[PATCH/RFC/GSoC 13/17] rebase-todo: introduce rebase_todo_list

[Paul Tan <pyokagan@gmail.com>]

Implement rebase_todo_list, which is a resizable array of
rebase_todo_items.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
---
 rebase-todo.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 rebase-todo.h |  27 +++++++++++++++
 2 files changed, 134 insertions(+)

diff --git a/rebase-todo.c b/rebase-todo.c
index ac6b222..4f14638 100644
--- a/rebase-todo.c
+++ b/rebase-todo.c
@@ -142,3 +142,110 @@ void strbuf_add_rebase_todo_item(struct strbuf *sb,
 
 	strbuf_addch(sb, '\n');
 }
+
+void rebase_todo_list_init(struct rebase_todo_list *list)
+{
+	list->items = NULL;
+	list->nr = 0;
+	list->alloc = 0;
+}
+
+void rebase_todo_list_clear(struct rebase_todo_list *list)
+{
+	unsigned int i;
+
+	for (i = 0; i < list->nr; i++)
+		rebase_todo_item_release(&list->items[i]);
+	free(list->items);
+	rebase_todo_list_init(list);
+}
+
+void rebase_todo_list_swap(struct rebase_todo_list *dst,
+			   struct rebase_todo_list *src)
+{
+	struct rebase_todo_list tmp = *dst;
+
+	*dst = *src;
+	*src = tmp;
+}
+
+unsigned int rebase_todo_list_count(const struct rebase_todo_list *list)
+{
+	unsigned int i, count = 0;
+
+	for (i = 0; i < list->nr; i++)
+		if (list->items[i].action != REBASE_TODO_NONE)
+			count++;
+	return count;
+}
+
+struct rebase_todo_item *rebase_todo_list_push(struct rebase_todo_list *list, const struct rebase_todo_item *src_item)
+{
+	struct rebase_todo_item *item = rebase_todo_list_push_empty(list);
+
+	rebase_todo_item_copy(item, src_item);
+	return item;
+}
+
+struct rebase_todo_item *rebase_todo_list_push_empty(struct rebase_todo_list *list)
+{
+	struct rebase_todo_item *item;
+
+	ALLOC_GROW(list->items, list->nr + 1, list->alloc);
+	item = &list->items[list->nr++];
+	rebase_todo_item_init(item);
+	return item;
+}
+
+struct rebase_todo_item *rebase_todo_list_push_noop(struct rebase_todo_list *list)
+{
+	struct rebase_todo_item *item = rebase_todo_list_push_empty(list);
+
+	item->action = REBASE_TODO_NOOP;
+	return item;
+}
+
+int rebase_todo_list_load(struct rebase_todo_list *list, const char *path, int abbrev)
+{
+	struct strbuf sb = STRBUF_INIT;
+	FILE *fp;
+
+	fp = fopen(path, "r");
+	if (!fp)
+		return error(_("could not open %s for reading"), path);
+
+	while (strbuf_getline(&sb, fp) != EOF) {
+		struct rebase_todo_item *item = rebase_todo_list_push_empty(list);
+		if (rebase_todo_item_parse(item, sb.buf, abbrev) < 0) {
+			rebase_todo_item_release(item);
+			list->nr--;
+			strbuf_release(&sb);
+			fclose(fp);
+			return -1;
+		}
+	}
+	strbuf_release(&sb);
+	fclose(fp);
+	return 0;
+}
+
+void rebase_todo_list_save(const struct rebase_todo_list *list, const char *filename, unsigned int offset, int abbrev)
+{
+	char *tmpfile = mkpathdup("%s.new", filename);
+	struct strbuf sb = STRBUF_INIT;
+	int fd;
+
+	for (; offset < list->nr; offset++)
+		strbuf_add_rebase_todo_item(&sb, &list->items[offset], abbrev);
+
+	fd = xopen(tmpfile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+	if (write_in_full(fd, sb.buf, sb.len) != sb.len)
+		die_errno(_("could not write to %s"), tmpfile);
+	close(fd);
+	strbuf_release(&sb);
+
+	if (rename(tmpfile, filename))
+		die_errno(_("rename failed"));
+
+	free(tmpfile);
+}
diff --git a/rebase-todo.h b/rebase-todo.h
index 2eedbb0..f602fd2 100644
--- a/rebase-todo.h
+++ b/rebase-todo.h
@@ -25,4 +25,31 @@ int rebase_todo_item_parse(struct rebase_todo_item *, const char *line, int abbr
 
 void strbuf_add_rebase_todo_item(struct strbuf *, const struct rebase_todo_item *, int abbrev);
 
+struct rebase_todo_list {
+	struct rebase_todo_item *items;
+	unsigned int nr, alloc;
+};
+
+#define REBASE_TODO_LIST_INIT { NULL, 0, 0 }
+
+void rebase_todo_list_init(struct rebase_todo_list *);
+
+void rebase_todo_list_clear(struct rebase_todo_list *);
+
+void rebase_todo_list_swap(struct rebase_todo_list *dst, struct rebase_todo_list *src);
+
+unsigned int rebase_todo_list_count(const struct rebase_todo_list *);
+
+struct rebase_todo_item *rebase_todo_list_push(struct rebase_todo_list *,
+					       const struct rebase_todo_item *);
+
+struct rebase_todo_item *rebase_todo_list_push_empty(struct rebase_todo_list *);
+
+struct rebase_todo_item *rebase_todo_list_push_noop(struct rebase_todo_list *);
+
+int rebase_todo_list_load(struct rebase_todo_list *, const char *path, int abbrev);
+
+void rebase_todo_list_save(const struct rebase_todo_list *, const char *path,
+			   unsigned int offset, int abbrev);
+
 #endif /* REBASE_TODO_H */
-- 
2.7.0