Subject: Re: [PATCH v3 19/44] refs-be-files.c: add a backend method structure with transaction functions

From: David Turner <[email-masked]>
Date: Mon, 12 Oct 2015 18:25:06 -0400

Please disregard this one; I rewrorded the commit message and forgot to
delete this patch.  

On Mon, 2015-10-12 at 17:51 -0400, David Turner wrote:
> From: Ronnie Sahlberg <[email-masked]>
> 
> Add a ref structure for backend methods. Start by adding a method pointer
> for the transaction commit function.
> 
> Add a function set_refs_backend to switch between backends. The files
> based backend is the default.
> 
> Signed-off-by: Ronnie Sahlberg <[email-masked]>
> Signed-off-by: David Turner <[email-masked]>
> ---
>  refs-be-files.c | 10 ++++++++--
>  refs.c          | 30 ++++++++++++++++++++++++++++++
>  refs.h          | 15 +++++++++++++++
>  3 files changed, 53 insertions(+), 2 deletions(-)
> 
> diff --git a/refs-be-files.c b/refs-be-files.c
> index 1308955..3050f1d 100644
> --- a/refs-be-files.c
> +++ b/refs-be-files.c
> @@ -3225,8 +3225,8 @@ static int ref_update_reject_duplicates(struct string_list *refnames,
>  	return 0;
>  }
>  
> -int ref_transaction_commit(struct ref_transaction *transaction,
> -			   struct strbuf *err)
> +static int files_transaction_commit(struct ref_transaction *transaction,
> +				    struct strbuf *err)
>  {
>  	int ret = 0, i;
>  	int n = transaction->nr;
> @@ -3612,3 +3612,9 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
>  	unlock_ref(lock);
>  	return -1;
>  }
> +
> +struct ref_be refs_be_files = {
> +	NULL,
> +	"files",
> +	files_transaction_commit,
> +};
> diff --git a/refs.c b/refs.c
> index 25ad3b5..f930fe0 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -4,6 +4,29 @@
>  #include "cache.h"
>  #include "refs.h"
>  #include "lockfile.h"
> +/*
> + * We always have a files backend and it is the default.
> + */
> +struct ref_be *the_refs_backend = &refs_be_files;
> +/*
> + * List of all available backends
> + */
> +struct ref_be *refs_backends = &refs_be_files;
> +
> +/*
> + * This function is used to switch to an alternate backend.
> + */
> +int set_refs_backend(const char *name)
> +{
> +	struct ref_be *be;
> +
> +	for (be = refs_backends; be; be = be->next)
> +		if (!strcmp(be->name, name)) {
> +			the_refs_backend = be;
> +			return 0;
> +		}
> +	return 1;
> +}
>  
>  static int is_per_worktree_ref(const char *refname)
>  {
> @@ -985,3 +1008,10 @@ int ref_transaction_verify(struct ref_transaction *transaction,
>  				      NULL, old_sha1,
>  				      flags, NULL, err);
>  }
> +
> +/* backend functions */
> +int ref_transaction_commit(struct ref_transaction *transaction,
> +			   struct strbuf *err)
> +{
> +	return the_refs_backend->transaction_commit(transaction, err);
> +}
> diff --git a/refs.h b/refs.h
> index 4940ae9..419abf4 100644
> --- a/refs.h
> +++ b/refs.h
> @@ -619,4 +619,19 @@ extern int reflog_expire(const char *refname, const unsigned char *sha1,
>  			 reflog_expiry_cleanup_fn cleanup_fn,
>  			 void *policy_cb_data);
>  
> +/* refs backends */
> +typedef int ref_transaction_commit_fn(struct ref_transaction *transaction,
> +				      struct strbuf *err);
> +typedef void ref_transaction_free_fn(struct ref_transaction *transaction);
> +
> +struct ref_be {
> +	struct ref_be *next;
> +	const char *name;
> +	ref_transaction_commit_fn *transaction_commit;
> +};
> +
> +
> +extern struct ref_be refs_be_files;
> +int set_refs_backend(const char *name);
> +
>  #endif /* REFS_H */