features/configuration 501

[sidke]

api

introduces a barebones configuration file to be used by rust-fil-proofs with a simple api:

set_config(key, value)

• set global config property named key to value value

get_config(key) -> value

• get global config property named key as a result

populate rust-fil-proofs.config.toml with any config options, or override by environment variables to the same name

order of preference is:

ENV > rust-fil-proofs.config.toml

usage:

extern crate config;
use config::get_config;

with

if get_config("MAXIMIZE_CONFIG")? {
  ...
}

default configuration

introduce new configuration options and their default values by extending this const defined in storage-proofs/src/config.rs

const DEFAULT_CONFIG: &[(&str, bool)] = &[
    ("MAXIMIZE_CACHING", false),
];

[porcuquine]

I'm not sold on the proliferation of crates, and the possibility of two distinct toml files is confusing (to me).

I think it would make more sense to put this in storage_proofs, with the defaults supplied in code by whichever consumers of the configuration define settings. Having a place to register configuration settings will also simplify derived configurations (as we've discussed), which will benefit from programmability.

We could do this with a macro inside a registration block in the initialization function, (e.g. def_config!{ MAXIMIZE_CACHING: false }, or whatever), eventually. For now, and maybe forever, simple function calls should be fine, register_config("MAXIMIZE_CACHING", false).

[porcuquine]

LGTM