Re: [PATCH v4 3/3] repo-settings: rename the traditional default fetch.negotiationAlgorithm

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 2, 2022, 17:50 UTC
Message-ID: <xmqqk0ed17l8.fsf@gitster.g>
In-Reply-To: <7500a4d2e44008b1d8df9cc8b24b67ff973a98ae.1643773361.git.gitgitgadget@gmail.com>

"Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 30 quoted lines

> diff --git a/repo-settings.c b/repo-settings.c
> index 41e1c30845f..b4fbd16cdcc 100644
> --- a/repo-settings.c
> +++ b/repo-settings.c
> @@ -26,7 +26,7 @@ void prepare_repo_settings(struct repository *r)
>  	/* Defaults */
>  	r->settings.index_version = -1;
>  	r->settings.core_untracked_cache = UNTRACKED_CACHE_KEEP;
> -	r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_DEFAULT;
> +	r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE;
>  
>  	/* Booleans config or default, cascades to other settings */
>  	repo_cfg_bool(r, "feature.manyfiles", &manyfiles, 0);
> @@ -81,12 +81,15 @@ void prepare_repo_settings(struct repository *r)
>  	}
>  
>  	if (!repo_config_get_string(r, "fetch.negotiationalgorithm", &strval)) {
> +		int fetch_default = r->settings.fetch_negotiation_algorithm;
>  		if (!strcasecmp(strval, "skipping"))
>  			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
>  		else if (!strcasecmp(strval, "noop"))
>  			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_NOOP;
> +		else if (!strcasecmp(strval, "consecutive"))
> +			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_CONSECUTIVE;
>  		else if (!strcasecmp(strval, "default"))
> -			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_DEFAULT;
> +			r->settings.fetch_negotiation_algorithm = fetch_default;
>  		else
>  			die("unknown fetch negotiation algorithm '%s'", strval);
>  	}

This

    - set the default to whatever experimental says
    - parse the configuration and set it 
      - to the specified value unless it is DEFAULT
      - to the value the experimental bit set as the default otherwise

certainly works, even though I find it a bit convoluted and backwards. I have slight preference to "if the user says 'default', hold onto it as a symbolic 'default' setting, and resolve it to a concrete value at the very end" pattern, which tends to handle the "reverting to default" case better.

There is the "manyfiles" precedent that sets index.version and core.untrackedCache irreversibly nearby, and I am sympathetic to whoever added the fetch_negotiation_algorithm support (it probably is not you, I am guessing) by mimicking it, so I am OK with the version posted as-is.

Thanks.