added struct Item and keyowrd EXPIRE so now we can track expire time of items in the db

1 files changed, 69 insertions, 28 deletions

diff --git a/handlers.go b/handlers.go
index 885e348..244d332 100644
--- a/handlers.go
+++ b/handlers.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"net"
 	"strconv"
+	"time"
 )
 
 func handleGet(conn net.Conn, args []string) {
@@ -18,13 +19,19 @@ func handleGet(conn net.Conn, args []string) {
 
     key := args[1]
 
-	value, exists := db.data[key]
+	item, exists := db.data[key]
 	if !exists {
 		conn.Write(serializeRESP(nil)) 
         return
 	}
 
-	strValue, ok := value.(string)
+	if item.ExpiresAt != nil && time.Now().After(*item.ExpiresAt) {
+		delete(db.data, key)
+		conn.Write(serializeRESP(nil))
+		return
+	}
+
+	strValue, ok := item.Value.(string)
 	if !ok {
 		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
         conn.Write(serializeRESP(err))
@@ -65,9 +72,9 @@ func handleSet(conn net.Conn, args []string) {
     }
 
 	key := args[1]
-	value := args[2]
+	item := Item{Value: args[2]}
 
-	db.data[key] = value
+	db.data[key] = item
 	conn.Write(serializeRESP(SimpleString("OK")))
 }
 
@@ -104,9 +111,9 @@ func handleIncr(conn net.Conn, args []string) {
 
 	key := args[1]
 
-	value, exists := db.data[key]
+	item, exists := db.data[key]
 	if exists {
-		strValue, ok := value.(string)
+		strValue, ok := item.Value.(string)
 		if !ok {
 			err := errors.New("value is not an integer or out of range")
 			conn.Write(serializeRESP(err))
@@ -121,10 +128,10 @@ func handleIncr(conn net.Conn, args []string) {
 		}
 
 		newValueStr := strconv.Itoa(currentInt + 1)
-		db.data[key] = newValueStr
+		db.data[key] = Item{Value: newValueStr}
 		conn.Write(serializeRESP(currentInt + 1))
 	} else {
-		db.data[key] = "1"
+		db.data[key] = Item{Value: "1"}
 		conn.Write(serializeRESP(1))
 	}
 }
@@ -141,9 +148,9 @@ func handleDecr(conn net.Conn, args []string) {
 
 	key := args[1]
 
-	value, exists := db.data[key]
+	item, exists := db.data[key]
 	if exists {
-		strValue, ok := value.(string)
+		strValue, ok := item.Value.(string)
 		if !ok {
 			err := errors.New("value is not an integer or out of range")
 			conn.Write(serializeRESP(err))
@@ -158,10 +165,10 @@ func handleDecr(conn net.Conn, args []string) {
 		}
 
 		newValueStr := strconv.Itoa(currentInt - 1)
-		db.data[key] = newValueStr
+		db.data[key] = Item{Value:newValueStr}
 		conn.Write(serializeRESP(currentInt - 1))
 	} else {
-		db.data[key] = "-1"
+		db.data[key] = Item{Value: "-1"}
 		conn.Write(serializeRESP(-1))
 	}
 }
@@ -185,7 +192,7 @@ func handleFlushall(conn net.Conn, args []string) {
 		return
     }
 
-	db.data = make(map[string]any)
+	db.data = make(map[string]Item)
 	conn.Write(serializeRESP(SimpleString("OK")))
 }
 
@@ -197,11 +204,11 @@ func handleRpush(conn net.Conn, args []string) {
 	defer db.mu.Unlock()
 
 	var list []string
-	existingValue, exists := db.data[key]
+	existingItem, exists := db.data[key]
 
 	if exists {
 		var ok bool
-		list, ok = existingValue.([]string)
+		list, ok = existingItem.Value.([]string)
 		if !ok {
 			err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
 			conn.Write(serializeRESP(err))
@@ -211,7 +218,7 @@ func handleRpush(conn net.Conn, args []string) {
 			list = []string{}
 		}
 	list = append(list, newItems...)
-	db.data[key] = list
+	db.data[key] = Item{Value: list}
 	conn.Write(serializeRESP(len(list)))
 }
 
@@ -234,14 +241,20 @@ func handleLrange(conn net.Conn, args []string) {
 
 	key := args[1]
 
-    value, exists := db.data[key]
+    item, exists := db.data[key]
     if !exists {
         conn.Write(serializeRESP([]string{}))
 
         return
     }
     
-    typedList, ok := value.([]string)
+	if item.ExpiresAt != nil && time.Now().After(*item.ExpiresAt) {
+		delete(db.data, key)
+		conn.Write(serializeRESP(nil))
+		return
+	}
+
+    typedList, ok := item.Value.([]string)
     if !ok {
 		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
 		conn.Write(serializeRESP(err))
@@ -288,13 +301,13 @@ func handleLpop(conn net.Conn, args []string){
     }
 
 	key := args[1]
-    value, exists := db.data[key]
+    item, exists := db.data[key]
     if !exists {
         conn.Write(serializeRESP(nil))
         return
     }
 
-	typedList, ok := value.([]string)
+	typedList, ok := item.Value.([]string)
     if !ok {
 		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
 		conn.Write(serializeRESP(err))
@@ -306,14 +319,14 @@ func handleLpop(conn net.Conn, args []string){
         return
     }
 
-	item := typedList[0]
+	newItem := typedList[0]
 	newList := typedList[1:]
 	if len(newList) <= 0 {
 		delete(db.data, key)
 	}else{
-		db.data[key] = newList
+		db.data[key] = Item{Value: newList}
 	}
-	conn.Write(serializeRESP(item))
+	conn.Write(serializeRESP(newItem))
 
 }
 
@@ -328,13 +341,13 @@ func handleRpop(conn net.Conn, args []string){
     }
 
 	key := args[1]
-    value, exists := db.data[key]
+    item, exists := db.data[key]
     if !exists {
         conn.Write(serializeRESP(nil))
         return
     }
 
-	typedList, ok := value.([]string)
+	typedList, ok := item.Value.([]string)
     if !ok {
 		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
 		conn.Write(serializeRESP(err))
@@ -346,13 +359,41 @@ func handleRpop(conn net.Conn, args []string){
         return
     }
 	
-	item := typedList[len(typedList)-1]
+	newItem := typedList[len(typedList)-1]
 	newList := typedList[:len(typedList)-1]
 	if len(newList) <= 0 {
 		delete(db.data, key)
 	}else{
-		db.data[key] = newList
+		db.data[key] = Item{Value: newList}
 	}
-	conn.Write(serializeRESP(item))
+	conn.Write(serializeRESP(newItem))
 
 }
+
+func handleExpire(conn net.Conn, args []string){
+	
+	if len(args) != 3 {
+        conn.Write(serializeRESP(errors.New("wrong number of arguments for 'EXPIRE'")))
+        return
+    }
+
+	key := args[1]
+    seconds, err := strconv.Atoi(args[2])
+	if err != nil {
+        conn.Write(serializeRESP(errors.New("ERR value is not an integer")))
+        return
+    }
+	db.mu.Lock()
+    defer db.mu.Unlock()
+
+	item, exists := db.data[key]
+    if !exists {
+        conn.Write(serializeRESP(0)) // Key doesn't exist
+        return
+    }
+
+	expiry := time.Now().Add(time.Duration(seconds) * time.Second)
+    item.ExpiresAt = &expiry
+    db.data[key] = item
+    conn.Write(serializeRESP(1))
+}
\ No newline at end of file