Improved performance of the data finalizer

src/data/Finalize.go

@@ -9,19 +9,22 @@ import (
 // It will try to reuse existing data whenever possible.
 func (data Data) Finalize() ([]byte, map[string]int32) {
 	var (
-		final     []byte
 		keys      = make([]string, 0, len(data))
 		positions = make(map[string]int32, len(data))
+		capacity  = 0
 	)
 
-	for key := range data {
+	for key, value := range data {
 		keys = append(keys, key)
+		capacity += len(value)
 	}
 
 	sort.SliceStable(keys, func(i, j int) bool {
 		return len(data[keys[i]]) > len(data[keys[j]])
 	})
 
+	final := make([]byte, 0, capacity)
+
 	for _, key := range keys {
 		raw := data[key]
 		position := bytes.Index(final, raw)

src/data/bench_test.go

@@ -0,0 +1,21 @@
+package data_test
+
+import (
+	"testing"
+
+	"git.urbach.dev/cli/q/src/data"
+)
+
+func BenchmarkFinalize(b *testing.B) {
+	d := data.Data{}
+	d.Insert("1", []byte("Beautiful is better than ugly."))
+	d.Insert("2", []byte("Explicit is better than implicit."))
+	d.Insert("3", []byte("Simple is better than complex."))
+	d.Insert("4", []byte("Complex is better than complicated."))
+	d.Insert("5", []byte("Flat is better than nested."))
+	d.Insert("6", []byte("Sparse is better than dense."))
+
+	for b.Loop() {
+		d.Finalize()
+	}
+}