/// <summary>
/// Constructor
/// </summary>
private MultiPartFile(Stream stream)
{
this.stream = stream;
this.partStart = 0;
this.Position = 0;
this.partEnd = stream.Length - 1;
this.Length = partEnd + 1;
this.next = null;
}
/// <summary>
/// Read from the MultiPartFile to a buffer
/// </summary>
public bool Read(byte[] x, int offset, int amount)
{
int bufpos;
MultiPartFile mf = this;
while (Position > mf.partEnd && mf.next != null)
{
mf = mf.next;
}
if (Position <= mf.partEnd)
{
mf.stream.Seek(Position - mf.partStart, SeekOrigin.Begin);
if (mf.partEnd + 1 - Position >= amount)
{
mf.stream.Read(x, offset, amount);
Position += amount;
}
else
{
byte[] buf = new byte[0xffff];
bufpos = 0;
do
{
if (mf.partEnd + 1 < Position + amount - bufpos)
{
mf.stream.Read(buf, bufpos, (int)(mf.partEnd + 1 - Position));
bufpos += (int)(mf.partEnd + 1 - Position);
Position = mf.partEnd + 1;
mf = mf.next;
}
else
{
mf.stream.Read(buf, bufpos, amount - bufpos);
Position += amount - bufpos;
bufpos = amount;
}
}while (bufpos != amount);
Array.ConstrainedCopy(buf, 0, x, offset, amount);
}
return(true);
}
return(false);
}
/// <summary>
/// Append a new MultiPartFile to the current one
/// </summary>
/// <param name="mpf">New MultiPartFile to append</param>
private bool Append(MultiPartFile mpf)
{
// If the part is invalid, we can't append
if (mpf == null)
{
return(false);
}
// Find the current last part
var mf = this;
while (next != null)
{
mf = mf.next;
}
// Assign the new part as the new end
mf.next = mpf;
mf.next.partStart = this.Length;
mf.next.partEnd += this.Length;
this.Length = mf.next.partEnd + 1;
return(true);
}
