public override int Read(byte[] array, int offset, int count)
{
if (_CacheBufferIndex != null)
{
int index = (int)(this.Position / CachedFileBufferManager.BufferUnitSize);
int offsetInBuffer = (int)(this.Position % CachedFileBufferManager.BufferUnitSize);
if (_CacheBufferIndex[index] != null)
{
CachedFileBufferManager.Buffer buffer = _CacheBufferIndex[index];
byte[] data = _CacheBufferIndex[index].Data;
if (data != null)
{
if (data.Length - offsetInBuffer - buffer.HeadPosition >= count)
{
//Data inside one block.
Array.Copy(data, offsetInBuffer + buffer.HeadPosition, array, offset, count);
Position += count;
return(count);
}
else
{
if (buffer.HeadPosition > 0 || index == _CacheBufferIndex.Length - 1 || count < 10 * 1024)
{
//Data outside one block. but the index is not the beginning of the block
//Or it is the last block
//Or small count less than 10K
//Return part of the data
int len = data.Length - offsetInBuffer - buffer.HeadPosition;
Array.Copy(data, offsetInBuffer + buffer.HeadPosition, array, offset, len);
Position += len;
return(len);
}
}
}
}
if ((_Type == CachedType.Dynamic || _Type == CachedType.Full) &&
CacheAllFinished)
{
OffsetLength ol = _LastOLWithBuffer[index];
if (offsetInBuffer >= ol.Offset && offsetInBuffer <= ol.Offset + ol.Length)
{
ol.Length += count - (ol.Offset + ol.Length - offsetInBuffer);
}
else
{
ol.Offset = offsetInBuffer;
ol.Length = count;
}
_LastOLWithBuffer[index] = ol;
if (ol.Length >= MinCacheLength)
{
//Cached
if (LoadToBuffer(count, Position))
{
return(Read(array, offset, count));
}
}
}
//return data from file
base.Seek(Position, SeekOrigin.Begin);
int retLen = base.Read(array, offset, count);
Position += retLen;
return(retLen);
}
return(base.Read(array, offset, count));
}
/// <summary>
/// Read and output to array
/// </summary>
/// <param name="array">array</param>
/// <param name="offsetInArray">offset in array</param>
/// <param name="offset">offset in file</param>
/// <param name="count">count want to read</param>
/// <returns>actual read count</returns>
public int Read(out byte[] array, out int offsetInArray, int count)
{
if (_CacheBufferIndex != null)
{
int index = (int)(this.Position / CachedFileBufferManager.BufferUnitSize);
int offsetInBuffer = (int)(this.Position % CachedFileBufferManager.BufferUnitSize);
if (_CacheBufferIndex[index] != null)
{
CachedFileBufferManager.Buffer buffer = _CacheBufferIndex[index];
byte[] data = _CacheBufferIndex[index].Data;
if (data != null)
{
if (data.Length - offsetInBuffer - buffer.HeadPosition >= count)
{
array = data;
offsetInArray = offsetInBuffer + buffer.HeadPosition;
Position += count;
return(count);
}
else
{
if (buffer.HeadPosition > 0 || index == _CacheBufferIndex.Length - 1 || count < 10 * 1024)
{
//Data outside one block. but the index is not the beginning of the block
//Or it is the last block
//Or small count less than 10K
//Return part of the data
array = new byte[count];
Stream.ReadToBuf(this, array, 0, ref count);
offsetInArray = 0;
return(count);
}
}
}
}
if ((_Type == CachedType.Dynamic || _Type == CachedType.Full) &&
CacheAllFinished)
{
OffsetLength ol = _LastOLWithBuffer[index];
if (offsetInBuffer >= ol.Offset && offsetInBuffer <= ol.Offset + ol.Length)
{
ol.Length += count - (ol.Offset + ol.Length - offsetInBuffer);
}
else
{
ol.Offset = offsetInBuffer;
ol.Length = count;
}
_LastOLWithBuffer[index] = ol;
if (ol.Length >= MinCacheLength)
{
//Cached
if (LoadToBuffer(count, Position))
{
return(Read(out array, out offsetInArray, count));
}
}
}
//return data from file
array = new byte[count];
Stream.ReadToBuf(this, array, 0, ref count);
offsetInArray = 0;
return(count);
}
array = new byte[count];
offsetInArray = 0;
Stream.ReadToBuf(this, array, 0, ref count);
return(count);
}
