Introduce signed range.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

MST: split up patch

include/qemu/range.h

@@ -3,6 +3,7 @@
 
 #include <inttypes.h>
 #include <qemu/typedefs.h>
+#include "qemu/queue.h"
 
 /*
  * Operations on 64 bit address ranges.
@@ -60,4 +61,75 @@ static inline int ranges_overlap(uint64_t first1, uint64_t len1,
     return !(last2 < first1 || last1 < first2);
 }
 
+/* 0,1 can merge with 1,2 but don't overlap */
+static inline bool ranges_can_merge(Range *range1, Range *range2)
+{
+    return !(range1->end < range2->begin || range2->end < range1->begin);
+}
+
+static inline int range_merge(Range *range1, Range *range2)
+{
+    if (ranges_can_merge(range1, range2)) {
+        if (range1->end < range2->end) {
+            range1->end = range2->end;
+        }
+        if (range1->begin > range2->begin) {
+            range1->begin = range2->begin;
+        }
+        return 0;
+    }
+
+    return -1;
+}
+
+static inline GList *g_list_insert_sorted_merged(GList *list,
+                                                 gpointer data,
+                                                 GCompareFunc func)
+{
+    GList *l, *next = NULL;
+    Range *r, *nextr;
+
+    if (!list) {
+        list = g_list_insert_sorted(list, data, func);
+        return list;
+    }
+
+    nextr = data;
+    l = list;
+    while (l && l != next && nextr) {
+        r = l->data;
+        if (ranges_can_merge(r, nextr)) {
+            range_merge(r, nextr);
+            l = g_list_remove_link(l, next);
+            next = g_list_next(l);
+            if (next) {
+                nextr = next->data;
+            } else {
+                nextr = NULL;
+            }
+        } else {
+            l = g_list_next(l);
+        }
+    }
+
+    if (!l) {
+        list = g_list_insert_sorted(list, data, func);
+    }
+
+    return list;
+}
+
+static inline gint range_compare(gconstpointer a, gconstpointer b)
+{
+    Range *ra = (Range *)a, *rb = (Range *)b;
+    if (ra->begin == rb->begin && ra->end == rb->end) {
+        return 0;
+    } else if (range_get_last(ra->begin, ra->end) <
+               range_get_last(rb->begin, rb->end)) {
+        return -1;
+    } else {
+        return 1;
+    }
+}
+
 #endif