Multifile Torrents

fileinfo/fileinfo.go

@@ -0,0 +1,52 @@
+package fileinfo
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+type FileInfo struct {
+	Length int      `bencode:"length"`
+	Path   []string `bencode:"path"`
+}
+
+func (file *FileInfo) WriteToDisk(buf []byte, files []FileInfo, path, torrentName string) error {
+	outputPath := createPath(path, torrentName, file.Path[0], files)
+
+	err := os.MkdirAll(filepath.Dir(outputPath), os.ModePerm)
+	if err != nil {
+		return err
+	}
+
+	fileBuf := make([]byte, file.Length)
+	copy(fileBuf, buf[getOffset(*file, files):getOffset(*file, files)+file.Length])
+
+	err = os.WriteFile(outputPath, fileBuf, os.ModePerm)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("saved file %s\n", file.Path[0])
+
+	return nil
+}
+
+func getOffset(file FileInfo, files []FileInfo) int {
+	offset := 0
+	for _, f := range files {
+		if f.Length == file.Length && f.Path[0] == file.Path[0] {
+			return offset
+		}
+		offset += f.Length
+	}
+	return -1
+}
+
+func createPath(path, torrentName, filename string, files []FileInfo) (outputPath string) {
+	if len(files) < 2 {
+		return filepath.Join(path, torrentName)
+	}
+
+	return filepath.Join(path, torrentName, filename)
+}

fileinfo/fileinfo_test.go

@@ -0,0 +1,66 @@
+package fileinfo
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCreatePathSingleFileTorrent(t *testing.T) {
+	files := []FileInfo{
+		{
+			Path:   []string{"archlinux-2019.12.01-x86_64.iso"},
+			Length: 1,
+		},
+	}
+
+	want := "test/archlinux-2019.12.01-x86_64.iso"
+	got := createPath("test", files[0].Path[0], "archlinux-2019.12.01-x86_64.iso", files)
+
+	assert.Equal(t, want, got)
+}
+
+func TestCreatePathMultiFileTorrent(t *testing.T) {
+	files := []FileInfo{
+		{
+			Path:   []string{"archlinux-2019.12.01-x86_64.iso"},
+			Length: 1,
+		},
+		{
+			Path:   []string{"sali.txt"},
+			Length: 1,
+		},
+	}
+
+	givenPath := "dir1"
+	torrentName := "dir2"
+
+	for _, file := range files {
+		want := fmt.Sprintf("%s/%s/%s", givenPath, torrentName, file.Path[0])
+		got := createPath(givenPath, torrentName, file.Path[0], files)
+		assert.Equal(t, want, got)
+	}
+}
+
+// good idea to test writes to the system?
+// func TestWriteToDisk(t *testing.T) {
+// 	buf := []byte("helloworld")
+// 	files := []FileInfo{
+// 		{
+// 			Path:   []string{"file1.txt"},
+// 			Length: 5,
+// 		},
+// 		{
+// 			Path:   []string{"file2.txt"},
+// 			Length: 5,
+// 		},
+// 	}
+// 	path := "dir1"
+// 	torrentName := "alexandria"
+
+// 	for _, file := range files {
+// 		err := file.WriteToDisk(buf, files, path, torrentName)
+// 		require.Nil(t, err)
+// 	}
+// }

go.sum

@@ -4,7 +4,6 @@ github.com/jackpal/bencode-go v0.0.0-20180813173944-227668e840fa h1:ym9I4Q1lJG8n
 github.com/jackpal/bencode-go v0.0.0-20180813173944-227668e840fa/go.mod h1:5FSBQ74yhCl5oQ+QxRPYzWMONFnxbL68/23eezsBI5c=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 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=

p2p/p2p.go

@@ -125,7 +125,7 @@ func attemptDownloadPiece(c *client.Client, pw *pieceWork) ([]byte, error) {
 func checkIntegrity(pw *pieceWork, buf []byte) error {
 	hash := sha1.Sum(buf)
 	if !bytes.Equal(hash[:], pw.hash[:]) {
-		return fmt.Errorf("Index %d failed integrity check", pw.index)
+		return fmt.Errorf("index %d failed integrity check", pw.index)
 	}
 	return nil
 }