cmd/uplinkng: add ranged download

This change adds the ability to download byte ranges
to uplinkng.

Extended the uplinkng Filesystem interface with Stat
method and an OpenOptions struct as parameter for the
Open method.

Also added a few tests for the ranged download

Change-Id: I89a7276a75c51a4b22d7a450f15b3eb18ba838d4

cmd/uplinkng/cmd_cp.go

@@ -13,6 +13,7 @@ import (
 	"github.com/zeebo/clingy"
 	"github.com/zeebo/errs"
 
+	"storj.io/common/ranger/httpranger"
 	"storj.io/common/sync2"
 	"storj.io/storj/cmd/uplinkng/ulext"
 	"storj.io/storj/cmd/uplinkng/ulfs"
@@ -27,6 +28,7 @@ type cmdCp struct {
 	parallelism int
 	dryrun      bool
 	progress    bool
+	byteRange   string
 
 	source ulloc.Location
 	dest   ulloc.Location
@@ -58,12 +60,16 @@ func (c *cmdCp) Setup(params clingy.Parameters) {
 	c.progress = params.Flag("progress", "Show a progress bar when possible", true,
 		clingy.Transform(strconv.ParseBool),
 	).(bool)
+	c.byteRange = params.Flag("range", "Downloads the specified range bytes of an object. For more information about the HTTP Range header, see https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35", "").(string)
 
 	c.source = params.Arg("source", "Source to copy", clingy.Transform(ulloc.Parse)).(ulloc.Location)
 	c.dest = params.Arg("dest", "Desination to copy", clingy.Transform(ulloc.Parse)).(ulloc.Location)
 }
 
 func (c *cmdCp) Execute(ctx clingy.Context) error {
+	if c.parallelism > 1 && c.byteRange != "" {
+		return errs.New("parallelism and range flags are mutually exclusive")
+	}
 	fs, err := c.ex.OpenFilesystem(ctx, c.access)
 	if err != nil {
 		return err
@@ -173,12 +179,44 @@ func (c *cmdCp) copyFile(ctx clingy.Context, fs ulfs.Filesystem, source, dest ul
 		return nil
 	}
 
-	rh, err := fs.Open(ctx, source)
+	var length int64
+	var openOpts *ulfs.OpenOptions
+
+	if c.byteRange != "" {
+		// TODO: we might want to avoid this call if ranged download will be used frequently
+		stat, err := fs.Stat(ctx, source)
+		if err != nil {
+			return err
+		}
+		byteRange, err := httpranger.ParseRange(c.byteRange, stat.ContentLength)
+		if err != nil && byteRange == nil {
+			return errs.New("error parsing byte range %q: %w", c.byteRange, err)
+		}
+		if len(byteRange) == 0 {
+			return errs.New("invalid range")
+		}
+		if len(byteRange) > 1 {
+			return errs.New("retrieval of multiple byte ranges of data not supported: %d provided", len(byteRange))
+		}
+
+		length = byteRange[0].Length
+
+		openOpts = &ulfs.OpenOptions{
+			Offset: byteRange[0].Start,
+			Length: byteRange[0].Length,
+		}
+	}
+
+	rh, err := fs.Open(ctx, source, openOpts)
 	if err != nil {
 		return err
 	}
 	defer func() { _ = rh.Close() }()
 
+	if length == 0 {
+		length = rh.Info().ContentLength
+	}
+
 	wh, err := fs.Create(ctx, dest)
 	if err != nil {
 		return err
@@ -188,7 +226,7 @@ func (c *cmdCp) copyFile(ctx clingy.Context, fs ulfs.Filesystem, source, dest ul
 	var bar *progressbar.ProgressBar
 	var writer io.Writer = wh
 
-	if length := rh.Info().ContentLength; progress && length >= 0 && !c.dest.Std() {
+	if progress && length >= 0 && !c.dest.Std() {
 		bar = progressbar.New64(length).SetWriter(ctx.Stdout())
 		writer = bar.NewProxyWriter(writer)
 		bar.Start()

cmd/uplinkng/cmd_cp_test.go

@@ -71,6 +71,26 @@ func TestCpDownload(t *testing.T) {
 
 		state.Succeed(t, "cp", "sj://user/fo", "/home/user/dest", "--recursive").RequireLocalFiles(t)
 	})
+
+	t.Run("Range", func(t *testing.T) {
+		state := ultest.Setup(commands,
+			ultest.WithFile("sj://user/file-for-byte-range", "abcdefghijklmnopqrstuvwxyz"),
+		)
+
+		// multiple byte ranges not supported
+		state.Fail(t, "cp", "sj://user/file-for-byte-range", "/home/user/dest/file-for-byte-range", "--range", "bytes=0-1,2-3").RequireFailure(t).RequireLocalFiles(t)
+
+		state.Succeed(t, "cp", "sj://user/file-for-byte-range", "/home/user/dest/file-for-byte-range", "--range", "bytes=0-2").RequireLocalFiles(t,
+			ultest.File{Loc: "/home/user/dest/file-for-byte-range", Contents: "abc"},
+		)
+
+		state.Succeed(t, "cp", "sj://user/file-for-byte-range", "/home/user/dest/file-for-byte-range", "--range", "bytes=-1").RequireLocalFiles(t,
+			ultest.File{Loc: "/home/user/dest/file-for-byte-range", Contents: "z"},
+		)
+
+		// invalid range
+		state.Fail(t, "cp", "sj://user/file-for-byte-range", "/home/user/dest/file-for-byte-range", "--range", "bytes=0,-1").RequireFailure(t).RequireLocalFiles(t)
+	})
 }
 
