Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/repository/db_pool.go

@@ -0,0 +1,68 @@
+// Package repository contains persistence infrastructure helpers.
+//
+// DB pool lifetimes are clamped here because lib/pq starts watchCancel
+// goroutines for context-aware queries. If a cloud proxy silently drops idle
+// TCP without RST/FIN, those goroutines can block in Read until database/sql
+// retires the connection. This is a short-term mitigation; the long-term
+// follow-up is migrating PostgreSQL access to jackc/pgx/v5/stdlib.
+package repository
+
+import (
+	"database/sql"
+	"log/slog"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+)
+
+const (
+	defaultConnMaxLifetime = 30 * time.Minute
+	defaultConnMaxIdleTime = 5 * time.Minute
+	maxConfiguredConnAge   = 24 * time.Hour
+)
+
+type dbPoolSettings struct {
+	MaxOpenConns    int
+	MaxIdleConns    int
+	ConnMaxLifetime time.Duration
+	ConnMaxIdleTime time.Duration
+}
+
+func clampDBPoolSettings(cfg *config.Config) dbPoolSettings {
+	return dbPoolSettings{
+		MaxOpenConns:    cfg.Database.MaxOpenConns,
+		MaxIdleConns:    cfg.Database.MaxIdleConns,
+		ConnMaxLifetime: clampDBPoolDuration("database.conn_max_lifetime_minutes", cfg.Database.ConnMaxLifetimeMinutes, defaultConnMaxLifetime),
+		ConnMaxIdleTime: clampDBPoolDuration("database.conn_max_idle_time_minutes", cfg.Database.ConnMaxIdleTimeMinutes, defaultConnMaxIdleTime),
+	}
+}
+
+func clampDBPoolDuration(key string, minutes int, fallback time.Duration) time.Duration {
+	if minutes <= 0 || minutes > int(maxConfiguredConnAge/time.Minute) {
+		slog.Warn("database connection pool duration clamped",
+			"key", key,
+			"before", minutes,
+			"after", int(fallback/time.Minute),
+		)
+		return fallback
+	}
+
+	return time.Duration(minutes) * time.Minute
+}
+
+func applyDBPoolSettings(db *sql.DB, cfg *config.Config) {
+	settings := clampDBPoolSettings(cfg)
+	db.SetMaxOpenConns(settings.MaxOpenConns)
+	db.SetMaxIdleConns(settings.MaxIdleConns)
+	db.SetConnMaxLifetime(settings.ConnMaxLifetime)
+	db.SetConnMaxIdleTime(settings.ConnMaxIdleTime)
+
+	slog.Info("database connection pool configured",
+		slog.Group("effective",
+			slog.Int("max_open", settings.MaxOpenConns),
+			slog.Int("max_idle", settings.MaxIdleConns),
+			slog.Duration("max_lifetime", settings.ConnMaxLifetime),
+			slog.Duration("max_idle_time", settings.ConnMaxIdleTime),
+		),
+	)
+}