More work on cache layer of new db backend

src/calibre/db/backend.py

@@ -8,7 +8,7 @@ __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
 # Imports {{{
-import os, shutil, uuid, json
+import os, shutil, uuid, json, glob
 from functools import partial
 
 import apsw
@@ -25,7 +25,7 @@ from calibre.utils.config import to_json, from_json, prefs, tweaks
 from calibre.utils.date import utcfromtimestamp, parse_date
 from calibre.utils.filenames import is_case_sensitive
 from calibre.db.tables import (OneToOneTable, ManyToOneTable, ManyToManyTable,
-        SizeTable, FormatsTable, AuthorsTable, IdentifiersTable)
+        SizeTable, FormatsTable, AuthorsTable, IdentifiersTable, CompositeTable)
 # }}}
 
 '''
@@ -624,7 +624,7 @@ class DB(object):
         base = max(self.FIELD_MAP.itervalues())
 
         for label_, data in self.custom_column_label_map.iteritems():
-            label = '#' + label_
+            label = self.field_metadata.custom_field_prefix + label_
             metadata = self.field_metadata[label].copy()
             link_table = self.custom_table_names(data['num'])[1]
             self.FIELD_MAP[data['num']] = base = base+1
@@ -652,6 +652,9 @@ class DB(object):
                         metadata['column'] = 'extra'
                         metadata['table'] = link_table
                         tables[label] = OneToOneTable(label, metadata)
+            else:
+                if data['datatype'] == 'composite':
+                    tables[label] = CompositeTable(label, metadata)
                 else:
                     tables[label] = OneToOneTable(label, metadata)
 
@@ -758,5 +761,28 @@ class DB(object):
                     pprint.pprint(table.metadata)
                     raise
 
+    def format_abspath(self, book_id, fmt, fname, path):
+        path = os.path.join(self.library_path, path)
+        fmt = ('.' + fmt.lower()) if fmt else ''
+        fmt_path = os.path.join(path, fname+fmt)
+        if os.path.exists(fmt_path):
+            return fmt_path
+        try:
+            candidates = glob.glob(os.path.join(path, '*'+fmt))
+        except: # If path contains strange characters this throws an exc
+            candidates = []
+        if fmt and candidates and os.path.exists(candidates[0]):
+            shutil.copyfile(candidates[0], fmt_path)
+            return fmt_path
+
+    def format_metadata(self, book_id, fmt, fname, path):
+        path = self.format_abspath(book_id, fmt, fname, path)
+        ans = {}
+        if path is not None:
+            stat = os.stat(path)
+            ans['size'] = stat.st_size
+            ans['mtime'] = utcfromtimestamp(stat.st_mtime)
+        return ans
+
    # }}}
 

src/calibre/db/cache.py

@@ -7,10 +7,14 @@ __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
+import os
+from collections import defaultdict
 from functools import wraps
 
 from calibre.db.locking import create_locks
 from calibre.db.fields import create_field
+from calibre.ebooks.book.base import Metadata
+from calibre.utils.date import now
 
 def api(f):
     f.is_cache_api = True
@@ -40,6 +44,7 @@ class Cache(object):
         self.backend = backend
         self.fields = {}
         self.read_lock, self.write_lock = create_locks()
+        self.format_metadata_cache = defaultdict(dict)
 
         # Implement locking for all simple read/write API methods
         # An unlocked version of the method is stored with the name starting
@@ -55,6 +60,27 @@ class Cache(object):
                 lock = self.read_lock if ira else self.write_lock
                 setattr(self, name, wrap_simple(lock, func))
 
+    def _format_abspath(self, book_id, fmt):
+        '''
+        Return absolute path to the ebook file of format `format`
+
+        WARNING: This method will return a dummy path for a network backend DB,
+        so do not rely on it, use format(..., as_path=True) instead.
+
+        Currently used only in calibredb list, the viewer and the catalogs (via
+        get_data_as_dict()).
+
+        Apart from the viewer, I don't believe any of the others do any file
+        I/O with the results of this call.
+        '''
+        try:
+            name = self.fields['formats'].format_fname(book_id, fmt)
+            path = self._field_for('path', book_id).replace('/', os.sep)
+        except:
+            return None
+        if name and path:
+            return self.backend.format_abspath(book_id, fmt, name, path)
+
     # Cache Layer API {{{
 
     @api
@@ -68,6 +94,8 @@ class Cache(object):
             for field, table in self.backend.tables.iteritems():
                 self.fields[field] = create_field(field, table)
 
