Refactor setting of EPUB metadata

Move it into the new opf module and also avoid several unnecessary mem
copies

src/calibre/ebooks/metadata/epub.py

@@ -8,18 +8,15 @@ __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 import os, re, posixpath
 from cStringIO import StringIO
 from contextlib import closing
-from future_builtins import map
 
 from calibre.utils.zipfile import ZipFile, BadZipfile, safe_replace
 from calibre.utils.localunzip import LocalZipFile
 from calibre.ebooks.BeautifulSoup import BeautifulStoneSoup
-from calibre.ebooks.metadata import MetaInformation
+from calibre.ebooks.metadata.opf import get_metadata as get_metadata_from_opf, set_metadata as set_metadata_opf
-from calibre.ebooks.metadata.opf import get_metadata as get_metadata_from_opf
 from calibre.ebooks.metadata.opf2 import OPF
 from calibre.ptempfile import TemporaryDirectory
 from calibre import CurrentDir, walk
 from calibre.constants import isosx
-from calibre.utils.localization import lang_as_iso639_1
 
 class EPubException(Exception):
     pass
@@ -263,61 +260,26 @@ def serialize_cover_data(new_cdata, cpath):
     from calibre.utils.img import save_cover_data_to
     return save_cover_data_to(new_cdata, data_fmt=os.path.splitext(cpath)[1][1:])
 
-def normalize_languages(opf_languages, mi_languages):
-    ' Preserve original country codes and use 2-letter lang codes where possible '
-    from calibre.spell import parse_lang_code
-    def parse(x):
-        try:
-            return parse_lang_code(x)
-        except ValueError:
-            return None
-    opf_languages = filter(None, map(parse, opf_languages))
-    cc_map = {c.langcode:c.countrycode for c in opf_languages}
-    mi_languages = filter(None, map(parse, mi_languages))
-    def norm(x):
-        lc = x.langcode
-        cc = x.countrycode or cc_map.get(lc, None)
-        lc = lang_as_iso639_1(lc) or lc
-        if cc:
-            lc += '-' + cc
-        return lc
-    return list(map(norm, mi_languages))
-
-def update_metadata(opf, mi, apply_null=False, update_timestamp=False, force_identifiers=False):
-    for x in ('guide', 'toc', 'manifest', 'spine'):
-        setattr(mi, x, None)
-    if mi.languages:
-        mi.languages = normalize_languages(list(opf.raw_languages) or [], mi.languages)
-
-    opf.smart_update(mi, apply_null=apply_null)
-    if getattr(mi, 'uuid', None):
-        opf.application_id = mi.uuid
-    if apply_null or force_identifiers:
-        opf.set_identifiers(mi.get_identifiers())
-    else:
-        orig = opf.get_identifiers()
-        orig.update(mi.get_identifiers())
-        opf.set_identifiers({k:v for k, v in orig.iteritems() if k and v})
-    if update_timestamp and mi.timestamp is not None:
-        opf.timestamp = mi.timestamp
-
 def set_metadata(stream, mi, apply_null=False, update_timestamp=False, force_identifiers=False):
     stream.seek(0)
     reader = get_zip_reader(stream, root=os.getcwdu())
-    raster_cover = reader.opf.raster_cover
-    mi = MetaInformation(mi)
     new_cdata = None
-    replacements = {}
     try:
         new_cdata = mi.cover_data[1]
         if not new_cdata:
             raise Exception('no cover')
-    except:
+    except Exception:
         try:
-            new_cdata = open(mi.cover, 'rb').read()
+            with lopen(mi.cover, 'rb') as f:
-        except:
+                new_cdata = f.read()
+        except Exception:
             pass
+
+    opfbytes, ver, raster_cover = set_metadata_opf(
+        reader.read_bytes(reader.opf_path), mi,
+        cover_data=new_cdata, apply_null=apply_null, update_timestamp=update_timestamp, force_identifiers=force_identifiers)
     cpath = None
+    replacements = {}
     if new_cdata and raster_cover:
         try:
             cpath = posixpath.join(posixpath.dirname(reader.opf_path),
@@ -330,15 +292,11 @@ def set_metadata(stream, mi, apply_null=False, update_timestamp=False, force_ide
             import traceback
             traceback.print_exc()
 
