Merge casey-zctextindex-fewer-conflicts-branch:

  - Indexes and Lexicon now much less likely to generate write conflicts.
    Previously *any* concurrent index/unindex operation would conflict

  - Performance and scalability fix for queries

lib/python/Products/ZCTextIndex/BaseIndex.py

@@ -20,7 +20,7 @@ import math
 from BTrees.IOBTree import IOBTree
 from BTrees.IIBTree import IIBTree, IIBucket, IITreeSet
 from BTrees.IIBTree import intersection, difference
-import BTrees.Length
+from BTrees.Length import Length
 
 from Products.ZCTextIndex.IIndex import IIndex
 from Products.ZCTextIndex import WidCode
@@ -83,12 +83,18 @@ class BaseIndex(Persistent):
         self._docwords = IOBTree()
 
         # Use a BTree length for efficient length computation w/o conflicts
-        self.length = BTrees.Length.Length()
+        self.length = Length()
+        self.document_count = Length()
 
     def length(self):
         """Return the number of words in the index."""
         # This is overridden per instance
         return len(self._wordinfo)
+        
+    def document_count(self):
+        """Return the number of documents in the index"""
+        # This is overridden per instance
+        return len(self._docweight)        
 
     def get_words(self, docid):
         """Return a list of the wordids for a given docid."""
@@ -104,6 +110,11 @@ class BaseIndex(Persistent):
         self._mass_add_wordinfo(wid2weight, docid)
         self._docweight[docid] = docweight
         self._docwords[docid] = WidCode.encode(wids)
+        try:
+            self.document_count.change(1)
+        except AttributeError:
+            # Upgrade document_count to Length object
+            self.document_count = Length(self.document_count())
         return len(wids)
 
     # A subclass may wish to extend or override this.  This is for adjusting
@@ -165,6 +176,11 @@ class BaseIndex(Persistent):
             self._del_wordinfo(wid, docid)
         del self._docwords[docid]
         del self._docweight[docid]
+        try:
+            self.document_count.change(-1)
+        except AttributeError:
+            # Upgrade document_count to Length object
+            self.document_count = Length(self.document_count())
 
     def search(self, term):
         wids = self._lexicon.termToWordIds(term)

lib/python/Products/ZCTextIndex/CosineIndex.py

@@ -69,7 +69,7 @@ class CosineIndex(BaseIndex):
     def _search_wids(self, wids):
         if not wids:
             return []
-        N = float(len(self._docweight))
+        N = float(self.document_count())
         L = []
         DictType = type({})
         for wid in wids:
@@ -86,7 +86,7 @@ class CosineIndex(BaseIndex):
         wids = []
         for term in terms:
             wids += self._lexicon.termToWordIds(term)
-        N = float(len(self._docweight))
+        N = float(self.document_count())
         sum = 0.0
         for wid in self._remove_oov_wids(wids):
             wt = inverse_doc_frequency(len(self._wordinfo[wid]), N)

lib/python/Products/ZCTextIndex/IIndex.py

@@ -20,6 +20,9 @@ class IIndex(Interface.Base):
     """Interface for an Index."""
 
     def length():
+        """Return the number of words in the index."""
+        
+    def document_count():
         """Return the number of documents in the index."""
 
     def get_words(docid):
@@ -62,10 +65,13 @@ class IIndex(Interface.Base):
         """
 
     def index_doc(docid, text):
-        "XXX"
+        """Add a document with the specified id and text to the index. If a
+        document by that id already exists, replace its text with the new
+        text provided
+        """
 
     def unindex_doc(docid):
-        "XXX"
+        """Remove the document with the specified id from the index"""
 
     def has_doc(docid):
         """Returns true if docid is an id of a document in the index"""

lib/python/Products/ZCTextIndex/Lexicon.py

@@ -16,6 +16,7 @@ import re
 
 from BTrees.IOBTree import IOBTree
 from BTrees.OIBTree import OIBTree
+from BTrees.Length import Length
 
 import ZODB
 from Persistence import Persistent
@@ -37,16 +38,13 @@ class Lexicon(Persistent):
         # we never saw before, and that isn't a known stopword (or otherwise
         # filtered out).  Returning a special wid value for OOV words is a
         # way to let clients know when an OOV word appears.
-        self._nextwid = 1
+        self.length = Length()
         self._pipeline = pipeline
 
