Re: [PATCH v2 05/27] upload-pack: factor out processing lines

[Stefan Beller <sbeller@google.com>]

On Thu, Jan 25, 2018 at 3:58 PM, Brandon Williams <bmwill@google.com> wrote:
> Factor out the logic for processing shallow, deepen, deepen_since, and
> deepen_not lines into their own functions to simplify the
> 'receive_needs()' function in addition to making it easier to reuse some
> of this logic when implementing protocol_v2.
>
> Signed-off-by: Brandon Williams <bmwill@google.com>
> ---
>  upload-pack.c | 113 ++++++++++++++++++++++++++++++++++++++--------------------
>  1 file changed, 74 insertions(+), 39 deletions(-)
>
> diff --git a/upload-pack.c b/upload-pack.c
> index 2ad73a98b..42d83d5b1 100644
> --- a/upload-pack.c
> +++ b/upload-pack.c
> @@ -724,6 +724,75 @@ static void deepen_by_rev_list(int ac, const char **av,
>         packet_flush(1);
>  }
>
> +static int process_shallow(const char *line, struct object_array *shallows)
> +{
> +       const char *arg;
> +       if (skip_prefix(line, "shallow ", &arg)) {

stylistic nit:

    You could invert the condition in each of the process_* functions
    to just have

        if (!skip_prefix...))
            return 0

        /* less indented code goes here */

        return 1;

    That way we have less indentation as well as easier code.
    (The reader doesn't need to keep in mind what the else
    part is about; it is a rather local decision to bail out instead
    of having the return at the end of the function.)

> +               struct object_id oid;
> +               struct object *object;
> +               if (get_oid_hex(arg, &oid))
> +                       die("invalid shallow line: %s", line);
> +               object = parse_object(&oid);
> +               if (!object)
> +                       return 1;
> +               if (object->type != OBJ_COMMIT)
> +                       die("invalid shallow object %s", oid_to_hex(&oid));
> +               if (!(object->flags & CLIENT_SHALLOW)) {
> +                       object->flags |= CLIENT_SHALLOW;
> +                       add_object_array(object, NULL, shallows);
> +               }
> +               return 1;
> +       }
> +
> +       return 0;
> +}
> +
> +static int process_deepen(const char *line, int *depth)
> +{
> +       const char *arg;
> +       if (skip_prefix(line, "deepen ", &arg)) {
> +               char *end = NULL;
> +               *depth = (int) strtol(arg, &end, 0);
> +               if (!end || *end || *depth <= 0)
> +                       die("Invalid deepen: %s", line);
> +               return 1;
> +       }
> +
> +       return 0;
> +}
> +
> +static int process_deepen_since(const char *line, timestamp_t *deepen_since, int *deepen_rev_list)
> +{
> +       const char *arg;
> +       if (skip_prefix(line, "deepen-since ", &arg)) {
> +               char *end = NULL;
> +               *deepen_since = parse_timestamp(arg, &end, 0);
> +               if (!end || *end || !deepen_since ||
> +                   /* revisions.c's max_age -1 is special */
> +                   *deepen_since == -1)
> +                       die("Invalid deepen-since: %s", line);
> +               *deepen_rev_list = 1;
> +               return 1;
> +       }
> +       return 0;
> +}
> +
> +static int process_deepen_not(const char *line, struct string_list *deepen_not, int *deepen_rev_list)
> +{
> +       const char *arg;
> +       if (skip_prefix(line, "deepen-not ", &arg)) {
> +               char *ref = NULL;
> +               struct object_id oid;
> +               if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
> +                       die("git upload-pack: ambiguous deepen-not: %s", line);
> +               string_list_append(deepen_not, ref);
> +               free(ref);
> +               *deepen_rev_list = 1;
> +               return 1;
> +       }
> +       return 0;
> +}
> +
>  static void receive_needs(void)
>  {
>         struct object_array shallows = OBJECT_ARRAY_INIT;
> @@ -745,49 +814,15 @@ static void receive_needs(void)
>                 if (!line)
>                         break;
>
> -               if (skip_prefix(line, "shallow ", &arg)) {
> -                       struct object_id oid;
> -                       struct object *object;
> -                       if (get_oid_hex(arg, &oid))
> -                               die("invalid shallow line: %s", line);
> -                       object = parse_object(&oid);
> -                       if (!object)
> -                               continue;
> -                       if (object->type != OBJ_COMMIT)
> -                               die("invalid shallow object %s", oid_to_hex(&oid));
> -                       if (!(object->flags & CLIENT_SHALLOW)) {
> -                               object->flags |= CLIENT_SHALLOW;
> -                               add_object_array(object, NULL, &shallows);
> -                       }
> +               if (process_shallow(line, &shallows))
>                         continue;
> -               }
> -               if (skip_prefix(line, "deepen ", &arg)) {
> -                       char *end = NULL;
> -                       depth = strtol(arg, &end, 0);
> -                       if (!end || *end || depth <= 0)
> -                               die("Invalid deepen: %s", line);
> +               if (process_deepen(line, &depth))
>                         continue;
> -               }
> -               if (skip_prefix(line, "deepen-since ", &arg)) {
> -                       char *end = NULL;
> -                       deepen_since = parse_timestamp(arg, &end, 0);
> -                       if (!end || *end || !deepen_since ||
> -                           /* revisions.c's max_age -1 is special */
> -                           deepen_since == -1)
> -                               die("Invalid deepen-since: %s", line);
> -                       deepen_rev_list = 1;
> +               if (process_deepen_since(line, &deepen_since, &deepen_rev_list))
>                         continue;
> -               }
> -               if (skip_prefix(line, "deepen-not ", &arg)) {
> -                       char *ref = NULL;
> -                       struct object_id oid;
> -                       if (expand_ref(arg, strlen(arg), &oid, &ref) != 1)
> -                               die("git upload-pack: ambiguous deepen-not: %s", line);
> -                       string_list_append(&deepen_not, ref);
> -                       free(ref);
> -                       deepen_rev_list = 1;
> +               if (process_deepen_not(line, &deepen_not, &deepen_rev_list))
>                         continue;
> -               }
> +
>                 if (!skip_prefix(line, "want ", &arg) ||
>                     get_oid_hex(arg, &oid_buf))
>                         die("git upload-pack: protocol error, "
> --
> 2.16.0.rc1.238.g530d649a79-goog
>