Re: [PATCH] diff_unique_abbrev(): document its assumtion and limitation
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Sep 30, 2016, 19:19 UTC
- Message-ID
- <xmqqd1jl9ovc.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <20160930180957.xj4jqoslbtevhqpb@sigill.intra.peff.net>
Jeff King <peff@peff.net> writes:
Show 7 quoted lines
> ... Now that function _would_ > want to be updated as a result of the other conversation (it would need > to do something sensible with "-1", like turning it into "7", or > whatever else is deemed reasonable outside of a repository). > > Anyway. I just wonder if you want to give it a better name while you are > at it.
I'd say the patch to introduce the new function that makes the old name potentially confusing is a good one to do the rename. Until then I do not think there is no need to rename the existing one ;-)
Related tangent about "like turning it into", I am thinking adding something like this as a preparatory step to Linus's auto-sizing serires. That way, we do not have to spell "7"
Having to spell FALLBACK_DEFAULT_ABBREV over and over again would be more irritating than having to spell "7" often, but I think it would be a sign of a deeper problem if it turns out we have to repeat this constant in many places, so an irritatingly long name may serve as a canary in the coalmine ;-)
-- >8 -- Subject: abbrev: add FALLBACK_DEFAULT_ABBREV to prepare for auto sizing
We'll be introducing a new way to decide the default abbreviation length by initialising DEFAULT_ABBREV to -1 to signal the first call to "find unique abbreviation" codepath to compute a reasonable value based on the number of objects we have to avoid collisions.
We have long relied on DEFAULT_ABBREV being a positive concrete value that is used as the abbreviation length when no extra configuration or command line option has overridden it. Some codepaths wants to use such a positive concrete default value even before making their first request to actually trigger the computation for the auto sized default.
Introduce FALLBACK_DEFAULT_ABBREV and use it to the code that attempts to align the report from "git fetch". For now, this macro is also used to initialize the default_abbrev variable, but the auto-sizing code will use -1 and then use the value of FALLBACK_DEFAULT_ABBREV as the starting point of auto-sizing.
Signed-off-by: Junio C Hamano <gitster@pobox.com> ---
builtin/fetch.c | 3 +++ cache.h | 3 +++ environment.c | 2 +- transport.h | 3 +-- 4 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/builtin/fetch.c b/builtin/fetch.c index e4639d8eb1..5d6994d8e7 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -16,6 +16,9 @@ #include "connected.h" #include "argv-array.h" +#define TRANSPORT_SUMMARY(x) \ + (int)(TRANSPORT_SUMMARY_WIDTH + strlen(x) - gettext_width(x)), (x) + static const char * const builtin_fetch_usage[] = { N_("git fetch [<options>] [<repository> [<refspec>...]]"), N_("git fetch [<options>] <group>"), diff --git a/cache.h b/cache.h index 4ff196c259..677554c59f 100644 --- a/cache.h +++ b/cache.h @@ -1133,6 +1133,9 @@ static inline unsigned int hexval(unsigned char c) #define MINIMUM_ABBREV minimum_abbrev #define DEFAULT_ABBREV default_abbrev +/* used when the code does not know or care what the default abbrev is */ +#define FALLBACK_DEFAULT_ABBREV 7 + struct object_context { unsigned char tree[20]; char path[PATH_MAX]; diff --git a/environment.c b/environment.c index 96160a75a5..c8860f722d 100644 --- a/environment.c +++ b/environment.c @@ -16,7 +16,7 @@ int trust_executable_bit = 1; int trust_ctime = 1; int check_stat = 1; int has_symlinks = 1; -int minimum_abbrev = 4, default_abbrev = 7; +int minimum_abbrev = 4, default_abbrev = FALLBACK_DEFAULT_ABBREV; int ignore_case; int assume_unchanged; int prefer_symlink_refs; diff --git a/transport.h b/transport.h index c68140892c..ea25e42317 100644 --- a/transport.h +++ b/transport.h @@ -135,8 +135,7 @@ struct transport { #define TRANSPORT_PUSH_CERT_IF_ASKED 4096 #define TRANSPORT_PUSH_ATOMIC 8192 -#define TRANSPORT_SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3) -#define TRANSPORT_SUMMARY(x) (int)(TRANSPORT_SUMMARY_WIDTH + strlen(x) - gettext_width(x)), (x) +#define TRANSPORT_SUMMARY_WIDTH (2 * FALLBACK_DEFAULT_ABBREV + 3) /* Returns a transport suitable for the url */ struct transport *transport_get(struct remote *, const char *);