sandboxed-api/sandboxed_api/var_pointable.h

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// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SANDBOXED_API_VAR_POINTABLE_H_
#define SANDBOXED_API_VAR_POINTABLE_H_
#include <memory>
#include "sandboxed_api/var_reg.h"
namespace sapi::v {
class Ptr;
// Needed so that we can use unique_ptr with incomplete type.
struct PtrDeleter {
void operator()(Ptr* p);
};
// Class that implements pointer support for different objects.
class Pointable {
public:
enum SyncType {
// Do not synchronize the underlying object after/before calls.
SYNC_NONE = 0x0,
// Synchronize the underlying object (send the data to the sandboxee)
// before the call takes place.
SYNC_BEFORE = 0x1,
// Synchronize the underlying object (retrieve data from the sandboxee)
// after the call has finished.
SYNC_AFTER = 0x2,
// Synchronize the underlying object with the remote object, by sending the
// data to the sandboxee before the call, and retrieving it from the
// sandboxee after the call has finished.
SYNC_BOTH = SYNC_BEFORE | SYNC_AFTER,
};
// Necessary to implement creation of Ptr in inheriting class as it is
// incomplete type here.
virtual Ptr* CreatePtr(SyncType type) = 0;
// Functions to get pointers with certain type of synchronization scheme.
Ptr* PtrNone() {
if (ptr_none_ == nullptr) {
ptr_none_.reset(CreatePtr(SYNC_NONE));
}
return ptr_none_.get();
}
Ptr* PtrBoth() {
if (ptr_both_ == nullptr) {
ptr_both_.reset(CreatePtr(SYNC_BOTH));
}
return ptr_both_.get();
}
Ptr* PtrBefore() {
if (ptr_before_ == nullptr) {
ptr_before_.reset(CreatePtr(SYNC_BEFORE));
}
return ptr_before_.get();
}
Ptr* PtrAfter() {
if (ptr_after_ == nullptr) {
ptr_after_.reset(CreatePtr(SYNC_AFTER));
}
return ptr_after_.get();
}
virtual ~Pointable() = default;
private:
std::unique_ptr<Ptr, PtrDeleter> ptr_none_;
std::unique_ptr<Ptr, PtrDeleter> ptr_both_;
std::unique_ptr<Ptr, PtrDeleter> ptr_before_;
std::unique_ptr<Ptr, PtrDeleter> ptr_after_;
};
} // namespace sapi::v
#endif // SANDBOXED_API_VAR_POINTABLE_H_