+            self.fields['ondevice'] = create_field('ondevice', None)
+
     @read_api
     def field_for(self, name, book_id, default_value=None):
         '''
@@ -82,6 +110,15 @@ class Cache(object):
         except (KeyError, IndexError):
             return default_value
 
+    @read_api
+    def composite_for(self, name, book_id, mi, default_value=''):
+        try:
+            f = self.fields[name]
+        except KeyError:
+            return default_value
+
+        f.render_composite(book_id, mi)
+
     @read_api
     def field_ids_for(self, name, book_id):
         '''
@@ -122,6 +159,135 @@ class Cache(object):
         '''
         return frozenset(iter(self.fields[name]))
 
+    @read_api
+    def author_data(self, author_id):
+        '''
+        Return author data as a dictionary with keys: name, sort, link
+
+        If no author with the specified id is found an empty dictionary is
+        returned.
+        '''
+        try:
+            return self.fields['authors'].author_data(author_id)
+        except (KeyError, IndexError):
+            return {}
+
+    @read_api
+    def format_metadata(self, book_id, fmt, allow_cache=True):
+        if not fmt:
+            return {}
+        fmt = fmt.upper()
+        if allow_cache:
+            x = self.format_metadata_cache[book_id].get(fmt, None)
+            if x is not None:
+                return x
+        try:
+            name = self.fields['formats'].format_fname(book_id, fmt)
+            path = self._field_for('path', book_id).replace('/', os.sep)
+        except:
+            return {}
+
+        ans = {}
+        if path and name:
+            ans = self.backend.format_metadata(book_id, fmt, name, path)
+            self.format_metadata_cache[book_id][fmt] = ans
+        return ans
+
+    @read_api
+    def get_metadata(self, book_id, get_cover=False,
+                     get_user_categories=True, cover_as_data=False):
+        '''
+        Convenience method to return metadata as a :class:`Metadata` object.
+        Note that the list of formats is not verified.
+        '''
+        mi = Metadata(None)
+
+        author_ids = self._field_ids_for('authors', book_id)
+        aut_list = [self._author_data(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 = now()
+        mi.timestamp   = self._field_for('timestamp', book_id, default_value=n)
+        mi.pubdate     = self._field_for('pubdate', book_id, default_value=n)
+        mi.uuid        = self._field_for('uuid', book_id,
+                default_value='dummy')
+        mi.title_sort  = self._field_for('sort', book_id,
+                default_value=_('Unknown'))
+        mi.book_size   = self._field_for('size', book_id, default_value=0)
+        mi.ondevice_col = self._field_for('ondevice', book_id, default_value='')
+        mi.last_modified = self._field_for('last_modified', book_id,
+                default_value=n)
+        formats = self._field_for('formats', book_id)
+        mi.format_metadata = {}
+        if not formats:
+            formats = None
+        else:
+            for f in formats:
+                mi.format_metadata[f] = self._format_metadata(book_id, f)
+            formats = ','.join(formats)
+        mi.formats = formats
+        mi.has_cover = _('Yes') if self._field_for('cover', book_id,
+                default_value=False) else ''
+        mi.tags = list(self._field_for('tags', book_id, default_value=()))
+        mi.series = self._field_for('series', book_id)
+        if mi.series:
+            mi.series_index = self._field_for('series_index', book_id,
+                    default_value=1.0)
+        mi.rating = self._field_for('rating', book_id)
+        mi.set_identifiers(self._field_for('identifiers', book_id,
+            default_value={}))
+        mi.application_id = book_id
+        mi.id = book_id
+        composites = {}
+        for key, meta in self.field_metadata.custom_iteritems():
+            mi.set_user_metadata(key, meta)
+            if meta['datatype'] == 'composite':
+                composites.append(key)
+            else:
+                mi.set(key, val=self._field_for(meta['label'], book_id),
+                        extra=self._field_for(meta['label']+'_index', book_id))
+        for c in composites:
+            mi.set(key, val=self._composite_for(key, book_id, mi))
+
+        user_cat_vals = {}
+        if get_user_categories:
+            user_cats = self.prefs['user_categories']
+            for ucat in user_cats:
+                res = []
+                for name,cat,ign in user_cats[ucat]:
+                    v = mi.get(cat, None)
+                    if isinstance(v, list):
+                        if name in v:
+                            res.append([name,cat])
+                    elif name == v:
+                        res.append([name,cat])
+                user_cat_vals[ucat] = res
+        mi.user_categories = user_cat_vals
+
+        if get_cover:
+            if cover_as_data:
+                cdata = self.cover(id, index_is_id=True)
+                if cdata:
+                    mi.cover_data = ('jpeg', cdata)
+            else:
+                mi.cover = self.cover(id, index_is_id=True, as_path=True)
+        return mi
+
     # }}}
 
