using System;

using System.Collections.Concurrent;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Simple.Data

{

class CachingAdapterFactory : AdapterFactory

{

public CachingAdapterFactory()

{

}

public CachingAdapterFactory(Composer composer) : base(composer)

{

}

private readonly ConcurrentDictionary<string, Adapter> _cache = new ConcurrentDictionary<string, Adapter>();

public override Adapter Create(string adapterName, IEnumerable<KeyValuePair<string, object>> settings)

{

List<KeyValuePair<string, object>> mat;

string hash;

if (settings == null)

{

mat = new List<KeyValuePair<string, object>>();

hash = adapterName;

}

else

{

mat = settings.ToList();

hash = HashSettings(adapterName, mat);

}

var adapter = _cache.GetOrAdd(hash, _ => DoCreate(adapterName, mat));

var cloneable = adapter as ICloneable;

if (cloneable != null) return (Adapter)cloneable.Clone();

return adapter;

}

private static string HashSettings(string adapterName, IEnumerable<KeyValuePair<string, object>> settings)

{

return adapterName +

string.Join("#", settings.Select(kvp => kvp.Key + "=" + kvp.Value));

}

public void Reset()

{

_cache.Clear();

}

}

}