From d38536d61a7b35d58c1a10494fdc5c6391fcbcaa Mon Sep 17 00:00:00 2001
From: kompotkot <zenitsws@gmail.com>
Date: Thu, 7 Oct 2021 14:49:19 +0000
Subject: [PATCH] Reuse db connections

---
 db/server/main.go | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/db/server/main.go b/db/server/main.go
index caae18b1..da9e452c 100644
--- a/db/server/main.go
+++ b/db/server/main.go
@@ -23,6 +23,17 @@ type BlockResponse struct {
 	BlockNumber uint64 `json:"block_number"`
 }
 
+var dbConnection *gorm.DB
+
+func InitDB() *gorm.DB {
+	db, err := gorm.Open(postgres.Open(MOONSTREAM_DB_URI), &gorm.Config{})
+	if err != nil {
+		log.Println("Database unavailable")
+		return nil
+	}
+	return db
+}
+
 // Extends handler with allowed CORS policies
 func setupCorsResponse(w *http.ResponseWriter, req *http.Request) {
 	for _, allowedOrigin := range strings.Split(MOONSTREAM_CORS_ALLOWED_ORIGINS, ",") {
@@ -58,14 +69,13 @@ func blockLatest(w http.ResponseWriter, req *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 
 	var latestBlock BlockResponse
-	db, err := gorm.Open(postgres.Open(MOONSTREAM_DB_URI), &gorm.Config{})
-	if err != nil {
+
+	if dbConnection == nil {
 		http.Error(w, http.StatusText(500), 500)
 		return
 	}
-
 	query := "SELECT block_number FROM ethereum_blocks ORDER BY block_number DESC LIMIT 1"
-	db.Raw(query, 1).Scan(&latestBlock.BlockNumber)
+	dbConnection.Raw(query, 1).Scan(&latestBlock.BlockNumber)
 
 	json.NewEncoder(w).Encode(latestBlock)
 }
@@ -77,6 +87,8 @@ func main() {
 	flag.StringVar(&listenPort, "port", "8080", "Server listen port")
 	flag.Parse()
 
+	dbConnection = InitDB()
+
 	address := listenAddr + ":" + listenPort
 	log.Printf("Starting server at %s\n", address)