Implement reinit_db() with apsw

src/calibre/db/__init__.py

@@ -132,7 +132,7 @@ def get_db_loader():
 
 '''
 Various things that require other things before they can be migrated:
-    1. Port library/restore.py, check_library.py and reinit_db() from debug.py
+    1. Port library/restore.py, check_library.py
     2. Check that content server reloading on metadata,db change, metadata
     backup, refresh gui on calibredb add and moving libraries all work (check
     them on windows as well for file locking issues)

src/calibre/debug.py

@@ -84,9 +84,47 @@ Everything after the -- is passed to the script.
 
     return parser
 
+def reinit_db_new(dbpath, callback=None, sql_dump=None):
+    from calibre.db.backend import Connection
+    import apsw
+    import shutil
+    from io import StringIO
+    from contextlib import closing
+    if callback is None:
+        callback = lambda x, y: None
+
+    with closing(Connection(dbpath)) as conn:
+        uv = conn.get('PRAGMA user_version;', all=False)
+        if sql_dump is None:
+            buf = StringIO()
+            shell = apsw.Shell(db=conn, stdout=buf)
+            shell.process_command('.dump')
+            sql = buf.getvalue().encode('utf-8')
+        else:
+            sql = open(sql_dump, 'rb').read()
+
+    dest = dbpath + '.tmp'
+    callback(1, True)
+    try:
+        with closing(Connection(dest)) as conn:
+            conn.execute(sql)
+            conn.execute('PRAGMA User_version=%d;'%int(uv))
+        os.remove(dbpath)
+        shutil.copyfile(dest, dbpath)
+    finally:
+        callback(1, False)
+        if os.path.exists(dest):
+            os.remove(dest)
+    prints('Database successfully re-initialized')
+
+
 def reinit_db(dbpath, callback=None, sql_dump=None):
     if not os.path.exists(dbpath):
         raise ValueError(dbpath + ' does not exist')
+    from calibre.utils.config_base import tweaks
+    if tweaks.get('use_new_db', False):
+        return reinit_db_new(dbpath, callback, sql_dump)
+
     from calibre.library.sqlite import connect
     from contextlib import closing
     import shutil