Feat/streaming optimization

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.20'
+        go-version: '1.24'
 
     - name: Install dependencies
       run: go mod download

go.mod

@@ -1,11 +1,17 @@
 module github.com/asticode/go-astisub
 
-go 1.13
+go 1.24.0
 
 require (
-	github.com/asticode/go-astikit v0.20.0
-	github.com/asticode/go-astits v1.8.0
+	github.com/asticode/go-astikit v0.57.1
+	github.com/asticode/go-astits v1.15.0
 	github.com/stretchr/testify v1.4.0
-	golang.org/x/net v0.0.0-20200904194848-62affa334b73
-	golang.org/x/text v0.3.2
+	golang.org/x/net v0.49.0
+	golang.org/x/text v0.33.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v2 v2.2.2 // indirect
 )

go.sum

@@ -1,7 +1,8 @@
-github.com/asticode/go-astikit v0.20.0 h1:+7N+J4E4lWx2QOkRdOf6DafWJMv6O4RRfgClwQokrH8=
-github.com/asticode/go-astikit v0.20.0/go.mod h1:h4ly7idim1tNhaVkdVBeXQZEE3L0xblP7fCWbgwipF0=
-github.com/asticode/go-astits v1.8.0 h1:rf6aiiGn/QhlFjNON1n5plqF3Fs025XLUwiQ0NB6oZg=
-github.com/asticode/go-astits v1.8.0/go.mod h1:DkOWmBNQpnr9mv24KfZjq4JawCFX1FCqjLVGvO0DygQ=
+github.com/asticode/go-astikit v0.30.0/go.mod h1:h4ly7idim1tNhaVkdVBeXQZEE3L0xblP7fCWbgwipF0=
+github.com/asticode/go-astikit v0.57.1 h1:fEykwH98Nny08kcRbk4uer+S8h0rKveCIpG9F6NVLuA=
+github.com/asticode/go-astikit v0.57.1/go.mod h1:fV43j20UZYfXzP9oBn33udkvCvDvCDhzjVqoLFuuYZE=
+github.com/asticode/go-astits v1.15.0 h1:yRyCiUc8Jj4F7clt2GDxHghMpWuFL5rkaLuGUd2/0J4=
+github.com/asticode/go-astits v1.15.0/go.mod h1:QSHmknZ51pf6KJdHKZHJTLlMegIrhega3LPWz3ND/iI=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pkg/profile v1.4.0/go.mod h1:NWz/XGvpEW1FyYQ7fCx4dqYBLlfTcE+A9FLAkNKqjFE=
@@ -10,18 +11,10 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20200904194848-62affa334b73 h1:MXfv8rhZWmFeqX3GNZRsd6vOLoaCHjYEX3qkRo3YBUA=
-golang.org/x/net v0.0.0-20200904194848-62affa334b73/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
-golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
+golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
+golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
+golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=

srt.go

@@ -1,6 +1,7 @@
 package astisub
 
 import (
+	"bufio"
 	"fmt"
 	"io"
 	"strconv"
@@ -220,49 +221,76 @@ func (s Subtitles) WriteToSRT(o io.Writer) (err error) {
 		return
 	}
 
+	// Init writer
+	w := bufio.NewWriter(o)
+	defer w.Flush()
+
 	// Add BOM header
-	var c []byte
-	c = append(c, BytesBOM...)
+	if _, err = w.Write(BytesBOM); err != nil {
+		err = fmt.Errorf("astisub: writing bom failed: %w", err)
+		return
+	}
 
 	// Loop through subtitles
 	for k, v := range s.Items {
 		// Add time boundaries
-		c = append(c, []byte(strconv.Itoa(k+1))...)
-		c = append(c, bytesLineSeparator...)
-		c = append(c, []byte(formatDurationSRT(v.StartAt))...)
-		c = append(c, bytesSRTTimeBoundariesSeparator...)
-		c = append(c, []byte(formatDurationSRT(v.EndAt))...)
-		c = append(c, bytesLineSeparator...)
+		if _, err = w.WriteString(strconv.Itoa(k + 1)); err != nil {
+			err = fmt.Errorf("astisub: writing index failed: %w", err)
+			return
+		}
+		if _, err = w.Write(bytesLineSeparator); err != nil {
+			err = fmt.Errorf("astisub: writing line separator failed: %w", err)
+			return
+		}
+		if _, err = w.WriteString(formatDurationSRT(v.StartAt)); err != nil {
+			err = fmt.Errorf("astisub: writing start at failed: %w", err)
+			return
+		}
+		if _, err = w.Write(bytesSRTTimeBoundariesSeparator); err != nil {
+			err = fmt.Errorf("astisub: writing time boundaries separator failed: %w", err)
+			return
+		}
+		if _, err = w.WriteString(formatDurationSRT(v.EndAt)); err != nil {
+			err = fmt.Errorf("astisub: writing end at failed: %w", err)
+			return
+		}
+		if _, err = w.Write(bytesLineSeparator); err != nil {
+			err = fmt.Errorf("astisub: writing line separator failed: %w", err)
+			return
+		}
 
