/* | |
* | |
* Licensed to the Apache Software Foundation (ASF) under one | |
* or more contributor license agreements. See the NOTICE file | |
* distributed with this work for additional information | |
* regarding copyright ownership. The ASF licenses this file | |
* to you under the Apache License, Version 2.0 (the | |
* "License"); you may not use this file except in compliance | |
* with the License. You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, | |
* software distributed under the License is distributed on an | |
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
* KIND, either express or implied. See the License for the | |
* specific language governing permissions and limitations | |
* under the License. | |
* | |
*/ | |
using System; | |
using System.Threading; | |
namespace common.org.apache.qpid.transport.util | |
{ | |
public class CircularBuffer<T> | |
{ | |
private readonly T[] buffer; | |
private Int32 nrp, nwp; | |
private readonly Int32 len; | |
private Int32 countValue; | |
private readonly Int32 add; | |
/// <summary> | |
/// Constructor creates N=len element | |
/// Circular Buffer that olds MemoryStream | |
/// </summary> | |
public CircularBuffer(Int32 len) | |
{ | |
buffer = new T[len]; | |
this.len = len; | |
add = 1 - len; | |
nrp = 0; | |
nwp = 0; | |
countValue = 0; | |
} | |
public void Enqueue(T t) | |
{ | |
lock (this) | |
{ | |
if (countValue >= (len - 1)) | |
{ | |
// wait for room to be available | |
Monitor.Wait(this); | |
} | |
bool notifyDequeue = countValue <= 0; | |
load(t); | |
if (notifyDequeue) //notifyDequeue) | |
{ | |
Monitor.PulseAll(this); | |
} | |
} | |
} | |
public T Dequeue() | |
{ | |
lock (this) | |
{ | |
if (countValue <= 0) | |
{ | |
Monitor.Wait(this); | |
} | |
bool notifyEnqueue = countValue >= (len - 1); | |
T temp = get(); | |
if (notifyEnqueue) //notifyEnqueue) | |
{ | |
Monitor.PulseAll(this); | |
} | |
return temp; | |
} | |
} | |
public void close() | |
{ | |
nrp = 0; | |
nwp = 0; | |
countValue = 0; | |
Array.Clear(buffer, 0, len); | |
lock (this) | |
{ | |
Monitor.PulseAll(this); | |
} | |
} | |
#region Private Support Functions | |
private void load(T t) | |
{ | |
Int32 i = nwp; | |
buffer[i] = t; | |
i += add; | |
if (i < 0) i += len; | |
nwp = i; | |
updateCount(); | |
} | |
private void updateCount() | |
{ | |
countValue = nwp - nrp; | |
if (countValue <= 0 ) | |
countValue += len; // modulo buffer size | |
} | |
private T get() | |
{ | |
Int32 i = nrp; | |
T temp = buffer[i]; | |
i += add; | |
if (i < 0) i += len; | |
nrp = i; | |
countValue--; | |
return (temp); | |
} | |
#endregion | |
} | |
} |