public override long Seek(long offset, SeekOrigin origin)
{
long newPosition = StreamHelpers.ComputeNewPosition(offset, origin, this.Length, this.Position);
if (newPosition < SignatureStream.HeaderLength)
{
this.InitializeHeader();
this.bufferStream.Seek(newPosition, SeekOrigin.Begin);
}
else
{
// if we are in the main section of the file, we calculate which block we are in
// then we seek to the point at the start of that block in the source file
// we refill the buffer and seek into it the remainder bytes
long adjustedPosition = newPosition - SignatureStream.HeaderLength;
int blockSize = (4 + this.settings.StrongSumLength);
long remainderBytes;
long blockNumber = Math.DivRem(adjustedPosition, blockSize, out remainderBytes);
this.inputStream.Seek(blockNumber * this.settings.BlockLength, SeekOrigin.Begin);
this.FillBuffer(); // this reads the next block and computes it's hash
this.bufferStream.Seek(remainderBytes, SeekOrigin.Begin);
}
this.currentPosition = newPosition;
return(this.currentPosition);
}
public override long Seek(long offset, SeekOrigin origin)
{
long num = StreamHelpers.ComputeNewPosition(offset, origin, Length, Position);
long num2 = 0L;
int i;
for (i = 0; i < commandSummary.Count; i++)
{
long num3 = num2;
CommandPosition commandPosition = commandSummary[i];
long num4 = num3 + commandPosition.Command.Length;
if (num4 > num)
{
break;
}
num2 = num4;
}
if (i == commandSummary.Count)
{
throw new ArgumentException("The specified offset is past the end of the stream");
}
delta.Seek(commandSummary[i].DeltaStartPosition, SeekOrigin.Begin);
Command command = ReadCommand(deltaReader);
currentCopyHelper = ConstructCopyHelperForCommand(command, input, delta);
currentCopyHelper.SeekForward(num - num2);
outputPosition = num;
return(num);
}
public override long Seek(long offset, SeekOrigin origin)
{
long num = StreamHelpers.ComputeNewPosition(offset, origin, Length, Position);
if (num < 12)
{
InitializeHeader();
bufferStream.Seek(num, SeekOrigin.Begin);
}
else
{
long a = num - 12;
int num2 = 4 + settings.StrongSumLength;
long result;
long num3 = Math.DivRem(a, num2, out result);
inputStream.Seek(num3 * settings.BlockLength, SeekOrigin.Begin);
FillBuffer();
bufferStream.Seek(result, SeekOrigin.Begin);
}
currentPosition = num;
return(currentPosition);
}
public override long Seek(long offset, SeekOrigin origin)
{
long newPosition = StreamHelpers.ComputeNewPosition(offset, origin, this.Length, this.Position);
// search until we find the command just before this position
long runningTotal = 0;
int i;
for (i = 0; i < this.commandSummary.Count; i++)
{
// if this is the first command that takes us past the desired position
long newTotal = runningTotal + this.commandSummary[i].Command.Length;
if (newTotal > newPosition)
{
break;
}
runningTotal = newTotal;
}
if (i == this.commandSummary.Count)
{
throw new ArgumentException("The specified offset is past the end of the stream");
}
// seek to the point that that command starts
this.delta.Seek(this.commandSummary[i].DeltaStartPosition, SeekOrigin.Begin);
// now read that command in
var command = ReadCommand(this.deltaReader);
// construct a copy helper to run that command
this.currentCopyHelper = ConstructCopyHelperForCommand(command, this.input, this.delta);
// finally seek into the copy helper for whatever bytes are left over
this.currentCopyHelper.SeekForward(newPosition - runningTotal);
this.outputPosition = newPosition;
return(newPosition);
}