internal static ConnectorPool GetOrAdd(string key, ConnectorPool pool)
{
lock (_lock)
{
if (TryGetValue(key, out var result))
{
return(result);
}
// May need to grow the array.
if (_nextSlot == _pools.Length)
{
var newPools = new (string, ConnectorPool)[_pools.Length * 2];
internal static bool TryGetValue(string key, out ConnectorPool pool)
{
// Note that pools never get removed. _pools is strictly append-only.
var nextSlot = _nextSlot;
var pools = _pools;
var sw = new SpinWait();
// First scan the pools and do reference equality on the connection strings
for (var i = 0; i < nextSlot; i++)
{
var cp = pools[i];
if (ReferenceEquals(cp.Key, key))
{
// It's possible that this pool entry is currently being written: the connection string
// component has already been writte, but the pool component is just about to be. So we
// loop on the pool until it's non-null
while (Volatile.Read(ref cp.Pool) == null)
{
sw.SpinOnce();
}
pool = cp.Pool;
return(true);
}
}
// Next try value comparison on the strings
for (var i = 0; i < nextSlot; i++)
{
var cp = pools[i];
if (cp.Key == key)
{
// See comment above
while (Volatile.Read(ref cp.Pool) == null)
{
sw.SpinOnce();
}
pool = cp.Pool;
return(true);
}
}
pool = null;
return(false);
}
public MultiHostConnectorPool(NpgsqlConnectionStringBuilder settings, string connString) : base(settings, connString)
{
var hosts = settings.Host !.Split(',');
_pools = new ConnectorPool[hosts.Length];
for (var i = 0; i < hosts.Length; i++)
{
var host = hosts[i].Trim();
var port = settings.Port;
var portSeparator = host.IndexOf(':');
if (portSeparator != -1)
{
port = int.Parse(host.Substring(portSeparator + 1));
host = host.Substring(0, portSeparator);
}
var poolSettings = settings.Clone();
poolSettings.Host = host;
poolSettings.Port = port;
_pools[i] = new ConnectorPool(poolSettings, poolSettings.ConnectionString, this);
}
}