Rev 3780: Teach CHKInventory with a parent_id_basename index how to load partial index contents. in http://people.ubuntu.com/~robertc/baz2.0/repository

[Robert Collins]

At http://people.ubuntu.com/~robertc/baz2.0/repository

------------------------------------------------------------
revno: 3780
revision-id: robertc at robertcollins.net-20081114033634-9ns1w15wx9f17tpk
parent: robertc at robertcollins.net-20081114032957-uqh1lsxe0s21vt8x
committer: Robert Collins <robertc at robertcollins.net>
branch nick: repository
timestamp: Fri 2008-11-14 14:36:34 +1100
message:
  Teach CHKInventory with a parent_id_basename index how to load partial index contents.
modified:
  bzrlib/inventory.py            inventory.py-20050309040759-6648b84ca2005b37
=== modified file 'bzrlib/inventory.py'
--- a/bzrlib/inventory.py	2008-11-14 02:19:53 +0000
+++ b/bzrlib/inventory.py	2008-11-14 03:36:34 +0000
@@ -1683,17 +1683,36 @@
     def children(self):
         """Access the list of children of this inventory.
 
-        Currently causes a full-load of all the children; a more sophisticated
-        proxy object is planned.
+        With a parent_id_basename_to_file_id index, loads all the children,
+        without loads the entire index. Without is bad. A more sophisticated
+        proxy object might be nice, to allow partial loading of children as
+        well when specific names are accessed. (So path traversal can be
+        written in the obvious way but not examine siblings.).
         """
         if self._children is not None:
             return self._children
+        if self._chk_inventory.parent_id_basename_to_file_id is None:
+            # Slow path - read the entire inventory looking for kids.
+            result = {}
+            for file_id, bytes in self._chk_inventory.id_to_entry.iteritems():
+                entry = self._chk_inventory._bytes_to_entry(bytes)
+                if entry.parent_id == self.file_id:
+                    result[entry.name] = entry
+            self._children = result
+            return result
         result = {}
+        # XXX: Todo - use proxy objects for the children rather than loading
+        # all when the attribute is referenced.
+        parent_id_index = self._chk_inventory.parent_id_basename_to_file_id
+        child_ids = set()
+        for (parent_id, name_utf8), file_id in parent_id_index.iteritems(
+            key_filter=[(self.file_id,)]):
+            child_ids.add((file_id,))
         # populate; todo: do by name
-        for file_id, bytes in self._chk_inventory.id_to_entry.iteritems():
+        id_to_entry = self._chk_inventory.id_to_entry
+        for file_id, bytes in id_to_entry.iteritems(child_ids):
             entry = self._chk_inventory._bytes_to_entry(bytes)
-            if entry.parent_id == self.file_id:
-                result[entry.name] = entry
+            result[entry.name] = entry
         self._children = result
         return result