fixed an n+1 bug with the query engine, and made it significantly more efficient

engine.go

@@ -82,39 +82,75 @@ func (e *Engine) InvalidateTable(tableName string) {
 	for _, query := range dependentQueries {
 		slog.Debug("Invalidating query", "query", query)
 		subscriptions := e.tracker.GetQuerySubscriptions(query)
-		slog.Debug("Subscriptions", "subscriptions", subscriptions)
+
+		groupedExecutions := make(map[string][]string)
+
+		type executionData struct {
+			Params map[string]interface{}
+			AuthID string
+		}
+		executionParams := make(map[string]executionData)
+
 		for _, subscription := range subscriptions {
-			slog.Debug("Invalidating subscription", "subscription", subscription["clientID"])
 			params := map[string]interface{}{}
 			err := json.Unmarshal([]byte(subscription["params"]), &params)
 			if err != nil {
 				slog.Error("Failed to unmarshal params", "error", err)
 				continue
 			}
-			_, err = e.ExecuteQuery(query, params, subscription["clientID"], false)
-			if err != nil {
-				slog.Error("Failed to execute query", "error", err)
-				continue
-			}
+			authID := e.tracker.GetAuthID(subscription["clientID"])
+			cacheKey := query + "?" + string(subscription["params"]) + "?" + authID
+			groupedExecutions[cacheKey] = append(groupedExecutions[cacheKey], subscription["clientID"])
+			executionParams[cacheKey] = executionData{Params: params, AuthID: authID}
+		}
+
+		for cacheKey, clients := range groupedExecutions {
+			data := executionParams[cacheKey]
+			go func() {
+				_, err := e.ExecuteQueryGroup(query, data.Params, data.AuthID, clients, cacheKey)
+				if err != nil {
+					slog.Error("Failed to execute query", "error", err)
+					return
+				}
+			}()
 		}
 	}
 }
 
+func (e *Engine) ExecuteQueryGroup(query string, params map[string]interface{}, authID string, clientIDs []string, cacheKey string) (interface{}, error) {
+	e.hashMu.RLock()
+	lastHash := e.queryHashes[cacheKey]
+	e.hashMu.RUnlock()
+
+	authCtx := &AuthCtx{UserID: authID, IsLoggedIn: authID != ""}
+	queryCtx := &QueryCtx{DB: e.db, AuthCtx: authCtx, Params: params}
+	result := e.queries[query](queryCtx)
+	responseJSON, err := json.Marshal(map[string]interface{}{"type": "query", "location": query, "data": result})
+	if err != nil {
+		return nil, err
+	}
+	queryHash := xxhash.Sum64(responseJSON)
+
+	if lastHash == queryHash {
+		return nil, nil
+	}
+
+	e.hashMu.Lock()
+	e.queryHashes[cacheKey] = queryHash
+	e.hashMu.Unlock()
+
+	for _, clientID := range clientIDs { // send the response to all clients in the group
+		e.tracker.SendMessage(clientID, responseJSON)
+	}
+	return result, nil
+}
+
 func (e *Engine) ExecuteQuery(query string, params map[string]interface{}, clientID string, forceSend bool) (interface{}, error) {
-	/*
-		TODO: implement the logic to execute the query
-		Steps needed:
-		1. Check which tables updated ✅
-		2. Get the queries that rely on the tables ✅
-		3. Get the subscriptions that need updating ✅
-		4. Calculate hash for every query
-		5. Send the updated queries if hash changed
-	*/
 	paramsJSON, err := json.Marshal(params)
 	if err != nil {
 		return nil, err
 	}
-	cacheKey := query + "?" + string(paramsJSON)
+	cacheKey := query + "?" + string(paramsJSON) + "?" + clientID
 	e.hashMu.Lock()
 	lastHash := e.queryHashes[cacheKey]
 	e.hashMu.Unlock()

reactivity/client.go

@@ -8,13 +8,22 @@ import (
 )
 
 type Client struct {
-	ID   string
-	Conn *websocket.Conn
-	Send chan []byte
+	ID     string
+	Conn   *websocket.Conn
+	Send   chan []byte
+	AuthID string
 }
 
 func NewClient(conn *websocket.Conn) *Client {
-	return &Client{ID: uuid.NewString(), Conn: conn, Send: make(chan []byte, 256)}
+	return &Client{ID: uuid.NewString(), Conn: conn, Send: make(chan []byte, 256), AuthID: ""}
+}
+
+func (c *Client) SetAuthID(authID string) {
+	c.AuthID = authID
+}
+
+func (c *Client) GetAuthID() string {
+	return c.AuthID
 }
 
 func (c *Client) WritePump() {

reactivity/tracker.go

@@ -32,6 +32,16 @@ func (t *Tracker) Untrack(c *Client) {
 	delete(t.clients, c.ID)
 }
 
+func (t *Tracker) SetAuthID(clientID string, authID string) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.clients[clientID].SetAuthID(authID)
+}
+
+func (t *Tracker) GetAuthID(clientID string) string {
+	return t.clients[clientID].GetAuthID()
+}
+
 func (t *Tracker) SubscribeToQuery(clientID string, query string, params string) {
 	t.mu.Lock()
 	defer t.mu.Unlock()