Split PokedexLookup(recreate=True) into its own method. #216

[zzz-pokedex.git] / pokedex / lookup.py

diff --git a/pokedex/lookup.py b/pokedex/lookup.py
index f029b77..cf6a15f 100644 (file)
--- a/pokedex/lookup.py
+++ b/pokedex/lookup.py
@@ -28,6 +28,24 @@ rx_is_number = re.compile('^\d+$')
 LookupResult = namedtuple('LookupResult',
     ['object', 'indexed_name', 'name', 'language', 'iso3166', 'exact'])
 
 LookupResult = namedtuple('LookupResult',
     ['object', 'indexed_name', 'name', 'language', 'iso3166', 'exact'])
 

+class UninitializedIndex(object):
+    class UninitializedIndexError(Exception):
+        pass
+
+    def __nonzero__(self):
+        """Dummy object should identify itself as False."""
+        return False
+
+    def __bool__(self):
+        """Python 3000 version of the above.  Future-proofing rules!"""
+        return False
+
+    def __getattr__(self, *args, **kwargs):
+        raise self.UninitializedIndexError(
+            "The lookup index does not exist.  Please use `pokedex setup` "
+            "or lookup.rebuild_index() to create it."
+        )
+

 class LanguageWeighting(whoosh.scoring.Weighting):
     """A scoring class that forces otherwise-equal English results to come
     before foreign results.
 class LanguageWeighting(whoosh.scoring.Weighting):
     """A scoring class that forces otherwise-equal English results to come
     before foreign results.


@@ -67,7 +85,7 @@ class PokedexLookup(object):
     )
 
 
     )
 
 

-    def __init__(self, directory=None, session=None, recreate=False):
+    def __init__(self, directory=None, session=None):

         """Opens the whoosh index stored in the named directory.  If the index
         doesn't already exist, it will be created.
 
         """Opens the whoosh index stored in the named directory.  If the index
         doesn't already exist, it will be created.
 


@@ -76,13 +94,9 @@ class PokedexLookup(object):
             `pokedex` egg directory.
 
         `session`
             `pokedex` egg directory.
 
         `session`

-            If the index needs to be created, this database session will be
-            used.  Defaults to an attempt to connect to the default SQLite
-            database installed by `pokedex setup`.
-
-        `recreate`
-            If set to True, the whoosh index will be created even if it already
-            exists.
+            Used for creating the index and retrieving objects.  Defaults to an
+            attempt to connect to the default SQLite database installed by
+            `pokedex setup`.

         """
 
         # By the time this returns, self.index, self.speller, and self.session
         """
 
         # By the time this returns, self.index, self.speller, and self.session


@@ -92,6 +106,7 @@ class PokedexLookup(object):
         if not directory:
             directory = pkg_resources.resource_filename('pokedex',
                                                         'data/whoosh-index')
         if not directory:
             directory = pkg_resources.resource_filename('pokedex',
                                                         'data/whoosh-index')

+        self.directory = directory

 
         if session:
             self.session = session
 
         if session:
             self.session = session


@@ -99,31 +114,33 @@ class PokedexLookup(object):
             self.session = connect()
 
         # Attempt to open or create the index
             self.session = connect()
 
         # Attempt to open or create the index

-        directory_exists = os.path.exists(directory)
-        if directory_exists and not recreate:
-            # Already exists; should be an index!  Bam, done.
-            try:
-                self.index = whoosh.index.open_dir(directory, indexname='MAIN')
-                spell_store = whoosh.filedb.filestore.FileStorage(directory)
-                self.speller = whoosh.spelling.SpellChecker(spell_store)
-                return
-            except whoosh.index.EmptyIndexError as e:
-                # Apparently not a real index.  Fall out and create it
-                pass
-
-        # Delete and start over if we're going to bail anyway.
-        if directory_exists and recreate:
-            # Be safe and only delete if it looks like a whoosh index, i.e.,
-            # everything starts with _
-            if all(f[0] == '_' for f in os.listdir(directory)):
-                shutil.rmtree(directory)
-                directory_exists = False
-
-        if not directory_exists:
-            os.mkdir(directory)
-
-
-        ### Create index
+        if not os.path.exists(directory) or not os.listdir(directory):
+            # Directory doesn't exist OR is empty; caller needs to use
+            # rebuild_index before doing anything.  Provide a dummy object that
+            # complains when used
+            self.index = UninitializedIndex()
+            self.speller = UninitializedIndex()
+            return
+
+        # Otherwise, already exists; should be an index!  Bam, done.
+        # Note that this will explode if the directory exists but doesn't
+        # contain an index; that's a feature
+        try:
+            self.index = whoosh.index.open_dir(directory, indexname='MAIN')
+        except whoosh.index.EmptyIndexError:
+            raise IOError(
+                "The index directory already contains files.  "
+                "Please use a dedicated directory for the lookup index."
+            )
+
+        # Create speller, and done
+        spell_store = whoosh.filedb.filestore.FileStorage(directory)
+        self.speller = whoosh.spelling.SpellChecker(spell_store)
+
+
+    def rebuild_index(self):
+        """Creates the index from scratch."""
+

         schema = whoosh.fields.Schema(
             name=whoosh.fields.ID(stored=True),
             table=whoosh.fields.ID(stored=True),
         schema = whoosh.fields.Schema(
             name=whoosh.fields.ID(stored=True),
             table=whoosh.fields.ID(stored=True),


@@ -133,8 +150,11 @@ class PokedexLookup(object):
             display_name=whoosh.fields.STORED,  # non-lowercased name
         )
 
             display_name=whoosh.fields.STORED,  # non-lowercased name
         )
 

-        self.index = whoosh.index.create_in(directory, schema=schema,
-                                            indexname='MAIN')
+        if not os.path.exists(self.directory):
+            os.mkdir(self.directory)
+
+        self.index = whoosh.index.create_in(self.directory, schema=schema,
+                                                            indexname='MAIN')

         writer = self.index.writer()
 
         # Index every name in all our tables of interest
         writer = self.index.writer()
 
         # Index every name in all our tables of interest