[PATCH 2 of 2] repoview: bypass changelog method to computed cache key

[Pierre-Yves David]

On 12/04/2015 03:06 PM, Pierre-Yves David wrote:
> # HG changeset patch
> # User Pierre-Yves David <pierre-yves.david at fb.com>
> # Date 1449267735 28800
> #      Fri Dec 04 14:22:15 2015 -0800
> # Node ID 43caa4b5b82cb482a59513ee78b5bd96abefb7cd
> # Parent  8daa6d98b6f67d39389bbd91d0a034466e1c965d
> # EXP-Topic clcachekey
> # Available At http://hg.netv6.net/marmoute-wip/mercurial/
> #              hg pull http://hg.netv6.net/marmoute-wip/mercurial/ -r 43caa4b5b82c
> repoview: bypass changelog method to computed cache key
>
> Getting the data necessary for the cache key using the changelog/revlog method
> adds a significant overhead. Given how simple the underlying implementation is
> and often this code is ran, it make sense to violate layering and directly
> compute the data.
>
> Testing `hg log` on Mozilla-central, this reduce the time spent on changelog
> cache validation by an extra half:
>
> before: 12.2s of 69s
> after:   6.1s of 62s
>
> Total speed up from this patch and it's parent is 3x
>
> (With stupid python profiler overhead)
>
> The global speedup without profiler overhead is still there,
>
> Before: 51s
> After:  39s (-23%)

Disabling my various extensions playing with namespace, the number move to

Before: 33.680
After:  29.290 (-15%)

-- 
Pierre-Yves David