Micro-optimizations

- Make structs smaller
- Introduce Result struct and use it to represent matched items instead of
  reusing Item struct for that purpose
- Avoid unnecessary memory allocation
- Avoid growing slice from the initial capacity
- Code cleanup

src/util/util.go

@@ -4,6 +4,7 @@ package util
 import "C"
 
 import (
+	"math"
 	"os"
 	"os/exec"
 	"time"
@@ -63,6 +64,15 @@ func Constrain(val int, min int, max int) int {
 	return val
 }
 
+func AsUint16(val int) uint16 {
+	if val > math.MaxUint16 {
+		return math.MaxUint16
+	} else if val < 0 {
+		return 0
+	}
+	return uint16(val)
+}
+
 // DurWithin limits the given time.Duration with the upper and lower bounds
 func DurWithin(
 	val time.Duration, min time.Duration, max time.Duration) time.Duration {