/// <summary>
/// 读取一个数据包
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected async Task <ArraySegment <byte> > ReadPackageAsync(CancellationToken token)
{
var stream = QpPackageHandler_Stream;
if (stream == null)
{
throw new ArgumentNullException(nameof(QpPackageHandler_Stream));
}
//最终包缓存
ArraySegment <byte> finalPackageBuffer;
//是否正在读取拆分包
bool isReadingSplitPackage = false;
int splitMsCapacity = 0;
MemoryStream splitMs = null;
while (true)
{
var currentRecvBuffer = recvBuffer;
//读取包头
var ret = await readData(stream, currentRecvBuffer, 0, PACKAGE_TOTAL_LENGTH_LENGTH, token);
if (token.IsCancellationRequested)
{
return(nullArraySegment);
}
if (ret == 0)
{
throw new IOException("未读取到数据！");
}
if (ret < PACKAGE_TOTAL_LENGTH_LENGTH)
{
throw new ProtocolException(new ArraySegment <byte>(recvBuffer, 0, ret), $"包头读取错误！包头长度：{PACKAGE_TOTAL_LENGTH_LENGTH}，读取数据长度：{ret}");
}
var currentRecvBuffer2 = recvBuffer;
//如果读取缓存数组对象变化
if (currentRecvBuffer != currentRecvBuffer2)
{
Array.Copy(currentRecvBuffer, currentRecvBuffer2, PACKAGE_TOTAL_LENGTH_LENGTH);
}
//包总长度
var packageTotalLength = ByteUtils.B2I_BE(recvBuffer, 0);
if (packageTotalLength < PACKAGE_HEAD_LENGTH)
{
throw new ProtocolException(new ArraySegment <byte>(recvBuffer, 0, ret), $"包长度[{packageTotalLength}]必须大于等于{PACKAGE_HEAD_LENGTH}！");
}
if (packageTotalLength > recvBuffer.Length)
{
throw new ProtocolException(new ArraySegment <byte>(recvBuffer, 0, ret), $"数据包总长度[{packageTotalLength}]大于缓存大小[{recvBuffer.Length}]");
}
//包体长度
var packageBodyLength = packageTotalLength - PACKAGE_TOTAL_LENGTH_LENGTH;
//读取包体
ret = await readData(stream, recvBuffer, PACKAGE_TOTAL_LENGTH_LENGTH, packageBodyLength, token);
if (token.IsCancellationRequested)
{
return(nullArraySegment);
}
if (ret < packageBodyLength)
{
throw new ProtocolException(new ArraySegment <byte>(recvBuffer, 0, PACKAGE_HEAD_LENGTH + ret), $"包体读取错误！包体长度：{packageBodyLength}，读取数据长度：{ret}");
}
var currentPackageBuffer = new ArraySegment <byte>(recvBuffer, 0, packageTotalLength);
//如果设置了压缩或者加密
if (options.InternalCompress || options.InternalEncrypt)
{
//如果设置了加密，则先解密
if (options.InternalEncrypt)
{
try
{
var retBuffer = dec.TransformFinalBlock(currentPackageBuffer.Array, PACKAGE_TOTAL_LENGTH_LENGTH + currentPackageBuffer.Offset, currentPackageBuffer.Count - PACKAGE_TOTAL_LENGTH_LENGTH);
var currentBuffer = getFreeBuffer(currentPackageBuffer.Array, recvBuffer, recvBuffer2);
packageTotalLength = PACKAGE_TOTAL_LENGTH_LENGTH + retBuffer.Length;
writePackageTotalLengthToBuffer(currentBuffer, 0, packageTotalLength);
Array.Copy(retBuffer, 0, currentBuffer, PACKAGE_TOTAL_LENGTH_LENGTH, retBuffer.Length);
currentPackageBuffer = new ArraySegment <byte>(currentBuffer, 0, packageTotalLength);
}
catch (Exception ex)
{
throw ex;
}
}
//如果设置了压缩，则先解压
if (options.InternalCompress)
{
var retBuffer = getFreeBuffer(currentPackageBuffer.Array, recvBuffer, recvBuffer2);
var count = 0;
using (var readMs = new MemoryStream(currentPackageBuffer.Array, PACKAGE_TOTAL_LENGTH_LENGTH + currentPackageBuffer.Offset, currentPackageBuffer.Count - PACKAGE_TOTAL_LENGTH_LENGTH, false))
using (var writeMs = new MemoryStream(retBuffer, 0, retBuffer.Length))
{
using (var gzStream = new GZipStream(readMs, CompressionMode.Decompress, true))
gzStream.CopyTo(writeMs);
count = Convert.ToInt32(writeMs.Position);
}
var currentBuffer = getFreeBuffer(retBuffer, recvBuffer, recvBuffer2);
packageTotalLength = PACKAGE_TOTAL_LENGTH_LENGTH + count;
writePackageTotalLengthToBuffer(currentBuffer, 0, packageTotalLength);
Array.Copy(retBuffer, 0, currentBuffer, PACKAGE_TOTAL_LENGTH_LENGTH, count);
currentPackageBuffer = new ArraySegment <byte>(currentBuffer, 0, packageTotalLength);
}
}
var packageType = (QpPackageType)currentPackageBuffer.Array[currentPackageBuffer.Offset + PACKAGE_HEAD_LENGTH - 1];
//如果当前包是拆分包
if (packageType == QpPackageType.Split)
{
if (!isReadingSplitPackage)
{
var tmpPackageBodyLength = ByteUtils.B2I_BE(currentPackageBuffer.Array, currentPackageBuffer.Offset + PACKAGE_HEAD_LENGTH);
splitMsCapacity = tmpPackageBodyLength;
if (splitMsCapacity <= 0)
{
throw new IOException($"拆分包中包长度[{splitMsCapacity}]必须为正数！");
}
if (splitMsCapacity > options.MaxPackageSize)
{
throw new IOException($"拆分包中包长度[{splitMsCapacity}]大于最大包大小[{options.MaxPackageSize}]");
}
splitMs = new MemoryStream(splitMsCapacity);
isReadingSplitPackage = true;
}
splitMs.Write(currentPackageBuffer.Array, currentPackageBuffer.Offset + PACKAGE_HEAD_LENGTH, currentPackageBuffer.Count - PACKAGE_HEAD_LENGTH);
//如果拆分包已经读取完成
if (splitMs.Position >= splitMsCapacity)
{
finalPackageBuffer = new ArraySegment <byte>(splitMs.ToArray());
splitMs.Dispose();
if (LogUtils.LogSplit)
{
LogUtils.Log("{0}: [Recv-SplitPackage]Length:{1}", DateTime.Now, finalPackageBuffer.Count);
}
break;
}
}
else
{
finalPackageBuffer = currentPackageBuffer;
break;
}
}
if (LogUtils.LogPackage)
{
LogUtils.Log(
"{0}: [Recv-Package]Length:{1}，Type:{2}，Content:{3}",
DateTime.Now,
finalPackageBuffer.Count,
(QpPackageType)finalPackageBuffer.Array[finalPackageBuffer.Offset + PACKAGE_HEAD_LENGTH - 1],
LogUtils.LogContent ?
BitConverter.ToString(finalPackageBuffer.Array, finalPackageBuffer.Offset, finalPackageBuffer.Count)
: LogUtils.NOT_SHOW_CONTENT_MESSAGE);
}
return(new ArraySegment <byte>(finalPackageBuffer.Array,
finalPackageBuffer.Offset,
finalPackageBuffer.Count));
}