Optimize DetectBest execution (#7)

Author: moredure

detector.go

@@ -85,11 +85,22 @@ var (
 
 // DetectBest returns the Result with highest Confidence.
 func (d *Detector) DetectBest(b []byte) (r *Result, err error) {
-	var all []Result
-	if all, err = d.DetectAll(b); err == nil {
-		r = &all[0]
+	input := newRecognizerInput(b, d.stripTag)
+	outputChan := make(chan recognizerOutput)
+	for _, r := range d.recognizers {
+		go matchHelper(r, input, outputChan)
+	}
+	var output Result
+	for i := 0; i < len(d.recognizers); i++ {
+		o := <-outputChan
+		if output.Confidence < o.Confidence {
+			output = Result(o)
+		}
+	}
+	if output.Confidence == 0 {
+		return nil, NotDetectedError
 	}
-	return
+	return &output, nil
 }
 
 // DetectAll returns all Results which have non-zero Confidence. The Results are sorted by Confidence in descending order.

detector_test.go

@@ -1,6 +1,7 @@
 package chardet_test
 
 import (
+	"bytes"
 	"github.com/gogs/chardet"
 	"io"
 	"os"
@@ -58,3 +59,12 @@ func TestDetector(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkDetectBest(b *testing.B) {
+	textDetector := chardet.NewTextDetector()
+	aaaa := bytes.Repeat([]byte("A"), 1024)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		textDetector.DetectBest(aaaa)
+	}
+}