Rev 3054: Tests that buffer_all does load all child indices, and but only if they need it. in http://bzr.arbash-meinel.com/branches/bzr/0.93-dev/index_buffer_all

[John Arbash Meinel]

At http://bzr.arbash-meinel.com/branches/bzr/0.93-dev/index_buffer_all

------------------------------------------------------------
revno: 3054
revision-id:john at arbash-meinel.com-20071130021614-hdymy9xgr32v0uee
parent: john at arbash-meinel.com-20071129232902-xlmhssl1u4lyct64
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: index_buffer_all
timestamp: Thu 2007-11-29 20:16:14 -0600
message:
  Tests that buffer_all does load all child indices, and but only if they need it.
modified:
  bzrlib/index.py                index.py-20070712131115-lolkarso50vjr64s-1
  bzrlib/tests/test_index.py     test_index.py-20070712131115-lolkarso50vjr64s-2
-------------- next part --------------
=== modified file 'bzrlib/index.py'
--- a/bzrlib/index.py	2007-11-29 23:29:02 +0000
+++ b/bzrlib/index.py	2007-11-30 02:16:14 +0000
@@ -1115,6 +1115,19 @@
             index.validate()
 
     def buffer_all(self):
+        """Pre-load all of the indexes.
+
+        This goes to every child index, and tells it to buffer all of its data
+        if it has not yet done so. Functions that need to call this should be
+        reworked to use an algorithm that does not require the whole history.
+        However, until they are fixed, this can be used to improve performance
+        for O(History) algorithms.
+        """
+        if 'evil' in debug.debug_flags:
+            # Do we want to use 4 here, since it is really the caller of the
+            # algorithm that needs buffer_all?
+            trace.mutter_callsite(3,
+                "buffer_all scales with size of history.")
         for index in self._indices:
             if index._nodes is None:
                 index._buffer_all()

=== modified file 'bzrlib/tests/test_index.py'
--- a/bzrlib/tests/test_index.py	2007-10-15 07:56:04 +0000
+++ b/bzrlib/tests/test_index.py	2007-11-30 02:16:14 +0000
@@ -825,6 +825,33 @@
         index.insert_index(0, index1)
         self.assertEqual([(index1, ('key', ), '')], list(index.iter_all_entries()))
 
+    def test_buffer_all(self):
+        log = []
+        def make_buffer_all(idx, name):
+            _buffer = idx._buffer_all
+            def _buffer_all():
+                log.append(name)
+                _buffer()
+            idx._buffer_all = _buffer_all
+
+        index1 = self.make_index('name1', nodes=[(('name', ), 'data', ())])
+        make_buffer_all(index1, 'index1')
+        index2 = self.make_index('name2', nodes=[(('2', ), '', ())])
+        make_buffer_all(index2, 'index2')
+        index = CombinedGraphIndex([index1, index2])
+        for idx in index._indices:
+            self.assertIs(None, idx._nodes)
+        self.assertEqual([], log)
+        index.buffer_all()
+        for idx in index._indices:
+            self.assertIsNot(None, idx._nodes)
+        self.assertEqual(['index1', 'index2'], log)
+        index.buffer_all() # All are already buffered
+        self.assertEqual(['index1', 'index2'], log)
+        index2._nodes = None
+        index.buffer_all()
+        self.assertEqual(['index1', 'index2', 'index2'], log)
+
     def test_iter_all_entries_empty(self):
         index = CombinedGraphIndex([])
         self.assertEqual([], list(index.iter_all_entries()))