fix the review history growing bug properly

anki/deck.py

@@ -54,7 +54,7 @@ decksTable = Table(
     Column('created', Float, nullable=False, default=time.time),
     Column('modified', Float, nullable=False, default=time.time),
     Column('description', UnicodeText, nullable=False, default=u""),
-    Column('version', Integer, nullable=False, default=29),
+    Column('version', Integer, nullable=False, default=30),
     Column('currentModelId', Integer, ForeignKey("models.id")),
     # syncing
     Column('syncName', UnicodeText),
@@ -2714,13 +2714,17 @@ where interval < 1""")
             deck.s.statement("pragma default_cache_size= 20000")
             deck.version = 28
             deck.s.commit()
-        if deck.version < 29:
+        if deck.version < 30:
             # remove duplicates from review history
             deck.s.statement("""
 delete from reviewHistory where id not in (
 select min(id) from reviewHistory group by cardId, time);""")
+            # add a unique index to prevent them from appearing
+            deck.s.statement("""
+create unique index ix_reviewHistory_unique
+on reviewHistory (cardId, time)""")
             deck.s.statement("vacuum")
-            deck.version = 29
+            deck.version = 30
             deck.s.commit()
         # this check we do regardless of version number since doing it on init
         # seems to crash

anki/history.py

@@ -18,8 +18,7 @@ from anki.db import *
 
 reviewHistoryTable = Table(
     'reviewHistory', metadata,
-    Column('id', Integer, primary_key=True),
-    Column('cardId', Integer, ForeignKey("cards.id")),
+    Column('cardId', Integer),
     Column('time', Float, nullable=False, default=time.time),
     Column('lastInterval', Float, nullable=False),
     Column('nextInterval', Float, nullable=False),
@@ -30,7 +29,8 @@ reviewHistoryTable = Table(
     Column('reps', Float, nullable=False),
     Column('thinkingTime', Float, nullable=False),
     Column('yesCount', Float, nullable=False),
-    Column('noCount', Float, nullable=False))
+    Column('noCount', Float, nullable=False),
+    PrimaryKeyConstraint("cardId", "time"))
 
 class CardHistoryEntry(object):
     "Create after rescheduling card."

anki/sync.py

@@ -627,7 +627,7 @@ from reviewHistory where time > :ls""",
         if not dlist:
             return
         self.deck.s.statements("""
-insert into reviewHistory
+insert or ignore into reviewHistory
 (cardId, time, lastInterval, nextInterval, ease, delay,
 lastFactor, nextFactor, reps, thinkingTime, yesCount, noCount)
 values