Implement refresh()

src/calibre/db/cache.py

@@ -114,6 +114,19 @@ class Cache(object):
         if self.dirtied_cache:
             self.dirtied_sequence = max(self.dirtied_cache.itervalues())+1
 
+    @write_api
+    def initialize_template_cache(self):
+        self.formatter_template_cache = {}
+
+    @write_api
+    def refresh(self):
+        self._initialize_template_cache()
+        for field in self.fields.itervalues():
+            if hasattr(field, 'clear_cache'):
+                field.clear_cache()  # Clear the composite cache
+            if hasattr(field, 'table'):
+                field.table.read(self.backend)  # Reread data from metadata.db
+
     @property
     def field_metadata(self):
         return self.backend.field_metadata

src/calibre/db/legacy.py

@@ -12,6 +12,7 @@ from functools import partial
 from calibre.db.backend import DB
 from calibre.db.cache import Cache
 from calibre.db.view import View
+from calibre.utils.date import utcnow
 
 class LibraryDatabase(object):
 
@@ -50,6 +51,8 @@ class LibraryDatabase(object):
             setattr(self, prop, partial(self.get_property,
                     loc=self.FIELD_MAP[fm]))
 
+        self.last_update_check = self.last_modified()
+
     def close(self):
         self.backend.close()
 
@@ -74,6 +77,11 @@ class LibraryDatabase(object):
     def last_modified(self):
         return self.backend.last_modified()
 
+    def check_if_modified(self):
+        if self.last_modified() > self.last_update_check:
+            self.refresh()
+        self.last_update_check = utcnow()
+
     @property
     def custom_column_num_map(self):
         return self.backend.custom_column_num_map
@@ -86,9 +94,21 @@ class LibraryDatabase(object):
     def FIELD_MAP(self):
         return self.backend.FIELD_MAP
 
+    @property
+    def formatter_template_cache(self):
+        return self.data.cache.formatter_template_cache
+
+    def initialize_template_cache(self):
+        self.data.cache.initialize_template_cache()
+
     def all_ids(self):
         for book_id in self.data.cache.all_book_ids():
             yield book_id
+
+    def refresh(self, field=None, ascending=True):
+        self.data.cache.refresh()
+        self.data.refresh(field=field, ascending=ascending)
+
     # }}}
 
 

src/calibre/db/tests/legacy.py

@@ -64,3 +64,15 @@ class LegacyTest(BaseTest):
 
     # }}}
 
+    def test_refresh(self):  # {{{
+        ' Test refreshing the view after a change to metadata.db '
+        db = self.init_legacy()
+        db2 = self.init_legacy()
+        self.assertEqual(db2.data.cache.set_field('title', {1:'xxx'}), set([1]))
+        db2.close()
+        del db2
+        self.assertNotEqual(db.title(1, index_is_id=True), 'xxx')
+        db.check_if_modified()
+        self.assertEqual(db.title(1, index_is_id=True), 'xxx')
+    # }}}
+

src/calibre/db/view.py

@@ -294,3 +294,11 @@ class View(object):
             self.marked_ids = dict(izip(id_dict.iterkeys(), imap(unicode,
                 id_dict.itervalues())))
 
+    def refresh(self, field=None, ascending=True):
+        self._map = tuple(self.cache.all_book_ids())
+        self._map_filtered = tuple(self._map)
+        if field is not None:
+            self.sort(field, ascending)
+        if self.search_restriction or self.base_restriction:
+            self.search('', return_matches=False)
+