public bool MovePrevious()
{
AllocationTableEntry currentEntry = Fat.Entries[PhysicalBlock + 1];
if (currentEntry.IsListStart())
{
return(false);
}
int newBlock = currentEntry.Prev & 0x7FFFFFFF;
AllocationTableEntry newEntry = Fat.Entries[newBlock];
if (newEntry.IsSingleBlockSegment())
{
CurrentSegmentSize = 1;
}
else
{
AllocationTableEntry lengthEntry = Fat.Entries[newBlock + 1];
CurrentSegmentSize = lengthEntry.Next - (newBlock - 1);
}
VirtualBlock -= CurrentSegmentSize;
PhysicalBlock = newBlock - 1;
return(true);
}
public AllocationTable(Stream tableStream)
{
int blockCount = (int)(tableStream.Length / 8);
Entries = new AllocationTableEntry[blockCount];
tableStream.Position = 0;
var reader = new BinaryReader(tableStream);
for (int i = 0; i < blockCount; i++)
{
int parent = reader.ReadInt32();
int child = reader.ReadInt32();
Entries[i] = new AllocationTableEntry {
Next = child, Prev = parent
};
}
}
public bool BeginIteration(int initialBlock)
{
AllocationTableEntry tableEntry = Fat.Entries[initialBlock + 1];
if (!tableEntry.IsListStart())
{
return(false);
}
if (tableEntry.IsSingleBlockSegment())
{
CurrentSegmentSize = 1;
}
else
{
AllocationTableEntry lengthEntry = Fat.Entries[initialBlock + 2];
CurrentSegmentSize = lengthEntry.Next - initialBlock;
}
PhysicalBlock = initialBlock;
return(true);
}
