protected void ProcessBlock(Byte[] block)
{
if (block[0] != 0x0a || block[1] != 0xf3)
{
throw new Exception("Missing extent tree header!");
}
UInt32 entry_count;
UInt32 max_entry_count;
UInt32 depth;
Utils.LoadLE16(out entry_count, block, 2);
Utils.LoadLE16(out max_entry_count, block, 4);
Utils.LoadLE16(out depth, block, 6);
if (depth == 0)
{
UInt32 extent_id;
UInt32 extent_length;
Int64 start_block;
Int64 temp;
for (uint i = 0; i < entry_count; i++)
{
Utils.LoadLE32(out extent_id, block, 12 + i * 12);
Utils.LoadLE16(out extent_length, block, 12 + i * 12 + 4);
Utils.LoadLE16To64(out temp, block, 12 + i * 12 + 6);
Utils.LoadLE32To64(out start_block, block, 12 + i * 12 + 8);
start_block += temp * 0x100000000;
extents.AddLast(new Extent(extent_id, start_block, extent_length));
if (current_extent == null)
{
current_extent = extents.First;
}
}
}
else
{
UInt32 id;
Int64 next_node;
Int64 temp;
for (uint i = 0; i < entry_count; i++)
{
Utils.LoadLE32(out id, block, 12 + i * 12);
Utils.LoadLE32To64(out next_node, block, 12 + i * 12 + 4);
Utils.LoadLE16To64(out temp, block, 12 + i * 12 + 8);
next_node += temp * 0x100000000;
Byte[] child_block = new Byte[filesystem.BlockSize];
filesystem.ReadBlock(child_block, next_node);
ProcessBlock(child_block);
}
}
}
public bool ReadNextBlock(Byte[] block)
{
if (direct_position < 12)
{
if (direct_block[direct_position] == 0)
{
return(false);
}
filesystem.ReadBlock(block, direct_block[direct_position++]);
return(true);
}
else
{
if (direct_block[direct_position] == 0 || direct_position > 14)
{
return(false);
}
while (indirect_level < direct_position - 11)
{
if (indirect_level == 0)
{
indirect_position.AddLast(0);
Byte[] ptr_block = new Byte[filesystem.BlockSize];
filesystem.ReadBlock(ptr_block, direct_block[direct_position]);
indirect_block.AddLast(ptr_block);
current_indirect_block = indirect_block.Last;
current_indirect_position = indirect_position.Last;
indirect_level++;
}
else
{
UInt32 intermediate_block_id;
Utils.LoadLE32(out intermediate_block_id,
current_indirect_block.Value,
current_indirect_position.Value);
if (intermediate_block_id == 0)
{
return(false);
}
indirect_position.AddLast(0);
Byte[] ptr_block = new Byte[filesystem.BlockSize];
filesystem.ReadBlock(ptr_block, intermediate_block_id);
indirect_block.AddLast(ptr_block);
current_indirect_block = indirect_block.Last;
current_indirect_position = indirect_position.Last;
indirect_level++;
}
}
UInt32 final_block_id;
Utils.LoadLE32(out final_block_id, current_indirect_block.Value, current_indirect_position.Value);
if (final_block_id == 0)
{
return(false);
}
filesystem.ReadBlock(block, final_block_id);
while (indirect_level > 0 && current_indirect_position.Value + 4 >= filesystem.BlockSize)
{
current_indirect_position = current_indirect_position.Previous;
current_indirect_block = current_indirect_block.Previous;
indirect_position.RemoveLast();
indirect_block.RemoveLast();
indirect_level--;
}
if (indirect_level == 0)
{
direct_position++;
}
else
{
current_indirect_position.Value += 4;
}
}
return(true);
}
