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62 lines
1.7 KiB
62 lines
1.7 KiB
/* |
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* Copyright (C) 2017 The Android Open Source Project |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0 |
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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#ifndef NETUTILS_MISC_H |
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#define NETUTILS_MISC_H |
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#include <map> |
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namespace android { |
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namespace netdutils { |
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// Lookup key in map, returing a default value if key is not found |
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template <typename U, typename V> |
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inline const V& findWithDefault(const std::map<U, V>& map, const U& key, const V& dflt) { |
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auto it = map.find(key); |
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return (it == map.end()) ? dflt : it->second; |
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} |
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// Movable, copiable, scoped lambda (or std::function) runner. Useful |
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// for running arbitrary cleanup or logging code when exiting a scope. |
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// |
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// Compare to defer in golang. |
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template <typename FnT> |
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class Cleanup { |
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public: |
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Cleanup() = delete; |
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Cleanup(FnT fn) : mFn(fn) {} |
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~Cleanup() { mFn(); } |
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void release() { mFn = {}; } |
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private: |
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FnT mFn; |
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}; |
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// Helper to make a new Cleanup. Avoids complex or impossible syntax |
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// when wrapping lambdas. |
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// |
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// Usage: |
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// auto cleanup = makeCleanup([](){ your_code_here; }); |
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template <typename FnT> |
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Cleanup<FnT> makeCleanup(FnT fn) { |
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return Cleanup<FnT>(fn); |
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} |
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} // namespace netdutils |
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} // namespace android |
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#endif /* NETUTILS_MISC_H */
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