Re: [PATCH v2 23/27] struct ref_update: Store refname as a FLEX_ARRAY.

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 1, 2014, 19:54 UTC
Message-ID: <xmqqd2h0zuyb.fsf@gitster.dls.corp.google.com>
In-Reply-To: <1395683820-17304-24-git-send-email-mhagger@alum.mit.edu>

Michael Haggerty <mhagger@alum.mit.edu> writes:

Show 20 quoted lines

> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
> ---
>  refs.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/refs.c b/refs.c
> index d72d0ab..2b80f6d 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -3274,11 +3274,11 @@ static int update_ref_write(const char *action, const char *refname,
>   * value or to zero to ensure the ref does not exist before update.
>   */
>  struct ref_update {
> -	const char *refname;
>  	unsigned char new_sha1[20];
>  	unsigned char old_sha1[20];
>  	int flags; /* REF_NODEREF? */
>  	int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
> +	const char refname[FLEX_ARRAY];
>  };

Yeah, as we no longer borrow a pointer but make our own copy since the earlier patch in the series, this perfectly makes sense.

Show 30 quoted lines

>  
>  /*
> @@ -3301,12 +3301,8 @@ static void ref_transaction_free(struct ref_transaction *transaction)
>  {
>  	int i;
>  
> -	for (i = 0; i < transaction->nr; i++) {
> -		struct ref_update *update = transaction->updates[i];
> -
> -		free((char *)update->refname);
> -		free(update);
> -	}
> +	for (i = 0; i < transaction->nr; i++)
> +		free(transaction->updates[i]);
>  
>  	free(transaction->updates);
>  	free(transaction);
> @@ -3320,9 +3316,10 @@ void ref_transaction_rollback(struct ref_transaction *transaction)
>  static struct ref_update *add_update(struct ref_transaction *transaction,
>  				     const char *refname)
>  {
> -	struct ref_update *update = xcalloc(1, sizeof(*update));
> +	size_t len = strlen(refname);
> +	struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
>  
> -	update->refname = xstrdup(refname);
> +	strcpy((char *)update->refname, refname);
>  	ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
>  	transaction->updates[transaction->nr++] = update;
>  	return update;