public ConnectionStringPool(string connectionString, ConnectionPool pool)
{
ConnectionString = connectionString;
Pool = pool;
}
public static ConnectionPool?GetPool(string connectionString)
{
// check single-entry MRU cache for this exact connection string; most applications have just one
// connection string and will get a cache hit here
var cache = s_mruCache;
if (cache?.ConnectionString == connectionString)
{
return(cache.Pool);
}
// check if pool has already been created for this exact connection string
if (s_pools.TryGetValue(connectionString, out var pool))
{
s_mruCache = new(connectionString, pool);
return(pool);
}
// parse connection string and check for 'Pooling' setting; return 'null' if pooling is disabled
var connectionStringBuilder = new MySqlConnectionStringBuilder(connectionString);
if (!connectionStringBuilder.Pooling)
{
s_pools.GetOrAdd(connectionString, default(ConnectionPool));
s_mruCache = new(connectionString, null);
return(null);
}
// check for pool using normalized form of connection string
var normalizedConnectionString = connectionStringBuilder.ConnectionString;
if (normalizedConnectionString != connectionString && s_pools.TryGetValue(normalizedConnectionString, out pool))
{
// try to set the pool for the connection string to the canonical pool; if someone else
// beats us to it, just use the existing value
pool = s_pools.GetOrAdd(connectionString, pool) !;
s_mruCache = new(connectionString, pool);
return(pool);
}
// create a new pool and attempt to insert it; if someone else beats us to it, just use their value
var connectionSettings = new ConnectionSettings(connectionStringBuilder);
var newPool = new ConnectionPool(connectionSettings);
pool = s_pools.GetOrAdd(normalizedConnectionString, newPool);
if (pool == newPool)
{
s_mruCache = new(connectionString, pool);
pool.StartReaperTask();
// if we won the race to create the new pool, also store it under the original connection string
if (connectionString != normalizedConnectionString)
{
s_pools.GetOrAdd(connectionString, pool);
}
}
else if (pool != newPool && Log.IsInfoEnabled())
{
Log.Info("Pool{0} was created but will not be used (due to race)", newPool.m_logArguments);
}
return(pool);
}
public LeastConnectionsLoadBalancer(ConnectionPool pool) => m_pool = pool;
