trailer: process trailers from input message and arguments
authorChristian Couder <chriscool@tuxfamily.org>
Mon, 13 Oct 2014 18:16:24 +0000 (20:16 +0200)
committerJunio C Hamano <gitster@pobox.com>
Mon, 13 Oct 2014 20:55:26 +0000 (13:55 -0700)
Implement the logic to process trailers from the input message
and from arguments.

At the beginning trailers from the input message are in their
own "in_tok" doubly linked list, and trailers from arguments
are in their own "arg_tok" doubly linked list.

The lists are traversed and when an "arg_tok" should be "applied",
it is removed from its list and inserted into the "in_tok" list.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
trailer.c
index ac323b12010ead397105d32b1bc94256fcb0ff8c..be0ad6558db75b11cb7a388b40ad7f0be5ed1d90 100644 (file)
--- a/trailer.c
+++ b/trailer.c
@@ -67,3 +67,213 @@ static int same_trailer(struct trailer_item *a, struct trailer_item *b)
 {
        return same_token(a, b) && same_value(a, b);
 }
+
+static void free_trailer_item(struct trailer_item *item)
+{
+       free(item->conf.name);
+       free(item->conf.key);
+       free(item->conf.command);
+       free((char *)item->token);
+       free((char *)item->value);
+       free(item);
+}
+
+static void update_last(struct trailer_item **last)
+{
+       if (*last)
+               while ((*last)->next != NULL)
+                       *last = (*last)->next;
+}
+
+static void update_first(struct trailer_item **first)
+{
+       if (*first)
+               while ((*first)->previous != NULL)
+                       *first = (*first)->previous;
+}
+
+static void add_arg_to_input_list(struct trailer_item *on_tok,
+                                 struct trailer_item *arg_tok,
+                                 struct trailer_item **first,
+                                 struct trailer_item **last)
+{
+       if (after_or_end(arg_tok->conf.where)) {
+               arg_tok->next = on_tok->next;
+               on_tok->next = arg_tok;
+               arg_tok->previous = on_tok;
+               if (arg_tok->next)
+                       arg_tok->next->previous = arg_tok;
+               update_last(last);
+       } else {
+               arg_tok->previous = on_tok->previous;
+               on_tok->previous = arg_tok;
+               arg_tok->next = on_tok;
+               if (arg_tok->previous)
+                       arg_tok->previous->next = arg_tok;
+               update_first(first);
+       }
+}
+
+static int check_if_different(struct trailer_item *in_tok,
+                             struct trailer_item *arg_tok,
+                             int check_all)
+{
+       enum action_where where = arg_tok->conf.where;
+       do {
+               if (!in_tok)
+                       return 1;
+               if (same_trailer(in_tok, arg_tok))
+                       return 0;
+               /*
+                * if we want to add a trailer after another one,
+                * we have to check those before this one
+                */
+               in_tok = after_or_end(where) ? in_tok->previous : in_tok->next;
+       } while (check_all);
+       return 1;
+}
+
+static void remove_from_list(struct trailer_item *item,
+                            struct trailer_item **first,
+                            struct trailer_item **last)
+{
+       struct trailer_item *next = item->next;
+       struct trailer_item *previous = item->previous;
+
+       if (next) {
+               item->next->previous = previous;
+               item->next = NULL;
+       } else if (last)
+               *last = previous;
+
+       if (previous) {
+               item->previous->next = next;
+               item->previous = NULL;
+       } else if (first)
+               *first = next;
+}
+
+static struct trailer_item *remove_first(struct trailer_item **first)
+{
+       struct trailer_item *item = *first;
+       *first = item->next;
+       if (item->next) {
+               item->next->previous = NULL;
+               item->next = NULL;
+       }
+       return item;
+}
+
+static void apply_arg_if_exists(struct trailer_item *in_tok,
+                               struct trailer_item *arg_tok,
+                               struct trailer_item *on_tok,
+                               struct trailer_item **in_tok_first,
