Get rid of author_link_map

Also implement support for link_maps metadata in EPUB3 and PDF.
Reading proceeds by returning the link_maps if present, otherwise look
for a legacy author_link_map and return a link_maps constructed from it.

Writing simply sets link_maps, which as per the sceme above takes
precedence anyway.

src/calibre/db/cache.py

@@ -325,19 +325,16 @@ class Cache:
         aut_list = [adata[i] for i in author_ids]
         aum = []
         aus = {}
-        aul = {}
         for rec in aut_list:
             aut = rec['name']
             aum.append(aut)
             aus[aut] = rec['sort']
-            aul[aut] = rec['link']
         mi.title       = self._field_for('title', book_id,
                 default_value=_('Unknown'))
         mi.authors     = aum
         mi.author_sort = self._field_for('author_sort', book_id,
                 default_value=_('Unknown'))
         mi.author_sort_map = aus
-        mi.author_link_map = aul
         mi.comments    = self._field_for('comments', book_id)
         mi.publisher   = self._field_for('publisher', book_id)
         n = utcnow()

src/calibre/db/lazy.py

@@ -315,7 +315,7 @@ getters = {
 for field in ('comments', 'publisher', 'identifiers', 'series', 'rating'):
     getters[field] = simple_getter(field)
 
-for field in ('author_sort_map', 'author_link_map'):
+for field in ('author_sort_map',):
     getters[field] = adata_getter(field)
 
 for field in ('timestamp', 'pubdate', 'last_modified'):

src/calibre/db/restore.py

@@ -5,18 +5,22 @@ __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import re, os, traceback, shutil, time
+import os
-from threading import Thread
+import re
+import shutil
+import time
+import traceback
+from contextlib import suppress
 from operator import itemgetter
+from threading import Thread
 
-from calibre.ptempfile import TemporaryDirectory
+from calibre import force_unicode, isbytestring
-from calibre.ebooks.metadata.opf2 import OPF
+from calibre.constants import filesystem_encoding
 from calibre.db.backend import DB, DBPrefs
 from calibre.db.cache import Cache
-from calibre.constants import filesystem_encoding
+from calibre.ebooks.metadata.opf2 import OPF
+from calibre.ptempfile import TemporaryDirectory
 from calibre.utils.date import utcfromtimestamp
-from calibre import isbytestring, force_unicode
-from polyglot.builtins import iteritems
 
 NON_EBOOK_EXTENSIONS = frozenset((
     'jpg', 'jpeg', 'gif', 'png', 'bmp',
@@ -59,7 +63,7 @@ class Restore(Thread):
         self.mismatched_dirs = []
         self.successes = 0
         self.tb = None
-        self.authors_links = {}
+        self.link_maps = {}
 
     @property
     def errors_occurred(self):
@@ -209,11 +213,13 @@ class Restore(Thread):
         else:
             self.mismatched_dirs.append(dirpath)
 
-        alm = mi.get('author_link_map', {})
+        alm = mi.get('link_maps', {})
-        for author, link in iteritems(alm):
+        for field, lmap in alm.items():
-            existing_link, timestamp = self.authors_links.get(author, (None, None))
+            dest = self.link_maps.setdefault(field, {})
-            if existing_link is None or existing_link != link and timestamp < mi.timestamp:
+            for item, link in lmap.items():
-                self.authors_links[author] = (link, mi.timestamp)
+                existing_link, timestamp = dest.get(item, (None, None))
+                if existing_link is None or existing_link != link and timestamp < mi.timestamp:
+                    dest[item] = link, mi.timestamp
 
     def create_cc_metadata(self):
         self.books.sort(key=itemgetter('timestamp'))
@@ -262,10 +268,9 @@ class Restore(Thread):
                 self.failed_restores.append((book, traceback.format_exc()))
             self.progress_callback(book['mi'].title, i+1)
 
-        id_map = db.get_item_ids('authors', [author for author in self.authors_links])
+        for field, lmap in self.link_maps.items():
-        link_map = {aid:self.authors_links[name][0] for name, aid in iteritems(id_map) if aid is not None}
+            with suppress(Exception):
-        if link_map:
+                db.set_link_map(field, {k:v[0] for k, v in lmap.items()})
-            db.set_link_for_authors(link_map)
         db.close()
 
     def replace_db(self):

src/calibre/db/tests/base.py

@@ -102,7 +102,7 @@ class BaseTest(unittest.TestCase):
         self.assertEqual(allfk1, allfk2)
 
         all_keys = {'format_metadata', 'id', 'application_id',
-                    'author_sort_map', 'author_link_map', 'book_size',
+                    'author_sort_map', 'link_maps', 'book_size',
                     'ondevice_col', 'last_modified', 'has_cover',
                     'cover_data'}.union(allfk1)
         for attr in all_keys:

src/calibre/db/tests/legacy.py

@@ -575,7 +575,6 @@ class LegacyTest(BaseTest):
         omi = [db.get_metadata(x) for x in (0, 1, 2)]
         nmi = [ndb.get_metadata(x) for x in (0, 1, 2)]
         self.assertEqual([x.author_sort_map for x in omi], [x.author_sort_map for x in nmi])
-        self.assertEqual([x.author_link_map for x in omi], [x.author_link_map for x in nmi])
         db.close()
 
         ndb = self.init_legacy(self.cloned_library)

