Search engine now should be db change change-proof
[wolnelektury.git] / apps / search / index.py
index d63d3f8..9d6d598 100644 (file)
@@ -1,7 +1,8 @@
 # -*- coding: utf-8 -*-
 
 from django.conf import settings
-from lucene import SimpleFSDirectory, IndexWriter, CheckIndex, \
+from django.dispatch import Signal
+from lucene import SimpleFSDirectory, NIOFSDirectory, IndexWriter, IndexReader, IndexWriterConfig, CheckIndex, \
     File, Field, Integer, \
     NumericField, Version, Document, JavaError, IndexSearcher, \
     QueryParser, PerFieldAnalyzerWrapper, \
@@ -27,7 +28,7 @@ from librarian import dcparser
 from librarian.parser import WLDocument
 from lxml import etree
 import catalogue.models
-from pdcounter.models import Author as PDCounterAuthor
+from pdcounter.models import Author as PDCounterAuthor, BookStub as PDCounterBook
 from multiprocessing.pool import ThreadPool
 from threading import current_thread
 import atexit
@@ -82,7 +83,7 @@ class IndexStore(object):
     """
     def __init__(self):
         self.make_index_dir()
-        self.store = SimpleFSDirectory(File(settings.SEARCH_INDEX))
+        self.store = NIOFSDirectory(File(settings.SEARCH_INDEX))
 
     def make_index_dir(self):
         try:
@@ -92,6 +93,9 @@ class IndexStore(object):
                 pass
             else: raise
 
+    def close(self):
+        self.store.close()
+
 
 class IndexChecker(IndexStore):
     def __init__(self):
@@ -111,7 +115,7 @@ class Snippets(object):
     """
     SNIPPET_DIR = "snippets"
 
-    def __init__(self, book_id):
+    def __init__(self, book_id, revision=None):
         try:
             os.makedirs(os.path.join(settings.SEARCH_INDEX, self.SNIPPET_DIR))
         except OSError as exc:
@@ -119,15 +123,33 @@ class Snippets(object):
                 pass
             else: raise
         self.book_id = book_id
+        self.revision = revision
         self.file = None
 
+    @property
+    def path(self):
+        if self.revision: fn = "%d.%d" % (self.book_id, self.revision)
+        else: fn = "%d" % self.book_id
+
+        return os.path.join(settings.SEARCH_INDEX, self.SNIPPET_DIR, fn)
+
     def open(self, mode='r'):
         """
         Open the snippet file. Call .close() afterwards.
         """
         if not 'b' in mode:
             mode += 'b'
-        self.file = open(os.path.join(settings.SEARCH_INDEX, self.SNIPPET_DIR, str(self.book_id)), mode)
+
+        if 'w' in mode:
+            if os.path.exists(self.path):
+                self.revision = 1
+                while True:
+                    if not os.path.exists(self.path):
+                        break
+                    self.revision += 1
+            print "using %s" % self.path
+
+        self.file = open(self.path, mode)
         self.position = 0
         return self
 
@@ -156,6 +178,17 @@ class Snippets(object):
         """Close snippet file"""
         self.file.close()
 
+    def remove(self):
+        self.revision = None
+        try:
+            os.unlink(self.path)
+            self.revision = 0
+            while True:
+                self.revision += 1
+                os.unlink(self.path)
+        except OSError:
+            pass
+
 
 class BaseIndex(IndexStore):
     """
@@ -169,11 +202,13 @@ class BaseIndex(IndexStore):
             analyzer = WLAnalyzer()
         self.analyzer = analyzer
 
-    def open(self, analyzer=None):
+    def open(self, timeout=None):
         if self.index:
             raise Exception("Index is already opened")
-        self.index = IndexWriter(self.store, self.analyzer,\
-                                 IndexWriter.MaxFieldLength.LIMITED)
+        conf = IndexWriterConfig(Version.LUCENE_34, self.analyzer)
+        if timeout:
+            conf.setWriteLockTimeout(long(timeout))
+        self.index = IndexWriter(self.store, conf)
         return self.index
 
     def optimize(self):
@@ -188,6 +223,10 @@ class BaseIndex(IndexStore):
         self.index.close()
         self.index = None
 
