public override void Add(char[] word, int start)
{
if (word.Length == start)
{
End = true;
return;
}
int c = (int)word[start];
if (_next == null)
{
_next = new BurstNavigable[TRIE_WIDTH];
}
BurstNavigable target = _next[c];
if (target == null)
{
// always start with a bucket.
target = new BurstCacheBucket();
_next[c] = target;
}
else if (target.ShouldBurst) // else OK because there's never any need to burst a brand new bucket
{
target = BurstThisBucket(target);
_next[c] = target;
}
target.Add(word, start + 1);
}
BurstTrieNode BurstThisBucket(BurstNavigable bucketIn)
{
BurstCacheBucket bucket = (BurstCacheBucket)bucketIn;
BurstTrieNode node = new BurstTrieNode
{
_next = new BurstNavigable[TRIE_WIDTH],
End = bucket.End
};
// node.me = key; // debug only
// TODO maybe make this a higher performance construct?
foreach (ArraySegment <char> item in bucket)
{
if (item.Count == 1) // in this case the suffix is consumed by the new trie node + entry (empty destination bucket, maybe, or now creating and adding to)
{
if (node._next[(int)item.Array[item.Offset]] == null)
{
BurstCacheBucket emptyBucket = new BurstCacheBucket();
emptyBucket.End = true;
node._next[(int)item.Array[item.Offset]] = emptyBucket; // only needed if it was not there, so maybe save this assignment
continue;
}
else // already a bucket there, from previous iteration in this loop
{
BurstCacheBucket reusingBucket = (BurstCacheBucket)node._next[(int)item.Array[item.Offset]];
reusingBucket.End = true;
continue;
}
}
else // there is more suffix that's not consumed by the new trie node + entry, so create / fill bucket
{
BurstNavigable nav = node._next[(int)item.Array[item.Offset]];
if (nav == null)
{
BurstCacheBucket newBucket = new BurstCacheBucket();
char[] arr = item.Array;
int offset = item.Offset;
newBucket.Add(arr, offset + 1, item.Count - 1);
node._next[(int)arr[offset]] = newBucket;
}
else
{
((BurstCacheBucket)nav).Add(item.Array, item.Offset + 1, item.Count - 1);
}
}
}
return(node);
}
public override bool IsPresent(char[] word, int start)
{
if (word.Length == start)
{
return(End);
}
if (_next == null)
{
return(false); // there's no further to look!
}
BurstNavigable target = _next[word[start]];
if (target == null)
{
return(false); // no potentially matching suffix
}
return(target.IsPresent(word, start + 1)); // 1 = me.Length
}
/// <summary>
/// Exports the whole trie into the supplied list.
/// </summary>
public override void Reconstruct(char[] trail, int length, List <string> pile)
{
if (_next == null)
{
pile.Add(new string(trail, 0, length));
// end of trail. build string and Add to pile.
return;
}
if (End)
{
pile.Add(new string(trail, 0, length));
}
for (int i = MINIMAL_WIDTH_USE; i < MAXIMAL_WIDTH_USE; i++) // TODO: optimize by holding onto minimum, maximum values actually used in this node
{
BurstNavigable node = _next[i];
if (node != null)
{
trail[length] = (char)i;
node.Reconstruct(trail, length + 1, pile);
}
}
}
