Implement the logic to process trailers from stdin and arguments.
At the beginning trailers from stdin 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@xxxxxxxxxxxxx>
---
trailer.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 198 insertions(+)
diff --git a/trailer.c b/trailer.c
index db93a63..52108c2 100644
--- a/trailer.c
+++ b/trailer.c
@@ -47,3 +47,201 @@ static size_t alnum_len(const char *buf, size_t len)
len--;
return len;
}
+
+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 add_arg_to_input_list(struct trailer_item *in_tok,
+ struct trailer_item *arg_tok)
+{
+ if (arg_tok->conf.where == WHERE_AFTER) {
+ arg_tok->next = in_tok->next;
+ in_tok->next = arg_tok;
+ arg_tok->previous = in_tok;
+ if (arg_tok->next)
+ arg_tok->next->previous = arg_tok;
+ } else {
+ arg_tok->previous = in_tok->previous;
+ in_tok->previous = arg_tok;
+ arg_tok->next = in_tok;
+ if (arg_tok->previous)
+ arg_tok->previous->next = arg_tok;
+ }
+}
+
+static int check_if_different(struct trailer_item *in_tok,
+ struct trailer_item *arg_tok,
+ int alnum_len, int check_all)
+{
+ enum action_where where = arg_tok->conf.where;
+ do {
+ if (!in_tok)
+ return 1;
+ if (same_trailer(in_tok, arg_tok, alnum_len))
+ return 0;
+ /*
+ * if we want to add a trailer after another one,
+ * we have to check those before this one
+ */
+ in_tok = (where == WHERE_AFTER) ? in_tok->previous : in_tok->next;
+ } while (check_all);
+ return 1;
+}
+
+static void apply_arg_if_exists(struct trailer_item *in_tok,
+ struct trailer_item *arg_tok,
+ int alnum_len)
+{
+ switch (arg_tok->conf.if_exists) {
+ case EXISTS_DO_NOTHING:
+ free_trailer_item(arg_tok);
+ break;
+ case EXISTS_OVERWRITE:
+ free((char *)in_tok->value);
+ in_tok->value = xstrdup(arg_tok->value);
+ free_trailer_item(arg_tok);
+ break;
+ case EXISTS_ADD:
+ add_arg_to_input_list(in_tok, arg_tok);
+ break;
+ case EXISTS_ADD_IF_DIFFERENT:
+ if (check_if_different(in_tok, arg_tok, alnum_len, 1))
+ add_arg_to_input_list(in_tok, arg_tok);
+ else
+ free_trailer_item(arg_tok);
+ break;
+ case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR:
+ if (check_if_different(in_tok, arg_tok, alnum_len, 0))
+ add_arg_to_input_list(in_tok, arg_tok);
+ else
+ free_trailer_item(arg_tok);
+ break;
+ }
+}
+
+static void remove_from_list(struct trailer_item *item,
+ struct trailer_item **first)
+{
+ if (item->next)
+ item->next->previous = item->previous;
+ if (item->previous)
+ item->previous->next = item->next;
+ else
+ *first = item->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 process_input_token(struct trailer_item *in_tok,
+ struct trailer_item **arg_tok_first,
+ enum action_where where)
+{
+ struct trailer_item *arg_tok;
+ struct trailer_item *next_arg;
+
+ int after = where == WHERE_AFTER;
+ int tok_alnum_len = alnum_len(in_tok->token, strlen(in_tok->token));
+
+ for (arg_tok = *arg_tok_first; arg_tok; arg_tok = next_arg) {
+ next_arg = arg_tok->next;
+ if (!same_token(in_tok, arg_tok, tok_alnum_len))
+ continue;
+ if (arg_tok->conf.where != where)
+ continue;
+ remove_from_list(arg_tok, arg_tok_first);
+ apply_arg_if_exists(in_tok, arg_tok, tok_alnum_len);
+ /*
+ * If arg has been added to input,
+ * then we need to process it too now.
+ */
+ if ((after ? in_tok->next : in_tok->previous) == arg_tok)
+ in_tok = arg_tok;
+ }
+}
+
+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 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 = (where == WHERE_AFTER) ? in_tok_last : in_tok_first;
+ if (*in_tok) {
+ add_arg_to_input_list(*in_tok, arg_tok);
+ *in_tok = arg_tok;
+ } else {
+ *in_tok_first = arg_tok;
+ *in_tok_last = arg_tok;
+ }
+ break;
+ }
+}
+
+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 *in_tok;
+ struct trailer_item *arg_tok;
+
+ if (!*arg_tok_first)
+ return;
+
+ /* Process input from end to start */
+ for (in_tok = *in_tok_last; in_tok; in_tok = in_tok->previous)
+ process_input_token(in_tok, arg_tok_first, WHERE_AFTER);
+
+ update_last(in_tok_last);
+
+ if (!*arg_tok_first)
+ return;
+
+ /* Process input from start to end */
+ for (in_tok = *in_tok_first; in_tok; in_tok = in_tok->next)
+ process_input_token(in_tok, arg_tok_first, WHERE_BEFORE);
+
+ update_first(in_tok_first);
+
+ /* Process args left */
+ while (*arg_tok_first) {
+ arg_tok = remove_first(arg_tok_first);
+ apply_arg_if_missing(in_tok_first, in_tok_last, arg_tok);
+ }
+}
--
1.9.0.164.g3aa33cd.dirty
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