+        index_changed.send_robust(self)
+
+        super(BaseIndex, self).close()
+
     def __enter__(self):
         self.open()
         return self
@@ -196,6 +235,9 @@ class BaseIndex(IndexStore):
         self.close()
 
 
+index_changed = Signal()
+
+
 class Index(BaseIndex):
     """
     Class indexing books.
@@ -203,31 +245,66 @@ class Index(BaseIndex):
     def __init__(self, analyzer=None):
         super(Index, self).__init__(analyzer)
 
-    def index_tags(self):
+    def index_tags(self, *tags, **kw):
         """
         Re-index global tag list.
         Removes all tags from index, then index them again.
         Indexed fields include: id, name (with and without polish stems), category
         """
-        q = NumericRangeQuery.newIntRange("tag_id", 0, Integer.MAX_VALUE, True, True)
-        self.index.deleteDocuments(q)
+        remove_only = kw.get('remove_only', False)
+        # first, remove tags from index.
+        if tags:
+            q = BooleanQuery()
+            for tag in tags:
+                b_id_cat = BooleanQuery()
+
+                q_id = NumericRangeQuery.newIntRange("tag_id", tag.id, tag.id, True, True)
+                b_id_cat.add(q_id, BooleanClause.Occur.MUST)
 
-        for tag in catalogue.models.Tag.objects.all():
-            doc = Document()
-            doc.add(NumericField("tag_id", Field.Store.YES, True).setIntValue(int(tag.id)))
-            doc.add(Field("tag_name", tag.name, Field.Store.NO, Field.Index.ANALYZED))
-            doc.add(Field("tag_name_pl", tag.name, Field.Store.NO, Field.Index.ANALYZED))
-            doc.add(Field("tag_category", tag.category, Field.Store.NO, Field.Index.NOT_ANALYZED))
-            self.index.addDocument(doc)
-
-        for pdtag in PDCounterAuthor.objects.all():
-            doc = Document()
-            doc.add(NumericField("tag_id", Field.Store.YES, True).setIntValue(int(pdtag.id)))
-            doc.add(Field("tag_name", pdtag.name, Field.Store.NO, Field.Index.ANALYZED))
-            doc.add(Field("tag_name_pl", pdtag.name, Field.Store.NO, Field.Index.ANALYZED))
-            doc.add(Field("tag_category", 'pdcounter', Field.Store.NO, Field.Index.NOT_ANALYZED))
-            doc.add(Field("is_pdcounter", 'true', Field.Store.YES, Field.Index.NOT_ANALYZED))
-            self.index.addDocument(doc)
+                if isinstance(tag, PDCounterAuthor):
+                    q_cat = TermQuery(Term('tag_category', 'pd_author'))
+                elif isinstance(tag, PDCounterBook):
+                    q_cat = TermQuery(Term('tag_category', 'pd_book'))
+                else:
+                    q_cat = TermQuery(Term('tag_category', tag.category))
+                b_id_cat.add(q_cat, BooleanClause.Occur.MUST)
+
+                q.add(b_id_cat, BooleanClause.Occur.SHOULD)
+        else:  # all
+            q = NumericRangeQuery.newIntRange("tag_id", 0, Integer.MAX_VALUE, True, True)
+            self.index.deleteDocuments(q)
+
+        if not remove_only:
+            # then add them [all or just one passed]
+            if not tags:
+                tags = catalogue.models.Tag.objects.exclude(category='set') + \
+                    PDCounterAuthor.objects.all() + \
+                    PDCounterBook.objects.all()
+
+            for tag in tags:
+                if isinstance(tag, PDCounterAuthor):
+                    doc = Document()
+                    doc.add(NumericField("tag_id", Field.Store.YES, True).setIntValue(int(tag.id)))
+                    doc.add(Field("tag_name", tag.name, Field.Store.NO, Field.Index.ANALYZED))
+                    doc.add(Field("tag_name_pl", tag.name, Field.Store.NO, Field.Index.ANALYZED))
+                    doc.add(Field("tag_category", 'pd_author', Field.Store.YES, Field.Index.NOT_ANALYZED))
+                    doc.add(Field("is_pdcounter", 'true', Field.Store.YES, Field.Index.NOT_ANALYZED))
+                    self.index.addDocument(doc)
+                elif isinstance(tag, PDCounterBook):
+                    doc = Document()
+                    doc.add(NumericField("tag_id", Field.Store.YES, True).setIntValue(int(tag.id)))
+                    doc.add(Field("tag_name", tag.title, Field.Store.NO, Field.Index.ANALYZED))
+                    doc.add(Field("tag_name_pl", tag.title, Field.Store.NO, Field.Index.ANALYZED))
+                    doc.add(Field("tag_category", 'pd_book', Field.Store.YES, Field.Index.NOT_ANALYZED))
+                    doc.add(Field("is_pdcounter", 'true', Field.Store.YES, Field.Index.NOT_ANALYZED))
+                    self.index.addDocument(doc)
+                else:
+                    doc = Document()
+                    doc.add(NumericField("tag_id", Field.Store.YES, True).setIntValue(int(tag.id)))
+                    doc.add(Field("tag_name", tag.name, Field.Store.NO, Field.Index.ANALYZED))
+                    doc.add(Field("tag_name_pl", tag.name, Field.Store.NO, Field.Index.ANALYZED))
+                    doc.add(Field("tag_category", tag.category, Field.Store.NO, Field.Index.NOT_ANALYZED))
+                    self.index.addDocument(doc)
 
