1 // Copyright (c) 2011 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 PPAPI_SHARED_IMPL_ID_ASSIGNMENT_H_
6 #define PPAPI_SHARED_IMPL_ID_ASSIGNMENT_H_
7
8 #include <limits>
9
10 #include "base/basictypes.h"
11 #include "ppapi/shared_impl/ppapi_shared_export.h"
12
13 namespace ppapi {
14
15 enum PPIdType {
16 PP_ID_TYPE_MODULE,
17 PP_ID_TYPE_INSTANCE,
18 PP_ID_TYPE_RESOURCE,
19 PP_ID_TYPE_VAR,
20
21 // Not a real type, must be last.
22 PP_ID_TYPE_COUNT
23 };
24
25 PPAPI_SHARED_EXPORT extern const unsigned int kPPIdTypeBits;
26
27 extern const int32 kMaxPPId;
28
29 // The least significant bits are the type, the rest are the value.
30 template <typename T>
MakeTypedId(T value,PPIdType type)31 inline T MakeTypedId(T value, PPIdType type) {
32 return (value << kPPIdTypeBits) | static_cast<T>(type);
33 }
34
35 template <typename T>
CheckIdType(T id,PPIdType type)36 inline bool CheckIdType(T id, PPIdType type) {
37 // Say a resource of 0 is always valid, since that means "no resource."
38 // You shouldn't be passing 0 var, instance, or module IDs around so those
39 // are still invalid.
40 if (type == PP_ID_TYPE_RESOURCE && !id)
41 return true;
42 const T mask = (static_cast<T>(1) << kPPIdTypeBits) - 1;
43 return (id & mask) == type;
44 }
45
46 } // namespace ppapi
47
48 #endif // PPAPI_SHARED_IMPL_ID_ASSIGNMENT_H_
49