"timeout" config value (#261)

beets/library.py

@@ -703,6 +703,7 @@ class Library(BaseLibrary):
                        directory='~/Music',
                        path_formats=None,
                        art_filename='cover',
+                       timeout=5.0,
                        item_fields=ITEM_FIELDS,
                        album_fields=ALBUM_FIELDS):
         if path == ':memory:':
@@ -717,7 +718,8 @@ class Library(BaseLibrary):
         self.path_formats = path_formats
         self.art_filename = bytestring_path(art_filename)
         
-        self.conn = sqlite3.connect(self.path)
+        self.timeout = timeout
+        self.conn = sqlite3.connect(self.path, timeout)
         self.conn.row_factory = sqlite3.Row
             # this way we can access our SELECT results like dictionaries
         

beets/ui/__init__.py

@@ -45,6 +45,7 @@ DEFAULT_PATH_FORMATS = {
     'singleton': 'Non-Album/$artist/$title',
 }
 DEFAULT_ART_FILENAME = 'cover'
+DEFAULT_TIMEOUT = 5.0
 
 
 # UI exception. Commands should throw this in order to display
@@ -639,12 +640,18 @@ def main(args=None, configfh=None):
             path_formats.update(config.items('paths'))
     art_filename = \
         config_val(config, 'beets', 'art_filename', DEFAULT_ART_FILENAME)
+    lib_timeout = config_val(config, 'beets', 'timeout', DEFAULT_TIMEOUT)
+    try:
+        lib_timeout = float(lib_timeout)
+    except ValueError:
+        lib_timeout = DEFAULT_TIMEOUT
     db_path = os.path.expanduser(libpath)
     try:
         lib = library.Library(db_path,
                               directory,
                               path_formats,
-                              art_filename)
+                              art_filename,
+                              lib_timeout)
     except sqlite3.OperationalError:
         raise UserError("database file %s could not be opened" % db_path)
     

docs/changelog.rst

@@ -41,6 +41,7 @@ Changelog
   via the ``ignore`` setting; see :doc:`/reference/config`.
 * The database now keeps track of files' modification times so that, during
   an ``update``, unmodified files can be skipped. (Thanks to Jos van der Til.)
+* A new ``timeout`` config value avoids database locking errors on slow systems.
 * Fix a crash after using the "as Tracks" option during import.
 * Fix a Unicode error when tagging items with missing titles.
 * Fix a crash when the state file (``~/.beetsstate``) became emptied or

docs/reference/config.rst

@@ -98,6 +98,11 @@ section header:
     only in the ``import`` command). Turn this off if your terminal doesn't
     support ANSI colors.
 
+``timeout``
+    The amount of time that the SQLite library should wait before raising an
+    exception when the database lock is contended. This should almost never need
+    to be changed except on very slow systems. Defaults to 5.0 (5 seconds).
+
 You can also configure the directory hierarchy beets uses to store music. That
 uses the ``[paths]`` section instead of the ``[beets]`` section. Each string is
 a `Python template string`_ that can refer to metadata fields (see below for