109 lines
3.1 KiB
C++
109 lines
3.1 KiB
C++
#include <vector>
|
|
#include <memory>
|
|
#include <mutex>
|
|
#include <functional>
|
|
#include <list>
|
|
#include <utility>
|
|
#include <boost/thread/shared_mutex.hpp>
|
|
|
|
template<typename Key,typename Value,typename Hash=std::hash<Key> >
|
|
class threadsafe_lookup_table
|
|
{
|
|
private:
|
|
class bucket_type
|
|
{
|
|
private:
|
|
typedef std::pair<Key,Value> bucket_value;
|
|
typedef std::list<bucket_value> bucket_data;
|
|
typedef typename bucket_data::iterator bucket_iterator;
|
|
|
|
bucket_data data;
|
|
mutable boost::shared_mutex mutex;
|
|
|
|
bucket_iterator find_entry_for(Key const& key) const
|
|
{
|
|
return std::find_if(data.begin(),data.end(),
|
|
[&](bucket_value const& item)
|
|
{return item.first==key;});
|
|
}
|
|
public:
|
|
Value value_for(Key const& key,Value const& default_value) const
|
|
{
|
|
boost::shared_lock<boost::shared_mutex> lock(mutex);
|
|
bucket_iterator const found_entry=find_entry_for(key);
|
|
return (found_entry==data.end())?
|
|
default_value : found_entry->second;
|
|
}
|
|
|
|
void add_or_update_mapping(Key const& key,Value const& value)
|
|
{
|
|
std::unique_lock<boost::shared_mutex> lock(mutex);
|
|
bucket_iterator const found_entry=find_entry_for(key);
|
|
if(found_entry==data.end())
|
|
{
|
|
data.push_back(bucket_value(key,value));
|
|
}
|
|
else
|
|
{
|
|
found_entry->second=value;
|
|
}
|
|
}
|
|
|
|
void remove_mapping(Key const& key)
|
|
{
|
|
std::unique_lock<boost::shared_mutex> lock(mutex);
|
|
bucket_iterator const found_entry=find_entry_for(key);
|
|
if(found_entry!=data.end())
|
|
{
|
|
data.erase(found_entry);
|
|
}
|
|
}
|
|
};
|
|
|
|
std::vector<std::unique_ptr<bucket_type> > buckets;
|
|
Hash hasher;
|
|
|
|
bucket_type& get_bucket(Key const& key) const
|
|
{
|
|
std::size_t const bucket_index=hasher(key)%buckets.size();
|
|
return *buckets[bucket_index];
|
|
}
|
|
|
|
public:
|
|
typedef Key key_type;
|
|
typedef Value mapped_type;
|
|
typedef Hash hash_type;
|
|
|
|
threadsafe_lookup_table(
|
|
unsigned num_buckets=19, Hash const& hasher_=Hash()):
|
|
buckets(num_buckets),hasher(hasher_)
|
|
{
|
|
for(unsigned i=0;i<num_buckets;++i)
|
|
{
|
|
buckets[i].reset(new bucket_type);
|
|
}
|
|
}
|
|
|
|
threadsafe_lookup_table(threadsafe_lookup_table const& other)=delete;
|
|
threadsafe_lookup_table& operator=(
|
|
threadsafe_lookup_table const& other)=delete;
|
|
|
|
Value value_for(Key const& key,
|
|
Value const& default_value=Value()) const
|
|
{
|
|
return get_bucket(key).value_for(key,default_value);
|
|
}
|
|
|
|
void add_or_update_mapping(Key const& key,Value const& value)
|
|
{
|
|
get_bucket(key).add_or_update_mapping(key,value);
|
|
}
|
|
|
|
void remove_mapping(Key const& key)
|
|
{
|
|
get_bucket(key).remove_mapping(key);
|
|
}
|
|
};
|
|
|
|
|