Re: [PATCH] fetch: remove fetch_if_missing=0

From: Junio C Hamano <gitster@pobox.com>
To: Jonathan Nieder <jrnieder@gmail.com>
Cc: Jonathan Tan <jonathantanmy@google.com>, git@vger.kernel.org
Subject: Re: [PATCH] fetch: remove fetch_if_missing=0
Date: Sat, 02 Nov 2019 14:55:10 +0900	[thread overview]
Message-ID: <xmqqv9s23jr5.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <20191101220537.GA249573@google.com> (Jonathan Nieder's message of "Fri, 1 Nov 2019 15:05:37 -0700")

Jonathan Nieder <jrnieder@gmail.com> writes:

>> @@ -1755,8 +1756,6 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
>>  
>>  	packet_trace_identity("fetch");
>>  
>> -	fetch_if_missing = 0;
>> -
>
> This is the scary part, but in an "uncomfortably exciting" sense rather
> than a worrying one.  Thanks for adding a test.
>
> [...]
>> --- a/fetch-pack.c
>> +++ b/fetch-pack.c
>> @@ -673,7 +673,8 @@ static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
>>  		struct object *o;
>>  
>>  		if (!has_object_file_with_flags(&ref->old_oid,
>> -						OBJECT_INFO_QUICK))
>> +						OBJECT_INFO_QUICK |
>> +							OBJECT_INFO_SKIP_FETCH_OBJECT))
>
> Should we make OBJECT_INFO_QUICK always imply
> OBJECT_INFO_SKIP_FETCH_OBJECT?  I would suspect that if we are willing to
> avoid checking thoroughly locally, checking remotely would be even more
> undesirable.

I think I've seen this mentioned a few times during this cycle in
the list archive ;-)

>> +	for i in $(seq 1 100)
>> +	do
>> +		echo line $i >>big-blob.txt
>> +	done &&
>
> Should this use test_seq for better portability?

Yup.

> nit: can avoid a subshell:
>
> 	test_seq 1 100 | sed -e 's/^/line /' >big-blob.txt

Yeah, but it costs process start-up and "sed" that may be rather
heavyweight.  At least

	for i in $(test_seq ...)
	do
		echo line $i
	done >big-blob.txt

would save repeated opening and closing the file, I'd think.

>> +	git hash-object big-blob.txt >hash &&
>> +	grep "want $(cat hash)" trace
>
> nit: can avoid using cat:
>
> 	hash=$(git hash-object big-blob.txt) &&
> 	grep "want $hash" trace
>
> Thanks and hope that helps,

Thanks, both.