libsmartcols: add scols_sort_table_by_tree()

Signed-off-by: Karel Zak <kzak@redhat.com>

libsmartcols/docs/libsmartcols-sections.txt

@@ -105,6 +105,7 @@ scols_copy_table
 scols_new_table
 scols_ref_table
 scols_sort_table
+scols_sort_table_by_tree
 scols_table_add_column
 scols_table_add_line
 scols_table_colors_wanted

libsmartcols/src/libsmartcols.h.in

@@ -268,7 +268,7 @@ extern FILE *scols_table_get_stream(const struct libscols_table *tb);
 extern int scols_table_reduce_termwidth(struct libscols_table *tb, size_t reduce);
 
 extern int scols_sort_table(struct libscols_table *tb, struct libscols_column *cl);
-
+extern int scols_sort_table_by_tree(struct libscols_table *tb);
 /*
  *
  */

libsmartcols/src/libsmartcols.sym

@@ -163,4 +163,5 @@ SMARTCOLS_2.30 {
 global:
 	scols_cell_get_alignment;
 	scols_table_move_column;
+	scols_sort_table_by_tree;
 } SMARTCOLS_2.29;

libsmartcols/src/table.c

@@ -1285,7 +1285,8 @@ static int sort_line_children(struct libscols_line *ln, struct libscols_column *
  * @tb: table
  * @cl: order by this column
  *
- * Orders the table by the column. See also scols_column_set_cmpfunc().
+ * Orders the table by the column. See also scols_column_set_cmpfunc(). If the
+ * tree output is enabled then children in the tree are recursively sorted too.
  *
  * Returns: 0, a negative value in case of an error.
  */
@@ -1309,6 +1310,58 @@ int scols_sort_table(struct libscols_table *tb, struct libscols_column *cl)
 	return 0;
 }
 
+static struct libscols_line *move_line_and_children(struct libscols_line *ln, struct libscols_line *pre)
+{
+	if (pre) {
+		list_del_init(&ln->ln_lines);			/* remove from old position */
+	        list_add(&ln->ln_lines, &pre->ln_lines);        /* add to the new place (behind @pre) */
+	}
+	pre = ln;
+
+	if (!list_empty(&ln->ln_branch)) {
+		struct list_head *p;
+
+		list_for_each(p, &ln->ln_branch) {
+			struct libscols_line *chld =
+					list_entry(p, struct libscols_line, ln_children);
+			pre = move_line_and_children(chld, pre);
+		}
+	}
+
+	return pre;
+}
+
+/**
+ * scols_sort_table_by_tree:
+ * @tb: table
+ *
+ * Reorders lines in the tree according to parent->child relation. Note that
+ * order of lines in the table is independent on the tree hierarchy.
+ *
+ * Returns: 0, a negative value in case of an error.
+ */
+int scols_sort_table_by_tree(struct libscols_table *tb)
+{
+	struct libscols_line *ln;
+	struct libscols_iter itr;
+
+	if (!tb)
+		return -EINVAL;
+
+	DBG(TAB, ul_debugobj(tb, "sorting table by tree"));
+
+	scols_reset_iter(&itr, SCOLS_ITER_FORWARD);
+	while (scols_table_next_line(tb, &itr, &ln) == 0) {
+		if (ln->parent)
+			continue;
+
+		move_line_and_children(ln, NULL);
+	}
+
+	return 0;
+}
+
+
 /**
  * scols_table_set_termforce:
  * @tb: table