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-rw-r--r--range.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/range.h b/range.h
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+++ b/range.h
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+#ifndef QEMU_RANGE_H
+#define QEMU_RANGE_H
+
+/* Get last byte of a range from offset + length.
+ * Undefined for ranges that wrap around 0. */
+static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
+{
+ return offset + len - 1;
+}
+
+/* Check whether a given range covers a given byte. */
+static inline int range_covers_byte(uint64_t offset, uint64_t len,
+ uint64_t byte)
+{
+ return offset <= byte && byte <= range_get_last(offset, len);
+}
+
+/* Check whether 2 given ranges overlap.
+ * Undefined if ranges that wrap around 0. */
+static inline int ranges_overlap(uint64_t first1, uint64_t len1,
+ uint64_t first2, uint64_t len2)
+{
+ uint64_t last1 = range_get_last(first1, len1);
+ uint64_t last2 = range_get_last(first2, len2);
+
+ return !(last2 < first1 || last1 < first2);
+}
+
+#endif