-        # Keep some statistics about indexing
-        self._nbytes = 0 # Number of bytes indexed (at start of pipeline)
-        self._nwords = 0 # Number of words indexed (after pipeline)
-
     def length(self):
         """Return the number of unique terms in the lexicon."""
-        return self._nextwid - 1
+        # Overridden in instances
+        return len(self._wids)
 
     def words(self):
         return self._wids.keys()
@@ -59,11 +57,15 @@ class Lexicon(Persistent):
 
     def sourceToWordIds(self, text):
         last = _text2list(text)
-        for t in last:
-            self._nbytes += len(t)
         for element in self._pipeline:
             last = element.process(last)
-        self._nwords += len(last)
+        if not hasattr(self.length, 'change'):
+            # Make sure length is overridden with a BTrees.Length.Length
+            self.length = Length(self.length())        
+        # Strategically unload the length value so that we get the most
+        # recent value written to the database to minimize conflicting wids
+        # XXX this will not work when MVCC is implemented in the ZODB...
+        self.length._p_deactivate()
         return map(self._getWordIdCreate, last)
 
     def termToWordIds(self, text):
@@ -138,9 +140,10 @@ class Lexicon(Persistent):
         return wid
 
     def _new_wid(self):
-        wid = self._nextwid
-        self._nextwid += 1
-        return wid
+        self.length.change(1)
+        while self._words.has_key(self.length()): # just to be safe
+            self.length.change(1)
+        return self.length()
 
 def _text2list(text):
     # Helper: splitter input may be a string or a list of strings

lib/python/Products/ZCTextIndex/OkapiIndex.py

@@ -18,6 +18,7 @@
 # understand what's going on.
 
 from BTrees.IIBTree import IIBucket
+from BTrees.Length import Length
 
 from Products.ZCTextIndex.IIndex import IIndex
 from Products.ZCTextIndex.BaseIndex import BaseIndex, \
@@ -50,20 +51,29 @@ class OkapiIndex(BaseIndex):
         # sum(self._docweight.values()), the total # of words in all docs
         # This is a long for "better safe than sorry" reasons.  It isn't
         # used often enough that speed should matter.
-        self._totaldoclen = 0L
+        # Use a BTree.Length.Length object to avoid concurrent write conflicts
+        self._totaldoclen = Length(0L)
 
     def index_doc(self, docid, text):
         count = BaseIndex.index_doc(self, docid, text)
-        self._totaldoclen += count
+        self._change_doc_len(count)
         return count
 
     def _reindex_doc(self, docid, text):
-        self._totaldoclen -= self._docweight[docid]
+        self._change_doc_len(-self._docweight[docid])
         return BaseIndex._reindex_doc(self, docid, text)
 
     def unindex_doc(self, docid):
-        self._totaldoclen -= self._docweight[docid]
+        self._change_doc_len(-self._docweight[docid])
         BaseIndex.unindex_doc(self, docid)
+    
+    def _change_doc_len(self, delta):
+        # Change total doc length used for scoring
+        try:
+            self._totaldoclen.change(delta)
+        except AttributeError:
+            # Opportunistically upgrade _totaldoclen attribute to Length object
+            self._totaldoclen = Length(long(self._totaldoclen + delta))
 
     # The workhorse.  Return a list of (IIBucket, weight) pairs, one pair
     # for each wid t in wids.  The IIBucket, times the weight, maps D to
@@ -76,8 +86,13 @@ class OkapiIndex(BaseIndex):
     def _search_wids(self, wids):
         if not wids:
             return []
-        N = float(len(self._docweight))  # total # of docs
-        meandoclen = self._totaldoclen / N
+        N = float(self.document_count())  # total # of docs
+        try:
+            doclen = self._totaldoclen()
+        except TypeError:
+            # _totaldoclen has not yet been upgraded
+            doclen = self._totaldoclen
+        meandoclen = doclen / N
         K1 = self.K1
         B = self.B
         K1_plus1 = K1 + 1.0
@@ -120,8 +135,13 @@ class OkapiIndex(BaseIndex):
     def _search_wids(self, wids):
         if not wids:
             return []
-        N = float(len(self._docweight))  # total # of docs
-        meandoclen = self._totaldoclen / N
+        N = float(self.document_count())  # total # of docs
+        try:
+            doclen = self._totaldoclen()
+        except TypeError:
+            # _totaldoclen has not yet been upgraded
+            doclen = self._totaldoclen
+        meandoclen = doclen / N
         #K1 = self.K1
         #B = self.B
         #K1_plus1 = K1 + 1.0

