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

From: Brandon Williams <[email-masked]>
Date: Fri, 26 Jan 2018 13:33:38 -0800

On 01/26, Stefan Beller wrote:
> On Thu, Jan 25, 2018 at 3:58 PM, Brandon Williams <[email-masked]> 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 <[email-masked]>
> > ---
> >  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.)

I was trying to move the existing code into helper functions so
rewriting them in transit may make it less reviewable?

> 
> > +               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
> >

-- 
Brandon Williams