Subject: Re: [PATCH v2 2/8] sha1-array: Implement oid_array_readonly_contains

From: SZEDER Gábor <[email-masked]>
Date: Mon, 28 Jan 2019 14:05:13 +0100

On Sun, Jan 27, 2019 at 11:41:22AM -0800, [email-masked] wrote:
> From: Stefan Xenos <[email-masked]>
> 
> Implement a "readonly_contains" function for oid_array that won't
> sort the array if it is unsorted. This can be used to test containment in
> the rare situations where the array order matters.
> 
> The function has intentionally been given a name that is more cumbersome
> than the "lookup" function, which is what most callers will will want
> in most situations.
> 
> Signed-off-by: Stefan Xenos <[email-masked]>
> ---
>  sha1-array.c               | 15 +++++++++++++++
>  sha1-array.h               |  2 ++
>  t/helper/test-sha1-array.c |  6 ++++++
>  t/t0064-sha1-array.sh      | 22 ++++++++++++++++++++++
>  4 files changed, 45 insertions(+)
> 
> diff --git a/sha1-array.c b/sha1-array.c
> index b94e0ec0f5..071fce7e90 100644
> --- a/sha1-array.c
> +++ b/sha1-array.c
> @@ -26,6 +26,21 @@ static const unsigned char *sha1_access(size_t index, void *table)
>  	return array[index].hash;
>  }
>  
> +int oid_array_readonly_contains(const struct oid_array* array,
> +	const struct object_id* oid)
> +{
> +	int i;
> +	if (array->sorted) {
> +		return sha1_pos(oid->hash, array->oid, array->nr, sha1_access) >= 0;
> +	}

Style nit: unnecessary braces.  According to CodingGuidelines we tend
not to use braces when the body of a loop or if statement is only a
single line.

> +	for (i = 0; i < array->nr; i++) {
> +		if (hashcmp(array->oid[i].hash, oid->hash) == 0) {

Please use oideq() instead.

> +			return 1;
> +		}
> +	}
> +	return 0;
> +}
> +
>  int oid_array_lookup(struct oid_array *array, const struct object_id *oid)
>  {
>  	if (!array->sorted)

> diff --git a/t/t0064-sha1-array.sh b/t/t0064-sha1-array.sh
> index 5dda570b9a..c1bac6fcdd 100755
> --- a/t/t0064-sha1-array.sh
> +++ b/t/t0064-sha1-array.sh
> @@ -32,6 +32,28 @@ test_expect_success 'ordered enumeration with duplicate suppression' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'readonly_contains finds existing' '
> +	echo 1 > expect &&
> +	echoid "" 88 44 aa 55 >> expect &&

Style nit: not space between redirection operator and filename.

> +	{
> +		echoid append 88 44 aa 55 &&
> +		echoid readonly_contains 55 &&
> +		echo for_each
> +	} | test-tool sha1-array >actual &&
> +	test_cmp expect actual
> +'
> +
> +test_expect_success 'readonly_contains non-existing query' '
> +	echo 0 > expect &&
> +	echoid "" 88 44 aa 55 >> expect &&
> +	{
> +		echoid append 88 44 aa 55 &&
> +		echoid readonly_contains 33 &&
> +		echo for_each
> +	} | test-tool sha1-array >actual &&
> +	test_cmp expect actual
> +'
> +
>  test_expect_success 'lookup' '
>  	{
>  		echoid append 88 44 aa 55 &&
> -- 
> 2.20.1.495.gaa96b0ce6b-goog
>