From 291a6c9044723fcbcce18a3cd12509d5fdac4702 Mon Sep 17 00:00:00 2001
From: alex <alexander.vrabel@proton.me>
Date: Mon, 6 Jul 2026 19:21:44 +0200
Subject: added hash support

---
 handlers.go | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 main.go     |  3 ++
 redisDB.go  |  8 ++++++
 3 files changed, 102 insertions(+)

diff --git a/handlers.go b/handlers.go
index 244d332..a6ae6ef 100644
--- a/handlers.go
+++ b/handlers.go
@@ -396,4 +396,95 @@ func handleExpire(conn net.Conn, args []string){
     item.ExpiresAt = &expiry
     db.data[key] = item
     conn.Write(serializeRESP(1))
+}
+
+func handleHset(conn net.Conn, args []string){
+
+	if len(args) < 4 || (len(args)-2)%2 != 0 {
+        err := errors.New("wrong number of arguments for 'HSET'")
+        conn.Write(serializeRESP(err))
+        return
+    }
+	key := args[1]
+	db.mu.Lock()
+    defer db.mu.Unlock()
+
+    item, exists := db.data[key]
+    
+    var hash map[string]string
+
+    if exists {
+        var ok bool
+        hash, ok = item.Value.(map[string]string)
+        if !ok {
+            conn.Write(serializeRESP(errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")))
+            return
+        }
+    } else {
+        hash = make(map[string]string)
+    }
+	count := 0
+	for i := 2; i < len(args); i += 2 {
+		hash[args[i]] = args[i+1]
+		count += 1
+	}	
+	db.data[key] = Item{Value: hash}
+	conn.Write(serializeRESP(count))
+}
+
+func handleHget(conn net.Conn, args []string) {
+    if len(args) != 3 {
+        conn.Write(serializeRESP(errors.New("ERR wrong number of arguments for 'HGET'")))
+        return
+    }
+
+    key := args[1]
+    field := args[2]
+
+    db.mu.Lock()
+    defer db.mu.Unlock()
+
+    item, exists := db.data[key]
+    if !exists {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+
+    hash, ok := item.Value.(map[string]string)
+    if !ok {
+        conn.Write(serializeRESP(errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")))
+        return
+    }
+
+    val, found := hash[field]
+    if !found {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+
+    conn.Write(serializeRESP(val))
+}
+
+func handleHgetall(conn net.Conn, args []string){
+	if len(args) != 2 {
+        conn.Write(serializeRESP(errors.New("ERR wrong number of arguments for 'HGETALL'")))
+        return
+    }
+	key := args[1]
+
+	db.mu.Lock()
+    defer db.mu.Unlock()
+
+    item, exists := db.data[key]
+    if !exists {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+
+    hash, ok := item.Value.(map[string]string)
+    if !ok {
+        conn.Write(serializeRESP(errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")))
+        return
+    }
+	conn.Write(serializeRESP(hash))
 }
\ No newline at end of file
diff --git a/main.go b/main.go
index ade1b76..a20db6a 100644
--- a/main.go
+++ b/main.go
@@ -29,6 +29,9 @@ var commandRegistry = map[string]handlerFunc{
     "LPOP":     handleLpop,
     "RPOP":     handleRpop,
 	"EXPIRE":	handleExpire,
+	"HSET":		handleHset,
+	"HGET":		handleHget,
+	"HGETALL":	handleHgetall,
 }
 
 func main() {
diff --git a/redisDB.go b/redisDB.go
index 9138971..74a7de6 100644
--- a/redisDB.go
+++ b/redisDB.go
@@ -36,6 +36,14 @@ func serializeRESP(v any) []byte {
 			result = append(result, serializeRESP(val[i])...)
 		}
 		return result
+	case map[string]string:
+		size := len(val)
+		result := []byte(fmt.Sprintf("*%d\r\n", size*2))
+		for key, value := range val {
+			result = append(result, serializeRESP(key)...)
+			result = append(result, serializeRESP(value)...)
+		}
+		return result
 	case SimpleString:
 		simpleStr := fmt.Sprintf("+%s\r\n", val)
 		return []byte(simpleStr)
-- 
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