using System;

using System.Collections.Generic;

using MLAPI.Logging;

namespace MLAPI.Serialization.Pooled

{

/// <summary>

/// Static class containing PooledBitStreams

/// </summary>

public static class BitStreamPool

{

private static byte createdStreams = 0;

private static readonly Queue<WeakReference> overflowStreams = new Queue<WeakReference>();

private static readonly Queue<PooledBitStream> streams = new Queue<PooledBitStream>();

/// <summary>

/// Retrieves an expandable PooledBitStream from the pool

/// </summary>

/// <returns>An expandable PooledBitStream</returns>

public static PooledBitStream GetStream()

{

if (overflowStreams.Count > 0)

{

if (LogHelper.CurrentLogLevel <= LogLevel.Developer) LogHelper.LogInfo("Retrieving PooledBitStream from overflow pool. Recent burst?");

WeakReference weakStream = null;

while (overflowStreams.Count > 0 && ((weakStream = overflowStreams.Dequeue()) == null || !weakStream.IsAlive)) ;

if (weakStream.IsAlive) return (PooledBitStream)weakStream.Target;

}

if (streams.Count == 0)

{

if (createdStreams == 254)

{

if (LogHelper.CurrentLogLevel <= LogLevel.Normal) LogHelper.LogWarning("255 streams have been created. Did you forget to dispose?");

}

else if (createdStreams < 255) createdStreams++;

return new PooledBitStream();

}

PooledBitStream stream = streams.Dequeue();

stream.SetLength(0);

stream.Position = 0;

return stream;

}

/// <summary>

/// Puts a PooledBitStream back into the pool

/// </summary>

/// <param name="stream">The stream to put in the pool</param>

public static void PutBackInPool(PooledBitStream stream)

{

if (streams.Count > 16)

{

//The user just created lots of streams without returning them in between.

//Streams are essentially byte array wrappers. This is valuable memory.

//Thus we put this stream as a weak reference incase of another burst

//But still leave it to GC

if (LogHelper.CurrentLogLevel <= LogLevel.Developer) LogHelper.LogInfo("Putting PooledBitStream into overflow pool. Did you forget to dispose?");

overflowStreams.Enqueue(new WeakReference(stream));

}

else

{

streams.Enqueue(stream);

}

}

}

}