Simplify Item structure

This commit compensates for the performance overhead from the
extended tiebreak option.

8 files changed, 43 insertions, 58 deletions

diff --git a/src/chunklist_test.go b/src/chunklist_test.go
index 6ddd336f..5f7481df 100644
--- a/src/chunklist_test.go
+++ b/src/chunklist_test.go
@@ -7,7 +7,7 @@ import (
 
 func TestChunkList(t *testing.T) {
 	// FIXME global
-	sortCriteria = []criterion{byMatchLen, byLength, byIndex}
+	sortCriteria = []criterion{byMatchLen, byLength}
 
 	cl := NewChunkList(func(s []byte, i int) *Item {
 		return &Item{text: []rune(string(s)), rank: buildEmptyRank(int32(i * 2))}
@@ -39,7 +39,7 @@ func TestChunkList(t *testing.T) {
 	if len(*chunk1) != 2 {
 		t.Error("Snapshot should contain only two items")
 	}
-	last := func(arr []int32) int32 {
+	last := func(arr [5]int32) int32 {
 		return arr[len(arr)-1]
 	}
 	if string((*chunk1)[0].text) != "hello" || last((*chunk1)[0].rank) != 0 ||
diff --git a/src/core.go b/src/core.go
index 1906c508..24af0507 100644
--- a/src/core.go
+++ b/src/core.go
@@ -103,7 +103,6 @@ func Run(opts *Options) {
 			runes, colors := ansiProcessor(data)
 			return &Item{
 				text:   runes,
-				index:  int32(index),
 				colors: colors,
 				rank:   buildEmptyRank(int32(index))}
 		})
@@ -120,7 +119,6 @@ func Run(opts *Options) {
 			item := Item{
 				text:     joinTokens(trans),
 				origText: &runes,
-				index:    int32(index),
 				colors:   nil,
 				rank:     buildEmptyRank(int32(index))}
 
diff --git a/src/item.go b/src/item.go
index a4fa609b..9200efbf 100644
--- a/src/item.go
+++ b/src/item.go
@@ -20,41 +20,41 @@ type Item struct {
 	text        []rune
 	origText    *[]rune
 	transformed []Token
-	index       int32
 	offsets     []Offset
 	colors      []ansiOffset
-	rank        []int32
+	rank        [5]int32
 }
 
 // Sort criteria to use. Never changes once fzf is started.
 var sortCriteria []criterion
 
-func isRankValid(rank []int32) bool {
+func isRankValid(rank [5]int32) bool {
 	// Exclude ordinal index
-	for i := 0; i < len(rank)-1; i++ {
-		if rank[i] > 0 {
+	for _, r := range rank[:4] {
+		if r > 0 {
 			return true
 		}
 	}
 	return false
 }
 
-func buildEmptyRank(index int32) []int32 {
-	len := len(sortCriteria)
-	arr := make([]int32, len)
-	arr[len-1] = index
-	return arr
+func buildEmptyRank(index int32) [5]int32 {
+	return [5]int32{0, 0, 0, 0, index}
+}
+
+func (item *Item) Index() int32 {
+	return item.rank[4]
 }
 
 // Rank calculates rank of the Item
-func (item *Item) Rank(cache bool) []int32 {
+func (item *Item) Rank(cache bool) [5]int32 {
 	if cache && isRankValid(item.rank) {
 		return item.rank
 	}
 	matchlen := 0
 	prevEnd := 0
 	lenSum := 0
-	minBegin := math.MaxUint16
+	minBegin := math.MaxInt32
 	for _, offset := range item.offsets {
 		begin := int(offset[0])
 		end := int(offset[1])
@@ -76,7 +76,7 @@ func (item *Item) Rank(cache bool) []int32 {
 	if matchlen == 0 {
 		matchlen = math.MaxInt32
 	}
-	rank := make([]int32, len(sortCriteria))
+	rank := buildEmptyRank(item.Index())
 	for idx, criterion := range sortCriteria {
 		var val int32
 		switch criterion {
@@ -100,8 +100,6 @@ func (item *Item) Rank(cache bool) []int32 {
 				// Empty offsets due to inverse terms.
 				val = 1
 			}
-		case byIndex:
-			val = item.index
 		}
 		rank[idx] = val
 	}
@@ -269,19 +267,15 @@ func (a ByRelevanceTac) Less(i, j int) bool {
 	return compareRanks(irank, jrank, true)
 }
 
