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// Copyright (C) 2018 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.
#include "base/Optional.h"
#include "base/Lock.h"
#include <functional>
#include <unordered_map>
namespace android {
namespace base {
// Static map class for use with LazyInstance or in global structures
// as a process-wide registry of something. Safe for concurrent accress.
template <class K, class V>
class StaticMap {
public:
StaticMap() = default;
void set(const K& key, const V& value) {
AutoLock lock(mLock);
mItems.emplace(key, value);
}
void erase(const K& key) {
AutoLock lock(mLock);
mItems.erase(key);
}
bool isPresent(const K& key) const {
AutoLock lock(mLock);
auto it = mItems.find(key);
return it != mItems.end();
}
android::base::Optional<V> get(const K& key) const {
AutoLock lock(mLock);
auto it = mItems.find(key);
if (it == mItems.end()) {
return android::base::kNullopt;
}
return it->second;
}
using ErasePredicate = std::function<bool(K, V)>;
void eraseIf(ErasePredicate p) {
AutoLock lock(mLock);
auto it = mItems.begin();
for (; it != mItems.end();) {
if (p(it->first, it->second)) {
it = mItems.erase(it);
} else {
++it;
}
}
}
void clear() {
AutoLock lock(mLock);
mItems.clear();
}
private:
using AutoLock = android::base::AutoLock;
using Lock = android::base::Lock;
mutable android::base::Lock mLock;
std::unordered_map<K, V> mItems;
};
} // namespace base
} // namespace android