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

@@ -85,8 +85,8 @@ CALIBRE_METADATA_FIELDS = frozenset((
     # a dict of user category names, where the value is a list of item names
     # from the book that are in that category
     'user_categories',
-    # a dict of author to an associated hyperlink
+    # a dict of items to associated hyperlink
-    'author_link_map',
+    'link_maps',
 ))
 
 ALL_METADATA_FIELDS =      SOCIAL_METADATA_FIELDS.union(

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

@@ -45,7 +45,6 @@ NULL_VALUES = {
                 'author_sort'  : _('Unknown'),
                 'title'        : _('Unknown'),
                 'user_categories' : {},
-                'author_link_map' : {},
                 'link_maps'    : {},
                 'language'     : 'und'
 }

src/calibre/ebooks/metadata/opf2.py

@@ -17,6 +17,7 @@ import os
 import re
 import sys
 import uuid
+from contextlib import suppress
 from lxml import etree
 
 from calibre import guess_type, prints
@@ -458,6 +459,37 @@ class MetadataField:
         obj.set_text(elem, self.renderer(val))
 
 
+class LinkMapsField:
+
+    def __get__(self, obj, type=None):
+        ans = obj.get_metadata_element('link_maps')
+        if ans is not None:
+            ans = obj.get_text(ans)
+            if ans:
+                with suppress(Exception):
+                    return json.loads(ans)
+        ans = obj.get_metadata_element('author_link_map')
+        if ans is not None:
+            ans = obj.get_text(ans)
+            if ans:
+                with suppress(Exception):
+                    return {'authors': json.loads(ans)}
+        return {}
+
+    def __set__(self, obj, val):
+        elem = obj.get_metadata_element('author_link_map')
+        if elem is not None:
+            elem.getparent().remove(elem)
+        elem = obj.get_metadata_element('link_maps')
+        if not val:
+            if elem is not None:
+                elem.getparent().remove(elem)
+            return
+        if elem is None:
+            elem = obj.create_metadata_element('link_maps', is_dc=False)
+        obj.set_text(elem, dump_dict(val))
+
+
 class TitleSortField(MetadataField):
 
     def __get__(self, obj, type=None):
@@ -593,10 +625,7 @@ class OPF:  # {{{
     user_categories = MetadataField('user_categories', is_dc=False,
                                     formatter=json.loads,
                                     renderer=dump_dict)
-    author_link_map = MetadataField('author_link_map', is_dc=False,
+    link_maps = LinkMapsField()
-                                formatter=json.loads, renderer=dump_dict)
-    link_map = MetadataField('link_maps', is_dc=False,
-                                formatter=json.loads, renderer=dump_dict)
 
     def __init__(self, stream, basedir=os.getcwd(), unquote_urls=True,
             populate_spine=True, try_to_guess_cover=False, preparsed_opf=None, read_toc=True):
@@ -667,6 +696,7 @@ class OPF:  # {{{
             ans.set_user_metadata(n, v)
 
         ans.set_identifiers(self.get_identifiers())
+        ans.link_maps = self.link_maps
 
         return ans
 
@@ -1312,7 +1342,7 @@ class OPF:  # {{{
         for attr in ('title', 'authors', 'author_sort', 'title_sort',
                      'publisher', 'series', 'series_index', 'rating',
                      'isbn', 'tags', 'category', 'comments', 'book_producer',
-                     'pubdate', 'user_categories', 'author_link_map', 'link_map'):
+                     'pubdate', 'user_categories', 'link_maps'):
             val = getattr(mi, attr, None)
             if attr == 'rating' and val:
                 val = float(val)
@@ -1673,9 +1703,7 @@ def metadata_to_opf(mi, as_string=True, default_lang=None):
 
     def meta(n, c):
         return factory('meta', name='calibre:' + n, content=c)
-    if getattr(mi, 'author_link_map', None) is not None:
+    if not mi.is_null('link_maps'):
-        meta('author_link_map', dump_dict(mi.author_link_map))
-    if getattr(mi, 'link_maps', None) is not None:
         meta('link_maps', dump_dict(mi.link_maps))
     if mi.series:
         meta('series', mi.series)

src/calibre/ebooks/metadata/opf3.py

@@ -865,16 +865,31 @@ def dict_reader(name, load=json.loads, try2=True):
 
 
 read_user_categories = dict_reader('user_categories')
-read_author_link_map = dict_reader('author_link_map')
+_read_link_maps = dict_reader('link_maps')
+_read_author_link_map = dict_reader('author_link_map')
 
