From 75b2496fa65189f59adaf15ab741f2ac1161f19a Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Tue, 26 May 2015 18:12:55 +0200
Subject: [PATCH] Fixes issue #7. mtredisalize implements Redis PING command.

---
 cmd/mtredisalize/connection.go | 9 +++++++++
 cmd/mtredisalize/parser.go     | 7 ++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/cmd/mtredisalize/connection.go b/cmd/mtredisalize/connection.go
index b834030..64cea82 100644
--- a/cmd/mtredisalize/connection.go
+++ b/cmd/mtredisalize/connection.go
@@ -13,6 +13,7 @@ import (
 
 var (
 	redisOk          = []byte("+OK\r\n")
+	redisPong        = []byte("+PONG\r\n")
 	redisError       = []byte("-ERR\r\n")
 	redisNoSuchBlock = []byte("$-1\r\n")
 	redisCrnl        = []byte("\r\n")
@@ -130,6 +131,14 @@ func (c *Connection) Hkeys(hash []byte) bool {
 	return true
 }
 
+func (c *Connection) Ping() bool {
+	if _, err := c.conn.Write(redisPong); err != nil {
+		logError(err)
+		return false
+	}
+	return true
+}
+
 func (c *Connection) HSpatial(hash, first, second []byte) bool {
 	var (
 		err    error
diff --git a/cmd/mtredisalize/parser.go b/cmd/mtredisalize/parser.go
index bd38351..daaae23 100644
--- a/cmd/mtredisalize/parser.go
+++ b/cmd/mtredisalize/parser.go
@@ -11,6 +11,7 @@ import (
 	"io"
 	"log"
 	"strconv"
+	"strings"
 )
 
 const maxBulkStringSize = 8 * 1024 * 1024
@@ -130,6 +131,7 @@ type RedisCommands interface {
 	Exec() bool
 	Hkeys(hash []byte) bool
 	HSpatial(hash, first, second []byte) bool
+	Ping() bool
 }
 
 type RedisCommandExecutor struct {
@@ -173,7 +175,7 @@ func (rce *RedisCommandExecutor) execute() bool {
 		log.Printf("WARN: Too less argument for command.")
 		return false
 	}
-	cmd := asString(rce.args[0])
+	cmd := strings.ToUpper(asString(rce.args[0]))
 	switch cmd {
 	case "HGET":
 		if l < 3 {
@@ -235,6 +237,9 @@ func (rce *RedisCommandExecutor) execute() bool {
 			return false
 		}
 		return rce.commands.HSpatial(hash, first, second)
+
+	case "PING":
+		return rce.commands.Ping()
 	}
 	log.Printf("WARN: unknown command: '%s'\n", cmd)
 	return false