add fingerprint function

cmd/main.go

@@ -31,7 +31,7 @@ func main() {
 		if q.Query == "" {
 			break
 		}
-		fmt.Printf("Time: %s\nUser: %s\nHost: %s\nID: %d\nSchema: %s\nLast_errno: %d\nKilled: %d\nQuery_time: %s\nLock_time: %s\nRows_sent: %d\nRows_examined: %d\nRows_affected: %d\nBytes_sent: %d\nQuery: %s\n\n",
+		fmt.Printf("Time: %s\nUser: %s\nHost: %s\nID: %d\nSchema: %s\nLast_errno: %d\nKilled: %d\nQuery_time: %s\nLock_time: %s\nRows_sent: %d\nRows_examined: %d\nRows_affected: %d\nBytes_sent: %d\nQuery: %s\n",
 			q.Time,
 			q.User,
 			q.Host,

slowql.go

@@ -2,6 +2,8 @@ package slowql
 
 import (
 	"bufio"
+	"crypto/md5"
+	"fmt"
 	"io"
 	"regexp"
 	"strconv"
@@ -57,8 +59,10 @@ func (p Parser) GetNext() (Query, error) {
 }
 
 // Fingerprint returns Query.query's MD5 fingerprint
-func (q *Query) Fingerprint() {
-
+func (q Query) Fingerprint() string {
+	h := md5.New()
+	io.WriteString(h, q.Query)
+	return fmt.Sprintf("%x", h.Sum(nil))
 }
 
 // NewParser creates the stack channel and launches background goroutines