lib/python/Products/ZCTextIndex/ZCTextIndex.py

@@ -173,13 +173,11 @@ class ZCTextIndex(Persistent, Acquisition.Implicit, SimpleItem):
         if text is None:
             return 0
         count = self.index.index_doc(docid, text)
-        self._p_changed = 1 # XXX
         return count
 
     def unindex_object(self, docid):
         if self.index.has_doc(docid):
             self.index.unindex_doc(docid)
-            self._p_changed = 1 # XXX
 
     def _apply_index(self, request, cid=''):
         """Apply query specified by request, a mapping containing the query.

lib/python/Products/ZCTextIndex/tests/mhindex.py

@@ -441,8 +441,6 @@ class Indexer:
             self.updatefolder(f, f.listmessages())
             print "Total", len(self.docpaths)
         self.commit()
-        print "Indexed", self.index.lexicon._nbytes, "bytes and",
-        print self.index.lexicon._nwords, "words;",
         print len(self.index.lexicon._words), "unique words."
 
     def updatefolder(self, f, msgs):

lib/python/Products/ZCTextIndex/tests/testIndex.py

@@ -12,8 +12,10 @@
 #
 ##############################################################################
 
+import os
 from unittest import TestCase, TestSuite, main, makeSuite
 
+from BTrees.Length import Length
 from Products.ZCTextIndex.Lexicon import Lexicon, Splitter
 from Products.ZCTextIndex.CosineIndex import CosineIndex
 from Products.ZCTextIndex.OkapiIndex import OkapiIndex
@@ -34,6 +36,8 @@ class IndexTest(TestCase):
         self.assert_(self.index.has_doc(DOCID))
         self.assert_(self.index._docweight[DOCID])
         self.assertEqual(len(self.index._docweight), 1)
+        self.assertEqual(
+            len(self.index._docweight), self.index.document_count())
         self.assertEqual(len(self.index._wordinfo), 5)
         self.assertEqual(len(self.index._docwords), 1)
         self.assertEqual(len(self.index.get_words(DOCID)), 5)
@@ -48,6 +52,8 @@ class IndexTest(TestCase):
         self.test_index_document(DOCID)
         self.index.unindex_doc(DOCID)
         self.assertEqual(len(self.index._docweight), 0)
+        self.assertEqual(
+            len(self.index._docweight), self.index.document_count())
         self.assertEqual(len(self.index._wordinfo), 0)
         self.assertEqual(len(self.index._docwords), 0)
         self.assertEqual(len(self.index._wordinfo),
@@ -60,6 +66,8 @@ class IndexTest(TestCase):
         self.index.index_doc(DOCID, doc)
         self.assert_(self.index._docweight[DOCID])
         self.assertEqual(len(self.index._docweight), 2)
+        self.assertEqual(
+            len(self.index._docweight), self.index.document_count())
         self.assertEqual(len(self.index._wordinfo), 8)
         self.assertEqual(len(self.index._docwords), 2)
         self.assertEqual(len(self.index.get_words(DOCID)), 4)
@@ -82,6 +90,8 @@ class IndexTest(TestCase):
         self.index.unindex_doc(1)
         DOCID = 2
         self.assertEqual(len(self.index._docweight), 1)
+        self.assertEqual(
+            len(self.index._docweight), self.index.document_count())
         self.assert_(self.index._docweight[DOCID])
         self.assertEqual(len(self.index._wordinfo), 4)
         self.assertEqual(len(self.index._docwords), 1)
@@ -101,6 +111,8 @@ class IndexTest(TestCase):
         self.assertEqual(len(self.index.get_words(DOCID)), 7)
         self.assertEqual(len(self.index._wordinfo),
                          self.index.length())
+        self.assertEqual(
+            len(self.index._docweight), self.index.document_count())
         wids = self.lexicon.termToWordIds("repeat")
         self.assertEqual(len(wids), 1)
         repititive_wid = wids[0]
@@ -145,9 +157,130 @@ class CosineIndexTest(IndexTest):
 class OkapiIndexTest(IndexTest):
     IndexFactory = OkapiIndex
 
