From b9f05bed7d2f7669044b6b2c234a3ea294588ff3 Mon Sep 17 00:00:00 2001
From: Arpad Ryszka <arpad@squareroundforest.org>
Date: Mon, 17 Jul 2017 23:59:26 +0200
Subject: [PATCH] simplify storage

---
 parse.go |   2 +-
 store.go | 120 +++++++++++++++++++------------------------------------
 2 files changed, 42 insertions(+), 80 deletions(-)

diff --git a/parse.go b/parse.go
index e4bbc5c..91bb52d 100644
--- a/parse.go
+++ b/parse.go
@@ -15,7 +15,7 @@ type parser interface {
 	nodeName() string
 	nodeID() int
 	setIncludedBy(parser, *idSet)
-	storeIncluded(*context, int, int)
+	storeIncluded(*context, int, int) // can be just an id set, taking what's excluded from the context
 	parse(Trace, *context)
 }
 
diff --git a/store.go b/store.go
index 557e377..36a7458 100644
--- a/store.go
+++ b/store.go
@@ -1,120 +1,82 @@
 package treerack
 
-type storeEntry struct {
-	match   *idSet
-	noMatch *idSet
-	matches   []int
-	all []int
-}
-
 type store struct {
-	entries []*storeEntry
-}
-
-func (s *store) getEntry(offset int) *storeEntry {
-	if len(s.entries) <= offset {
-		return nil
-	}
-
-	return s.entries[offset]
+	noMatch []*idSet
+	match [][]int
 }
 
 func (s *store) hasNoMatch(offset, id int) bool {
-	e := s.getEntry(offset)
-	if e == nil {
+	if len(s.noMatch) <= offset || s.noMatch[offset] == nil {
 		return false
 	}
 
-	return e.noMatch.has(id)
+	return s.noMatch[offset].has(id)
 }
 
 func (s *store) getMatch(offset, id int) (int, bool, bool) {
-	e := s.getEntry(offset)
-	if e == nil {
-		return 0, false, false
-	}
-
-	if e.noMatch.has(id) {
+	if s.hasNoMatch(offset, id) {
 		return 0, false, true
 	}
 
-	if !e.match.has(id) {
+	if len(s.match) <= offset {
 		return 0, false, false
 	}
 
-	for i := 0; i < len(e.matches); i += 2 {
-		if e.matches[i] == id {
-			return e.matches[i + 1], true, true
+	var (
+		found bool
+		length int
+	)
+
+	for i := 0; i < len(s.match[offset]); i++ {
+		if s.match[offset][i] != id {
+			continue
+		}
+
+		found = true
+		if s.match[offset][i + 1] > length {
+			length = s.match[offset][i + 1]
 		}
 	}
 
-	return 0, false, false
+	return length, found, found
 }
 
 func (s *store) ensureOffset(offset int) {
-	if len(s.entries) > offset {
+	if len(s.match) > offset {
 		return
 	}
 
-	if cap(s.entries) > offset {
-		s.entries = s.entries[:offset+1]
+	if cap(s.match) > offset {
+		s.match = s.match[:offset+1]
 		return
 	}
 
-	s.entries = s.entries[:cap(s.entries)]
-	for len(s.entries) <= offset {
-		s.entries = append(s.entries, nil)
+	s.match = s.match[:cap(s.match)]
+	for i := len(s.match); i <= offset; i++ {
+		s.match = append(s.match, nil)
 	}
 }
 
-func (s *store) ensureEntry(offset int) *storeEntry {
-	s.ensureOffset(offset)
-	e := s.entries[offset]
-	if e != nil {
-		return e
-	}
-
-	e = &storeEntry{
-		match:   &idSet{},
-		noMatch: &idSet{},
-	}
-
-	s.entries[offset] = e
-	return e
-}
-
 func (s *store) setMatch(offset, id, to int) {
-	e := s.ensureEntry(offset)
-
-	e.match.set(id)
-	for i := 0; i < len(e.matches); i += 2 {
-		if e.matches[i] == id {
-			if to > e.matches[i + 1] {
-				e.matches[i + 1] = to
-			}
-
-			if to != e.matches[i + 1] {
-				e.all = append(e.all, id, to)
-			}
-
-			return
-		}
-	}
-
-	e.matches = append(e.matches, id, to)
+	s.ensureOffset(offset)
+	s.match[offset] = append(s.match[offset], id, to)
 }
 
 func (s *store) setNoMatch(offset, id int) {
-	e := s.ensureEntry(offset)
-
-	if e.match.has(id) {
-		return
+	if len(s.noMatch) <= offset {
+		if cap(s.noMatch) > offset {
+			s.noMatch = s.noMatch[:offset + 1]
+		} else {
+			s.noMatch = s.noMatch[:cap(s.noMatch)]
+			for i := len(s.noMatch); i <= offset; i++ {
+				s.noMatch = append(s.noMatch, nil)
+			}
+		}
 	}
 
-	e.noMatch.set(id)
-}
+	if s.noMatch[offset] == nil {
+		s.noMatch[offset] = &idSet{}
+	}
 
-func (s *store) add(offset, id, to int) {
-	e := s.ensureEntry(offset)
-	e.all = append(e.all, id, to)
+	s.noMatch[offset].set(id)
 }