[PATCH 3 of 4 lazy-manifest] manifest: use lazymanifest instead of manifestdict

[Durham Goode]

On 1/8/15 12:35 PM, Augie Fackler wrote:
> # HG changeset patch
> # User Augie Fackler <augie at google.com>
> # Date 1420746668 18000
> #      Thu Jan 08 14:51:08 2015 -0500
> # Node ID 07da98fd38a1269c899b3c81fbe23dbc807511d0
> # Parent  1165b1c87091d12209a3346834be5c1e3db8a9e4
> manifest: use lazymanifest instead of manifestdict
>
> Before any of my related changes on mozilla-central:
>
> perfmanifest tip
> ! wall 0.268805 comb 0.260000 user 0.260000 sys 0.000000 (best of 37)
> perftags
> ! result: 162
> ! wall 0.007099 comb 0.000000 user 0.000000 sys 0.000000 (best of 401)
> perfstatus
> ! wall 0.415680 comb 0.420000 user 0.260000 sys 0.160000 (best of 24)
> hgperf export tip
> ! wall 0.142118 comb 0.140000 user 0.140000 sys 0.000000 (best of 67)
>
> after all of my changes on mozilla-central:
>
> ./hg:
> perfmanifest tip
> ! wall 0.232640 comb 0.230000 user 0.220000 sys 0.010000 (best of 43)
> perftags
> ! result: 162
> ! wall 0.007057 comb 0.010000 user 0.000000 sys 0.010000 (best of 395)
> perfstatus
> ! wall 0.415503 comb 0.420000 user 0.280000 sys 0.140000 (best of 24)
> hgperf export tip
> ! wall 0.025096 comb 0.030000 user 0.030000 sys 0.000000 (best of 102)
>
> so it's no real change in performance on perf{manifest,tags,status},
> but is a huge win on 'hgperf export tip'.
>
Very nice! Is there any performance difference for arbitrary manifest 
diffs?  Like what happens in merge.update for hg update/rebase/etc?