public byte[] Get(TrieNode node, TrieKey key)
{
if (node == null)
{
return(null);
}
if (node.NodeType == TrieNode.TrieNodeType.BranchNode)
{
if (key.IsEmpty)
{
return(node.BranchNodeGetValue());
}
TrieNode child = node.BranchNodeGetChild(key.GetHex(0));
return(Get(child, key.Shift(1)));
}
else
{
TrieKey k = key.MatchAndShift(node.KVNodeGetKey());
if (k == null)
{
return(null);
}
if (node.NodeType == TrieNode.TrieNodeType.KVNodeValue)
{
return(k.IsEmpty ? node.KVNodeGetValue() : null);
}
else
{
return(Get(node.KVNodeGetChildNode(), k));
}
}
}
public override bool Equals(object obj)
{
if (obj == null)
{
return(false);
}
if (GetType() != obj.GetType())
{
return(false);
}
TrieKey k = (TrieKey)obj;
int len = GetLength();
if (len != k.GetLength())
{
return(false);
}
for (int i = 0; i < len; i++)
{
if (GetHex(i) != k.GetHex(i))
{
return(false);
}
}
return(IsTerminal == k.IsTerminal);
}
public TrieKey MatchAndShift(TrieKey k)
{
int len = GetLength();
int klen = k.GetLength();
if (len < klen)
{
return(null);
}
if ((this.off & 1) == (k.off & 1))
{
// optimization to compare whole keys bytes
if ((this.off & 1) == 1 && GetHex(0) != k.GetHex(0))
{
return(null);
}
int idx1 = (this.off + 1) >> 1;
int idx2 = (k.off + 1) >> 1;
int l = klen >> 1;
for (int i = 0; i < l; i++, idx1++, idx2++)
{
if (this.key[idx1] != k.key[idx2])
{
return(null);
}
}
}
else
{
for (int i = 0; i < klen; i++)
{
if (GetHex(i) != k.GetHex(i))
{
return(null);
}
}
}
return(Shift(klen));
}
public TrieKey GetCommonPrefix(TrieKey k)
{
int prefix_length = 0;
int thisLength = GetLength();
int klen = k.GetLength();
while (prefix_length < thisLength && prefix_length < klen && GetHex(prefix_length) == k.GetHex(prefix_length))
{
prefix_length++;
}
byte[] prefix_key = new byte[(prefix_length + 1) >> 1];
TrieKey ret = new TrieKey(prefix_key, (prefix_length & 1) == 0 ? 0 : 1,
prefix_length == GetLength() && prefix_length == k.GetLength() && terminal && k.IsTerminal);
for (int i = 0; i < prefix_length; i++)
{
ret.SetHex(i, k.GetHex(i));
}
return(ret);
}
public TrieKey Concat(TrieKey k)
{
if (IsTerminal)
{
throw new System.Exception("Can' append to terminal key: " + this + " + " + k);
}
int len = GetLength();
int klen = k.GetLength();
int new_len = len + klen;
byte[] newKeyBytes = new byte[(new_len + 1) >> 1];
TrieKey ret = new TrieKey(newKeyBytes, new_len & 1, k.IsTerminal);
for (int i = 0; i < len; i++)
{
ret.SetHex(i, GetHex(i));
}
for (int i = 0; i < klen; i++)
{
ret.SetHex(len + i, k.GetHex(i));
}
return(ret);
}
private TrieNode Insert(TrieNode node, TrieKey key, object node_or_value)
{
if (node.NodeType == TrieNode.TrieNodeType.BranchNode)
{
if (key.IsEmpty)
{
return(node.BranchNodeSetValue((byte[])node_or_value));
}
TrieNode child = node.BranchNodeGetChild(key.GetHex(0));
if (child != null)
{
return(node.BranchNodeSetChild(key.GetHex(0), Insert(child, key.Shift(1), node_or_value)));
}
else
{
TrieKey child_key = key.Shift(1);
TrieNode new_child;
if (!child_key.IsEmpty)
{
new_child = new TrieNode(this, child_key, node_or_value);
}
else
{
new_child = node_or_value is TrieNode ? (TrieNode)node_or_value : new TrieNode(this, child_key, node_or_value);
}
return(node.BranchNodeSetChild(key.GetHex(0), new_child));
}
}
else
{
TrieKey current_node_key = node.KVNodeGetKey();
TrieKey common_prefix = key.GetCommonPrefix(current_node_key);
if (common_prefix.IsEmpty)
{
TrieNode new_branch = new TrieNode(this);
Insert(new_branch, current_node_key, node.KVNodeGetValueOrNode());
Insert(new_branch, key, node_or_value);
node.Dispose();
return(new_branch);
}
else if (common_prefix.Equals(key))
{
return(node.KVNodeSetValueOrNode(node_or_value));
}
else if (common_prefix.Equals(current_node_key))
{
Insert(node.KVNodeGetChildNode(), key.Shift(common_prefix.GetLength()), node_or_value);
return(node.Invalidate());
}
else
{
TrieNode new_branch = new TrieNode(this);
TrieNode newKvNode = new TrieNode(this, common_prefix, new_branch);
Insert(newKvNode, current_node_key, node.KVNodeGetValueOrNode());
Insert(newKvNode, key, node_or_value);
node.Dispose();
return(newKvNode);
}
}
}
public TrieNode Delete(TrieNode node, TrieKey key)
{
TrieNode kv_node = null;
if (node.NodeType == TrieNode.TrieNodeType.BranchNode)
{
if (key.IsEmpty)
{
node.BranchNodeSetValue(null);
}
else
{
int index = key.GetHex(0);
TrieNode child = node.BranchNodeGetChild(index);
if (child == null)
{
return(node);
}
TrieNode new_node = Delete(child, key.Shift(1));
node.BranchNodeSetChild(index, new_node);
if (new_node != null)
{
return(node);
}
}
int compact_index = node.BranchNodeCompactIndex();
if (compact_index < 0)
{
return(node);
}
node.Dispose();
if (compact_index == 16)
{
return(new TrieNode(this, TrieKey.Empty(true), node.BranchNodeGetValue()));
}
else
{
kv_node = new TrieNode(this, TrieKey.SingleHex(compact_index), node.BranchNodeGetChild(compact_index));
}
}
else
{
TrieKey k = key.MatchAndShift(node.KVNodeGetKey());
if (k == null)
{
return(node);
}
else if (node.NodeType == TrieNode.TrieNodeType.KVNodeValue)
{
if (k.IsEmpty)
{
node.Dispose();
return(null);
}
else
{
return(node);
}
}
else
{
TrieNode child = Delete(node.KVNodeGetChildNode(), k);
if (child == null)
{
throw new System.Exception("Shouldn't happen");
}
kv_node = node.KVNodeSetValueOrNode(child);
}
}
TrieNode new_child = kv_node.KVNodeGetChildNode();
if (new_child.NodeType != TrieNode.TrieNodeType.BranchNode)
{
TrieKey new_key = kv_node.KVNodeGetKey().Concat(new_child.KVNodeGetKey());
TrieNode new_node = new TrieNode(this, new_key, new_child.KVNodeGetValueOrNode());
new_child.Dispose();
kv_node.Dispose();
return(new_node);
}
else
{
return(kv_node);
}
}