     def create_book_doc(self, book):
         """
@@ -239,12 +316,16 @@ class Index(BaseIndex):
             doc.add(NumericField("parent_id", Field.Store.YES, True).setIntValue(int(book.parent.id)))
         return doc
 
-    def remove_book(self, book):
+    def remove_book(self, book, remove_snippets=True):
         """Removes a book from search index.
         book - Book instance."""
         q = NumericRangeQuery.newIntRange("book_id", book.id, book.id, True, True)
         self.index.deleteDocuments(q)
 
+        if remove_snippets:
+            snippets = Snippets(book.id)
+            snippets.remove()
+
     def index_book(self, book, book_info=None, overwrite=True):
         """
         Indexes the book.
@@ -252,7 +333,9 @@ class Index(BaseIndex):
         and calls self.index_content() to index the contents of the book.
         """
         if overwrite:
-            self.remove_book(book)
+            # we don't remove snippets, since they might be still needed by
+            # threads using not reopened index
+            self.remove_book(book, remove_snippets=False)
 
         book_doc = self.create_book_doc(book)
         meta_fields = self.extract_metadata(book, book_info)
@@ -262,7 +345,6 @@ class Index(BaseIndex):
                     book_doc.add(elem)
             else:
                 book_doc.add(f)
-
         self.index.addDocument(book_doc)
         del book_doc
 
@@ -331,10 +413,13 @@ class Index(BaseIndex):
                                                (dt.year, dt.month, dt.day), Field.Store.NO, Field.Index.NOT_ANALYZED)
 
         # get published date
-        source = book_info.source_name
-        match = self.published_date_re.search(source)
-        if match is not None:
-            fields["published_date"] = Field("published_date", str(match.groups()[0]), Field.Store.YES, Field.Index.NOT_ANALYZED)
+        pd = None
+        if hasattr(book_info, 'source_name') and book_info.source_name:
+            match = self.published_date_re.search(book_info.source_name)
+            if match is not None:
+                pd = str(match.groups()[0])
+        if not pd: pd = ""
+        fields["published_date"] = Field("published_date", pd, Field.Store.YES, Field.Index.NOT_ANALYZED)
 
         return fields
 
@@ -369,11 +454,18 @@ class Index(BaseIndex):
             return []
 
