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85c8e3660d
The --analyze mode was extremely slow for the freebsd/freebsd repo on github; digging in, the is_ancestor() function was being called a huge number of times -- about 22 times per commit on average (and about 17 million times overall). The analyze mode uses is_ancestor() to determine whether a rename equivalency class should be broken (i.e. renaming A->B mean all versions of A and B are just different versions of the same file, but if someone adds a new A in some commit which contains the A->B rename in its history then this equivalence class no longer holds). Each is_ancestor() call potentially has to walk a tree of dependencies all the way back to a sufficient depth where it can realize that the commit cannot be an ancestor; this can be a very long walk. We can speed this up by keeping track of some previous is_ancestor() results. If commit F is not an ancestor of commit G, then F cannot be an ancestor of children of G (unless that child has multiple parents; but even in that case F can only be an ancestor through one of the parents other than G). Similarly, if F is an ancestor of commit G, then F will always be an ancestor of any children of G. Cache results from previous calls to is_ancestor() and use them to accelerate subsequent calls. Signed-off-by: Elijah Newren <newren@gmail.com> |
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| .. | ||
| t9390 | ||
| t9391 | ||
| run_coverage | ||
| t9390-filter-repo.sh | ||
| t9391-filter-repo-lib-usage.sh | ||
| t9392-python-callback.sh | ||
| test-lib-functions.sh | ||
| test-lib.sh | ||