Rev 4675: Implement CHKInventory.filter() on the new subset. in http://bazaar.launchpad.net/~jameinel/bzr/2.0.1-faster-log-dir-bug374730

[John Arbash Meinel]

At http://bazaar.launchpad.net/~jameinel/bzr/2.0.1-faster-log-dir-bug374730

------------------------------------------------------------
revno: 4675
revision-id: john at arbash-meinel.com-20090924193615-s58xz6bq2237tx26
parent: john at arbash-meinel.com-20090924192645-hyy1ycnnk6u3j5j6
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: 2.0.1-faster-log-dir-bug374730
timestamp: Thu 2009-09-24 14:36:15 -0500
message:
  Implement CHKInventory.filter() on the new subset.
  
  With this implementation, we can probably filter() without reading all nodes,
  which is the goal of the exercise.
-------------- next part --------------
=== modified file 'bzrlib/inventory.py'
--- a/bzrlib/inventory.py	2009-09-24 19:26:45 +0000
+++ b/bzrlib/inventory.py	2009-09-24 19:36:15 +0000
@@ -1639,14 +1639,29 @@
         (interesting,
          parent_to_children) = self._expand_fileids_to_parents_and_children(
                                 specific_fileids)
-        entries = self.iter_entries()
-        other = Inventory(entries.next()[1].file_id)
+        # There is some overlap here, but we assume that all interesting items
+        # are in the _fileid_to_entry_cache because we had to read them to
+        # determine if they were a dir we wanted to recurse, or just a file
+        # This should give us all the entries we'll want to add, so start
+        # adding
+        other = Inventory(self.root_id)
         other.root.revision = self.root.revision
         other.revision_id = self.revision_id
-        for path, entry in entries:
-            file_id = entry.file_id
-            if file_id in interesting:
-                other.add(entry.copy())
+        if not interesting: # empty filter
+            return other
+        cache = self._fileid_to_entry_cache
+        remaining_children = collections.deque(parent_to_children[self.root_id])
+        while remaining_children:
+            file_id = remaining_children.popleft()
+            ie = cache[file_id]
+            if ie.kind == 'directory':
+                ie = ie.copy() # We create a copy to depopulate the .children attribute
+            # TODO: depending on the uses of 'other' we should probably alwyas
+            #       '.copy()' to prevent someone from mutating other and
+            #       invaliding our internal cache
+            other.add(ie)
+            if file_id in parent_to_children:
+                remaining_children.extend(parent_to_children[file_id])
         return other
 
     @staticmethod