         def walker(node, ignore_tags=[]):
-            yield node, None
-            for child in filter(lambda n: n.tag not in ignore_tags, list(node)):
-                for b, e in walker(child):
-                    yield b, e
-            yield None, node
+
+            if node.tag not in ignore_tags:
+                yield node, None, None
+                if node.text is not None:
+                    yield None, node.text, None
+                for child in list(node):
+                    for b, t, e in walker(child):
+                        yield b, t, e
+                yield None, None, node
+
+            if node.tail is not None:
+                yield None, node.tail, None
             return
 
         def fix_format(text):
@@ -400,12 +492,16 @@ class Index(BaseIndex):
                     .setIntValue('header_span' in fields and fields['header_span'] or 1))
             doc.add(Field('header_type', fields["header_type"], Field.Store.YES, Field.Index.NOT_ANALYZED))
 
+            print ">>[%s]>%s<<<" % (fields.get('fragment_anchor', ''), fields['content'])
+
             doc.add(Field('content', fields["content"], Field.Store.NO, Field.Index.ANALYZED, \
                           Field.TermVector.WITH_POSITIONS_OFFSETS))
 
             snip_pos = snippets.add(fields["content"])
             doc.add(NumericField("snippets_position", Field.Store.YES, True).setIntValue(snip_pos[0]))
             doc.add(NumericField("snippets_length", Field.Store.YES, True).setIntValue(snip_pos[1]))
+            if snippets.revision:
+                doc.add(NumericField("snippets_revision", Field.Store.YES, True).setIntValue(snippets.revision))
 
             if 'fragment_anchor' in fields:
                 doc.add(Field("fragment_anchor", fields['fragment_anchor'],
@@ -445,35 +541,50 @@ class Index(BaseIndex):
 
                 # section content
                 content = []
-                footnote = None
-
-                for start, end in walker(header, ignore_tags=self.ignore_content_tags):
-                    # handle footnotes
-                    # if start is not None and start.tag in self.footnote_tags:
-                    #     footnote = ' '.join(start.itertext())
-                    # elif end is not None and footnote is not None and end.tag in self.footnote_tags:
-                    #     doc = add_part(snippets, header_index=position, header_type=header.tag,
-                    #                    content=footnote)
+                footnote = []
 
-                    #     self.index.addDocument(doc)
+                def all_content(text):
+                    for frag in fragments.values():
+                        frag['content'].append(text)
+                    content.append(text)
+                handle_text = [all_content]
 
-                    #     footnote = None
 
+                for start, text, end in walker(header, ignore_tags=self.ignore_content_tags):
+                    # handle footnotes
+                    if start is not None and start.tag in self.footnote_tags:
+                        footnote = []
+                        def collect_footnote(t):
+                            footnote.append(t)
+                        handle_text.append(collect_footnote)
+                    elif end is not None and footnote is not [] and end.tag in self.footnote_tags:
+                        handle_text.pop()
+                        doc = add_part(snippets, header_index=position, header_type=header.tag,
+                                       content=u''.join(footnote),
+                                       is_footnote=Field("is_footnote", 'true', Field.Store.NO, Field.Index.NOT_ANALYZED))
+                
+                        self.index.addDocument(doc)
+                        #print "@ footnote text: %s" % footnote
+                        footnote = []
+                    
                     # handle fragments and themes.
                     if start is not None and start.tag == 'begin':
                         fid = start.attrib['id'][1:]
                         fragments[fid] = {'content': [], 'themes': [], 'start_section': position, 'start_header': header.tag}
 
+                    # themes for this fragment
                     elif start is not None and start.tag == 'motyw':
                         fid = start.attrib['id'][1:]
+                        handle_text.append(None)
                         if start.text is not None:
                             fragments[fid]['themes'] += map(str.strip, map(give_me_utf8, start.text.split(',')))
+                    elif end is not None and end.tag == 'motyw':
+                        handle_text.pop()
 
                     elif start is not None and start.tag == 'end':
                         fid = start.attrib['id'][1:]
                         if fid not in fragments:
                             continue  # a broken <end> node, skip it
-                                      #                        import pdb; pdb.set_trace()
                         frag = fragments[fid]
                         if frag['themes'] == []:
                             continue  # empty themes list.
@@ -486,22 +597,20 @@ class Index(BaseIndex):
                                        fragment_anchor=fid,
                                        content=fix_format(frag['content']),
                                        themes=frag['themes'])
-
+                        #print '@ FRAG %s' % frag['content']
                         self.index.addDocument(doc)
 