 func TestCpUpload(t *testing.T) {

cmd/uplinkng/ulfs/filesystem.go

@@ -33,14 +33,21 @@ type RemoveOptions struct {
 
 func (ro *RemoveOptions) isPending() bool { return ro != nil && ro.Pending }
 
+// OpenOptions describes options for Filesystem.Open.
+type OpenOptions struct {
+	Offset int64
+	Length int64
+}
+
 // Filesystem represents either the local Filesystem or the data backed by a project.
 type Filesystem interface {
 	Close() error
-	Open(ctx clingy.Context, loc ulloc.Location) (ReadHandle, error)
+	Open(ctx clingy.Context, loc ulloc.Location, opts *OpenOptions) (ReadHandle, error)
 	Create(ctx clingy.Context, loc ulloc.Location) (WriteHandle, error)
 	Remove(ctx context.Context, loc ulloc.Location, opts *RemoveOptions) error
 	List(ctx context.Context, prefix ulloc.Location, opts *ListOptions) (ObjectIterator, error)
 	IsLocalDir(ctx context.Context, loc ulloc.Location) bool
+	Stat(ctx context.Context, loc ulloc.Location) (*ObjectInfo, error)
 }
 
 //

cmd/uplinkng/ulfs/local.go

@@ -5,6 +5,7 @@ package ulfs
 
 import (
 	"context"
+	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -25,11 +26,17 @@ func NewLocal() *Local {
 }
 
 // Open returns a read ReadHandle for the given local path.
-func (l *Local) Open(ctx context.Context, path string) (ReadHandle, error) {
+func (l *Local) Open(ctx context.Context, path string, opts *OpenOptions) (ReadHandle, error) {
 	fh, err := os.Open(path)
 	if err != nil {
 		return nil, errs.Wrap(err)
 	}
+
+	if opts != nil {
+		fr := io.NewSectionReader(fh, opts.Offset, opts.Length)
+		return newGenericReadHandle(fr), nil
+	}
+
 	return newOSReadHandle(fh)
 }
 
@@ -143,6 +150,20 @@ func (l *Local) IsLocalDir(ctx context.Context, path string) bool {
 	return fi.IsDir()
 }
 
+// Stat returns an ObjectInfo describing the provided path.
+func (l *Local) Stat(ctx context.Context, path string) (*ObjectInfo, error) {
+	fi, err := os.Stat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ObjectInfo{
+		Loc:           ulloc.NewLocal(path),
+		Created:       fi.ModTime(),
+		ContentLength: fi.Size(),
+	}, nil
+}
+
 type namedFileInfo struct {
 	os.FileInfo
 	name string

cmd/uplinkng/ulfs/mixed.go

@@ -32,11 +32,11 @@ func (m *Mixed) Close() error {
 }
 
 // Open returns a ReadHandle to either a local file, remote object, or stdin.
-func (m *Mixed) Open(ctx clingy.Context, loc ulloc.Location) (ReadHandle, error) {
+func (m *Mixed) Open(ctx clingy.Context, loc ulloc.Location, opts *OpenOptions) (ReadHandle, error) {
 	if bucket, key, ok := loc.RemoteParts(); ok {
-		return m.remote.Open(ctx, bucket, key)
+		return m.remote.Open(ctx, bucket, key, opts)
 	} else if path, ok := loc.LocalParts(); ok {
-		return m.local.Open(ctx, path)
+		return m.local.Open(ctx, path, opts)
 	}
 	return newGenericReadHandle(ctx.Stdin()), nil
 }
@@ -79,3 +79,13 @@ func (m *Mixed) IsLocalDir(ctx context.Context, loc ulloc.Location) bool {
 	}
 	return false
 }
+
+// Stat returns information about an object at the specified Location.
+func (m *Mixed) Stat(ctx context.Context, loc ulloc.Location) (*ObjectInfo, error) {
+	if bucket, key, ok := loc.RemoteParts(); ok {
+		return m.remote.Stat(ctx, bucket, key)
+	} else if path, ok := loc.LocalParts(); ok {
+		return m.local.Stat(ctx, path)
+	}
+	return nil, errs.New("unable to stat loc %q", loc.Loc())
+}

cmd/uplinkng/ulfs/remote.go

@@ -31,14 +31,31 @@ func (r *Remote) Close() error {
 }
 
 // Open returns a ReadHandle for the object identified by a given bucket and key.
-func (r *Remote) Open(ctx context.Context, bucket, key string) (ReadHandle, error) {
+func (r *Remote) Open(ctx context.Context, bucket, key string, opts *OpenOptions) (ReadHandle, error) {
-	fh, err := r.project.DownloadObject(ctx, bucket, key, nil)
+	var downloadOpts *uplink.DownloadOptions
+	if opts != nil {
+		downloadOpts = &uplink.DownloadOptions{
+			Offset: opts.Offset,
+			Length: opts.Length,
+		}
+	}
+	fh, err := r.project.DownloadObject(ctx, bucket, key, downloadOpts)
 	if err != nil {
 		return nil, errs.Wrap(err)
 	}
 	return newUplinkReadHandle(bucket, fh), nil
 }
 
