Add versioning to perf SQL database

perf/go/util/util.go

 package util
 
 import "sort"
 
 func In(s string, a []string) bool {
         for _, x := range a {
                 if x == s {
                         return true
                 }
         }
@@ skipping 28 matching lines @@
         }
         // Since they are the same size we only need to check from one side, i.e.
         // compare a's values to b's values.
         for k, v := range a {
                 if bv, ok := b[k]; !ok || bv != v {
                         return false
                 }
         }
         return true
 }
+
+// This is sad, but apparently there is no library function to get the absolute
+// value of an int.
+func AbsInt(v int) int {
+        if v < 0 {
+                return -v
+        }
+        return v
+}
+
+// Returns -1, 1 or 0 depending on the sign of v.
+func SignInt(v int) int {
+        if v < 0 {
+                return -1
+        }
+        if v > 0 {
+                return 1
+        }
+        return 0
+}