+                               struct trailer_item **in_tok_last)
+{
+       switch (arg_tok->conf.if_exists) {
+       case EXISTS_DO_NOTHING:
+               free_trailer_item(arg_tok);
+               break;
+       case EXISTS_REPLACE:
+               add_arg_to_input_list(on_tok, arg_tok,
+                                     in_tok_first, in_tok_last);
+               remove_from_list(in_tok, in_tok_first, in_tok_last);
+               free_trailer_item(in_tok);
+               break;
+       case EXISTS_ADD:
+               add_arg_to_input_list(on_tok, arg_tok,
+                                     in_tok_first, in_tok_last);
+               break;
+       case EXISTS_ADD_IF_DIFFERENT:
+               if (check_if_different(in_tok, arg_tok, 1))
+                       add_arg_to_input_list(on_tok, arg_tok,
+                                             in_tok_first, in_tok_last);
+               else
+                       free_trailer_item(arg_tok);
+               break;
+       case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR:
+               if (check_if_different(on_tok, arg_tok, 0))
+                       add_arg_to_input_list(on_tok, arg_tok,
+                                             in_tok_first, in_tok_last);
+               else
+                       free_trailer_item(arg_tok);
+               break;
+       }
+}
+
+static void apply_arg_if_missing(struct trailer_item **in_tok_first,
+                                struct trailer_item **in_tok_last,
+                                struct trailer_item *arg_tok)
+{
+       struct trailer_item **in_tok;
+       enum action_where where;
+
+       switch (arg_tok->conf.if_missing) {
+       case MISSING_DO_NOTHING:
+               free_trailer_item(arg_tok);
+               break;
+       case MISSING_ADD:
+               where = arg_tok->conf.where;
+               in_tok = after_or_end(where) ? in_tok_last : in_tok_first;
+               if (*in_tok) {
+                       add_arg_to_input_list(*in_tok, arg_tok,
+                                             in_tok_first, in_tok_last);
+               } else {
+                       *in_tok_first = arg_tok;
+                       *in_tok_last = arg_tok;
+               }
+               break;
+       }
+}
+
+static int find_same_and_apply_arg(struct trailer_item **in_tok_first,
+                                  struct trailer_item **in_tok_last,
+                                  struct trailer_item *arg_tok)
+{
+       struct trailer_item *in_tok;
+       struct trailer_item *on_tok;
+       struct trailer_item *following_tok;
+
+       enum action_where where = arg_tok->conf.where;
+       int middle = (where == WHERE_AFTER) || (where == WHERE_BEFORE);
+       int backwards = after_or_end(where);
+       struct trailer_item *start_tok = backwards ? *in_tok_last : *in_tok_first;
+
+       for (in_tok = start_tok; in_tok; in_tok = following_tok) {
+               following_tok = backwards ? in_tok->previous : in_tok->next;
+               if (!same_token(in_tok, arg_tok))
+                       continue;
+               on_tok = middle ? in_tok : start_tok;
+               apply_arg_if_exists(in_tok, arg_tok, on_tok,
+                                   in_tok_first, in_tok_last);
+               return 1;
+       }
+       return 0;
+}
+
+static void process_trailers_lists(struct trailer_item **in_tok_first,
+                                  struct trailer_item **in_tok_last,
+                                  struct trailer_item **arg_tok_first)
+{
+       struct trailer_item *arg_tok;
+       struct trailer_item *next_arg;
+
+       if (!*arg_tok_first)
+               return;
+
+       for (arg_tok = *arg_tok_first; arg_tok; arg_tok = next_arg) {
+               int applied = 0;
+
+               next_arg = arg_tok->next;
+               remove_from_list(arg_tok, arg_tok_first, NULL);
+
+               applied = find_same_and_apply_arg(in_tok_first,
+                                                 in_tok_last,
+                                                 arg_tok);
+
+               if (!applied)
+                       apply_arg_if_missing(in_tok_first,
+                                            in_tok_last,
+                                            arg_tok);
+       }
+}