Mercurial > hg
view mercurial/cffi/bdiffbuild.py @ 34065:c6c8a52e28c9
revset: optimize "draft() & ::x" pattern
The `draft() & ::x` type query could be common for selecting one or more
draft feature branches being worked on.
Before this patch, `::x` may travel through the changelog DAG for a long
distance until it gets a smaller revision number than `min(draft())`. It
could be very slow on long changelog with distant (in terms of revision
numbers) drafts.
This patch adds a fast path for this situation, and will stop traveling the
changelog DAG once `::x` hits a non-draft revision.
The fast path also works for `secret()` and `not public()`.
To measure the performance difference, I used drawdag to create a repo that
emulates distant drafts:
DRAFT4
|
DRAFT3 # draft
/
PUBLIC9999 # public
|
PUBLIC9998
|
. DRAFT2
. |
. DRAFT1 # draft
| /
PUBLIC0001 # public
And measured the performance using the repo:
(BEFORE)
$ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
! wall 0.017132 comb 0.010000 user 0.010000 sys 0.000000 (best of 156)
$ hg perfrevset 'draft() & ::(all())'
! wall 0.024221 comb 0.030000 user 0.030000 sys 0.000000 (best of 113)
(AFTER)
$ hg perfrevset 'draft() & ::(DRAFT2+DRAFT4)'
! wall 0.000243 comb 0.000000 user 0.000000 sys 0.000000 (best of 9303)
$ hg perfrevset 'draft() & ::(all())'
! wall 0.004319 comb 0.000000 user 0.000000 sys 0.000000 (best of 655)
Differential Revision: https://phab.mercurial-scm.org/D441
author | Jun Wu <quark@fb.com> |
---|---|
date | Mon, 28 Aug 2017 14:49:00 -0700 |
parents | 2dcb3d52ef41 |
children | 0585337ea787 |
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from __future__ import absolute_import import cffi import os ffi = cffi.FFI() ffi.set_source("mercurial.cffi._bdiff", open(os.path.join(os.path.join(os.path.dirname(__file__), '..'), 'bdiff.c')).read(), include_dirs=['mercurial']) ffi.cdef(""" struct bdiff_line { int hash, n, e; ssize_t len; const char *l; }; struct bdiff_hunk; struct bdiff_hunk { int a1, a2, b1, b2; struct bdiff_hunk *next; }; int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr); int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn, struct bdiff_hunk *base); void bdiff_freehunks(struct bdiff_hunk *l); void free(void*); """) if __name__ == '__main__': ffi.compile()