public static List <string> Match(this SniffingNode currentNode, int depth, byte[] data, bool matchAll = false)
{
var ret = new List <string>();
Match(data, depth, currentNode, ret, matchAll);
return(ret);
}
private static void Match(byte[] data, int depth, SniffingNode node, List <string> store, bool matchAll)
{
//如果 depth 的值（即节点深度）超出 data 长度，结束迭代匹配
if (depth == data.Length)
{
return;
}
node.Children.TryGetValue(data[depth], out var current);
//如果 current 节点为 null，表示未命中节点，结束迭代匹配
if (current == null)
{
return;
}
//如果 current 节点的扩展名清单不为空，记录结果
if (current.ExtensionNames != null)
{
store.AddRange(current.ExtensionNames);
if (!matchAll)
{
return;
}
}
//Children 为空，不再继续迭代，结束匹配
if (current.Children == null)
{
return;
}
Match(data, depth + 1, current, store, matchAll);
}
private static void Update(SniffingNode parent, byte[] data, string[] extensionNames, int depth)
{
SniffingNode current;
if (parent.Children == null)
{
parent.Children = new SortedList <byte, SniffingNode>(Convert.ToInt32(128 / Math.Pow(2, depth)));
}
//如果子节点内不包含指定的 byte 索引，则创建相应子节点至 Children
if (!parent.Children.ContainsKey(data[depth]))
{
current = new SniffingNode(parent, depth);
parent.Children.Add(data[depth], current);
}
else
{
if (!parent.Children.TryGetValue(data[depth], out current))
{
throw new InvalidOperationException($"Invalid operation: cannot find value for '{data[depth]}', depth = {depth}.");
}
}
//最后一位判断
if (depth == (data.Length - 1))
{
if (current.ExtensionNames == null)
{
current.ExtensionNames = new List <string>(4);
}
current.ExtensionNames.AddRange(extensionNames);
return;
}
Update(current, data, extensionNames, depth + 1);
}
public SniffingNode(SniffingNode parent, int depth)
{
Parent = parent;
Depth = depth;
}
public static void Update(this SniffingNode parent, IReadOnlyList <byte> data, IReadOnlyList <string> extensionNames, int depth)
{
Update(parent, data.ToArray(), extensionNames.ToArray(), depth);
}
