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 most significant bits are the type, the rest are the value. 30 template <typename T> inline T MakeTypedId(T value, PPIdType type) { 31 return (value << kPPIdTypeBits) | static_cast<T>(type); 32 } 33 34 template <typename T> inline bool CheckIdType(T id, PPIdType type) { 35 // Say a resource of 0 is always valid, since that means "no resource." 36 // You shouldn't be passing 0 var, instance, or module IDs around so those 37 // are still invalid. 38 if (type == PP_ID_TYPE_RESOURCE && !id) 39 return true; 40 const T mask = (static_cast<T>(1) << kPPIdTypeBits) - 1; 41 return (id & mask) == type; 42 } 43 44 } // namespace ppapi 45 46 #endif // PPAPI_SHARED_IMPL_ID_ASSIGNMENT_H_ 47
