[Qemu-devel] [PATCH v1 4/7] range: add some more functions

[David Hildenbrand <david@redhat.com>]

Add some more functions that will be used in memory-device context.

range_init(): Init using lower bound and size
range_valid(): Check if there would be an overflow when initializin
range_size(): Extract the size of a range
range_overlaps_range(): Check for overlaps of two ranges
range_contains_range(): Check if one range is contained in the other
range_starts_before_range(): Check if one range starts before another
range_ends_after_range(): Check if one range ends after another

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 include/qemu/range.h | 80 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/include/qemu/range.h b/include/qemu/range.h
index 7e75f4e655..18e8acf22f 100644
--- a/include/qemu/range.h
+++ b/include/qemu/range.h
@@ -112,6 +112,86 @@ static inline uint64_t range_upb(Range *range)
     return range->upb;
 }
 
+/*
+ * Initialize @range to span the interval [@lob,@lob + @size - 1].
+ * @size may be 0.
+ */
+static inline void range_init(Range *range, uint64_t lob, uint64_t size)
+{
+    range->lob = lob;
+    range->upb = lob + size - 1;
+    range_invariant(range);
+}
+
+/*
+ * Check if the interval [@lob,@lob + @size - 1] would be valid or not
+ * (result in an overflow).
+ */
+static inline bool range_valid(uint64_t lob, uint64_t size)
+{
+    return lob + size >= lob;
+}
+
+/*
+ * Get the size of @range.
+ */
+static inline uint64_t range_size(const Range *range)
+{
+    return range->upb - range->lob + 1;
+}
+
+/*
+ * Check if @range1 overlaps with @range2. If one of the ranges is empty,
+ * the result is always "false".
+ */
+static inline bool range_overlaps_range(const Range *range1,
+                                        const Range *range2)
+{
+    if (range_is_empty(range1) || range_is_empty(range2)) {
+        return false;
+    }
+    return !(range2->upb < range1->lob || range1->upb < range2->lob);
+}
+
+/*
+ * Check if @range1 contains @range2. If one of the ranges is empty,
+ * the result is always "false".
+ */
+static inline bool range_contains_range(const Range *range1,
+                                        const Range *range2)
+{
+    if (range_is_empty(range1) || range_is_empty(range2)) {
+        return false;
+    }
+    return range1->lob <= range2->lob && range1->upb >= range2->upb;
+}
+
+/*
+ * Check if @range1 starts before @range2. If one of the ranges is empty,
+ * the result is alsways "false".
+ */
+static inline bool range_starts_before_range(const Range *range1,
+                                             const Range *range2)
+{
+    if (range_is_empty(range1) || range_is_empty(range2)) {
+        return false;
+    }
+    return range1->lob < range2->lob;
+}
+
+/*
+ * Check if @range1 ends after @range2. If one of the ranges is empty,
+ * the result is alsways "false".
+ */
+static inline bool range_ends_after_range(const Range *range1,
+                                          const Range *range2)
+{
+    if (range_is_empty(range1) || range_is_empty(range2)) {
+        return false;
+    }
+    return range1->upb > range2->upb;
+}
+
 /*
  * Extend @range to the smallest interval that includes @extend_by, too.
  */
-- 
2.17.1