
 
     def reset_theme_counter(self):
         return tags
 
     def reset_theme_counter(self):
@@ -852,7 +772,7 @@ class Book(models.Model):
             return
 
         cache_key = "Book.theme_counter/%d" % self.id
             return
 
         cache_key = "Book.theme_counter/%d" % self.id
-        cache.delete(cache_key)
+        permanent_cache.delete(cache_key)
         if self.parent:
             self.parent.reset_theme_counter()
 
         if self.parent:
             self.parent.reset_theme_counter()
 
@@ -860,18 +780,18 @@ class Book(models.Model):
     def theme_counter(self):
         if self.id:
             cache_key = "Book.theme_counter/%d" % self.id
     def theme_counter(self):
         if self.id:
             cache_key = "Book.theme_counter/%d" % self.id
-            tags = cache.get(cache_key)
+            tags = permanent_cache.get(cache_key)
         else:
             tags = None
 
         if tags is None:
             tags = {}
         else:
             tags = None
 
         if tags is None:
             tags = {}
-            for fragment in Fragment.tagged.with_any([self.book_tag()]).order_by():
-                for tag in fragment.tags.filter(category='theme').order_by():
+            for fragment in Fragment.tagged.with_any([self.book_tag()]).order_by().iterator():
+                for tag in fragment.tags.filter(category='theme').order_by().iterator():
                     tags[tag.pk] = tags.get(tag.pk, 0) + 1
 
             if self.id:
                     tags[tag.pk] = tags.get(tag.pk, 0) + 1
 
             if self.id:
-                cache.set(cache_key, tags, CACHE_FOREVER)
+                permanent_cache.set(cache_key, tags)
         return tags
 
     def pretty_title(self, html_links=False):
         return tags
 
     def pretty_title(self, html_links=False):
@@ -893,7 +813,7 @@ class Book(models.Model):
 
     @classmethod
     def tagged_top_level(cls, tags):
 
     @classmethod
     def tagged_top_level(cls, tags):
-        """ Returns top-level books tagged with `tags'.
+        """ Returns top-level books tagged with `tags`.
 
         It only returns those books which don't have ancestors which are
         also tagged with those tags.
 
         It only returns those books which don't have ancestors which are
         also tagged with those tags.
@@ -902,8 +822,9 @@ class Book(models.Model):
         # get relevant books and their tags
         objects = cls.tagged.with_all(tags)
         # eliminate descendants
         # get relevant books and their tags
         objects = cls.tagged.with_all(tags)
         # eliminate descendants
-        l_tags = Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in objects])
-        descendants_keys = [book.pk for book in cls.tagged.with_any(l_tags)]
+        l_tags = Tag.objects.filter(category='book',
+            slug__in=[book.book_tag_slug() for book in objects.iterator()])
+        descendants_keys = [book.pk for book in cls.tagged.with_any(l_tags).iterator()]
         if descendants_keys:
             objects = objects.exclude(pk__in=descendants_keys)
 
         if descendants_keys:
             objects = objects.exclude(pk__in=descendants_keys)
 
@@ -922,19 +843,20 @@ class Book(models.Model):
                 'title', 'parent', 'slug')
         if filter:
             books = books.filter(filter).distinct()
                 'title', 'parent', 'slug')
         if filter:
             books = books.filter(filter).distinct()
-            book_ids = set((book.pk for book in books))
-            for book in books:
+            
+            book_ids = set(b['pk'] for b in books.values("pk").iterator())
+            for book in books.iterator():
                 parent = book.parent_id
                 if parent not in book_ids:
                     parent = None
                 books_by_parent.setdefault(parent, []).append(book)
         else:
                 parent = book.parent_id
                 if parent not in book_ids:
                     parent = None
                 books_by_parent.setdefault(parent, []).append(book)
         else:
-            for book in books:
+            for book in books.iterator():
                 books_by_parent.setdefault(book.parent_id, []).append(book)
 
         orphans = []
         books_by_author = SortedDict()
                 books_by_parent.setdefault(book.parent_id, []).append(book)
 
         orphans = []
         books_by_author = SortedDict()
-        for tag in Tag.objects.filter(category='author'):
+        for tag in Tag.objects.filter(category='author').iterator():
             books_by_author[tag] = []
 
         for book in books_by_parent.get(None,()):
             books_by_author[tag] = []
 
         for book in books_by_parent.get(None,()):
@@ -956,14 +878,25 @@ class Book(models.Model):
         "LP": (3, u"liceum"),
     }
     def audiences_pl(self):
         "LP": (3, u"liceum"),
     }
     def audiences_pl(self):
-        audiences = self.get_extra_info_value().get('audiences', [])
+        audiences = self.extra_info.get('audiences', [])
         audiences = sorted(set([self._audiences_pl[a] for a in audiences]))
         return [a[1] for a in audiences]
 
         audiences = sorted(set([self._audiences_pl[a] for a in audiences]))
         return [a[1] for a in audiences]
 