+class TestIndexConflict(TestCase):
+    
+    storage = None
+
+    def tearDown(self):
+        if self.storage is not None:
+            self.storage.close()
+
+    def openDB(self):
+        from ZODB.FileStorage import FileStorage
+        from ZODB.DB import DB
+        n = 'fs_tmp__%s' % os.getpid()
+        self.storage = FileStorage(n)
+        self.db = DB(self.storage)
+        
+    def test_index_doc_conflict(self):
+        self.index = OkapiIndex(Lexicon())
+        self.openDB()
+        r1 = self.db.open().root()
+        r1['i'] = self.index
+        get_transaction().commit()
+        
+        r2 = self.db.open().root()
+        copy = r2['i']
+        # Make sure the data is loaded
+        list(copy._docweight.items())
+        list(copy._docwords.items())
+        list(copy._wordinfo.items())
+        list(copy._lexicon._wids.items())
+        list(copy._lexicon._words.items())
+        
+        self.assertEqual(self.index._p_serial, copy._p_serial)
+        
+        self.index.index_doc(0, 'The time has come')
+        get_transaction().commit()
+        
+        copy.index_doc(1, 'That time has gone')
+        get_transaction().commit()
+
+    def test_reindex_doc_conflict(self):
+        self.index = OkapiIndex(Lexicon())
+        self.index.index_doc(0, 'Sometimes change is good')
+        self.index.index_doc(1, 'Then again, who asked')
+        self.openDB()
+        r1 = self.db.open().root()
+        r1['i'] = self.index
+        get_transaction().commit()
+        
+        r2 = self.db.open().root()
+        copy = r2['i']
+        # Make sure the data is loaded
+        list(copy._docweight.items())
+        list(copy._docwords.items())
+        list(copy._wordinfo.items())
+        list(copy._lexicon._wids.items())
+        list(copy._lexicon._words.items())
+        
+        self.assertEqual(self.index._p_serial, copy._p_serial)
+        
+        self.index.index_doc(0, 'Sometimes change isn\'t bad')
+        get_transaction().commit()
+        
+        copy.index_doc(1, 'Then again, who asked you?')
+        get_transaction().commit()
+        
+class TestUpgrade(TestCase):
+
+    def test_query_before_totaldoclen_upgrade(self):
+        self.index1 = OkapiIndex(Lexicon(Splitter()))
+        self.index1.index_doc(0, 'The quiet of night')
+        # Revert index1 back to a long to simulate an older index instance
+        self.index1._totaldoclen = long(self.index1._totaldoclen())
+        self.assertEqual(len(self.index1.search('night')), 1)
+    
+    def test_upgrade_totaldoclen(self):
+        self.index1 = OkapiIndex(Lexicon())
+        self.index2 = OkapiIndex(Lexicon())
+        self.index1.index_doc(0, 'The quiet of night')
+        self.index2.index_doc(0, 'The quiet of night')
+        # Revert index1 back to a long to simulate an older index instance
+        self.index1._totaldoclen = long(self.index1._totaldoclen())
+        self.index1.index_doc(1, 'gazes upon my shadow')
+        self.index2.index_doc(1, 'gazes upon my shadow')
+        self.assertEqual(
+            self.index1._totaldoclen(), self.index2._totaldoclen())
+        self.index1._totaldoclen = long(self.index1._totaldoclen())
+        self.index1.unindex_doc(0)
+        self.index2.unindex_doc(0)
+        self.assertEqual(
+            self.index1._totaldoclen(), self.index2._totaldoclen())
+
+    def test_query_before_document_count_upgrade(self):
+        self.index1 = OkapiIndex(Lexicon(Splitter()))
+        self.index1.index_doc(0, 'The quiet of night')
+        # Revert index1 back to a long to simulate an older index instance
+        del self.index1.document_count
+        self.assertEqual(len(self.index1.search('night')), 1)
+    
+    def test_upgrade_document_count(self):
+        self.index1 = OkapiIndex(Lexicon())
+        self.index2 = OkapiIndex(Lexicon())
+        self.index1.index_doc(0, 'The quiet of night')
+        self.index2.index_doc(0, 'The quiet of night')
+        # Revert index1 back to simulate an older index instance
+        del self.index1.document_count
+        self.index1.index_doc(1, 'gazes upon my shadow')
+        self.index2.index_doc(1, 'gazes upon my shadow')
+        self.assert_(self.index1.document_count.__class__ is Length)
+        self.assertEqual(
+            self.index1.document_count(), self.index2.document_count())
+        del self.index1.document_count
+        self.index1.unindex_doc(0)
+        self.index2.unindex_doc(0)
+        self.assert_(self.index1.document_count.__class__ is Length)
+        self.assertEqual(
+            self.index1.document_count(), self.index2.document_count())
+        
+        
+        
 def test_suite():
     return TestSuite((makeSuite(CosineIndexTest),
                       makeSuite(OkapiIndexTest),
+                      makeSuite(TestIndexConflict),
+                      makeSuite(TestUpgrade),
                     ))
 
