1 //
2 // Safe wrapper for a string and its UTF8 encoding
3 //
4 // Authors:
5 //   Aleksey Kliger <aleksey@xamarin.com>
6 //   Rodrigo Kumpera <kumpera@xamarin.com>
7 //
8 // Copyright 2016 Dot net foundation.
9 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
10 //
11 
12 using System;
13 using System.Runtime.CompilerServices;
14 
15 namespace Mono  {
16 	internal struct SafeStringMarshal : IDisposable {
17 		readonly string str;
18 		IntPtr marshaled_string;
19 
20 		[MethodImplAttribute(MethodImplOptions.InternalCall)]
StringToUtf8Mono.SafeStringMarshal21 		public extern static IntPtr StringToUtf8 (string str);
22 
23 		[MethodImplAttribute(MethodImplOptions.InternalCall)]
GFreeMono.SafeStringMarshal24 		public extern static void GFree (IntPtr ptr);
25 
SafeStringMarshalMono.SafeStringMarshal26 		public SafeStringMarshal (string str) {
27 			this.str = str;
28 			this.marshaled_string = IntPtr.Zero;
29 		}
30 
31 		public IntPtr Value {
32 			get {
33 				if (marshaled_string == IntPtr.Zero && str != null)
34 					marshaled_string = StringToUtf8 (str);
35 				return marshaled_string;
36 			}
37 		}
38 
DisposeMono.SafeStringMarshal39 		public void Dispose () {
40 			if (marshaled_string != IntPtr.Zero) {
41 				GFree (marshaled_string);
42 				marshaled_string = IntPtr.Zero;
43 			}
44 		}
45 	}
46 }
47