From 82d7bd3d571ce3464156938657564bb352c2a21c Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 30 Jul 2013 10:56:04 +0530
Subject: [PATCH] newdb: Speed up set_metadata() by not committing the db after
 individual field writes

---
 src/calibre/db/cache.py | 77 +++++++++++++++++++++--------------------
 1 file changed, 39 insertions(+), 38 deletions(-)

diff --git a/src/calibre/db/cache.py b/src/calibre/db/cache.py
index 5c0a7fda59..d311cbadde 100644
--- a/src/calibre/db/cache.py
+++ b/src/calibre/db/cache.py
@@ -1084,11 +1084,6 @@ class Cache(object):
                 else:
                     raise
 
-        for field in ('rating', 'series_index', 'timestamp'):
-            val = getattr(mi, field)
-            if val is not None:
-                protected_set_field(field, val)
-
         # force_changes has no effect on cover manipulation
         cdata = mi.cover_data[1]
         if cdata is None and isinstance(mi.cover, basestring) and mi.cover and os.access(mi.cover, os.R_OK):
@@ -1099,42 +1094,48 @@ class Cache(object):
         if cdata is not None:
             self._set_cover({book_id: cdata})
 
-        for field in ('author_sort', 'publisher', 'series', 'tags', 'comments',
-            'languages', 'pubdate'):
-            val = mi.get(field, None)
-            if (force_changes and val is not None) or not mi.is_null(field):
-                protected_set_field(field, val)
+        with self.backend.conn:  # Speed up set_metadata by not operating in autocommit mode
+            for field in ('rating', 'series_index', 'timestamp'):
+                val = getattr(mi, field)
+                if val is not None:
+                    protected_set_field(field, val)
 
-        val = mi.get('title_sort', None)
-        if (force_changes and val is not None) or not mi.is_null('title_sort'):
-            protected_set_field('sort', val)
+            for field in ('author_sort', 'publisher', 'series', 'tags', 'comments',
+                'languages', 'pubdate'):
+                val = mi.get(field, None)
+                if (force_changes and val is not None) or not mi.is_null(field):
+                    protected_set_field(field, val)
 
-        # identifiers will always be replaced if force_changes is True
-        mi_idents = mi.get_identifiers()
-        if force_changes:
-            protected_set_field('identifiers', mi_idents)
-        elif mi_idents:
-            identifiers = self._field_for('identifiers', book_id, default_value={})
-            for key, val in mi_idents.iteritems():
-                if val and val.strip():  # Don't delete an existing identifier
-                    identifiers[icu_lower(key)] = val
-            protected_set_field('identifiers', identifiers)
+            val = mi.get('title_sort', None)
+            if (force_changes and val is not None) or not mi.is_null('title_sort'):
+                protected_set_field('sort', val)
 
-        user_mi = mi.get_all_user_metadata(make_copy=False)
-        fm = self.field_metadata
-        for key in user_mi.iterkeys():
-            if (key in fm and
-                    user_mi[key]['datatype'] == fm[key]['datatype'] and
-                    (user_mi[key]['datatype'] != 'text' or
-                     user_mi[key]['is_multiple'] == fm[key]['is_multiple'])):
-                val = mi.get(key, None)
-                if force_changes or val is not None:
-                    protected_set_field(key, val)
-                    idx = key + '_index'
-                    if idx in self.fields:
-                        extra = mi.get_extra(key)
-                        if extra is not None or force_changes:
-                            protected_set_field(idx, extra)
+            # identifiers will always be replaced if force_changes is True
+            mi_idents = mi.get_identifiers()
+            if force_changes:
+                protected_set_field('identifiers', mi_idents)
+            elif mi_idents:
+                identifiers = self._field_for('identifiers', book_id, default_value={})
+                for key, val in mi_idents.iteritems():
+                    if val and val.strip():  # Don't delete an existing identifier
+                        identifiers[icu_lower(key)] = val
+                protected_set_field('identifiers', identifiers)
+
+            user_mi = mi.get_all_user_metadata(make_copy=False)
+            fm = self.field_metadata
+            for key in user_mi.iterkeys():
+                if (key in fm and
+                        user_mi[key]['datatype'] == fm[key]['datatype'] and
+                        (user_mi[key]['datatype'] != 'text' or
+                        user_mi[key]['is_multiple'] == fm[key]['is_multiple'])):
+                    val = mi.get(key, None)
+                    if force_changes or val is not None:
+                        protected_set_field(key, val)
+                        idx = key + '_index'
+                        if idx in self.fields:
+                            extra = mi.get_extra(key)
+                            if extra is not None or force_changes:
+                                protected_set_field(idx, extra)
 
     @write_api
     def add_format(self, book_id, fmt, stream_or_path, replace=True, run_hooks=True, dbapi=None):