Delay load the metadata read/write subsystem

src/calibre/gui2/device.py

@@ -25,7 +25,6 @@ from calibre.devices.errors import FreeSpaceError
 from calibre.devices.apple.driver import ITUNES_ASYNC
 from calibre.devices.folder_device.driver import FOLDER_DEVICE
 from calibre.devices.bambook.driver import BAMBOOK, BAMBOOKWifi
-from calibre.ebooks.metadata.meta import set_metadata
 from calibre.constants import DEBUG
 from calibre.utils.config import prefs, tweaks
 from calibre.utils.magick.draw import thumbnail
@@ -334,6 +333,7 @@ class DeviceManager(Thread): # {{{
 
     def _upload_books(self, files, names, on_card=None, metadata=None, plugboards=None):
         '''Upload books to device: '''
+        from calibre.ebooks.metadata.meta import set_metadata
         if hasattr(self.connected_device, 'set_plugboards') and \
                 callable(self.connected_device.set_plugboards):
             self.connected_device.set_plugboards(plugboards, find_plugboard)

src/calibre/gui2/dialogs/metadata_bulk.py

@@ -13,7 +13,6 @@ from calibre.gui2.dialogs.metadata_bulk_ui import Ui_MetadataBulkDialog
 from calibre.gui2.dialogs.tag_editor import TagEditor
 from calibre.ebooks.metadata import string_to_authors, authors_to_string, title_sort
 from calibre.ebooks.metadata.book.base import composite_formatter
-from calibre.ebooks.metadata.meta import get_metadata
 from calibre.gui2.custom_column_widgets import populate_metadata_page
 from calibre.gui2 import error_dialog, ResizableDialog, UNDEFINED_QDATE, \
     gprefs, question_dialog
@@ -26,6 +25,7 @@ from calibre.utils.magick.draw import identify_data
 from calibre.utils.date import qt_to_dt
 
 def get_cover_data(path): # {{{
+    from calibre.ebooks.metadata.meta import get_metadata
     old = prefs['read_file_metadata']
     if not old:
         prefs['read_file_metadata'] = True

src/calibre/gui2/dialogs/metadata_single.py

@@ -25,7 +25,6 @@ from calibre.ebooks import BOOK_EXTENSIONS
 from calibre.ebooks.metadata import string_to_authors, \
         authors_to_string, check_isbn, title_sort
 from calibre.ebooks.metadata.covers import download_cover
-from calibre.ebooks.metadata.meta import get_metadata
 from calibre.ebooks.metadata import MetaInformation
 from calibre.utils.config import prefs, tweaks
 from calibre.utils.date import qt_to_dt, local_tz, utcfromtimestamp
@@ -353,6 +352,7 @@ class MetadataSingleDialog(ResizableDialog, Ui_MetadataSingleDialog):
             self.formats_changed = True
 
     def get_selected_format_metadata(self):
+        from calibre.ebooks.metadata.meta import get_metadata
         old = prefs['read_file_metadata']
         if not old:
             prefs['read_file_metadata'] = True

src/calibre/gui2/library/models.py

@@ -18,7 +18,6 @@ from calibre.ptempfile import PersistentTemporaryFile
 from calibre.utils.config import tweaks, prefs
 from calibre.utils.date import dt_factory, qt_to_dt, isoformat
 from calibre.utils.icu import sort_key
-from calibre.ebooks.metadata.meta import set_metadata as _set_metadata
 from calibre.utils.search_query_parser import SearchQueryParser
 from calibre.library.caches import _match, CONTAINS_MATCH, EQUALS_MATCH, \
     REGEXP_MATCH, MetadataBackup, force_to_bool
@@ -478,6 +477,7 @@ class BooksModel(QAbstractTableModel): # {{{
     def get_preferred_formats_from_ids(self, ids, formats,
                               set_metadata=False, specific_format=None,
                               exclude_auto=False, mode='r+b'):
+        from calibre.ebooks.metadata.meta import set_metadata as _set_metadata
         ans = []
         need_auto = []
         if specific_format is not None:
@@ -526,6 +526,7 @@ class BooksModel(QAbstractTableModel): # {{{
     def get_preferred_formats(self, rows, formats, paths=False,
                               set_metadata=False, specific_format=None,
                               exclude_auto=False):
+        from calibre.ebooks.metadata.meta import set_metadata as _set_metadata
         ans = []
         need_auto = []
         if specific_format is not None:

