Geodata: Reduce memory usage again (#5975)

https://github.com/XTLS/Xray-core/pull/5975#issuecomment-4274779560

common/geodata/strmatcher/matcherset_domain.go

@@ -0,0 +1,79 @@
+package strmatcher
+
+type trieNode2 struct {
+	matched  bool
+	children map[string]*trieNode2
+}
+
+// DomainMatcherSet is an implementation of MatcherSet.
+// It uses trie to optimize both memory consumption and lookup speed. Trie node is domain label based.
+type DomainMatcherSet struct {
+	root *trieNode2
+}
+
+func NewDomainMatcherSet() *DomainMatcherSet {
+	return &DomainMatcherSet{
+		root: new(trieNode2),
+	}
+}
+
+// AddDomainMatcher implements MatcherSetForDomain.AddDomainMatcher.
+func (s *DomainMatcherSet) AddDomainMatcher(matcher DomainMatcher) {
+	node := s.root
+	pattern := matcher.Pattern()
+	for i := len(pattern); i > 0; {
+		var part string
+		for j := i - 1; ; j-- {
+			if pattern[j] == '.' {
+				part = pattern[j+1 : i]
+				i = j
+				break
+			}
+			if j == 0 {
+				part = pattern[j:i]
+				i = j
+				break
+			}
+		}
+		if node.children == nil {
+			node.children = make(map[string]*trieNode2)
+		}
+		next := node.children[part]
+		if next == nil {
+			next = new(trieNode2)
+			node.children[part] = next
+		}
+		node = next
+	}
+
+	node.matched = true
+}
+
+// MatchAny implements MatcherSet.MatchAny.
+func (s *DomainMatcherSet) MatchAny(input string) bool {
+	node := s.root
+	for i := len(input); i > 0; {
+		for j := i - 1; ; j-- {
+			if input[j] == '.' {
+				node = node.children[input[j+1:i]]
+				i = j
+				break
+			}
+			if j == 0 {
+				node = node.children[input[j:i]]
+				i = j
+				break
+			}
+		}
+		if node == nil {
+			return false
+		}
+		if node.matched {
+			return true
+		}
+		if node.children == nil {
+			return false
+		}
+	}
+	return false
+}