coreapi: DAG API proposal

License: MIT
Signed-off-by: Łukasz Magiera <magik6k@gmail.com>

core/coreapi/coreapi.go

@@ -24,6 +24,10 @@ func (api *CoreAPI) Unixfs() coreiface.UnixfsAPI {
 	return (*UnixfsAPI)(api)
 }
 
+func (api *CoreAPI) Dag() coreiface.DagAPI {
+	return (*DagAPI)(api)
+}
+
 func (api *CoreAPI) ResolveNode(ctx context.Context, p coreiface.Path) (coreiface.Node, error) {
 	p, err := api.ResolvePath(ctx, p)
 	if err != nil {

core/coreapi/dag.go

@@ -0,0 +1,67 @@
+package coreapi
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	gopath "path"
+
+	coreiface "github.com/ipfs/go-ipfs/core/coreapi/interface"
+	coredag "github.com/ipfs/go-ipfs/core/coredag"
+
+	cid "gx/ipfs/QmNp85zy9RLrQ5oQD4hPyS39ezrrXpcaa7R4Y9kxdWQLLQ/go-cid"
+)
+
+type DagAPI CoreAPI
+
+func (api *DagAPI) Add(ctx context.Context, src io.Reader, inputEnc string, format cid.Prefix) ([]coreiface.Node, error) {
+	codec, ok := cid.CodecToStr[format.Codec]
+	if !ok {
+		return nil, fmt.Errorf("invalid codec %d", format.Codec)
+	}
+
+	nds, err := coredag.ParseInputs(inputEnc, codec, src, format.MhType, format.MhLength)
+	if err != nil {
+		return nil, err
+	}
+	if len(nds) == 0 {
+		return nil, fmt.Errorf("no node returned from ParseInputs")
+	}
+
+	out := make([]coreiface.Node, len(nds))
+	for n, nd := range nds {
+		_, err := api.node.DAG.Add(nd)
+		if err != nil {
+			return nil, err
+		}
+		out[n] = nd
+	}
+
+	return out, nil
+}
+
+func (api *DagAPI) Get(ctx context.Context, path coreiface.Path) (coreiface.Node, error) {
+	return api.core().ResolveNode(ctx, path)
+}
+
+func (api *DagAPI) Tree(ctx context.Context, p coreiface.Path, depth int) ([]coreiface.Path, error) {
+	n, err := api.Get(ctx, p)
+	if err != nil {
+		return nil, err
+	}
+	paths := n.Tree("", depth)
+	out := make([]coreiface.Path, len(paths))
+	for n, p2 := range paths {
+		out[n], err = ParsePath(gopath.Join(p.String(), p2))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return out, nil
+}
+
+func (api *DagAPI) core() coreiface.CoreAPI {
+	return (*CoreAPI)(api)
+}

core/coreapi/interface/interface.go

@@ -28,8 +28,10 @@ type Reader interface {
 
 type CoreAPI interface {
 	Unixfs() UnixfsAPI
+	Dag() DagAPI
+
 	ResolvePath(context.Context, Path) (Path, error)
-	ResolveNode(context.Context, Path) (Node, error)
+	ResolveNode(context.Context, Path) (Node, error) //TODO: should this get dropped in favor of DagAPI.Get?
 }
 
 type UnixfsAPI interface {
@@ -38,6 +40,12 @@ type UnixfsAPI interface {
 	Ls(context.Context, Path) ([]*Link, error)
 }
 
+type DagAPI interface {
+	Add(ctx context.Context, src io.Reader, inputEnc string, format cid.Prefix) ([]Node, error)
+	Get(ctx context.Context, path Path) (Node, error)
+	Tree(ctx context.Context, path Path, depth int) ([]Path, error)
+}
+
 // type ObjectAPI interface {
 // 	New() (cid.Cid, Object)
 // 	Get(string) (Object, error)