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//
// Copyright (C) 2014 The Android Open Source Project
//
// 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 UPDATE_ENGINE_UPDATE_MANAGER_POLICY_UTILS_H_
#define UPDATE_ENGINE_UPDATE_MANAGER_POLICY_UTILS_H_
#include <string>
#include <vector>
#include "update_engine/update_manager/policy.h"
// Checks that the passed pointer value is not null, returning kFailed on the
// current context and setting the *error description when it is null. The
// intended use is to validate variable failures while using
// EvaluationContext::GetValue, for example:
//
// const int* my_value = ec->GetValue(state->my_provider()->var_my_value());
// POLICY_CHECK_VALUE_AND_FAIL(my_value, error);
//
#define POLICY_CHECK_VALUE_AND_FAIL(ptr, error) \
do { \
if ((ptr) == nullptr) { \
*(error) = #ptr " is required but is null."; \
return EvalStatus::kFailed; \
} \
} while (false)
namespace chromeos_update_manager {
// Call the passed-in Policy method on a series of Policy implementations, until
// one of them renders a decision by returning a value other than
// |EvalStatus::kContinue|.
template <typename T, typename R, typename... Args>
EvalStatus ConsultPolicies(const std::vector<Policy const*> policies,
T policy_method,
EvaluationContext* ec,
State* state,
std::string* error,
R* result,
Args... args) {
for (auto policy : policies) {
EvalStatus status =
(policy->*policy_method)(ec, state, error, result, args...);
if (status != EvalStatus::kContinue) {
return status;
}
}
return EvalStatus::kContinue;
}
// Base class implementation that returns |EvalStatus::kContinue| for all
// decisions, to be used as a base-class for various Policy facets that only
// pertain to certain situations. This might be better folded into Policy
// instead of using pure-virtual methods on that class.
class PolicyImplBase : public Policy {
public:
// Policy overrides.
EvalStatus UpdateCheckAllowed(EvaluationContext* ec,
State* state,
std::string* error,
UpdateCheckParams* result) const override {
return EvalStatus::kContinue;
};
EvalStatus UpdateCanBeApplied(
EvaluationContext* ec,
State* state,
std::string* error,
chromeos_update_engine::ErrorCode* result,
chromeos_update_engine::InstallPlan* install_plan) const override {
return EvalStatus::kContinue;
};
EvalStatus UpdateCanStart(EvaluationContext* ec,
State* state,
std::string* error,
UpdateDownloadParams* result,
UpdateState update_state) const override {
return EvalStatus::kContinue;
};
EvalStatus P2PEnabled(EvaluationContext* ec,
State* state,
std::string* error,
bool* result) const override {
return EvalStatus::kContinue;
};
EvalStatus P2PEnabledChanged(EvaluationContext* ec,
State* state,
std::string* error,
bool* result,
bool prev_result) const override {
return EvalStatus::kContinue;
};
};
} // namespace chromeos_update_manager
#endif // UPDATE_ENGINE_UPDATE_MANAGER_POLICY_UTILS_H_