 
-def dict_writer(name, serialize=dump_dict, remove2=True):
+def read_link_maps(root, prefixes, refines):
+    ans = _read_link_maps(root, prefixes, refines)
+    if ans is not None:
+        return ans
+    ans = _read_author_link_map(root, prefixes, refines)
+    if ans:
+        ans = {k: v for k, v in ans.items() if v}
+        if ans:
+            return {'authors': ans}
+
+
+def dict_writer(name, serialize=dump_dict, remove2=True, extra_remove=''):
     pq = f'{CALIBRE_PREFIX}:{name}'
 
     def writer(root, prefixes, refines, val):
         if remove2:
             for meta in XPath('./opf:metadata/opf:meta[@name="calibre:%s"]' % name)(root):
                 remove_element(meta, refines)
+        if extra_remove:
+            for meta in XPath('./opf:metadata/opf:meta[@name="calibre:%s"]' % extra_remove)(root):
+                remove_element(meta, refines)
         for meta in XPath('./opf:metadata/opf:meta[@property]')(root):
             prop = expand_prefix(meta.get('property'), prefixes)
             if prop.lower() == pq:
@@ -889,7 +904,7 @@ def dict_writer(name, serialize=dump_dict, remove2=True):
 
 
 set_user_categories = dict_writer('user_categories')
-set_author_link_map = dict_writer('author_link_map')
+set_link_maps = dict_writer('link_maps', extra_remove='author_link_map')
 
 
 def deserialize_user_metadata(val):
@@ -1054,7 +1069,7 @@ def read_metadata(root, ver=None, return_extra_data=False):
     s, si = read_series(root, prefixes, refines)
     if s:
         ans.series, ans.series_index = s, si
-    ans.author_link_map = read_author_link_map(root, prefixes, refines) or ans.author_link_map
+    ans.link_maps = read_link_maps(root, prefixes, refines) or ans.link_maps
     ans.user_categories = read_user_categories(root, prefixes, refines) or ans.user_categories
     for name, fm in iteritems(read_user_metadata(root, prefixes, refines) or {}):
         ans.set_user_metadata(name, fm)
@@ -1105,8 +1120,8 @@ def apply_metadata(root, mi, cover_prefix='', cover_data=None, apply_null=False,
         set_rating(root, prefixes, refines, mi.rating)
     if ok('series'):
         set_series(root, prefixes, refines, mi.series, mi.series_index or 1)
-    if ok('author_link_map'):
+    if ok('link_maps'):
-        set_author_link_map(root, prefixes, refines, getattr(mi, 'author_link_map', None))
+        set_link_maps(root, prefixes, refines, getattr(mi, 'link_maps', None))
     if ok('user_categories'):
         set_user_categories(root, prefixes, refines, getattr(mi, 'user_categories', None))
     # We ignore apply_null for the next two to match the behavior with opf2.py

src/calibre/ebooks/metadata/opf3_test.py

@@ -2,29 +2,29 @@
 # License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
 
+import unittest
 from collections import defaultdict
 from io import BytesIO
-import unittest
 
 from calibre.ebooks.metadata.book import ALL_METADATA_FIELDS
-from calibre.utils.xml_parse import safe_xml_fromstring
 from calibre.ebooks.metadata.opf2 import OPF
 from calibre.ebooks.metadata.opf3 import (
-    parse_prefixes, reserved_prefixes, expand_prefix, read_identifiers,
+    CALIBRE_PREFIX, Author, XPath, apply_metadata, ensure_is_only_raster_cover,
-    read_metadata, set_identifiers, XPath, set_application_id, read_title,
+    ensure_prefix, expand_prefix, parse_prefixes, read_authors, read_book_producers,
-    read_refines, set_title, read_title_sort, read_languages, set_languages,
+    read_comments, read_identifiers, read_languages, read_last_modified, read_link_maps,
-    read_authors, Author, set_authors, ensure_prefix, read_prefixes,
+    read_metadata, read_prefixes, read_pubdate, read_publisher, read_raster_cover,
-    read_book_producers, set_book_producers, read_timestamp, set_timestamp,
+    read_rating, read_refines, read_series, read_tags, read_timestamp, read_title,
-    read_pubdate, set_pubdate, CALIBRE_PREFIX, read_last_modified, read_comments,
+    read_title_sort, read_user_categories, read_user_metadata, reserved_prefixes,
-    set_comments, read_publisher, set_publisher, read_tags, set_tags, read_rating,
+    set_application_id, set_authors, set_book_producers, set_comments, set_identifiers,
-    set_rating, read_series, set_series, read_user_metadata, set_user_metadata,
+    set_languages, set_link_maps, set_pubdate, set_publisher, set_rating, set_series,
-    read_author_link_map, read_user_categories, set_author_link_map, set_user_categories,
+    set_tags, set_timestamp, set_title, set_user_categories, set_user_metadata,
-    apply_metadata, read_raster_cover, ensure_is_only_raster_cover
 )
+
 # This import is needed to prevent a test from running slowly
 from calibre.ebooks.oeb.polish.pretty import pretty_opf, pretty_xml_tree  # noqa
+from calibre.utils.xml_parse import safe_xml_fromstring
 
