-/*
-Generates ids for comparable values.
-Id=0 is reserved for "no value".
-
-Is fast at:
-- Returning value by id (very fast)
-- Returning id by value
-- Generating a new id for a value
-
-Is not able to:
-- Remove an id/value pair (is possible to implement but slow)
-*/
-template<typename T>
-class MutexedIdGenerator
-{
-public:
- MutexedIdGenerator()
- {
- }
-
- // Returns true if found
- bool getValue(u32 id, T &value)
- {
- if(id == 0)
- return false;
- JMutexAutoLock lock(m_mutex);
- if(m_id_to_value.size() < id)
- return false;
- value = m_id_to_value[id-1];
- return true;
- }
-
- // If id exists for value, returns the id.
- // Otherwise generates an id for the value.
- u32 getId(const T &value)
- {
- JMutexAutoLock lock(m_mutex);
- typename std::map<T, u32>::iterator n;
- n = m_value_to_id.find(value);
- if(n != m_value_to_id.end())
- return n->second;
- m_id_to_value.push_back(value);
- u32 new_id = m_id_to_value.size();
- m_value_to_id.insert(value, new_id);
- return new_id;
- }
-
-private:
- JMutex m_mutex;
- // Values are stored here at id-1 position (id 1 = [0])
- std::vector<T> m_id_to_value;
- std::map<T, u32> m_value_to_id;
-};