-func compareRanks(irank []int32, jrank []int32, tac bool) bool {
-	lastIdx := len(irank) - 1
-	for idx, left := range irank {
+func compareRanks(irank [5]int32, jrank [5]int32, tac bool) bool {
+	for idx := 0; idx < 4; idx++ {
+		left := irank[idx]
 		right := jrank[idx]
-		if tac && idx == lastIdx {
-			left = left * -1
-			right = right * -1
-		}
 		if left < right {
 			return true
 		} else if left > right {
 			return false
 		}
 	}
-	return true
+	return (irank[4] <= jrank[4]) != tac
 }
diff --git a/src/item_test.go b/src/item_test.go
index f26f8370..d1c30d77 100644
--- a/src/item_test.go
+++ b/src/item_test.go
@@ -23,17 +23,17 @@ func TestOffsetSort(t *testing.T) {
 }
 
 func TestRankComparison(t *testing.T) {
-	if compareRanks([]int32{3, 0, 5}, []int32{2, 0, 7}, false) ||
-		!compareRanks([]int32{3, 0, 5}, []int32{3, 0, 6}, false) ||
-		!compareRanks([]int32{1, 2, 3}, []int32{1, 3, 2}, false) ||
-		!compareRanks([]int32{0, 0, 0}, []int32{0, 0, 0}, false) {
+	if compareRanks([5]int32{3, 0, 0, 0, 5}, [5]int32{2, 0, 0, 0, 7}, false) ||
+		!compareRanks([5]int32{3, 0, 0, 0, 5}, [5]int32{3, 0, 0, 0, 6}, false) ||
+		!compareRanks([5]int32{1, 2, 0, 0, 3}, [5]int32{1, 3, 0, 0, 2}, false) ||
+		!compareRanks([5]int32{0, 0, 0, 0, 0}, [5]int32{0, 0, 0, 0, 0}, false) {
 		t.Error("Invalid order")
 	}
 
-	if compareRanks([]int32{3, 0, 5}, []int32{2, 0, 7}, true) ||
-		!compareRanks([]int32{3, 0, 5}, []int32{3, 0, 6}, false) ||
-		!compareRanks([]int32{1, 2, 3}, []int32{1, 3, 2}, true) ||
-		!compareRanks([]int32{0, 0, 0}, []int32{0, 0, 0}, false) {
+	if compareRanks([5]int32{3, 0, 0, 0, 5}, [5]int32{2, 0, 0, 0, 7}, true) ||
+		!compareRanks([5]int32{3, 0, 0, 0, 5}, [5]int32{3, 0, 0, 0, 6}, false) ||
+		!compareRanks([5]int32{1, 2, 0, 0, 3}, [5]int32{1, 3, 0, 0, 2}, true) ||
+		!compareRanks([5]int32{0, 0, 0, 0, 0}, [5]int32{0, 0, 0, 0, 0}, false) {
 		t.Error("Invalid order (tac)")
 	}
 }
@@ -41,16 +41,16 @@ func TestRankComparison(t *testing.T) {
 // Match length, string length, index
 func TestItemRank(t *testing.T) {
 	// FIXME global
-	sortCriteria = []criterion{byMatchLen, byLength, byIndex}
+	sortCriteria = []criterion{byMatchLen, byLength}
 
 	strs := [][]rune{[]rune("foo"), []rune("foobar"), []rune("bar"), []rune("baz")}
-	item1 := Item{text: strs[0], index: 1, offsets: []Offset{}}
+	item1 := Item{text: strs[0], offsets: []Offset{}, rank: [5]int32{0, 0, 0, 0, 1}}
 	rank1 := item1.Rank(true)
-	if rank1[0] != math.MaxInt32 || rank1[1] != 3 || rank1[2] != 1 {
+	if rank1[0] != math.MaxInt32 || rank1[1] != 3 || rank1[4] != 1 {
 		t.Error(item1.Rank(true))
 	}
 	// Only differ in index
-	item2 := Item{text: strs[0], index: 0, offsets: []Offset{}}
+	item2 := Item{text: strs[0], offsets: []Offset{}}
 
 	items := []*Item{&item1, &item2}
 	sort.Sort(ByRelevance(items))
@@ -66,10 +66,10 @@ func TestItemRank(t *testing.T) {
 	}
 