-read_author_link_map, read_user_categories, set_author_link_map, set_user_categories
+read_user_categories, set_user_categories, read_link_maps, set_link_maps
 
 TEMPLATE = '''<package xmlns="http://www.idpf.org/2007/opf" version="3.0" prefix="calibre: %s" unique-identifier="uid"><metadata xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:opf="http://www.idpf.org/2007/opf">{metadata}</metadata><manifest>{manifest}</manifest></package>''' % CALIBRE_PREFIX  # noqa
 default_refines = defaultdict(list)
@@ -288,7 +288,7 @@ class TestOPF3(unittest.TestCase):
             f = globals()['set_' + name]
             f(root, read_prefixes(root), read_refines(root), val)
             return rt(root, name)
-        for name in 'author_link_map user_categories'.split():
+        for name in 'link_maps user_categories'.split():
             root = self.get_opf('''<meta name="calibre:%s" content='{"1":1}'/>''' % name)
             self.ae({'1':1}, rt(root, name))
             root = self.get_opf(f'''<meta name="calibre:{name}" content='{{"1":1}}'/><meta property="calibre:{name}">{{"2":2}}</meta>''')
@@ -328,7 +328,7 @@ class TestOPF3(unittest.TestCase):
         <dc:subject>conversion</dc:subject>
         <dc:subject>docs</dc:subject>
         <dc:subject>ebook</dc:subject>
-        <meta content="{&quot;Kovid Goyal&quot;: &quot;&quot;}" name="calibre:author_link_map"/>
+        <meta content="{&quot;Kovid Goyal&quot;: &quot;https://kovidgoyal.net&quot;}" name="calibre:author_link_map"/>
         <meta content="Demos" name="calibre:series"/>
         <meta content="1" name="calibre:series_index"/>
         <meta content="10" name="calibre:rating"/>

src/calibre/ebooks/metadata/xmp.py

@@ -289,13 +289,20 @@ def metadata_from_xmp_packet(raw_bytes):
             if val:
                 setattr(mi, x, val)
                 break
-    for x in ('author_link_map', 'user_categories'):
+    for x in ('link_maps', 'user_categories'):
         val = first_simple('//calibre:'+x, root)
         if val:
             try:
                 setattr(mi, x, json.loads(val))
-            except:
+            except Exception:
                 pass
+        elif x == 'link_maps':
+            val = first_simple('//calibre:author_link_map', root)
+            if val:
+                try:
+                    setattr(mi, x, {'authors': json.loads(val)})
+                except Exception:
+                    pass
 
     languages = multiple_sequences('//dc:language', root)
     if languages:
@@ -526,7 +533,7 @@ def metadata_to_xmp_packet(mi):
         create_series(calibre, mi.series, mi.series_index)
     if not mi.is_null('timestamp'):
         create_simple_property(calibre, 'calibre:timestamp', isoformat(mi.timestamp, as_utc=False))
-    for x in ('author_link_map', 'user_categories'):
+    for x in ('link_maps', 'user_categories'):
         val = getattr(mi, x, None)
         if val:
             create_simple_property(calibre, 'calibre:'+x, dump_dict(val))

src/calibre/utils/formatter_functions.py

@@ -2014,7 +2014,10 @@ class BuiltinAuthorLinks(BuiltinFormatterFunction):
 
     def evaluate(self, formatter, kwargs, mi, locals, val_sep, pair_sep):
         if hasattr(mi, '_proxy_metadata'):
-            link_data = mi._proxy_metadata.author_link_map
+            link_data = mi._proxy_metadata.link_maps
+            if not link_data:
+                return ''
+            link_data = link_data.get('authors')
             if not link_data:
                 return ''
             names = sorted(link_data.keys(), key=sort_key)