tags_older_than()

src/calibre/db/__init__.py

@@ -107,12 +107,10 @@ Various things that require other things before they can be migrated:
     1. From initialize_dynamic(): set_saved_searches,
                     load_user_template_functions. Also add custom
                     columns/categories/searches info into
-                    self.field_metadata. Finally, implement metadata dirtied
-                    functionality.
+                    self.field_metadata.
     2. Catching DatabaseException and sqlite.Error when creating new
     libraries/switching/on calibre startup.
-    3. From refresh in the legacy interface: Rember to flush the composite
-    column template cache.
+    3. Port library/restore.py
     4. Replace the metadatabackup thread with the new implementation when using the new backend.
     5. In the new API refresh() does not re-read from disk. That might break a
     few things, for example content server reloading on db change as well as

src/calibre/db/cache.py

@@ -1280,6 +1280,51 @@ class Cache(object):
     def refresh_ondevice(self):
         self.fields['ondevice'].clear_caches()
 
+    @read_api
+    def tags_older_than(self, tag, delta=None, must_have_tag=None, must_have_authors=None):
+        '''
+        Return the ids of all books having the tag ``tag`` that are older than
+        than the specified time. tag comparison is case insensitive.
+
+        :param delta: A timedelta object or None. If None, then all ids with
+        the tag are returned.
+        :param must_have_tag: If not None the list of matches will be
+        restricted to books that have this tag
+        :param must_have_authors: A list of authors. If not None the list of
+        matches will be restricted to books that have these authors (case
+        insensitive).
+        '''
+        tag_map = {icu_lower(v):k for k, v in self._get_id_map('tags').iteritems()}
+        tag = icu_lower(tag.strip())
+        mht = icu_lower(must_have_tag.strip()) if must_have_tag else None
+        tag_id, mht_id = tag_map.get(tag, None), tag_map.get(mht, None)
+        ans = set()
+        if mht_id is None and mht:
+            return ans
+        if tag_id is not None:
+            tagged_books = self._books_for_field('tags', tag_id)
+            if mht_id is not None and tagged_books:
+                tagged_books = tagged_books.intersection(self._books_for_field('tags', mht_id))
+            if tagged_books:
+                if must_have_authors is not None:
+                    amap = {icu_lower(v):k for k, v in self._get_id_map('authors').iteritems()}
+                    books = None
+                    for author in must_have_authors:
+                        abooks = self._books_for_field('authors', amap.get(icu_lower(author), None))
+                        books = abooks if books is None else books.intersection(abooks)
+                        if not books:
+                            break
+                    tagged_books = tagged_books.intersection(books or set())
+                if delta is None:
+                    ans = tagged_books
+                else:
+                    now = nowf()
+                    for book_id in tagged_books:
+                        ts = self._field_for('timestamp', book_id)
+                        if (now - ts) > delta:
+                            ans.add(book_id)
+        return ans
+
     # }}}
 
 class SortKey(object):  # {{{

src/calibre/db/legacy.py

@@ -472,6 +472,10 @@ class LibraryDatabase(object):
     def refresh_ondevice(self):
         self.new_api.refresh_ondevice()
 
+    def tags_older_than(self, tag, delta, must_have_tag=None, must_have_authors=None):
+        for book_id in sorted(self.new_api.tags_older_than(tag, delta=delta, must_have_tag=must_have_tag, must_have_authors=must_have_authors)):
+            yield book_id
+
     # Private interface {{{
     def __iter__(self):
         for row in self.data.iterall():

src/calibre/db/tests/legacy.py

@@ -153,13 +153,19 @@ class LegacyTest(BaseTest):
     # }}}
 
     def test_legacy_direct(self):  # {{{
-        'Test methods that are directly equivalent in the old and new interface'
+        'Test read-only methods that are directly equivalent in the old and new interface'
         from calibre.ebooks.metadata.book.base import Metadata
+        from datetime import timedelta
         ndb = self.init_legacy(self.cloned_library)
         db = self.init_old()
 
         for meth, args in {
             'get_next_series_num_for': [('A Series One',)],
+            '@tags_older_than': [
+                ('News', None), ('Tag One', None), ('xxxx', None), ('Tag One', None, 'News'), ('News', None, 'xxxx'),
+                ('News', None, None, ['xxxxxxx']), ('News', None, 'Tag One', ['Author Two', 'Author One']),
+                ('News', timedelta(0), None, None), ('News', timedelta(100000)),
+            ],
             'format':[(1, 'FMT1', True), (2, 'FMT1', True), (0, 'xxxxxx')],
             'has_format':[(1, 'FMT1', True), (2, 'FMT1', True), (0, 'xxxxxx')],
             '@format_files':[(0,),(1,),(2,)],
@@ -208,13 +214,13 @@ class LegacyTest(BaseTest):
             'books_in_series_of':[(0,), (1,), (2,)],
             'books_with_same_title':[(Metadata(db.title(0)),), (Metadata(db.title(1)),), (Metadata('1234'),)],
         }.iteritems():
+            fmt = lambda x: x
+            if meth[0] in {'!', '@'}:
+                fmt = {'!':dict, '@':frozenset}[meth[0]]
+                meth = meth[1:]
+            elif meth == 'get_authors_with_ids':
+                fmt = lambda val:{x[0]:tuple(x[1:]) for x in val}
             for a in args:
-                fmt = lambda x: x
-                if meth[0] in {'!', '@'}:
-                    fmt = {'!':dict, '@':frozenset}[meth[0]]
-                    meth = meth[1:]
-                elif meth == 'get_authors_with_ids':
-                    fmt = lambda val:{x[0]:tuple(x[1:]) for x in val}
                 self.assertEqual(fmt(getattr(db, meth)(*a)), fmt(getattr(ndb, meth)(*a)),
                                  'The method: %s() returned different results for argument %s' % (meth, a))
         db.close()