add buffered reading and writing

3 files changed, 16 insertions, 4 deletions

diff --git a/go.mod b/go.mod
index 5bf475a..11123b7 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,7 @@ module go.metala.org/retaart
 
 go 1.21.5
 
-require github.com/spf13/pflag v1.0.5
+require (
+	github.com/klauspost/readahead v1.4.0
+	github.com/spf13/pflag v1.0.5
+)
diff --git a/go.sum b/go.sum
index 287f6fa..5c12cd1 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,4 @@
+github.com/klauspost/readahead v1.4.0 h1:w4hQ3BpdLjBnRQkZyNi+nwdHU7eGP9buTexWK9lU7gY=
+github.com/klauspost/readahead v1.4.0/go.mod h1:7bolpMKhT5LKskLwYXGSDOyA2TYtMFgdgV0Y8gy7QhA=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
diff --git a/main.go b/main.go
index f65b88d..89dba8d 100644
--- a/main.go
+++ b/main.go
@@ -2,11 +2,13 @@ package main
 
 import (
 	"archive/tar"
+	"bufio"
 	"io"
 	"log"
 	"os"
 	"path"
 
+	"github.com/klauspost/readahead"
 	flag "github.com/spf13/pflag"
 )
 
@@ -32,14 +34,19 @@ func main() {
 }
 
 func process(params processParams, logger *Logger) error {
-	tr := tar.NewReader(os.Stdin)
-	tw := tar.NewWriter(os.Stdout)
+	in := readahead.NewReader(os.Stdin)
+	defer in.Close()
+	out := bufio.NewWriter(os.Stdout)
+	defer out.Flush()
+
+	tr := tar.NewReader(in)
+	tw := tar.NewWriter(out)
 	defer tw.Close()
 	for {
 		hdr, err := tr.Next()
 		if err == io.EOF {
 			if params.concatenate {
-				tr = tar.NewReader(os.Stdin)
+				tr = tar.NewReader(in)
 				hdr, err = tr.Next()
 				if err == io.EOF {
 					break