 # Testing {{{

src/calibre/db/fields.py

@@ -66,6 +66,60 @@ class OneToOneField(Field):
     def iter_book_ids(self):
         return self.table.book_col_map.iterkeys()
 
+class CompositeField(OneToOneField):
+
+    def __init__(self, *args, **kwargs):
+        OneToOneField.__init__(self, *args, **kwargs)
+
+        self._render_cache = {}
+
+    def render_composite(self, book_id, mi):
+        ans = self._render_cache.get(book_id, None)
+        if ans is None:
+            ans = mi.get(self.metadata['label'])
+            self._render_cache[book_id] = ans
+        return ans
+
+    def clear_cache(self):
+        self._render_cache = {}
+
+    def pop_cache(self, book_id):
+        self._render_cache.pop(book_id, None)
+
+class OnDeviceField(OneToOneField):
+
+    def __init__(self, name, table):
+        self.name = name
+        self.book_on_device_func = None
+
+    def book_on_device(self, book_id):
+        if callable(self.book_on_device_func):
+            return self.book_on_device_func(book_id)
+        return None
+
+    def set_book_on_device_func(self, func):
+        self.book_on_device_func = func
+
+    def for_book(self, book_id, default_value=None):
+        loc = []
+        count = 0
+        on = self.book_on_device(book_id)
+        if on is not None:
+            m, a, b, count = on[:4]
+            if m is not None:
+                loc.append(_('Main'))
+            if a is not None:
+                loc.append(_('Card A'))
+            if b is not None:
+                loc.append(_('Card B'))
+        return ', '.join(loc) + ((' (%s books)'%count) if count > 1 else '')
+
+    def __iter__(self):
+        return iter(())
+
+    def iter_book_ids(self):
+        return iter(())
+
 class ManyToOneField(Field):
 
     def for_book(self, book_id, default_value=None):
@@ -107,11 +161,33 @@ class ManyToManyField(Field):
     def __iter__(self):
         return self.table.id_map.iterkeys()
 
+class AuthorsField(ManyToManyField):
+
+    def author_data(self, author_id):
+        return {
+            'name' : self.table.id_map[author_id],
+            'sort' : self.table.asort_map[author_id],
+            'link' : self.table.alink_map[author_id],
+        }
+
+class FormatsField(ManyToManyField):
+
+    def format_fname(self, book_id, fmt):
+        return self.table.fname_map[book_id][fmt.upper()]
+
 def create_field(name, table):
     cls = {
             ONE_ONE : OneToOneField,
             MANY_ONE : ManyToOneField,
             MANY_MANY : ManyToManyField,
         }[table.table_type]
+    if name == 'authors':
+        cls = AuthorsField
+    elif name == 'ondevice':
+        cls = OnDeviceField
+    elif name == 'formats':
+        cls = FormatsField
+    elif table.metadata['datatype'] == 'composite':
+        cls = CompositeField
     return cls(name, table)
 

src/calibre/db/tables.py

@@ -77,6 +77,17 @@ class SizeTable(OneToOneTable):
                 'WHERE data.book=books.id) FROM books'):
             self.book_col_map[row[0]] = self.unserialize(row[1])
 
+class CompositeTable(OneToOneTable):
+
+    def read(self, db):
+        self.book_col_map = {}
+        d = self.metadata['display']
+        self.composite_template = ['composite_template']
+        self.contains_html = d['contains_html']
+        self.make_category = d['make_category']
+        self.composite_sort = d['composite_sort']
+        self.use_decorations = d['use_decorations']
+
 class ManyToOneTable(Table):
 
     '''
@@ -144,11 +155,11 @@ class AuthorsTable(ManyToManyTable):
 
     def read_id_maps(self, db):
         self.alink_map = {}
-        self.sort_map  = {}
+        self.asort_map  = {}
         for row in db.conn.execute(
                 'SELECT id, name, sort, link FROM authors'):
             self.id_map[row[0]] = row[1]
-            self.sort_map[row[0]] = (row[2] if row[2] else
+            self.asort_map[row[0]] = (row[2] if row[2] else
                     author_to_author_sort(row[1]))
             self.alink_map[row[0]] = row[3]
 
