private bool RemovemHelper(byte[] prefix, int start, byte[] pipe)
{
if (prefix == null || prefix.Length == start)
{
if (m_pipes != null)
{
bool erased = m_pipes.Remove(pipe);
Debug.Assert(erased);
if (m_pipes.Count == 0)
{
m_pipes = null;
}
}
return(m_pipes == null);
}
byte c = prefix[start];
if (m_count == 0 || c < m_min || c >= m_min + m_count)
{
return(false);
}
Mtrie nextNode =
m_count == 1 ? m_next[0] : m_next[c - m_min];
if (nextNode == null)
{
return(false);
}
bool ret = nextNode.RemovemHelper(prefix, start + 1, pipe);
if (nextNode.IsRedundant)
{
Debug.Assert(m_count > 0);
if (m_count == 1)
{
m_next = null;
m_count = 0;
--m_liveNodes;
Debug.Assert(m_liveNodes == 0);
}
else
{
m_next[c - m_min] = null;
Debug.Assert(m_liveNodes > 1);
--m_liveNodes;
// Compact the table if possible
if (m_liveNodes == 1)
{
// If there's only one live node in the table we can
// switch to using the more compact single-node
// representation
int i;
for (i = 0; i < m_count; ++i)
{
if (m_next[i] != null)
{
break;
}
}
Debug.Assert(i < m_count);
m_min += i;
m_count = 1;
Mtrie old = m_next[i];
m_next = new Mtrie[] { old };
}
else if (c == m_min)
{
// We can compact the table "from the left"
int i;
for (i = 1; i < m_count; ++i)
{
if (m_next[i] != null)
{
break;
}
}
Debug.Assert(i < m_count);
m_min += i;
m_count -= i;
m_next = Realloc(m_next, m_count, false);
}
else if (c == m_min + m_count - 1)
{
// We can compact the table "from the right"
int i;
for (i = 1; i < m_count; ++i)
{
if (m_next[m_count - 1 - i] != null)
{
break;
}
}
Debug.Assert(i < m_count);
m_count -= i;
m_next = Realloc(m_next, m_count, true);
}
}
}
return(ret);
}