Re: [PATCH v4 1/9] sha1-array: provide oid_array_filter

> Helped-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  Documentation/technical/api-oid-array.txt |  5 +++++
>  sha1-array.c                              | 17 +++++++++++++++++
>  sha1-array.h                              |  3 +++
>  3 files changed, 25 insertions(+)

>
> diff --git a/Documentation/technical/api-oid-array.txt b/Documentation/technical/api-oid-array.txt
> index 9febfb1d528..c97428c2c34 100644
> --- a/Documentation/technical/api-oid-array.txt
> +++ b/Documentation/technical/api-oid-array.txt
> @@ -48,6 +48,11 @@ Functions
>  	is not sorted, this function has the side effect of sorting
>  	it.
>  
> +`oid_array_filter`::
> +	Apply the callback function `want` to each entry in the array,
> +	retaining only the entries for which the function returns true.
> +	Preserve the order of the entries that are retained.
> +
>  Examples
>  --------
>  
> diff --git a/sha1-array.c b/sha1-array.c
> index b94e0ec0f5e..d922e94e3fc 100644
> --- a/sha1-array.c
> +++ b/sha1-array.c
> @@ -77,3 +77,20 @@ int oid_array_for_each_unique(struct oid_array *array,
>  	}
>  	return 0;
>  }
> +
> +void oid_array_filter(struct oid_array *array,
> +		      for_each_oid_fn want,
> +		      void *cb_data)
> +{
> +	unsigned nr = array->nr, src, dst;
> +	struct object_id *oids = array->oid;
> +
> +	for (src = dst = 0; src < nr; src++) {
> +		if (want(&oids[src], cb_data)) {
> +			if (src != dst)
> +				oidcpy(&oids[dst], &oids[src]);
> +			dst++;
> +		}
> +	}
> +	array->nr = dst;
> +}
> diff --git a/sha1-array.h b/sha1-array.h
> index 232bf950172..55d016c4bf7 100644
> --- a/sha1-array.h
> +++ b/sha1-array.h
> @@ -22,5 +22,8 @@ int oid_array_for_each(struct oid_array *array,
>  int oid_array_for_each_unique(struct oid_array *array,
>  			      for_each_oid_fn fn,
>  			      void *data);
> +void oid_array_filter(struct oid_array *array,
> +		      for_each_oid_fn want,
> +		      void *cbdata);
>  
>  #endif /* SHA1_ARRAY_H */