Add list_head based double linked list

* src/list.h: New data structure.
src/Makefile.am (patch_SOURCES): Add list.h.

2 files changed, 57 insertions, 1 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index ee773cd..4fe71d2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -32,7 +32,8 @@ patch_SOURCES = \
 	util.c \
 	util.h \
 	version.c \
-	version.h
+	version.h \
+	list.h
 
 AM_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib
 patch_LDADD = $(LDADD) $(top_builddir)/lib/libpatch.a $(LIB_CLOCK_GETTIME) \
diff --git a/src/list.h b/src/list.h
new file mode 100644
index 0000000..11d1184
--- /dev/null
+++ b/src/list.h
@@ -0,0 +1,55 @@
+#ifndef __LIST_H
+#define __LIST_H
+
+#include <stdbool.h>
+
+struct list_head {
+  struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+  struct list_head name = LIST_HEAD_INIT(name)
+
+static inline void INIT_LIST_HEAD(struct list_head *list)
+{
+  list->next = list;
+  list->prev = list;
+}
+
+static inline void
+list_add (struct list_head *entry, struct list_head *head)
+{
+  struct list_head *next = head->next;
+  entry->prev = head;
+  entry->next = next;
+  next->prev = head->next = entry;
+}
+
+static inline void
+list_del (struct list_head *entry)
+{
+  struct list_head *next = entry->next;
+  struct list_head *prev = entry->prev;
+  next->prev = prev;
+  prev->next = next;
+}
+
+static inline void
+list_del_init (struct list_head *entry)
+{
+  list_del(entry);
+  INIT_LIST_HEAD(entry);
+}
+
+static inline bool
+list_empty (const struct list_head *head)
+{
+  return head->next == head;
+}
+
+#define list_entry(ptr, type, member) \
+  (type *)( (char *)(ptr) - offsetof(type, member) )
+
+#endif  /* __LIST_H */