Decompose DagArchive from unixfs tar

License: MIT
Signed-off-by: rht <rhtbot@gmail.com>

unixfs/archive/archive.go

@@ -0,0 +1,83 @@
+package archive
+
+import (
+	"bufio"
+	"compress/gzip"
+	"io"
+	"path"
+
+	cxt "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
+
+	mdag "github.com/ipfs/go-ipfs/merkledag"
+	tar "github.com/ipfs/go-ipfs/unixfs/archive/tar"
+	uio "github.com/ipfs/go-ipfs/unixfs/io"
+)
+
+// DefaultBufSize is the buffer size for gets. for now, 1MB, which is ~4 blocks.
+// TODO: does this need to be configurable?
+var DefaultBufSize = 1048576
+
+// DagArchive is equivalent to `ipfs getdag $hash | maybe_tar | maybe_gzip`
+func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService, archive bool, compression int) (io.Reader, error) {
+
+	_, filename := path.Split(name)
+
+	// need to connect a writer to a reader
+	piper, pipew := io.Pipe()
+
+	// use a buffered writer to parallelize task
+	bufw := bufio.NewWriterSize(pipew, DefaultBufSize)
+
+	// compression determines whether to use gzip compression.
+	var maybeGzw io.Writer
+	if compression != gzip.NoCompression {
+		var err error
+		maybeGzw, err = gzip.NewWriterLevel(bufw, compression)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		maybeGzw = bufw
+	}
+
+	if !archive && compression != gzip.NoCompression {
+		// the case when the node is a file
+		dagr, err := uio.NewDagReader(ctx, nd, dag)
+		if err != nil {
+			pipew.CloseWithError(err)
+			return nil, err
+		}
+
+		go func() {
+			if _, err := dagr.WriteTo(maybeGzw); err != nil {
+				pipew.CloseWithError(err)
+				return
+			}
+			pipew.Close() // everything seems to be ok.
+		}()
+	} else {
+		// the case for 1. archive, and 2. not archived and not compressed, in which tar is used anyway as a transport format
+
+		// construct the tar writer
+		w, err := tar.NewWriter(ctx, dag, archive, compression, maybeGzw)
+		if err != nil {
+			return nil, err
+		}
+
+		go func() {
+			// write all the nodes recursively
+			if err := w.WriteNode(nd, filename); err != nil {
+				pipew.CloseWithError(err)
+				return
+			}
+			if err := bufw.Flush(); err != nil {
+				pipew.CloseWithError(err)
+				return
+			}
+			w.Close()
+			pipew.Close() // everything seems to be ok.
+		}()
+	}
+
+	return piper, nil
+}

unixfs/archive/tar/writer.go

@@ -2,8 +2,6 @@ package tar
 
 import (
 	"archive/tar"
-	"bufio"
-	"compress/gzip"
 	"io"
 	"path"
 	"time"
@@ -17,73 +15,6 @@ import (
 	upb "github.com/ipfs/go-ipfs/unixfs/pb"
 )
 
-// DefaultBufSize is the buffer size for gets. for now, 1MB, which is ~4 blocks.
-// TODO: does this need to be configurable?
-var DefaultBufSize = 1048576
-
-// DagArchive is equivalent to `ipfs getdag $hash | maybe_tar | maybe_gzip`
-func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService, archive bool, compression int) (io.Reader, error) {
-
-	_, filename := path.Split(name)
-
-	// need to connect a writer to a reader
-	piper, pipew := io.Pipe()
-
-	// use a buffered writer to parallelize task
-	bufw := bufio.NewWriterSize(pipew, DefaultBufSize)
-
-	// compression determines whether to use gzip compression.
-	var maybeGzw io.Writer
-	if compression != gzip.NoCompression {
-		var err error
-		maybeGzw, err = gzip.NewWriterLevel(bufw, compression)
-		if err != nil {
-			return nil, err
-		}
-	} else {
-		maybeGzw = bufw
-	}
-
-	// construct the tar writer
-	w, err := NewWriter(ctx, dag, archive, compression, maybeGzw)
-	if err != nil {
-		return nil, err
-	}
-
-	// write all the nodes recursively
-	go func() {
-		if !archive && compression != gzip.NoCompression {
-			// the case when the node is a file
-			dagr, err := uio.NewDagReader(w.ctx, nd, w.Dag)
-			if err != nil {
-				pipew.CloseWithError(err)
-				return
-			}
-
-			if _, err := dagr.WriteTo(maybeGzw); err != nil {
-				pipew.CloseWithError(err)
-				return
-			}
-		} else {
-			// the case for 1. archive, and 2. not archived and not compressed, in which tar is used anyway as a transport format
-			if err := w.WriteNode(nd, filename); err != nil {
-				pipew.CloseWithError(err)
-				return
-			}
-		}
-
-		if err := bufw.Flush(); err != nil {
-			pipew.CloseWithError(err)
-			return
-		}
-
-		w.Close()
-		pipew.Close() // everything seems to be ok.
-	}()
-
-	return piper, nil
-}
-
 // Writer is a utility structure that helps to write
 // unixfs merkledag nodes as a tar archive format.
 // It wraps any io.Writer.