private VRange Find(uint offset)
{
if (_cache.InRange((int)offset))
{
return(_cache);
}
int min = 0, max = _ranges.Count - 1;
while (min <= max)
{
int check = (min + max + 1) / 2;
VRange r = _ranges[check];
if (offset < r.Start)
{
max = check - 1;
}
else if (offset > r.LastValidOffset)
{
min = check + 1;
}
else
{
return(r);
}
}
return(null);
}
public void Add(VRange range)
{
if (_ranges.Count == 0)
{
_ranges.Add(range);
_cache = _ranges[0];
return;
}
VRange prev = _ranges.Last();
if (range.Start != (prev.Start + prev.Length))
{
throw new VFileException(String.Format("Range mismatch on add - {0} != {1} + {2}", range.Start, prev.Start, prev.Length));
}
VRangeHandle hprev = prev as VRangeHandle, hcurr = range as VRangeHandle;
if ((hprev != null) && (hcurr != null) && (hprev.Handle == hcurr.Handle) && ((hprev.Offset + hprev.Length) == hcurr.Offset))
{
(prev as VRangeHandle).Length += range.Length;
//DebugLogger.WriteLine("---expanding existing range");
}
else
{
_ranges.Last().Next = range;
_ranges.Add(range);
}
_cache = _ranges[0];
}
public void Read(uint offset, uint length, IntPtr dest, ref uint bytesRead)
{
VRange r = _cache = Find(offset);
bytesRead = 0;
uint remaining = length;
do
{
uint read = 0;
uint roffset = offset - r.Start;
uint toread = Math.Min(remaining, r.Length - roffset);
r.Read(roffset, toread, dest, ref read);
bytesRead += read;
dest += (int)read;
offset += read;
remaining -= read;
if (read < toread)
{
return;
}
r = r.Next;
} while (remaining > 0 && r != null);
}
