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[Qemu-devel] [PATCH v3 4/7] range: add some more functions
From: |
David Hildenbrand |
Subject: |
[Qemu-devel] [PATCH v3 4/7] range: add some more functions |
Date: |
Tue, 23 Oct 2018 17:23:03 +0200 |
Add some more functions that will be used in memory-device context.
range_init(): Init using lower bound and size, check for validity
range_init_nofail(): Init using lower bound and size, validity asserted
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
Signed-off-by: David Hildenbrand <address@hidden>
---
include/qemu/range.h | 62 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/include/qemu/range.h b/include/qemu/range.h
index 7e75f4e655..ba606c6bc0 100644
--- a/include/qemu/range.h
+++ b/include/qemu/range.h
@@ -112,6 +112,68 @@ static inline uint64_t range_upb(Range *range)
return range->upb;
}
+/*
+ * Initialize @range to span the interval address@hidden,@lob + @size - 1].
+ * @size may be 0. If the range would overflow, returns -ERANGE, otherwise
+ * 0.
+ */
+static inline int QEMU_WARN_UNUSED_RESULT range_init(Range *range, uint64_t
lob,
+ uint64_t size)
+{
+ if (lob + size < lob) {
+ return -ERANGE;
+ }
+ range->lob = lob;
+ range->upb = lob + size - 1;
+ range_invariant(range);
+ return 0;
+}
+
+/*
+ * Initialize @range to span the interval address@hidden,@lob + @size - 1].
+ * @size may be 0. Range must not overflow.
+ */
+static inline void range_init_nofail(Range *range, uint64_t lob, uint64_t size)
+{
+ range->lob = lob;
+ range->upb = lob + size - 1;
+ range_invariant(range);
+}
+
+/*
+ * 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;
+}
+
/*
* Extend @range to the smallest interval that includes @extend_by, too.
*/
--
2.17.1