                         # Collect content.
-                    elif start is not None:
-                        for frag in fragments.values():
-                            frag['content'].append(start.text)
-                        content.append(start.text)
-                    elif end is not None:
-                        for frag in fragments.values():
-                            frag['content'].append(end.tail)
-                        content.append(end.tail)
+
+                    if text is not None and handle_text is not []:
+                        hdl = handle_text[-1]
+                        if hdl is not None:
+                            hdl(text)
 
                         # in the end, add a section text.
                 doc = add_part(snippets, header_index=position, header_type=header.tag,
                                content=fix_format(content))
+                #print '@ CONTENT: %s' % fix_format(content)
 
                 self.index.addDocument(doc)
 
@@ -530,12 +639,12 @@ class ReusableIndex(Index):
     """
     index = None
 
-    def open(self, analyzer=None, threads=4):
-        if ReusableIndex.index is not None:
+    def open(self, analyzer=None, **kw):
+        if ReusableIndex.index:
             self.index = ReusableIndex.index
         else:
             print("opening index")
-            Index.open(self, analyzer)
+            Index.open(self, analyzer, **kw)
             ReusableIndex.index = self.index
             atexit.register(ReusableIndex.close_reusable)
 
@@ -545,13 +654,17 @@ class ReusableIndex(Index):
 
     @staticmethod
     def close_reusable():
-        if ReusableIndex.index is not None:
+        if ReusableIndex.index:
+            print("closing index")
             ReusableIndex.index.optimize()
             ReusableIndex.index.close()
             ReusableIndex.index = None
 
+            index_changed.send_robust(None)
+
     def close(self):
-        pass
+        if ReusableIndex.index:
+            ReusableIndex.index.commit()
 
 
 class JoinSearch(object):
@@ -615,9 +728,10 @@ class SearchResult(object):
         self.book_id = int(stored.get("book_id"))
 
         pd = stored.get("published_date")
-        if pd is None:
-            pd = 0
-        self.published_date = int(pd)
+        try:
+            self.published_date = int(pd)
+        except ValueError:
+            self.published_date = 0
 
         header_type = stored.get("header_type")
         # we have a content hit in some header of fragment
@@ -651,6 +765,8 @@ class SearchResult(object):
         return self
 
     def get_book(self):
+        if hasattr(self, '_book'):
+            return self._book
         return catalogue.models.Book.objects.get(id=self.book_id)
 
     book = property(get_book)
@@ -669,7 +785,10 @@ class SearchResult(object):
 
         # to sections and fragments
         frags = filter(lambda r: r[FRAGMENT] is not None, self._hits)
+
         sect = filter(lambda r: r[FRAGMENT] is None, self._hits)
+
+        # sections not covered by fragments
         sect = filter(lambda s: 0 == len(filter(
             lambda f: s[POSITION][POSITION_INDEX] >= f[POSITION][POSITION_INDEX]
             and s[POSITION][POSITION_INDEX] < f[POSITION][POSITION_INDEX] + f[POSITION][POSITION_SPAN],
@@ -677,15 +796,20 @@ class SearchResult(object):
 
         hits = []
 
-        # remove duplicate fragments
-        fragments = {}
-        for f in frags:
-            fid = f[FRAGMENT]
-            if fid in fragments:
-                if fragments[fid][SCORE] >= f[SCORE]:
-                    continue
-            fragments[fid] = f
-        frags = fragments.values()
+        def remove_duplicates(lst, keyfn, compare):
+            els = {}
+            for e in lst:
+                eif = keyfn(e)
+                if eif in els:
+                    if compare(els[eif], e) >= 1:
+                        continue
+                els[eif] = e
+            return els.values()
+
+        # remove fragments with duplicated fid's and duplicated snippets
+        frags = remove_duplicates(frags, lambda f: f[FRAGMENT], lambda a, b: cmp(a[SCORE], b[SCORE]))
+        frags = remove_duplicates(frags, lambda f: f[OTHER]['snippets'] and f[OTHER]['snippets'][0] or hash(f),
+                                  lambda a, b: cmp(a[SCORE], b[SCORE]))
 