@@ -158,14 +169,19 @@ class FormatsTable(ManyToManyTable):
         pass
 
     def read_maps(self, db):
+        self.fname_map = {}
         for row in db.conn.execute('SELECT book, format, name FROM data'):
             if row[1] is not None:
-                if row[1] not in self.col_book_map:
+                fmt = row[1].upper()
-                    self.col_book_map[row[1]] = []
+                if fmt not in self.col_book_map:
-                self.col_book_map[row[1]].append(row[0])
+                    self.col_book_map[fmt] = []
+                self.col_book_map[fmt].append(row[0])
                 if row[0] not in self.book_col_map:
                     self.book_col_map[row[0]] = []
-                self.book_col_map[row[0]].append((row[1], row[2]))
+                self.book_col_map[row[0]].append(fmt)
+                if row[0] not in self.fname_map:
+                    self.fname_map[row[0]] = {}
+                self.fname_map[row[0]][fmt] = row[2]
 
         for key in tuple(self.col_book_map.iterkeys()):
             self.col_book_map[key] = tuple(self.col_book_map[key])
@@ -185,12 +201,9 @@ class IdentifiersTable(ManyToManyTable):
                     self.col_book_map[row[1]] = []
                 self.col_book_map[row[1]].append(row[0])
                 if row[0] not in self.book_col_map:
-                    self.book_col_map[row[0]] = []
+                    self.book_col_map[row[0]] = {}
-                self.book_col_map[row[0]].append((row[1], row[2]))
+                self.book_col_map[row[0]][row[1]] = row[2]
 
         for key in tuple(self.col_book_map.iterkeys()):
             self.col_book_map[key] = tuple(self.col_book_map[key])
 
-        for key in tuple(self.book_col_map.iterkeys()):
-            self.book_col_map[key] = tuple(self.book_col_map[key])
-

src/calibre/db/view.py

@@ -7,15 +7,77 @@ __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
+from functools import partial
 
 class View(object):
 
     def __init__(self, cache):
         self.cache = cache
-        self._field_idx_map = {}
+        self._field_getters = {}
         for col, idx in cache.backend.FIELD_MAP.iteritems():
             if isinstance(col, int):
-                pass # custom column
+                label = self.cache.backend.custom_column_num_map[col]['label']
+                label = (self.cache.backend.field_metadata.custom_field_prefix
+                        + label)
+                self._field_getters[idx] = partial(self.get, label)
             else:
-                self._field_idx_map[idx] = col
+                try:
+                    self._field_getters[idx] = {
+                        'id'      : self._get_id,
+                        'au_map'  : self.get_author_data,
+                        'ondevice': self.get_ondevice,
+                        'marked'  : self.get_is_marked,
+                    }[col]
+                except KeyError:
+                    self._field_getters[idx] = partial(self.get, col)
+
+        self._map = list(self.cache.all_book_ids())
+        self._map_filtered = list(self._map)
+
+    def _get_id(self, idx, index_is_id=True):
+        ans = idx if index_is_id else self.index_to_id(idx)
+        return ans
+
+    def get_field_map_field(self, row, col, index_is_id=True):
+        '''
+        Supports the legacy FIELD_MAP interface for getting metadata. Do not use
+        in new code.
+        '''
+        getter = self._field_getters[col]
+        return getter(row, index_is_id=index_is_id)
+
+    def index_to_id(self, idx):
+        pass
+
+    def get(self, field, idx, index_is_id=True, default_value=None):
+        id_ = idx if index_is_id else self.index_to_id(idx)
+        return self.cache.field_for(field, id_)
+
+    def get_ondevice(self, idx, index_is_id=True, default_value=False):
+        pass
+
+    def get_is_marked(self, idx, index_is_id=True, default_value=False):
+        pass
+
+    def get_author_data(self, idx, index_is_id=True, default_value=()):
+        '''
+        Return author data for all authors of the book identified by idx as a
+        tuple of dictionaries. The dictionaries should never be empty, unless
+        there is a bug somewhere. The list could be empty if idx point to an
+        non existent book, or book with no authors (though again a book with no
+        authors should never happen).
+
+        Each dictionary has the keys: name, sort, link. Link can be an empty
+        string.
+
+        default_value is ignored, this method always returns a tuple
+        '''
+        id_ = idx if index_is_id else self.index_to_id(idx)
+        with self.cache.read_lock:
+            ids = self.cache._field_ids_for('authors', id_)
+            ans = []
+            for id_ in ids:
+                ans.append(self.cache._author_data(id_))
+        return tuple(ans)
+