1 // Copyright 2016 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef MOJO_PUBLIC_CPP_BINDINGS_STRING_TRAITS_STRING_PIECE_H_
6 #define MOJO_PUBLIC_CPP_BINDINGS_STRING_TRAITS_STRING_PIECE_H_
7 
8 #include "base/strings/string_piece.h"
9 #include "mojo/public/cpp/bindings/string_traits.h"
10 
11 namespace mojo {
12 
13 template <>
14 struct StringTraits<base::StringPiece> {
15   static bool IsNull(const base::StringPiece& input) {
16     // base::StringPiece is always converted to non-null mojom string. We could
17     // have let StringPiece containing a null data pointer map to null mojom
18     // string, but StringPiece::empty() returns true in this case. It seems
19     // confusing to mix the concept of empty and null strings, especially
20     // because they mean different things in mojom.
21     return false;
22   }
23 
24   static void SetToNull(base::StringPiece* output) {
25     // Convert null to an "empty" base::StringPiece.
26     output->set(nullptr, 0);
27   }
28 
29   static size_t GetSize(const base::StringPiece& input) { return input.size(); }
30 
31   static const char* GetData(const base::StringPiece& input) {
32     return input.data();
33   }
34 
35   static bool Read(StringDataView input, base::StringPiece* output) {
36     output->set(input.storage(), input.size());
37     return true;
38   }
39 };
40 
41 }  // namespace mojo
42 
43 #endif  // MOJO_PUBLIC_CPP_BINDINGS_STRING_TRAITS_STRING_PIECE_H_
44