changed equality check of states

ss/mast.go

@@ -58,6 +58,7 @@ func buildMast(input PairSlice) (m *mast) {
 
 	const initialMastSize = 1024
 	m = new(mast)
+	dic := make(map[uint][]*state)
 	m.states = make([]*state, 0, initialMastSize)
 	m.finalStates = make([]*state, 0, initialMastSize)
 
@@ -69,23 +70,17 @@ func buildMast(input PairSlice) (m *mast) {
 	for _, pair := range input {
 		in, out := pair.In, pair.Out
 		prefixLen := commonPrefixLen(in, prev)
-		candidate := m.finalStates
 		for i := len(prev); i > prefixLen; i-- {
 			var s *state
-			detected := false
-			if candidate != nil {
-				for _, c := range candidate {
+			if cs, ok := dic[buf[i].hcode]; ok {
+				for _, c := range cs {
 					if c.eq(buf[i]) {
-						buf[i].renew()
 						s = c
-						candidate = c.Prev
-						detected = true
 						break
 					}
 				}
 			}
-			if !detected {
-				candidate = nil
+			if s == nil {
 				s = &state{}
 				*s = *buf[i]
 				buf[i].renew()
@@ -129,23 +124,20 @@ func buildMast(input PairSlice) (m *mast) {
 		prev = in
 	}
 	// flush the buf
-	candidate := m.finalStates
 	for i := len(prev); i > 0; i-- {
 		var s *state
-		detected := false
-		if candidate != nil {
-			for _, c := range candidate {
+		if cs, ok := dic[buf[i].hcode]; ok {
+			for _, c := range cs {
 				if c.eq(buf[i]) {
 					s = c
-					candidate = c.Prev
-					detected = true
 					break
 				}
 			}
 		}
-		if !detected {
-			candidate = nil
-			s = buf[i]
+		if s == nil {
+			s = &state{}
+			*s = *buf[i]
+			buf[i].renew()
 			m.addState(s)
 		}
 		buf[i-1].setTransition(prev[i-1], s)

ss/state.go

@@ -2,6 +2,7 @@ package ss
 
 import (
 	"fmt"
+	"hash/fnv"
 )
 
 type stringSet map[string]bool
@@ -13,6 +14,7 @@ type state struct {
 	Tail    stringSet
 	IsFinal bool
 	Prev    []*state
+	hcode   uint
 }
 
 func newState() (n *state) {
@@ -45,10 +47,18 @@ func (n *state) tails() (t []string) {
 
 func (n *state) setOutput(ch byte, out string) {
 	n.Output[ch] = out
+
+	const magic = 8191
+	h := fnv.New32a()
+	h.Write([]byte(out))
+	n.hcode += (uint(ch) + uint(h.Sum32())) * magic
 }
 
 func (n *state) setTransition(ch byte, next *state) {
 	n.Trans[ch] = next
+
+	const magic = 1001
+	n.hcode += (uint(ch) + uint(next.ID)) * magic
 }
 
 func (n *state) setInvTransition() {
@@ -63,6 +73,7 @@ func (n *state) renew() {
 	n.Tail = make(stringSet)
 	n.IsFinal = false
 	n.Prev = make([]*state, 0)
+	n.hcode = 0
 }
 
 func (n *state) eq(dst *state) bool {
@@ -72,6 +83,9 @@ func (n *state) eq(dst *state) bool {
 	if n == dst {
 		return true
 	}
+	if n.hcode != dst.hcode {
+		return false
+	}
 	if len(n.Trans) != len(dst.Trans) ||
 		len(n.Output) != len(dst.Output) ||
 		len(n.Tail) != len(dst.Tail) ||