| /* |
| * |
| * 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 |
| } |
| } |