How to drain your laptop battery using Jigsaw

[David M. Lloyd]

On 12/21/2011 05:07 PM, Jesse Glick wrote:
> On 12/21/2011 05:40 PM, David M. Lloyd wrote:
>> This basically implies #2 of your solution though we did not add
>> any run-time measures to verify version constraints (we came to the
>> conclusion that this was an install-time concern
>
> Well the problem is essentially the same whether you interpret
> dependency ranges eagerly during installation of a root "application"
> module, or lazily the first time the application is run and caching
> thereafter, or simply every time it is run. Obviously a user might
> accept a twenty-second pause installing a module while rejecting a
> one-second pause when launching it, but resolution as per Jigsaw's
> current specification can take time exponential in the number of modules
> - thus (potentially) intractable even for installation.

Yeah that's a good point.  At most we considered a simple verification 
type of constraint at install (or run) time which would be a single 
linear scan of immediate dependencies (to verify consumption of proper 
versions) and immediate dependents (this would apply to install time 
only to ensure that the module installation wouldn't introduce an 
invalid dependency in another module).  This keeps the algorithm simple 
and doesn't introduce scalability problems based upon the number of 
installed module.

-- 
- DML