-    update_metadata(reader.opf, mi, apply_null=apply_null,
-                    update_timestamp=update_timestamp, force_identifiers=force_identifiers)
-
-    newopf = reader.opf.render()
     if isinstance(reader.archive, LocalZipFile):
-        reader.archive.safe_replace(reader.container[OPF.MIMETYPE], newopf,
+        reader.archive.safe_replace(reader.container[OPF.MIMETYPE], opfbytes,
             extra_replacements=replacements)
     else:
-        safe_replace(stream, reader.container[OPF.MIMETYPE], newopf,
+        safe_replace(stream, reader.container[OPF.MIMETYPE], opfbytes,
             extra_replacements=replacements)
     try:
         if cpath is not None:

src/calibre/ebooks/metadata/opf.py

@@ -7,7 +7,8 @@ from __future__ import (unicode_literals, division, absolute_import,
 
 from calibre.ebooks.metadata import parse_opf_version
 from calibre.ebooks.metadata.opf2 import OPF
-from calibre.ebooks.metadata.utils import parse_opf
+from calibre.ebooks.metadata.utils import parse_opf, normalize_languages
+from calibre.ebooks.metadata import MetaInformation
 
 class DummyFile(object):
 
@@ -24,3 +25,33 @@ def get_metadata(stream):
     ver = parse_opf_version(root.get('version'))
     opf = OPF(None, preparsed_opf=root, read_toc=False)
     return opf.to_book_metadata(), ver, opf.raster_cover, opf.first_spine_item()
+
+def set_metadata_opf2(root, mi, cover_data=None, apply_null=False, update_timestamp=False, force_identifiers=False):
+    mi = MetaInformation(mi)
+    for x in ('guide', 'toc', 'manifest', 'spine'):
+        setattr(mi, x, None)
+    opf = OPF(None, preparsed_opf=root, read_toc=False)
+    if mi.languages:
+        mi.languages = normalize_languages(list(opf.raw_languages) or [], mi.languages)
+
+    opf.smart_update(mi, apply_null=apply_null)
+    if getattr(mi, 'uuid', None):
+        opf.application_id = mi.uuid
+    if apply_null or force_identifiers:
+        opf.set_identifiers(mi.get_identifiers())
+    else:
+        orig = opf.get_identifiers()
+        orig.update(mi.get_identifiers())
+        opf.set_identifiers({k:v for k, v in orig.iteritems() if k and v})
+    if update_timestamp and mi.timestamp is not None:
+        opf.timestamp = mi.timestamp
+    return opf.render(), opf.raster_cover
+
+def set_metadata(stream, mi, cover_data=None, apply_null=False, update_timestamp=False, force_identifiers=False):
+    if isinstance(stream, bytes):
+        stream = DummyFile(stream)
+    root = parse_opf(stream)
+    ver = parse_opf_version(root.get('version'))
+    opfbytes, raster_cover = set_metadata_opf2(
+        root, mi, cover_data=cover_data, apply_null=apply_null, update_timestamp=update_timestamp, force_identifiers=force_identifiers)
+    return opfbytes, ver, raster_cover

src/calibre/ebooks/metadata/utils.py

@@ -4,9 +4,13 @@
 
 from __future__ import (unicode_literals, division, absolute_import,
                         print_function)
+from future_builtins import map
+
+from lxml import etree
 
 from calibre.ebooks.chardet import xml_to_unicode
-from lxml import etree
+from calibre.spell import parse_lang_code
+from calibre.utils.localization import lang_as_iso639_1
 
 PARSER = etree.XMLParser(recover=True, no_network=True)
 
@@ -25,3 +29,22 @@ def parse_opf(stream_or_path):
     return root
 
 
+def normalize_languages(opf_languages, mi_languages):
+    ' Preserve original country codes and use 2-letter lang codes where possible '
+    def parse(x):
+        try:
+            return parse_lang_code(x)
+        except ValueError:
+            return None
+    opf_languages = filter(None, map(parse, opf_languages))
+    cc_map = {c.langcode:c.countrycode for c in opf_languages}
+    mi_languages = filter(None, map(parse, mi_languages))
+    def norm(x):
+        lc = x.langcode
+        cc = x.countrycode or cc_map.get(lc, None)
+        lc = lang_as_iso639_1(lc) or lc
+        if cc:
+            lc += '-' + cc
+        return lc
+    return list(map(norm, mi_languages))
+