 if __name__=='__main__':

lib/python/Products/ZCTextIndex/tests/testLexicon.py

@@ -12,9 +12,11 @@
 #
 ##############################################################################
 
-import sys
+import os, sys
 from unittest import TestCase, TestSuite, main, makeSuite
 
+import ZODB
+
 from Products.ZCTextIndex.Lexicon import Lexicon
 from Products.ZCTextIndex.Lexicon import Splitter, CaseNormalizer
 
@@ -134,9 +136,59 @@ class Test(TestCase):
         words = HTMLWordSplitter().process(words)
         self.assertEqual(words, expected)
         locale.setlocale(locale.LC_ALL, loc) # restore saved locale
+        
+    def testUpgradeLength(self):
+        from BTrees.Length import Length
+        lexicon = Lexicon(Splitter())
+        del lexicon.length # Older instances don't override length
+        lexicon.sourceToWordIds('how now brown cow')
+        self.assert_(lexicon.length.__class__ is Length)        
+        
+class TestLexiconConflict(TestCase):
+    
+    storage = None
+
+    def tearDown(self):
+        if self.storage is not None:
+            self.storage.close()
+
+    def openDB(self):
+        from ZODB.FileStorage import FileStorage
+        from ZODB.DB import DB
+        n = 'fs_tmp__%s' % os.getpid()
+        self.storage = FileStorage(n)
+        self.db = DB(self.storage)
+        
+    def testAddWordConflict(self):
+        self.l = Lexicon(Splitter())
+        self.openDB()
+        r1 = self.db.open().root()
+        r1['l'] = self.l
+        get_transaction().commit()
+        
+        r2 = self.db.open().root()
+        copy = r2['l']
+        # Make sure the data is loaded
+        list(copy._wids.items())
+        list(copy._words.items())
+        copy.length()
+        
+        self.assertEqual(self.l._p_serial, copy._p_serial)
+        
+        self.l.sourceToWordIds('mary had a little lamb')
+        get_transaction().commit()
+        
+        copy.sourceToWordIds('whose fleece was')
+        copy.sourceToWordIds('white as snow')
+        get_transaction().commit()
+        self.assertEqual(copy.length(), 11)
+        self.assertEqual(copy.length(), len(copy._words))
 
 def test_suite():
-    return makeSuite(Test)
+    suite = TestSuite()
+    suite.addTest(makeSuite(Test))
+    suite.addTest(makeSuite(TestLexiconConflict))
+    return suite
 
 if __name__=='__main__':
     main(defaultTest='test_suite')

lib/python/Products/ZCTextIndex/tests/testZCTextIndex.py

@@ -331,7 +331,7 @@ class OkapiIndexTests(ZCIndexTestsBase, testIndex.OkapiIndexTest):
         self._checkAbsoluteScores()
 
     def _checkAbsoluteScores(self):
-        self.assertEqual(self.index._totaldoclen, 6)
+        self.assertEqual(self.index._totaldoclen(), 6)
         # So the mean doc length is 2.  We use that later.
 
         r, num = self.zc_index.query("one")