jellyfin-server/Emby.Common.Implementations/IO/SharpCifs/Smb/BufferCache.cs

// This code is derived from jcifs smb client library <jcifs at samba dot org>
// Ported by J. Arturo <webmaster at komodosoft dot net>
//  
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
namespace SharpCifs.Smb
{
    public class BufferCache
    {
        private static readonly int MaxBuffers = Config.GetInt("jcifs.smb.maxBuffers", 16);

        internal static object[] Cache = new object[MaxBuffers];

        private static int _freeBuffers;

        public static byte[] GetBuffer()
        {
            lock (Cache)
            {
                byte[] buf;
                if (_freeBuffers > 0)
                {
                    for (int i = 0; i < MaxBuffers; i++)
                    {
                        if (Cache[i] != null)
                        {
                            buf = (byte[])Cache[i];
                            Cache[i] = null;
                            _freeBuffers--;
                            return buf;
                        }
                    }
                }
                buf = new byte[SmbComTransaction.TransactionBufSize];
                return buf;
            }
        }

        internal static void GetBuffers(SmbComTransaction req, SmbComTransactionResponse rsp)
        {
            lock (Cache)
            {
                req.TxnBuf = GetBuffer();
                rsp.TxnBuf = GetBuffer();
            }
        }

        public static void ReleaseBuffer(byte[] buf)
        {
            lock (Cache)
            {
                if (_freeBuffers < MaxBuffers)
                {
                    for (int i = 0; i < MaxBuffers; i++)
                    {
                        if (Cache[i] == null)
                        {
                            Cache[i] = buf;
                            _freeBuffers++;
                            return;
                        }
                    }
                }
            }
        }
    }
}