static byte[] calculate_hash(string input)
{
byte[] input_bytes = get_length_seq(input);
// Initialize the queue
FlipCircleQueue fcq = apply_operations(input_bytes);
return(extract_hash(fcq));
}
static byte[] extract_hash(FlipCircleQueue fcq)
{
Node node = fcq.head;
byte[] sums = new byte[QUEUE_SIZE / 16];
for (int i = 0; i < QUEUE_SIZE; i++)
{
sums [i / 16] = (byte)(sums [i / 16] ^ (byte)node.value);
node = fcq.get_next(node);
}
return(sums);
}
static string extract_hash(FlipCircleQueue fcq)
{
Node node = fcq.head;
byte[] sums = new byte[QUEUE_SIZE / 16];
for (int i = 0; i < QUEUE_SIZE; i++)
{
sums [i / 16] = (byte)(sums [i / 16] ^ (byte)node.value);
node = fcq.get_next(node);
}
return(BitConverter.ToString(sums).Replace("-", "").ToLower());
}
public void merge(FlipCircleQueue other)
{
Node node = other.head;
while (true)
{
Node next_node = other.get_next(node);
this.add_node(node);
if (next_node == other.head)
{
break;
}
node = next_node;
}
}
static FlipCircleQueue apply_operations(byte[] input_bytes)
{
FlipCircleQueue fcq = new FlipCircleQueue();
for (int i = 0; i < QUEUE_SIZE; i++)
{
fcq.add_node(i);
}
uint skip_size = 0;
// Once we move the queue head back and force, we need to keep
// track of the original start position for the final calculation.
long start_pos = 0;
for (int iteration = 0; iteration < 64; iteration++)
{
foreach (uint l in input_bytes)
{
if (l > 0)
{
FlipCircleQueue cut = fcq.cut(fcq.head, l);
cut.flip();
cut.reset_head(cut.n_from_head(1));
fcq.merge(cut);
}
fcq.reset_head(fcq.n_from_head(skip_size));
start_pos = (QUEUE_SIZE + start_pos - l - skip_size) % QUEUE_SIZE;
skip_size++;
}
}
// Calculate the hash
start_pos = (start_pos + QUEUE_SIZE) % QUEUE_SIZE;
fcq.reset_head(fcq.n_from_head((uint)start_pos));
return(fcq);
}
public FlipCircleQueue cut(Node start, uint len)
{
Node end = n_from_node(start, len - 1);
Node pre_start = get_prev(start);
Node post_end = get_next(end);
if (start == post_end)
{
this.head = null;
}
else
{
set_prev(post_end, pre_start);
this.head = post_end;
}
FlipCircleQueue new_queue = new FlipCircleQueue(
start, end, this.next_direction
);
return(new_queue);
}
