完善主程序

helper/data.go

@@ -0,0 +1,32 @@
+package helper
+
+import (
+	"unsafe"
+)
+
+// slice is the runtime representation of a slice.
+// It cannot be used safely or portably and its representation may
+// change in a later release.
+//
+// Unlike reflect.SliceHeader, its Data field is sufficient to guarantee the
+// data it references will not be garbage collected.
+type slice struct {
+	data unsafe.Pointer
+	len  int
+	cap  int
+}
+
+// BytesToString 没有内存开销的转换
+func BytesToString(b []byte) string {
+	return *(*string)(unsafe.Pointer(&b))
+}
+
+// StringToBytes 没有内存开销的转换
+func StringToBytes(s string) (b []byte) {
+	bh := (*slice)(unsafe.Pointer(&b))
+	sh := (*slice)(unsafe.Pointer(&s)) // 不要访问 sh.cap
+	bh.data = sh.data
+	bh.len = sh.len
+	bh.cap = sh.len
+	return b
+}

helper/file.go

@@ -0,0 +1,15 @@
+package helper
+
+import "os"
+
+// IsExist 文件/路径存在
+func IsExist(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil || os.IsExist(err)
+}
+
+// IsNotExist 文件/路径不存在
+func IsNotExist(path string) bool {
+	_, err := os.Stat(path)
+	return err != nil && os.IsNotExist(err)
+}