snapshot of https://github.com/go-gitea/gitea.git (main, 2026-09-15; blobs > 131072B omitted)

modules/util/trie.go

@@ -0,0 +1,56 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package util
+
+type trieEdge struct {
+	b    byte
+	node *TrieNode
+}
+
+// TrieNode represents a node in a slice-based Trie for fast byte-sequence prefix matching.
+type TrieNode struct {
+	children []trieEdge
+	isEnd    bool
+}
+
+func (t *TrieNode) child(b byte) *TrieNode {
+	for _, edge := range t.children {
+		if edge.b == b {
+			return edge.node
+		}
+	}
+	return nil
+}
+
+// Insert adds a string (byte sequence) to the Trie.
+func (t *TrieNode) Insert(val string) {
+	curr := t
+	for i := 0; i < len(val); i++ {
+		next := curr.child(val[i])
+		if next == nil {
+			next = &TrieNode{}
+			curr.children = append(curr.children, trieEdge{b: val[i], node: next})
+		}
+		curr = next
+	}
+	curr.isEnd = true
+}
+
+// Match returns the length of the longest matching prefix starting at index `start` in string `s`.
+// It returns -1 if no prefix is matched.
+func (t *TrieNode) Match(s string, start int) int {
+	curr := t
+	matchLen := -1
+	for j := start; j < len(s); j++ {
+		next := curr.child(s[j])
+		if next == nil {
+			break
+		}
+		curr = next
+		if curr.isEnd {
+			matchLen = j - start + 1
+		}
+	}
+	return matchLen
+}