         # remove duplicate sections
         sections = {}
@@ -707,7 +831,7 @@ class SearchResult(object):
 
         for f in frags:
             try:
-                frag = catalogue.models.Fragment.objects.get(anchor=f[FRAGMENT])
+                frag = catalogue.models.Fragment.objects.get(anchor=f[FRAGMENT], book__id=self.book_id)
             except catalogue.models.Fragment.DoesNotExist:
                 # stale index
                 continue
@@ -758,8 +882,6 @@ class SearchResult(object):
     def __cmp__(self, other):
         c = cmp(self.score, other.score)
         if c == 0:
-            if not hasattr(other,'published_date') or not hasattr(self, 'published_date'):
-                import pdb; pdb.set_trace()
             # this is inverted, because earlier date is better
             return cmp(other.published_date, self.published_date)
         else:
@@ -869,12 +991,32 @@ class Search(IndexStore):
         IndexStore.__init__(self)
         self.analyzer = WLAnalyzer()  # PolishAnalyzer(Version.LUCENE_34)
         # self.analyzer = WLAnalyzer()
-        self.searcher = IndexSearcher(self.store, True)
+        reader = IndexReader.open(self.store, True)
+        self.searcher = IndexSearcher(reader)
         self.parser = QueryParser(Version.LUCENE_34, default_field,
                                   self.analyzer)
 
         self.parent_filter = TermsFilter()
         self.parent_filter.addTerm(Term("is_book", "true"))
+        index_changed.connect(self.reopen)
+
+    def close(self):
+        reader = self.searcher.getIndexReader()
+        self.searcher.close()
+        reader.close()
+        super(Search, self).close()
+        index_changed.disconnect(self.reopen)
+
+    def reopen(self, **unused):
+        reader = self.searcher.getIndexReader()
+        rdr = reader.reopen()
+        print "got signal to reopen index"
+        if not rdr.equals(reader):
+            print "will reopen index"
+            oldsearch = self.searcher
+            self.searcher = IndexSearcher(rdr)
+            oldsearch.close()
+            reader.close()
 
     def query(self, query):
         """Parse query in default Lucene Syntax. (for humans)
@@ -1188,18 +1330,28 @@ class Search(IndexStore):
         length = stored.get('snippets_length')
         if position is None or length is None:
             return None
+        revision = stored.get('snippets_revision')
+        if revision: revision = int(revision)
         # locate content.
-        snippets = Snippets(stored.get('book_id')).open()
+        book_id = int(stored.get('book_id'))
+        snippets = Snippets(book_id, revision=revision).open()
         try:
-            text = snippets.get((int(position),
-                                 int(length)))
-        finally:
-            snippets.close()
+            try:
+                text = snippets.get((int(position),
+                                     int(length)))
+            finally:
+                snippets.close()
 
-        tokenStream = TokenSources.getAnyTokenStream(self.searcher.getIndexReader(), scoreDoc.doc, field, self.analyzer)
-        #  highlighter.getBestTextFragments(tokenStream, text, False, 10)
-        snip = highlighter.getBestFragments(tokenStream, text, 3, "...")
+            tokenStream = TokenSources.getAnyTokenStream(self.searcher.getIndexReader(), scoreDoc.doc, field, self.analyzer)
+            #  highlighter.getBestTextFragments(tokenStream, text, False, 10)
+            snip = highlighter.getBestFragments(tokenStream, text, 3, "...")
 