+    def choose_fragment(self):
+        tag = self.book_tag()
+        fragments = Fragment.tagged.with_any([tag])
+        if fragments.exists():
+            return fragments.order_by('?')[0]
+        elif self.parent:
+            return self.parent.choose_fragment()
+        else:
+            return None
+
 
 def _has_factory(ftype):
     has = lambda self: bool(getattr(self, "%s_file" % ftype))
 
 def _has_factory(ftype):
     has = lambda self: bool(getattr(self, "%s_file" % ftype))
-    has.short_description = t.upper()
+    has.short_description = ftype.upper()
+    has.__doc__ = None
     has.boolean = True
     has.__name__ = "has_%s_file" % ftype
     return has
     has.boolean = True
     has.__name__ = "has_%s_file" % ftype
     return has
@@ -980,6 +913,7 @@ for t in Book.formats:
 
 
 class Fragment(models.Model):
 
 
 class Fragment(models.Model):
+    """Represents a themed fragment of a book."""
     text = models.TextField()
     short_text = models.TextField(editable=False)
     anchor = models.CharField(max_length=120)
     text = models.TextField()
     short_text = models.TextField(editable=False)
     anchor = models.CharField(max_length=120)
@@ -1003,12 +937,16 @@ class Fragment(models.Model):
 
         cache_key = "Fragment.short_html/%d/%s"
         for lang, langname in settings.LANGUAGES:
 
         cache_key = "Fragment.short_html/%d/%s"
         for lang, langname in settings.LANGUAGES:
-            cache.delete(cache_key % (self.id, lang))
+            permanent_cache.delete(cache_key % (self.id, lang))
+
+    def get_short_text(self):
+        """Returns short version of the fragment."""
+        return self.short_text if self.short_text else self.text
 
     def short_html(self):
         if self.id:
             cache_key = "Fragment.short_html/%d/%s" % (self.id, get_language())
 
     def short_html(self):
         if self.id:
             cache_key = "Fragment.short_html/%d/%s" % (self.id, get_language())
-            short_html = cache.get(cache_key)
+            short_html = permanent_cache.get(cache_key)
         else:
             short_html = None
 
         else:
             short_html = None
 
@@ -1018,7 +956,7 @@ class Fragment(models.Model):
             short_html = unicode(render_to_string('catalogue/fragment_short.html',
                 {'fragment': self}))
             if self.id:
             short_html = unicode(render_to_string('catalogue/fragment_short.html',
                 {'fragment': self}))
             if self.id:
-                cache.set(cache_key, short_html, CACHE_FOREVER)
+                permanent_cache.set(cache_key, short_html)
             return mark_safe(short_html)
 
 
             return mark_safe(short_html)
 
 
@@ -1051,7 +989,7 @@ def _tags_updated_handler(sender, affected_tags, **kwargs):
     # reset tag global counter
     # we want Tag.changed_at updated for API to know the tag was touched
     for tag in affected_tags:
     # reset tag global counter
     # we want Tag.changed_at updated for API to know the tag was touched
     for tag in affected_tags:
-        touch_tag.delay(tag)
+        tasks.touch_tag(tag)
 
     # if book tags changed, reset book tag counter
     if isinstance(sender, Book) and \
 
     # if book tags changed, reset book tag counter
     if isinstance(sender, Book) and \
@@ -1072,8 +1010,24 @@ def _pre_delete_handler(sender, instance, **kwargs):
         instance.book.save()
 pre_delete.connect(_pre_delete_handler)
 
         instance.book.save()
 pre_delete.connect(_pre_delete_handler)
 
+
 def _post_save_handler(sender, instance, **kwargs):
     """ refresh all the short_html stuff on BookMedia update """
     if sender == BookMedia:
         instance.book.save()
 post_save.connect(_post_save_handler)
 def _post_save_handler(sender, instance, **kwargs):
     """ refresh all the short_html stuff on BookMedia update """
     if sender == BookMedia:
         instance.book.save()
 post_save.connect(_post_save_handler)
+
+
+if not settings.NO_SEARCH_INDEX:
+    @django.dispatch.receiver(post_delete, sender=Book)
+    def _remove_book_from_index_handler(sender, instance, **kwargs):
+        """ remove the book from search index, when it is deleted."""
+        import search
+        search.JVM.attachCurrentThread()
+        idx = search.Index()
+        idx.open(timeout=10000)  # 10 seconds timeout.
+        try:
+            idx.remove_book(instance)
+            idx.index_tags()
+        finally:
+            idx.close()