chore: optimize string search with Aho–Corasick algorithm (#1476)

* chore: optimize string search with Aho–Corasick algorithm

* chore: optimize keywords replacer

* fix: replacer bugs

* chore: reorder members

core/stringx/node.go

@@ -2,6 +2,8 @@ package stringx
 
 type node struct {
 	children map[rune]*node
+	fail     *node
+	depth    int
 	end      bool
 }
 
@@ -12,17 +14,19 @@ func (n *node) add(word string) {
 	}
 
 	nd := n
-	for _, char := range chars {
+	var depth int
+	for i, char := range chars {
 		if nd.children == nil {
 			child := new(node)
-			nd.children = map[rune]*node{
-				char: child,
-			}
+			child.depth = i + 1
+			nd.children = map[rune]*node{char: child}
 			nd = child
 		} else if child, ok := nd.children[char]; ok {
 			nd = child
+			depth++
 		} else {
 			child := new(node)
+			child.depth = i + 1
 			nd.children[char] = child
 			nd = child
 		}
@@ -30,3 +34,68 @@ func (n *node) add(word string) {
 
 	nd.end = true
 }
+
+func (n *node) build() {
+	n.fail = n
+	for _, child := range n.children {
+		child.fail = n
+		n.buildNode(child)
+	}
+}
+
+func (n *node) buildNode(nd *node) {
+	if nd.children == nil {
+		return
+	}
+
+	var fifo []*node
+	for key, child := range nd.children {
+		fifo = append(fifo, child)
+
+		if fail, ok := nd.fail.children[key]; ok {
+			child.fail = fail
+		} else {
+			child.fail = n
+		}
+	}
+
+	for _, val := range fifo {
+		n.buildNode(val)
+	}
+}
+
+func (n *node) find(chars []rune) []scope {
+	var scopes []scope
+	size := len(chars)
+	cur := n
+
+	for i := 0; i < size; i++ {
+		child, ok := cur.children[chars[i]]
+		if ok {
+			cur = child
+		} else if cur == n {
+			continue
+		} else {
+			cur = cur.fail
+			if child, ok = cur.children[chars[i]]; !ok {
+				continue
+			}
+			cur = child
+		}
+
+		if child.end {
+			scopes = append(scopes, scope{
+				start: i + 1 - child.depth,
+				stop:  i + 1,
+			})
+		}
+		if child.fail != n && child.fail.end {
+			scopes = append(scopes, scope{
+				start: i + 1 - child.fail.depth,
+				stop:  i + 1,
+			})
+		}
+	}
+
+	return scopes
+}