+        except Exception, e:
+            e2 = e
+            if hasattr(e, 'getJavaException'):
+                e2 = unicode(e.getJavaException())
+            raise Exception("Problem fetching snippets for book %d, @%d len=%d" % (book_id, int(position), int(length)),
+                e2)
         return snip
 
     @staticmethod
@@ -1231,13 +1383,25 @@ class Search(IndexStore):
         for found in tops.scoreDocs:
             doc = self.searcher.doc(found.doc)
             is_pdcounter = doc.get('is_pdcounter')
-            if is_pdcounter:
-                tag = PDCounterAuthor.objects.get(id=doc.get('tag_id'))
-            else:
-                tag = catalogue.models.Tag.objects.get(id=doc.get("tag_id"))
-                # don't add the pdcounter tag if same tag already exists
-            if not (is_pdcounter and filter(lambda t: tag.slug == t.slug, tags)):
-                tags.append(tag)
+            category = doc.get('tag_category')
+            try:
+                if is_pdcounter == 'true':
+                    if category == 'pd_author':
+                        tag = PDCounterAuthor.objects.get(id=doc.get('tag_id'))
+                    elif category == 'pd_book':
+                        tag = PDCounterBook.objects.get(id=doc.get('tag_id'))
+                        tag.category = 'pd_book'  # make it look more lik a tag.
+                    else:
+                        print "Warning. cannot get pdcounter tag_id=%d from db; cat=%s" % (int(doc.get('tag_id')), category)
+                else:
+                    tag = catalogue.models.Tag.objects.get(id=doc.get("tag_id"))
+                    # don't add the pdcounter tag if same tag already exists
+                if not (is_pdcounter and filter(lambda t: tag.slug == t.slug, tags)):
+                    tags.append(tag)
+            except catalogue.models.Tag.DoesNotExist: pass
+            except PDCounterAuthor.DoesNotExist: pass
+            except PDCounterBook.DoesNotExist: pass
+
                 #            print "%s (%d) -> %f" % (tag, tag.id, found.score)
         print 'returning %s' % tags
         return tags
@@ -1250,7 +1414,9 @@ class Search(IndexStore):
         tops = self.searcher.search(query, filter, max_results)
         for found in tops.scoreDocs:
             doc = self.searcher.doc(found.doc)
-            bks.append(catalogue.models.Book.objects.get(id=doc.get("book_id")))
+            try:
+                bks.append(catalogue.models.Book.objects.get(id=doc.get("book_id")))
+            except catalogue.models.Book.DoesNotExist: pass
         return bks
 
     def make_prefix_phrase(self, toks, field):
@@ -1279,7 +1445,7 @@ class Search(IndexStore):
 
         return only_term
 
-    def hint_tags(self, string, max_results=50, pdcounter=True, prefix=True):
+    def hint_tags(self, string, max_results=50, pdcounter=True, prefix=True, fuzzy=False):
         """
         Return auto-complete hints for tags
         using prefix search.
@@ -1291,14 +1457,14 @@ class Search(IndexStore):
             if prefix:
                 q = self.make_prefix_phrase(toks, field)
             else:
-                q = self.make_term_query(toks, field)
+                q = self.make_term_query(toks, field, fuzzy=fuzzy)
             top.add(BooleanClause(q, BooleanClause.Occur.SHOULD))
 
         no_book_cat = self.term_filter(Term("tag_category", "book"), inverse=True)
 
         return self.search_tags(top, no_book_cat, max_results=max_results, pdcounter=pdcounter)
 
-    def hint_books(self, string, max_results=50, prefix=True):
+    def hint_books(self, string, max_results=50, prefix=True, fuzzy=False):
         """
         Returns auto-complete hints for book titles
         Because we do not index 'pseudo' title-tags.
@@ -1309,7 +1475,7 @@ class Search(IndexStore):
         if prefix:
             q = self.make_prefix_phrase(toks, 'title')
         else:
-            q = self.make_term_query(toks, 'title')
+            q = self.make_term_query(toks, 'title', fuzzy=fuzzy)
 
         return self.search_books(q, self.term_filter(Term("is_book", "true")), max_results=max_results)