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#ifndef QPID_CLUSTER_LOCKEDMAP_H
#define QPID_CLUSTER_LOCKEDMAP_H
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 "qpid/sys/Mutex.h"
#include <map>
namespace qpid {
namespace cluster {
/**
* A reader-writer locked thread safe map.
*/
template <class Key, class Value>
class LockedMap
{
public:
/** Get value associated with key, returns Value() if none. */
Value get(const Key& key) const {
sys::RWlock::ScopedRlock r(lock);
typename Map::const_iterator i = map.find(key);
return (i == map.end()) ? Value() : i->second;
}
/** Update value with the value for key.
*@return true if key was found.
*/
bool get(const Key& key, Value& value) const {
sys::RWlock::ScopedRlock r(lock);
typename Map::const_iterator i = map.find(key);
if (i != map.end()) {
value = i->second;
return true;
}
return false;
}
/** Associate value with key, overwriting any previous value for key. */
void put(const Key& key, const Value& value) {
sys::RWlock::ScopedWlock w(lock);
map[key] = value;
}
/** Associate value with key if there is not already a value associated with key.
* Returns true if the value was added.
*/
bool add(const Key& key, const Value& value) {
sys::RWlock::ScopedWlock w(lock);
return map.insert(std::make_pair(key, value)).second;
}
/** Erase the value associated with key if any. Return true if a value was erased. */
bool erase(const Key& key) {
sys::RWlock::ScopedWlock w(lock);
return map.erase(key);
}
/** Remove and return value associated with key, returns Value() if none. */
Value pop(const Key& key) {
sys::RWlock::ScopedWlock w(lock);
Value value;
typename Map::iterator i = map.find(key);
if (i != map.end()) {
value = i->second;
map.erase(i);
}
return value;
}
private:
typedef std::map<Key, Value> Map;
Map map;
mutable sys::RWlock lock;
};
}} // namespace qpid::cluster
#endif /*!QPID_CLUSTER_LOCKEDMAP_H*/
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