[Monotone-devel] Re: speed of "mtn ls branches"

[Lapo Luchini]

Daniel Carosone wrote:
> Let's think about what the user might be asking for:
> 
>  - show me branches that are alive/interesting (for checkout,
>    propagate, etc).  This is "ls branches" and should validate branch
>    and suspend certs, and filter accordingly.  Clearly, the common
>    operation.
> 
> Apart from the speed issue, shell completion probably wants the first
> form. I'd find it kinda odd if I was offered completions that "ls
> branches" didn't show, and I'd probably want to be sure by typing
> explicitly where I wanted to use a suspended or invalid name.  Which
> still leaves the speed issue.

I certainly agree... OTOH on my host a "ls branches" on the monotone DB
takes around 15" first run, 3.75" with hot cache.

While it is IMHO acceptable for CLI usage, it's not very good for
automatic completion... (OTOH there are )

We should maybe trade in some "security" with speed, e.g. mantaining a
DB table with a "cache of valid and not suspended branches".

Pros: would certainly be faster
Cons: data should be updated on certain events (sy/ci), complicating the
workflow, and could be out of sync; data contained couldn't be trusted

...but it's not like people is looking at "ls branches" to make big
decisions or something, and every cert is verified on the actual
checkout/update/commit, so even if an hypotetical attacker has corrupted
that cache, it wouldn't be so bad.