 	// Sort by relevance
-	item3 := Item{text: strs[1], rank: []int32{0, 0, 2}, offsets: []Offset{Offset{1, 3}, Offset{5, 7}}}
-	item4 := Item{text: strs[1], rank: []int32{0, 0, 2}, offsets: []Offset{Offset{1, 2}, Offset{6, 7}}}
-	item5 := Item{text: strs[2], rank: []int32{0, 0, 2}, offsets: []Offset{Offset{1, 3}, Offset{5, 7}}}
-	item6 := Item{text: strs[2], rank: []int32{0, 0, 2}, offsets: []Offset{Offset{1, 2}, Offset{6, 7}}}
+	item3 := Item{text: strs[1], rank: [5]int32{0, 0, 0, 0, 2}, offsets: []Offset{Offset{1, 3}, Offset{5, 7}}}
+	item4 := Item{text: strs[1], rank: [5]int32{0, 0, 0, 0, 2}, offsets: []Offset{Offset{1, 2}, Offset{6, 7}}}
+	item5 := Item{text: strs[2], rank: [5]int32{0, 0, 0, 0, 2}, offsets: []Offset{Offset{1, 3}, Offset{5, 7}}}
+	item6 := Item{text: strs[2], rank: [5]int32{0, 0, 0, 0, 2}, offsets: []Offset{Offset{1, 2}, Offset{6, 7}}}
 	items = []*Item{&item1, &item2, &item3, &item4, &item5, &item6}
 	sort.Sort(ByRelevance(items))
 	if items[0] != &item6 || items[1] != &item4 ||
diff --git a/src/merger_test.go b/src/merger_test.go
index 34efc84d..472e2048 100644
--- a/src/merger_test.go
+++ b/src/merger_test.go
@@ -23,7 +23,7 @@ func randItem() *Item {
 	}
 	return &Item{
 		text:    []rune(str),
-		index:   rand.Int31(),
+		rank:    buildEmptyRank(rand.Int31()),
 		offsets: offsets}
 }
 
diff --git a/src/options.go b/src/options.go
index 30e00160..6399343c 100644
--- a/src/options.go
+++ b/src/options.go
@@ -83,7 +83,6 @@ const (
 	byLength
 	byBegin
 	byEnd
-	byIndex
 )
 
 func defaultMargin() [4]string {
@@ -147,7 +146,7 @@ func defaultOptions() *Options {
 		Delimiter:   Delimiter{},
 		Sort:        1000,
 		Tac:         false,
-		Criteria:    []criterion{byMatchLen, byLength, byIndex},
+		Criteria:    []criterion{byMatchLen, byLength},
 		Multi:       false,
 		Ansi:        false,
 		Mouse:       true,
@@ -382,7 +381,6 @@ func parseTiebreak(str string) []criterion {
 		switch str {
 		case "index":
 			check(&hasIndex, "index")
-			criteria = append(criteria, byIndex)
 		case "length":
 			check(&hasLength, "length")
 			criteria = append(criteria, byLength)
@@ -396,9 +394,6 @@ func parseTiebreak(str string) []criterion {
 			errorExit("invalid sort criterion: " + str)
 		}
 	}
-	if !hasIndex {
-		criteria = append(criteria, byIndex)
-	}
 	return criteria
 }
 
diff --git a/src/pattern.go b/src/pattern.go
index 4c61b87d..af73b674 100644
--- a/src/pattern.go
+++ b/src/pattern.go
@@ -306,10 +306,9 @@ func dupItem(item *Item, offsets []Offset) *Item {
 		text:        item.text,
 		origText:    item.origText,
 		transformed: item.transformed,
-		index:       item.index,
 		offsets:     offsets,
 		colors:      item.colors,
-		rank:        buildEmptyRank(item.index)}
+		rank:        buildEmptyRank(item.Index())}
 }
 
 func (p *Pattern) basicMatch(item *Item) (int, int, int) {
diff --git a/src/terminal.go b/src/terminal.go
index c9b80565..381ae7c5 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -464,7 +464,6 @@ func (t *Terminal) printHeader() {
 		state = newState
 		item := &Item{
 			text:   []rune(trimmed),
-			index:  0,
 			colors: colors,
 			rank:   buildEmptyRank(0)}
 
@@ -491,7 +490,7 @@ func (t *Terminal) printList() {
 }
 
 func (t *Terminal) printItem(item *Item, current bool) {
-	_, selected := t.selected[item.index]
+	_, selected := t.selected[item.Index()]
 	if current {
 		C.CPrint(C.ColCursor, true, ">")
 		if selected {
@@ -836,8 +835,8 @@ func (t *Terminal) Loop() {
 			}
 		}
 		selectItem := func(item *Item) bool {
-			if _, found := t.selected[item.index]; !found {
-				t.selected[item.index] = selectedItem{time.Now(), item.StringPtr(t.ansi)}
+			if _, found := t.selected[item.Index()]; !found {
+				t.selected[item.Index()] = selectedItem{time.Now(), item.StringPtr(t.ansi)}
 				return true
 			}
 			return false
@@ -845,7 +844,7 @@ func (t *Terminal) Loop() {
 		toggleY := func(y int) {
 			item := t.merger.Get(y)
 			if !selectItem(item) {
-				delete(t.selected, item.index)
+				delete(t.selected, item.Index())
 			}
 		}
 		toggle := func() {
@@ -934,7 +933,7 @@ func (t *Terminal) Loop() {
 				if t.multi {
 					for i := 0; i < t.merger.Length(); i++ {
 						item := t.merger.Get(i)
-						delete(t.selected, item.index)
+						delete(t.selected, item.Index())
 					}
 					req(reqList, reqInfo)
 				}