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qpkg/TODO: cleanup and added new task for consideration

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- TODO: added section for tasks done
- TODO: search tree optimization is done
- TODO: added idea of supporting other database formats in the same family
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Werner Almesberger 2010-11-20 07:18:44 -03:00
parent 9481934c9a
commit 07a4422641
1 changed files with 27 additions and 17 deletions
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qpkg/TODO
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@ -1,20 +1,5 @@
- optimize the search trees. Right now, we have 81812 calls to make_id
for 14601 packages, resulting in 7420560 calls to comp_id.
There can be at most 2 new identifiers per package (package name and
version), so a perfectly balanced tree should have a depth of no more
than 14. If we assume that each call to make_id searches to the bottom,
we'd get 1145368 calls to comp_id, about 15% of the current number.
So the tree is clearly degenerated.
Update: after switching to red-black trees, we get only 1497604 calls
to comp_id. This is 130% of the "good case" estimate above. Insertion
of a new node is currently done with two lookups, so we'll get rid of
some more lookups after further optimization.
Update: after merging the two lookups per new node into one, we're at
1172642 calls to comp_id, or 102% of the predicted "good case".
Still left to do
================
- check whether introducing a new package would cause a conflict
@ -36,3 +21,28 @@
- check database for internal consistency
- implement keyword search
- consider also supporting the similar but not identical (parent ?) format
of /var/lib/dpkg/status and /var/lib/apt/lists/*Packages
Done
====
- optimize the search trees. Right now, we have 81812 calls to make_id
for 14601 packages, resulting in 7420560 calls to comp_id.
There can be at most 2 new identifiers per package (package name and
version), so a perfectly balanced tree should have a depth of no more
than 14. If we assume that each call to make_id searches to the bottom,
we'd get 1145368 calls to comp_id, about 15% of the current number.
So the tree is clearly degenerated.
Update: after switching to red-black trees, we get only 1497604 calls
to comp_id. This is 130% of the "good case" estimate above. Insertion
of a new node is currently done with two lookups, so we'll get rid of
some more lookups after further optimization.
Update: after merging the two lookups per new node into one, we're at
1172642 calls to comp_id, or 102% of the predicted "good case".