feat/optimize: add userspace routing and optimize domain routing (#18)

component/routing/domain_matcher/go_regexp_nfa.go

@@ -0,0 +1,93 @@
+/*
+ * SPDX-License-Identifier: AGPL-3.0-only
+ * Copyright (c) 2023, v2rayA Organization <team@v2raya.org>
+ */
+
+package domain_matcher
+
+import (
+	"fmt"
+	"github.com/v2rayA/dae/common/consts"
+	"regexp"
+	"strings"
+)
+
+type GoRegexpNfa struct {
+	validIndexes []int
+	nfa          []*regexp.Regexp
+	toBuild      [][]string
+	err          error
+}
+
+func NewGoRegexpNfa(bitLength int) *GoRegexpNfa {
+	return &GoRegexpNfa{
+		nfa:     make([]*regexp.Regexp, bitLength),
+		toBuild: make([][]string, bitLength),
+	}
+}
+func (n *GoRegexpNfa) AddSet(bitIndex int, patterns []string, typ consts.RoutingDomainKey) {
+	if n.err != nil {
+		return
+	}
+	switch typ {
+	case consts.RoutingDomainKey_Full:
+		for _, d := range patterns {
+			n.toBuild[bitIndex] = append(n.toBuild[bitIndex], "^"+d+"$")
+		}
+	case consts.RoutingDomainKey_Suffix:
+		for _, d := range patterns {
+			n.toBuild[bitIndex] = append(n.toBuild[bitIndex], "."+strings.TrimPrefix(d, ".")+"$")
+			n.toBuild[bitIndex] = append(n.toBuild[bitIndex], "^"+d+"$")
+		}
+	case consts.RoutingDomainKey_Keyword:
+		for _, d := range patterns {
+			n.toBuild[bitIndex] = append(n.toBuild[bitIndex], d)
+		}
+	case consts.RoutingDomainKey_Regex:
+		for _, d := range patterns {
+			// Check if it is a valid regexp.
+			if _, err := regexp.Compile(d); err != nil {
+				n.err = fmt.Errorf("failed to compile regex: %v", d)
+				return
+			}
+			n.toBuild[bitIndex] = append(n.toBuild[bitIndex], d)
+		}
+	default:
+		n.err = fmt.Errorf("unknown RoutingDomainKey: %v", typ)
+		return
+	}
+}
+func (n *GoRegexpNfa) MatchDomainBitmap(domain string) (bitmap []uint32) {
+	N := len(n.nfa) / 32
+	if len(n.nfa)%32 != 0 {
+		N++
+	}
+	bitmap = make([]uint32, N)
+	domain = strings.ToLower(strings.TrimSuffix(domain, "."))
+	for _, i := range n.validIndexes {
+		if n.nfa[i].MatchString(domain) {
+			bitmap[i/32] |= 1 << (i % 32)
+		}
+	}
+	return bitmap
+}
+func (n *GoRegexpNfa) Build() error {
+	if n.err != nil {
+		return n.err
+	}
+	n.validIndexes = make([]int, 0, len(n.toBuild)/8)
+	for i, toBuild := range n.toBuild {
+		if len(toBuild) == 0 {
+			continue
+		}
+		r, err := regexp.Compile(strings.Join(toBuild, "|"))
+		if err != nil {
+			return fmt.Errorf("failed to build NFA: %w", err)
+		}
+		n.nfa[i] = r
+		n.validIndexes = append(n.validIndexes, i)
+	}
+	// Release it.
+	n.toBuild = nil
+	return nil
+}