1 files changed, 113 insertions, 0 deletions
diff --git a/src/elist.h b/src/elist.h
new file mode 100644
index 0000000..da6d172
--- /dev/null
+++ b/src/elist.h
@@ -0,0 +1,113 @@
+/*
+Copyright (C) 2016  Paweł Redman
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 3
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software Foundation,
+Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
+*/
+
+#define offsetin(V, M) ((size_t)&(V)->M - (size_t)(V))
+
+typedef struct {
+	void *prev, *next;
+} elist_header_t;
+
+static inline elist_header_t *elist_header(void *entry, size_t offs)
+{
+	return (elist_header_t*)((char*)entry + offs);
+}
+
+static inline void elist_append_real(void **head, void *entry, size_t offs)
+{
+	elist_header_t *head_header, *entry_header;
+
+	entry_header = elist_header(entry, offs);
+
+	if (!*head) {
+		*head = entry;
+		entry_header->prev = entry;
+		entry_header->next = NULL;
+		return;
+	}
+
+	head_header = elist_header(*head, offs);
+
+	entry_header->prev = head_header->prev;
+	if (head_header->prev)
+		elist_header(head_header->prev, offs)->next = entry;
+	head_header->prev = entry;
+
+	entry_header->next = NULL;
+}
+
+#define elist_append(head, entry, member) \
+elist_append_real((void**)(head), (entry), offsetin((entry), member))
+
+#define elist_next(entry, member) \
+(elist_header((entry), offsetin((entry), member))->next)
+
+#define elist_for(iter, head, member) \
+for ((iter) = (head); (iter); (iter) = elist_next((iter), member))
+
+static inline void elist_unlink_real(void **head, void *entry, size_t offs)
+{
+	elist_header_t *entry_header;
+
+	entry_header = elist_header(entry, offs);
+
+	if (entry_header->prev && *head != entry) {
+		elist_header_t *prev_header;
+		prev_header = elist_header(entry_header->prev, offs);
+		prev_header->next = entry_header->next;
+	}
+
+	if (entry_header->next) {
+		elist_header_t *next_header;
+		next_header = elist_header(entry_header->next, offs);
+		next_header->prev = entry_header->prev;
+	} else {
+		elist_header_t *head_header;
+		head_header = elist_header(*head, offs);
+		head_header->prev = entry_header->prev;
+	}
+
+	if (*head == entry)
+		*head = entry_header->next;
+
+}
+
+#define elist_unlink(head, entry, member) \
+elist_unlink_real((void**)(head), (entry), offsetin((entry), member))
+
+static inline void elist_append_list_real(void **head1, void *head2, size_t offs)
+{
+	elist_header_t *head1_header, *head2_header, *last1_header;
+
+	if (!*head1) {
+		*head1 = head2;
+		return;
+	}
+
+	if (!head2)
+		return;
+
+	head1_header = elist_header(head1, offs);
+	head2_header = elist_header(head2, offs);
+	last1_header = elist_header(head1_header->prev, offs);
+	head1_header->prev = head2_header->prev;
+	last1_header->next = head2;
+	head2_header->prev = head1_header->prev;
+}
+
+#define elist_append_list(head1, head2, member) \
+elist_append_list_real((void**)(head1), (head2), offsetin((head2), member))