根据系统内存自动调节ttlcache的最大条目

internal/ttlcache/system.go

@@ -0,0 +1,23 @@
+// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package ttlcache
+
+import (
+	"github.com/shirou/gopsutil/mem"
+)
+
+var systemTotalMemory = -1
+
+func systemMemoryGB() int {
+	if systemTotalMemory > 0 {
+		return systemTotalMemory
+	}
+
+	stat, err := mem.VirtualMemory()
+	if err != nil {
+		return 0
+	}
+
+	systemTotalMemory = int(stat.Total / 1024 / 1024 / 1024)
+	return systemTotalMemory
+}