Speed up reading of metadata from PDF files on the device

src/calibre/customize/__init__.py

@@ -181,6 +181,10 @@ class MetadataReaderPlugin(Plugin):
 
     type = _('Metadata reader')
 
+    def __init__(self, *args, **kwargs):
+        Plugin.__init__(self, *args, **kwargs)
+        self.quick = False
+
     def get_metadata(self, stream, type):
         '''
         Return metadata for the file represented by stream (a file like object

src/calibre/customize/builtins.py

@@ -182,7 +182,9 @@ class PDFMetadataReader(MetadataReaderPlugin):
     description = _('Read metadata from %s files')%'PDF'
 
     def get_metadata(self, stream, ftype):
-        from calibre.ebooks.metadata.pdf import get_metadata
+        from calibre.ebooks.metadata.pdf import get_metadata, get_quick_metadata
+        if self.quick:
+            return get_quick_metadata(stream)
         return get_metadata(stream)
 
 class RARMetadataReader(MetadataReaderPlugin):

src/calibre/customize/ui.py

@@ -145,6 +145,20 @@ def metadata_writers():
             ans.add(plugin)
     return ans
 
+class QuickMetadata(object):
+
+    def __init__(self):
+        self.quick = False
+
+    def __enter__(self):
+        self.quick = True
+
+    def __exit__(self, *args):
+        self.quick = False
+
+quick_metadata = QuickMetadata()
+
+
 def get_file_type_metadata(stream, ftype):
     mi = MetaInformation(None, None)
     ftype = ftype.lower().strip()
@@ -153,6 +167,7 @@ def get_file_type_metadata(stream, ftype):
             if not is_disabled(plugin):
                 with plugin:
                     try:
+                        plugin.quick = quick_metadata.quick
                         mi = plugin.get_metadata(stream, ftype.lower().strip())
                         break
                     except:

src/calibre/devices/jetbook/driver.py

@@ -110,8 +110,7 @@ class JETBOOK(USBMS):
 
             return txt
 
-        from calibre.devices.usbms.driver import metadata_from_formats
+        mi = cls.metadata_from_formats([path])
-        mi = metadata_from_formats([path])
 
         if (mi.title==_('Unknown') or mi.authors==[_('Unknown')]) \
                 and '#' in mi.title:

src/calibre/ebooks/metadata/pdf.py

@@ -18,7 +18,16 @@ except:
 from calibre.ebooks.metadata import MetaInformation, authors_to_string
 from calibre.utils.pdftk import set_metadata as pdftk_set_metadata
 from calibre.utils.podofo import get_metadata as podofo_get_metadata, \
-    set_metadata as podofo_set_metadata, Unavailable, write_first_page
+    set_metadata as podofo_set_metadata, Unavailable, write_first_page, \
+    get_metadata_quick
+
+def get_quick_metadata(stream):
+    raw = stream.read()
+    mi = get_metadata_quick(raw)
+    if mi.title == '_':
+        mi.title = getattr(stream, 'name', _('Unknown'))
+        mi.title = mi.title.rpartition('.')[0]
+    return mi
 
 
 def get_metadata(stream, extract_cover=True):

src/calibre/utils/podofo/__init__.py

@@ -80,6 +80,21 @@ def get_metadata(stream):
     if os.path.exists(pt.name): os.remove(pt.name)
     return mi
 
+def get_metadata_quick(raw):
+    p = podofo.PDFDoc()
+    p.load(raw)
+    title = p.title
+    if not title:
+        title = '_'
+    author = p.author
+    authors = string_to_authors(author) if author else  [_('Unknown')]
+    creator = p.creator
+    mi = MetaInformation(title, authors)
+    if creator:
+        mi.book_producer = creator
+    return mi
+
+
 def get_metadata_(path):
     p = podofo.PDFDoc()
     p.open(path)