From cdb33cf6a86a1e9293f257ad305d49cd78b18021 Mon Sep 17 00:00:00 2001
From: Damien Elmes <git@ichi2.net>
Date: Sun, 4 Dec 2011 13:51:13 +0900
Subject: [PATCH] don't bump mod time unless the db has actually been changed

---
 anki/collection.py | 15 +++++++++------
 anki/db.py         |  8 ++++++++
 anki/decks.py      |  1 +
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/anki/collection.py b/anki/collection.py
index e14c5e6f6..d2eb2ea21 100644
--- a/anki/collection.py
+++ b/anki/collection.py
@@ -96,15 +96,18 @@ conf, models, decks, dconf, tags from col""")
 crt=?, mod=?, scm=?, dty=?, usn=?, ls=?, conf=?""",
             self.crt, self.mod, self.scm, self.dty,
             self._usn, self.ls, simplejson.dumps(self.conf))
-        self.models.flush()
-        self.decks.flush()
-        self.tags.flush()
 
     def save(self, name=None, mod=None):
         "Flush, commit DB, and take out another write lock."
-        self.flush(mod=mod)
-        self.db.commit()
-        self.lock()
+        # let the managers conditionally flush
+        self.models.flush()
+        self.decks.flush()
+        self.tags.flush()
+        # and flush deck + bump mod if db has been changed
+        if self.db.mod:
+            self.flush(mod=mod)
+            self.db.commit()
+            self.lock()
         self._markOp(name)
         self._lastSave = time.time()
 
diff --git a/anki/db.py b/anki/db.py
index 7db4497c2..f6d53345d 100644
--- a/anki/db.py
+++ b/anki/db.py
@@ -17,8 +17,14 @@ class DB(object):
             self._db.text_factory = text
         self._path = path
         self.echo = os.environ.get("DBECHO")
+        self.mod = False
 
     def execute(self, sql, *a, **ka):
+        s = sql.strip().lower()
+        # mark modified?
+        for stmt in "insert", "update", "delete":
+            if s.startswith(stmt):
+                self.mod = True
         if self.echo:
             print sql #, a, ka
         if ka:
@@ -30,6 +36,7 @@ class DB(object):
         return res
 
     def executemany(self, sql, l):
+        self.mod = True
         if self.echo:
             print sql #, l
         self._db.executemany(sql, l)
@@ -38,6 +45,7 @@ class DB(object):
         self._db.commit()
 
     def executescript(self, sql):
+        self.mod = True
         if self.echo:
             print sql
         self._db.executescript(sql)
diff --git a/anki/decks.py b/anki/decks.py
index a4a76a098..1cb727760 100644
--- a/anki/decks.py
+++ b/anki/decks.py
@@ -29,6 +29,7 @@ defaultDeck = {
     'lrnToday': [0, 0],
     'timeToday': [0, 0], # time in ms
     'conf': 1,
+    'usn': 0,
 }
 
 # configuration only available to top level decks