lib9p

commit c54bd7bd95c5e307ea841e1ad305380fadbacee6
parent 6bb0c54f45ad73569895e28fe3fcaf977839371c
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Sun, 10 Sep 2023 11:44:09 +0900

change ReadAt

Diffstat:
M
cmd/numfs.go
 | 
42
+++++++++++++++++-------------------------

1 file changed, 17 insertions(+), 25 deletions(-)
diff --git a/cmd/numfs.go b/cmd/numfs.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"flag"
 	"fmt"
 	"io"
@@ -20,13 +21,12 @@ func init() {
 	root = &numFile{
 		fs:   fsys,
 		id:   -1,
-		text: "",
-		offset: 0,
+		reader: nil,
 		children: []*numFile{
-			&numFile{fsys, 0, "0\n", 0, nil},
-			&numFile{fsys, 1, "1\n", 0, nil},
-			&numFile{fsys, 2, "2\n", 0, nil},
-			&numFile{fsys, 3, "3\n", 0, nil},
+			&numFile{fsys, 0, bytes.NewReader([]byte("0\n")), nil},
+			&numFile{fsys, 1, bytes.NewReader([]byte("1\n")), nil},
+			&numFile{fsys, 2, bytes.NewReader([]byte("2\n")), nil},
+			&numFile{fsys, 3, bytes.NewReader([]byte("3\n")), nil},
 		},
 	}
 }
@@ -59,8 +59,7 @@ func (fsys *numFS) Open(name string) (lib9p.File, error) {
 type numFile struct {
 	fs       *numFS
 	id       int
-	text     string
-	offset   int
+	reader   *bytes.Reader
 	children []*numFile
 }
 
@@ -95,7 +94,7 @@ func (f *numFile) Stat() (*lib9p.FileInfo, error) {
 	if f.id == -1 {
 		length = 0
 	} else {
-		length = int64(len(f.text))
+		length = f.reader.Size()
 	}
 	stat.Length = length
 	stat.Name = fmt.Sprintf("%d", f.id)
@@ -109,16 +108,18 @@ func (f *numFile) Read(p []byte) (int, error) {
 	if f.id == -1 {
 		return 0, fmt.Errorf("is a directory")
 	}
-	var n int
-	for n = 0; n < len(p) && n < len(f.text) - f.offset; n++ {
-		p[n] = f.text[f.offset + n]
+	return f.reader.Read(p)
+}
+
+func (f *numFile) ReadAt(p []byte, off int64) (n int, err error) {
+	if f.id == -1 {
+		return 0, fmt.Errorf("is a directory")
 	}
-	f.offset += n
-	return n, nil
+	return f.reader.ReadAt(p, off)
 }
 
 func (f *numFile) Close() error {
-	f.offset = 0
+	f.reader.Seek(0, io.SeekStart)
 	return nil
 }
 
@@ -126,18 +127,9 @@ func (f *numFile) PathName() string {
 	if f.id == -1 {
 		return "."
 	}
-	return f.text
+	return fmt.Sprintf("%d", f.id)
 }
 
-func (f *numFile) ReadAt(p []byte, off int64) (n int, err error) {
-	if off >= int64(len(f.text)) {
-		return 0, io.EOF
-	}
-	for n = 0; n < len(p) && int64(n) < int64(len(f.text)) - off; n++ {
-		p[n] = f.text[off + int64(n)]
-	}
-	return n, nil
-}
 
 func (f *numFile) Parent() (lib9p.File, error) { return root, nil }