4 files changed, 77 insertions, 45 deletions

diff --git a/handlers.go b/handlers.go
index 305d526..aefea85 100644
--- a/handlers.go
+++ b/handlers.go
@@ -3,50 +3,42 @@ package main
 import (
 	"errors"
 	"net"
-	"path/filepath"
-	"sort"
-	"strconv"
 	"time"
 )
 
 func handleGet(conn net.Conn, args []string) {
-	db.mu.Lock()
-	defer db.mu.Unlock()
-
 	if len(args) != 2 {
         err := errors.New("wrong number of arguments for 'GET'")
         conn.Write(serializeRESP(err))
 		return
     }
+    
+	key := args[1]
 
-    key := args[1]
+	result := db.Execute(key, func(s *Shard) interface{}{
+		item, exists := s.data[key]
+		if !exists {
+			return nil
+		}
 
-	item, exists := db.data[key]
-	if !exists {
-		conn.Write(serializeRESP(nil)) 
-        return
-	}
+		if item.ExpiresAt != nil && time.Now().After(*item.ExpiresAt) {
+			delete(s.data, key)
+			return nil
+		}
 
-	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")
+			return err
+		}
+		return strValue
+	})
 
-	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))
-        return
-	}
 
-	conn.Write(serializeRESP(strValue))
+	conn.Write(serializeRESP(result))
 }
 
 func handleExists(conn net.Conn, args []string) {
-	db.mu.Lock()
-	defer db.mu.Unlock()
-
 	if len(args) != 2 {
         err := errors.New("wrong number of arguments for 'EXISTS'")
         conn.Write(serializeRESP(err))
@@ -54,13 +46,16 @@ func handleExists(conn net.Conn, args []string) {
     }
 
 	key := args[1]
+	result := db.Execute(key, func(s *Shard) interface{}{
+		_, exists := s.data[key]
+		if exists {
+			return 1
+		} else {
+			return 0
+		}
+	})
 
-	_, exists := db.data[key]
-	if exists {
-		conn.Write(serializeRESP(1))
-	} else {
-		conn.Write(serializeRESP(0))
-	}
+	conn.Write(serializeRESP(result))
 }
 
 func handleSet(conn net.Conn, args []string) {
@@ -74,12 +69,15 @@ func handleSet(conn net.Conn, args []string) {
     }
 
 	key := args[1]
-	item := Item{Value: args[2]}
+	result := db.Execute(key, func(s *Shard) interface{}{
+		item := Item{Value: args[2]}
+		s.data[key] = item
+		return SimpleString("OK")
+	})
 
-	db.data[key] = item
-	conn.Write(serializeRESP(SimpleString("OK")))
+	conn.Write(serializeRESP(result))
 }
-
+/*
 func handleDel(conn net.Conn, args []string) {
 	db.mu.Lock()
 	defer db.mu.Unlock()
@@ -730,4 +728,5 @@ func handleLrem(conn net.Conn, args []string){
 	item.Value = list
 	db.data[key] = item
 	conn.Write(serializeRESP(counter))
-}
\ No newline at end of file
+}
+*/
\ No newline at end of file
diff --git a/main.go b/main.go
index 8edf10f..5e56280 100644
--- a/main.go
+++ b/main.go
@@ -7,7 +7,6 @@ import (
 	"net"
 	"os"
 	"strings"
-	"time"
 )
 
 
@@ -18,9 +17,9 @@ type handlerFunc func(net.Conn, []string)
 var commandRegistry = map[string]handlerFunc{
     "GET":      handleGet,
     "SET":      handleSet,
-    "DEL":      handleDel,
+//    "DEL":      handleDel,
     "EXISTS":   handleExists,
-    "INCR":     handleIncr,
+/*    "INCR":     handleIncr,
     "DECR":     handleDecr,
     "PING":     handlePing,
     "FLUSHALL": handleFlushall,
@@ -38,12 +37,20 @@ var commandRegistry = map[string]handlerFunc{
 	"TYPE":		handleType,
 	"DBSIZE":	handleDbsize,
 	"KEYS":		handleKeys,
-	"LREM":		handleLrem,
+	"LREM":		handleLrem,*/
 }
 
 func main() {
-	db = RedisDB{data: make(map[string]Item)}
+	numShards := 16
+	shards := make([]*Shard, numShards)
 
+	for i := 0; i < numShards; i++ {
+    	shards[i] = &Shard{
+        data: make(map[string]Item),
+    }
+}
+	db = RedisDB{shards: shards}
+/*
 	go func() {
 		ticker := time.NewTicker(1 * time.Second)
 		for range ticker.C {
@@ -56,7 +63,7 @@ func main() {
 			db.mu.Unlock()
 		}
 	}()
-
+*/
 	listener, err := net.Listen("tcp", ":6379")
 	if err != nil {
 		fmt.Println("error starting server: ", err)
diff --git a/redisDB.go b/redisDB.go
index 74a7de6..939fbbe 100644
--- a/redisDB.go
+++ b/redisDB.go
@@ -9,13 +9,21 @@ type Item struct {
 	Value any
 	ExpiresAt *time.Time
 }
+
 type RedisDB struct {
 	mu   sync.Mutex
-	data map[string]Item
+	shards []*Shard
 }
 
 type SimpleString string
 
+func (db *RedisDB) Execute(key string, fn func(*Shard) interface{}) interface{} {
+    shard := db.getShard(key)
+    shard.mu.Lock()
+    defer shard.mu.Unlock()
+    return fn(shard)
+}
+
 func serializeRESP(v any) []byte {
     switch val := v.(type) {
     case string:
diff --git a/shards.go b/shards.go
new file mode 100644
index 0000000..55ab976
--- /dev/null
+++ b/shards.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"hash/fnv"
+	"sync"
+)
+type Shard struct{
+	mu sync.Mutex
+	data map[string]Item
+}
+
+func (db *RedisDB) getShard(key string)*Shard{
+	hash := fnv.New64a()
+	hash.Write([]byte(key))
+	val := hash.Sum64()
+
+	return db.shards[val%16]
+}
\ No newline at end of file