Add a set of simple version comparison helpers

[ccan] / ccan / version / version.h

diff --git a/ccan/version/version.h b/ccan/version/version.h
new file mode 100644 (file)
index 0000000..8820f17
--- /dev/null
+++ b/ccan/version/version.h
@@ -0,0 +1,80 @@
+/*****************************************************************************
+ *
+ * version - simple version handling functions for major.minor version
+ * types
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ ****************************************************************************/
+
+#ifndef CCAN_VERSION_H
+#define CCAN_VERSION_H
+
+#include <stdint.h>
+
+struct version {
+       uint32_t _v; /* major << 16  | minor */
+};
+
+/**
+ * version_major - return the major version of the given struct
+ * @v: the version number to obtain the major number from
+ */
+static inline uint16_t version_major(struct version v) {
+       return (v._v & 0xFFFF0000) >> 16;
+}
+
+/**
+ * version_minor - return the minor version of the given struct
+ * @v: the version number to obtain the minor number from
+ */
+static inline uint16_t version_minor(const struct version v) {
+       return v._v & 0xFFFF;
+}
+
+/**
+ * version - create a new version number
+ * @major: major version number
+ * @minor: minor version number
+ */
+static inline struct version version(uint16_t major, uint16_t minor)
+{
+       struct version v = { ._v = major << 16 | minor };
+       return v;
+}
+
+/**
+ * version_cmp - compare two versions
+ * @a: the first version number
+ * @b: the second version number
+ * @return a number greater, equal, or less than 0 if a is greater, equal or
+ * less than b, respectively
+ *
+ * Example:
+ *     struct version a = version(1, 0);
+ *     struct version b = version(1, 3);
+ *     if (version_cmp(a, b) < 0)
+ *             printf("b is smaller than b\n");
+ */
+static inline int version_cmp(struct version a, struct version b)
+{
+       return  (a._v == b._v) ? 0 : (a._v > b._v) ? 1 : - 1;
+}
+
+#endif /* CCAN_VERSION_H */