src/calibre/gui2/widgets.py

@@ -19,7 +19,6 @@ from calibre.gui2 import NONE, error_dialog, pixmap_to_data, gprefs
 from calibre.gui2.filename_pattern_ui import Ui_Form
 from calibre import fit_image
 from calibre.ebooks import BOOK_EXTENSIONS
-from calibre.ebooks.metadata.meta import metadata_from_filename
 from calibre.utils.config import prefs, XMLConfig, tweaks
 from calibre.gui2.progress_indicator import ProgressIndicator as _ProgressIndicator
 from calibre.gui2.dnd import dnd_has_image, dnd_get_image, dnd_get_files, \
@@ -95,6 +94,7 @@ class FilenamePattern(QWidget, Ui_Form):
         self.re.setCurrentIndex(0)
 
     def do_test(self):
+        from calibre.ebooks.metadata.meta import metadata_from_filename
         try:
             pat = self.pattern()
         except Exception as err:

src/calibre/library/database2.py

@@ -15,7 +15,8 @@ from math import ceil
 from PyQt4.QtGui import QImage
 
 from calibre import prints
-from calibre.ebooks.metadata import title_sort, author_to_author_sort
+from calibre.ebooks.metadata import (title_sort, author_to_author_sort,
+        string_to_authors, authors_to_string)
 from calibre.ebooks.metadata.opf2 import metadata_to_opf
 from calibre.library.database import LibraryDatabase
 from calibre.library.field_metadata import FieldMetadata, TagsIcons
@@ -24,9 +25,7 @@ from calibre.library.caches import ResultCache
 from calibre.library.custom_columns import CustomColumns
 from calibre.library.sqlite import connect, IntegrityError
 from calibre.library.prefs import DBPrefs
-from calibre.ebooks.metadata import string_to_authors, authors_to_string
 from calibre.ebooks.metadata.book.base import Metadata
-from calibre.ebooks.metadata.meta import get_metadata, metadata_from_formats
 from calibre.constants import preferred_encoding, iswindows, isosx, filesystem_encoding
 from calibre.ptempfile import PersistentTemporaryFile
 from calibre.customize.ui import run_plugins_on_import
@@ -2729,6 +2728,8 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         self.set_identifier(id_, 'isbn', isbn, notify=notify, commit=commit)
 
     def add_catalog(self, path, title):
+        from calibre.ebooks.metadata.meta import get_metadata
+
         format = os.path.splitext(path)[1][1:].lower()
         with lopen(path, 'rb') as stream:
             matches = self.data.get_matches('title', '='+title)
@@ -2764,6 +2765,8 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
 
 
     def add_news(self, path, arg):
+        from calibre.ebooks.metadata.meta import get_metadata
+
         format = os.path.splitext(path)[1][1:].lower()
         stream = path if hasattr(path, 'read') else lopen(path, 'rb')
         stream.seek(0)
@@ -3157,6 +3160,8 @@ books_series_link      feeds
                 yield formats
 
     def import_book_directory_multiple(self, dirpath, callback=None):
+        from calibre.ebooks.metadata.meta import metadata_from_formats
+
         duplicates = []
         for formats in self.find_books_in_directory(dirpath, False):
             mi = metadata_from_formats(formats)
@@ -3172,6 +3177,7 @@ books_series_link      feeds
         return duplicates
 
     def import_book_directory(self, dirpath, callback=None):
+        from calibre.ebooks.metadata.meta import metadata_from_formats
         dirpath = os.path.abspath(dirpath)
         formats = self.find_books_in_directory(dirpath, True)
         formats = list(formats)[0]

src/calibre/library/save_to_disk.py

@@ -14,7 +14,6 @@ from calibre.utils.formatter import TemplateFormatter
 from calibre.utils.filenames import shorten_components_to, supports_long_names, \
                                     ascii_filename
 from calibre.ebooks.metadata.opf2 import metadata_to_opf
-from calibre.ebooks.metadata.meta import set_metadata
 from calibre.constants import preferred_encoding
 from calibre.ebooks.metadata import fmt_sidx
 from calibre.ebooks.metadata import title_sort
@@ -251,6 +250,7 @@ def save_book_to_disk(id_, db, root, opts, length):
 
 def do_save_book_to_disk(id_, mi, cover, plugboards,
         format_map, root, opts, length):
+    from calibre.ebooks.metadata.meta import set_metadata
     available_formats = [x.lower().strip() for x in format_map.keys()]
     if opts.formats == 'all':
         asked_formats = available_formats