From 81af991c58bcd2c69bf2c3424253a8167f520c0f Mon Sep 17 00:00:00 2001
From: bel <bel>
Date: Sat, 14 Dec 2024 21:32:39 -0700
Subject: [PATCH] locking

---
 cmd/server/db.go | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/cmd/server/db.go b/cmd/server/db.go
index bd8f05a..c8f60fa 100644
--- a/cmd/server/db.go
+++ b/cmd/server/db.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"io"
+	"sync"
 	"time"
 
 	_ "github.com/glebarez/sqlite"
@@ -12,6 +13,7 @@ import (
 type DB struct {
 	scheme string
 	conn   string
+	rw     *sync.RWMutex
 }
 
 func NewDB(ctx context.Context, scheme, conn string) (DB, error) {
@@ -21,6 +23,7 @@ func NewDB(ctx context.Context, scheme, conn string) (DB, error) {
 	db := DB{
 		scheme: scheme,
 		conn:   conn,
+		rw:     &sync.RWMutex{},
 	}
 
 	sql, err := db.dial(ctx)
@@ -53,7 +56,19 @@ func NewDB(ctx context.Context, scheme, conn string) (DB, error) {
 	return db, err
 }
 
+func (db DB) WithLock(cb func() error) error {
+	db.rw.Lock()
+	defer db.rw.Unlock()
+	return cb()
+}
+
 func (db DB) Exec(ctx context.Context, q string, args ...any) error {
+	db.rw.RLock()
+	defer db.rw.RUnlock()
+	return db.exec(ctx, q, args...)
+}
+
+func (db DB) exec(ctx context.Context, q string, args ...any) error {
 	c, err := db.dial(ctx)
 	if err != nil {
 		return err
@@ -65,6 +80,12 @@ func (db DB) Exec(ctx context.Context, q string, args ...any) error {
 }
 
 func (db DB) Query(ctx context.Context, cb func(*sql.Rows) error, q string, args ...any) error {
+	db.rw.RLock()
+	defer db.rw.RUnlock()
+	return db.query(ctx, cb, q, args...)
+}
+
+func (db DB) query(ctx context.Context, cb func(*sql.Rows) error, q string, args ...any) error {
 	c, err := db.dial(ctx)
 	if err != nil {
 		return err