+// Stat returns information about an object at the specified key.
+func (r *Remote) Stat(ctx context.Context, bucket, key string) (*ObjectInfo, error) {
+	fstat, err := r.project.StatObject(ctx, bucket, key)
+	if err != nil {
+		return nil, errs.Wrap(err)
+	}
+	stat := uplinkObjectToObjectInfo(bucket, fstat)
+	return &stat, nil
+}
+
 // Create returns a WriteHandle for the object identified by a given bucket and key.
 func (r *Remote) Create(ctx context.Context, bucket, key string) (WriteHandle, error) {
 	fh, err := r.project.UploadObject(ctx, bucket, key, nil)

cmd/uplinkng/ultest/filesystem.go

@@ -77,7 +77,7 @@ func (tfs *testFilesystem) Close() error {
 	return nil
 }
 
-func (tfs *testFilesystem) Open(ctx clingy.Context, loc ulloc.Location) (_ ulfs.ReadHandle, err error) {
+func (tfs *testFilesystem) Open(ctx clingy.Context, loc ulloc.Location, opts *ulfs.OpenOptions) (_ ulfs.ReadHandle, err error) {
 	if loc.Std() {
 		return &byteReadHandle{Buffer: bytes.NewBufferString("-")}, nil
 	}
@@ -86,6 +86,11 @@ func (tfs *testFilesystem) Open(ctx clingy.Context, loc ulloc.Location) (_ ulfs.
 	if !ok {
 		return nil, errs.New("file does not exist")
 	}
+
+	if opts != nil {
+		return &byteReadHandle{Buffer: bytes.NewBufferString(mf.contents[opts.Offset:(opts.Offset + opts.Length)])}, nil
+	}
+
 	return &byteReadHandle{Buffer: bytes.NewBufferString(mf.contents)}, nil
 }
 
@@ -194,6 +199,23 @@ func (tfs *testFilesystem) IsLocalDir(ctx context.Context, loc ulloc.Location) (
 	return ok && (ulloc.CleanPath(path) == "." || tfs.locals[path])
 }
 
+func (tfs *testFilesystem) Stat(ctx context.Context, loc ulloc.Location) (*ulfs.ObjectInfo, error) {
+	if loc.Std() {
+		return nil, errs.New("unable to stat loc %q", loc.Loc())
+	}
+
+	mf, ok := tfs.files[loc]
+	if !ok {
+		return nil, errs.New("file does not exist: %q", loc.Loc())
+	}
+
+	return &ulfs.ObjectInfo{
+		Loc:           loc,
+		Created:       time.Unix(mf.created, 0),
+		ContentLength: int64(len(mf.contents)),
+	}, nil
+}
+
 func (tfs *testFilesystem) mkdirAll(ctx context.Context, dir string) error {
 	i := 0
 	for i < len(dir) {

scripts/test-uplinkng.sh

@@ -72,6 +72,27 @@ uplinkng cp  "sj://$BUCKET/diff-size-segments"           "$DST_DIR" --progress=f
 
 uplinkng ls "sj://$BUCKET/small-upload-testfile" --access $STORJ_ACCESS | grep "small-upload-testfile"
 
+# test ranged download of object
+uplinkng cp "sj://$BUCKET/small-upload-testfile" "$DST_DIR/file-from-cp-range" --progress=false --range bytes=0-5
+EXPECTED_FILE_SIZE="6"
+ACTUAL_FILE_SIZE=$(get_file_size "$DST_DIR/file-from-cp-range")
+if [ "$EXPECTED_FILE_SIZE" != "$ACTUAL_FILE_SIZE" ]
+then
+    echo "expected downloaded file size to be equal to $EXPECTED_FILE_SIZE, got $ACTUAL_FILE_SIZE"
+    exit 1
+fi
+
+# test ranged download with multiple byte range
+set +e
+EXPECTED_ERROR="retrieval of multiple byte ranges of data not supported: 2 provided"
+ERROR=$(uplinkng cp "sj://$BUCKET/small-upload-testfile" "$DST_DIR/file-from-cp-range" --range bytes=0-5,6-10)
+if [ $ERROR != $EXPECTED_ERROR ]
+then
+    echo EXPECTED_ERROR
+    exit 1
+fi
+set -e
+
 uplinkng rm "sj://$BUCKET/small-upload-testfile"        --access $STORJ_ACCESS
 uplinkng rm "sj://$BUCKET/big-upload-testfile"          --access $STORJ_ACCESS
 uplinkng rm "sj://$BUCKET/multisegment-upload-testfile" --access $STORJ_ACCESS