Fix threading problem with formatter in ebooks.metadata.book.base.py.

src/calibre/ebooks/metadata/book/base.py

@@ -70,6 +70,7 @@ class SafeFormat(TemplateFormatter):
             return ''
         return v
 
+# DEPRECATED. This is not thread safe. Do not use.
 composite_formatter = SafeFormat()
 
 class Metadata(object):
@@ -110,6 +111,7 @@ class Metadata(object):
                 # List of strings or []
                 self.author = list(authors) if authors else []# Needed for backward compatibility
                 self.authors = list(authors) if authors else []
+        self.formatter = SafeFormat()
 
     def is_null(self, field):
         '''
@@ -146,7 +148,7 @@ class Metadata(object):
                 return val
             if val is None:
                 d['#value#'] = 'RECURSIVE_COMPOSITE FIELD (Metadata) ' + field
-                val = d['#value#'] = composite_formatter.safe_format(
+                val = d['#value#'] = self.formatter.safe_format(
                                             d['display']['composite_template'],
                                             self,
                                             _('TEMPLATE ERROR'),
@@ -423,11 +425,12 @@ class Metadata(object):
         '''
         if not ops:
             return
+        formatter = SafeFormat()
         for op in ops:
             try:
                 src = op[0]
                 dest = op[1]
-                val = composite_formatter.safe_format\
+                val = formatter.safe_format\
                     (src, other, 'PLUGBOARD TEMPLATE ERROR', other)
                 if dest == 'tags':
                     self.set(dest, [f.strip() for f in val.split(',') if f.strip()])

src/calibre/gui2/dialogs/metadata_bulk.py

@@ -12,7 +12,7 @@ from PyQt4.Qt import Qt, QDialog, QGridLayout, QVBoxLayout, QFont, QLabel, \
 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.book.base import SafeFormat
 from calibre.gui2.custom_column_widgets import populate_metadata_page
 from calibre.gui2 import error_dialog, ResizableDialog, UNDEFINED_QDATE, \
     gprefs, question_dialog
@@ -499,7 +499,7 @@ class MetadataBulkDialog(ResizableDialog, Ui_MetadataBulkDialog):
     def s_r_get_field(self, mi, field):
         if field:
             if field == '{template}':
-                v = composite_formatter.safe_format\
+                v = SafeFormat().safe_format\
                     (unicode(self.s_r_template.text()), mi, _('S/R TEMPLATE ERROR'), mi)
                 return [v]
             fm = self.db.metadata_for_field(field)

src/calibre/gui2/dialogs/template_dialog.py

@@ -11,7 +11,7 @@ from PyQt4.Qt import (Qt, QDialog, QDialogButtonBox, QSyntaxHighlighter, QFont,
 from calibre.gui2 import error_dialog
 from calibre.gui2.dialogs.template_dialog_ui import Ui_TemplateDialog
 from calibre.utils.formatter_functions import formatter_functions
-from calibre.ebooks.metadata.book.base import composite_formatter, Metadata
+from calibre.ebooks.metadata.book.base import SafeFormat, Metadata
 from calibre.library.coloring import (displayable_columns)
 
 
@@ -270,7 +270,7 @@ class TemplateDialog(QDialog, Ui_TemplateDialog):
             self.highlighter.regenerate_paren_positions()
             self.text_cursor_changed()
             self.template_value.setText(
-                composite_formatter.safe_format(cur_text, self.mi,
+                SafeFormat().safe_format(cur_text, self.mi,
                                                 _('EXCEPTION: '), self.mi))
 
     def text_cursor_changed(self):

src/calibre/gui2/library/models.py

@@ -14,7 +14,7 @@ from PyQt4.Qt import (QAbstractTableModel, Qt, pyqtSignal, QIcon, QImage,
 from calibre.gui2 import NONE, UNDEFINED_QDATE
 from calibre.utils.pyparsing import ParseException
 from calibre.ebooks.metadata import fmt_sidx, authors_to_string, string_to_authors
-from calibre.ebooks.metadata.book.base import composite_formatter
+from calibre.ebooks.metadata.book.base import SafeFormat
 from calibre.ptempfile import PersistentTemporaryFile
 from calibre.utils.config import tweaks, prefs
 from calibre.utils.date import dt_factory, qt_to_dt
@@ -91,6 +91,7 @@ class BooksModel(QAbstractTableModel): # {{{
         self.current_highlighted_idx = None
         self.highlight_only = False
         self.colors = frozenset([unicode(c) for c in QColor.colorNames()])
+        self.formatter = SafeFormat()
         self.read_config()
 
     def change_alignment(self, colname, alignment):
@@ -711,7 +712,7 @@ class BooksModel(QAbstractTableModel): # {{{
                 try:
                     if mi is None:
                         mi = self.db.get_metadata(id_, index_is_id=True)
-                    color = composite_formatter.safe_format(fmt, mi, '', mi)
+                    color = self.formatter.safe_format(fmt, mi, '', mi)
                     if color in self.colors:
                         color = QColor(color)
                         if color.isValid():