 		// Loop through lines
 		for _, l := range v.Lines {
-			c = append(c, []byte(l.srtBytes())...)
+			if err = l.writeSRT(w); err != nil {
+				return
+			}
 		}
 
 		// Add new line
-		c = append(c, bytesLineSeparator...)
-	}
-
-	// Remove last new line
-	c = c[:len(c)-1]
-
-	// Write
-	if _, err = o.Write(c); err != nil {
-		err = fmt.Errorf("astisub: writing failed: %w", err)
-		return
+		if k < len(s.Items)-1 {
+			if _, err = w.Write(bytesLineSeparator); err != nil {
+				err = fmt.Errorf("astisub: writing line separator failed: %w", err)
+				return
+			}
+		}
 	}
 	return
 }
 
-func (l Line) srtBytes() (c []byte) {
+func (l Line) writeSRT(w io.Writer) (err error) {
 	for _, li := range l.Items {
-		c = append(c, li.srtBytes()...)
+		if err = li.writeSRT(w); err != nil {
+			return
+		}
+	}
+	if _, err = w.Write(bytesLineSeparator); err != nil {
+		err = fmt.Errorf("astisub: writing line separator failed: %w", err)
+		return
 	}
-	c = append(c, bytesLineSeparator...)
 	return
 }
 
-func (li LineItem) srtBytes() (c []byte) {
+func (li LineItem) writeSRT(w io.Writer) (err error) {
 	// Get color
 	var color string
 	if li.InlineStyle != nil && li.InlineStyle.SRTColor != nil {
@@ -282,32 +310,52 @@ func (li LineItem) srtBytes() (c []byte) {
 
 	// Append
 	if color != "" {
-		c = append(c, []byte("<font color=\""+color+"\">")...)
+		if _, err = w.Write([]byte("<font color=\"" + color + "\">")); err != nil {
+			return fmt.Errorf("astisub: writing font color failed: %w", err)
+		}
 	}
 	if b {
-		c = append(c, []byte("<b>")...)
+		if _, err = w.Write([]byte("<b>")); err != nil {
+			return fmt.Errorf("astisub: writing bold failed: %w", err)
+		}
 	}
 	if i {
-		c = append(c, []byte("<i>")...)
+		if _, err = w.Write([]byte("<i>")); err != nil {
+			return fmt.Errorf("astisub: writing italics failed: %w", err)
+		}
 	}
 	if u {
-		c = append(c, []byte("<u>")...)
+		if _, err = w.Write([]byte("<u>")); err != nil {
+			return fmt.Errorf("astisub: writing underline failed: %w", err)
+		}
 	}
 	if pos != 0 {
-		c = append(c, []byte(fmt.Sprintf(`{\an%d}`, pos))...)
+		if _, err = w.Write([]byte(fmt.Sprintf(`{\an%d}`, pos))); err != nil {
+			return fmt.Errorf("astisub: writing position failed: %w", err)
+		}
+	}
+	if _, err = w.Write([]byte(escapeHTML(li.Text))); err != nil {
+		return fmt.Errorf("astisub: writing text failed: %w", err)
 	}
-	c = append(c, []byte(escapeHTML(li.Text))...)
 	if u {
-		c = append(c, []byte("</u>")...)
+		if _, err = w.Write([]byte("</u>")); err != nil {
+			return fmt.Errorf("astisub: writing underline close failed: %w", err)
+		}
 	}
 	if i {
-		c = append(c, []byte("</i>")...)
+		if _, err = w.Write([]byte("</i>")); err != nil {
+			return fmt.Errorf("astisub: writing italics close failed: %w", err)
+		}
 	}
 	if b {
-		c = append(c, []byte("</b>")...)
+		if _, err = w.Write([]byte("</b>")); err != nil {
+			return fmt.Errorf("astisub: writing bold close failed: %w", err)
+		}
 	}
 	if color != "" {
-		c = append(c, []byte("</font>")...)
+		if _, err = w.Write([]byte("</font>")); err != nil {
+			return fmt.Errorf("astisub: writing font close failed: %w", err)
+		}
 	}
 	return
 }

srt_test.go

@@ -171,3 +171,16 @@ func TestSRTParseDuration(t *testing.T) {
 	assert.Equal(t, 5*time.Second+985*time.Millisecond, s.Items[1].EndAt)
 	assert.Equal(t, "Duration without colon milliseconds", s.Items[1].Lines[0].String())
 }
+
+func BenchmarkWriteToSRT(b *testing.B) {
+	s, err := astisub.OpenFile("./testdata/example-in.srt")
+	if err != nil {
+		b.Fatal(err)
+	}
+	w := &bytes.Buffer{}
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		w.Reset()
+		s.WriteToSRT(w)
+	}
+}