Merge pull request #4471 from ipfs/feat/coreapi/dag

RFC: coreapi.Dag

core/coreapi/coreapi.go

@@ -25,6 +25,10 @@ func (api *CoreAPI) Unixfs() coreiface.UnixfsAPI {
 	return (*UnixfsAPI)(api)
 }
 
+func (api *CoreAPI) Dag() coreiface.DagAPI {
+	return &DagAPI{api, nil}
+}
+
 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 +1,77 @@
+package coreapi
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	gopath "path"
+
+	coreiface "github.com/ipfs/go-ipfs/core/coreapi/interface"
+	caopts "github.com/ipfs/go-ipfs/core/coreapi/interface/options"
+	coredag "github.com/ipfs/go-ipfs/core/coredag"
+
+	cid "gx/ipfs/QmeSrf6pzut73u6zLQkRFQ3ygt3k6XFT2kjdYP8Tnkwwyg/go-cid"
+)
+
+type DagAPI struct {
+	*CoreAPI
+	*caopts.DagOptions
+}
+
+func (api *DagAPI) Put(ctx context.Context, src io.Reader, opts ...caopts.DagPutOption) (coreiface.Path, error) {
+	settings, err := caopts.DagPutOptions(opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	codec, ok := cid.CodecToStr[settings.Codec]
+	if !ok {
+		return nil, fmt.Errorf("invalid codec %d", settings.Codec)
+	}
+
+	nds, err := coredag.ParseInputs(settings.InputEnc, codec, src, settings.MhType, settings.MhLength)
+	if err != nil {
+		return nil, err
+	}
+	if len(nds) == 0 {
+		return nil, fmt.Errorf("no node returned from ParseInputs")
+	}
+
+	_, err = api.node.DAG.Add(nds[0])
+	if err != nil {
+		return nil, err
+	}
+
+	return ParseCid(nds[0].Cid()), 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, opts ...caopts.DagTreeOption) ([]coreiface.Path, error) {
+	settings, err := caopts.DagTreeOptions(opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	n, err := api.Get(ctx, p)
+	if err != nil {
+		return nil, err
+	}
+	paths := n.Tree("", settings.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 api.CoreAPI
+}

core/coreapi/dag_test.go

@@ -0,0 +1,117 @@
+package coreapi_test
+
+import (
+	"context"
+	"path"
+	"strings"
+	"testing"
+
+	coreapi "github.com/ipfs/go-ipfs/core/coreapi"
+
+	mh "gx/ipfs/QmYeKnKpubCMRiq3PGZcTREErthbb5Q9cXsCoSkD9bjEBd/go-multihash"
+)
+
+var (
+	treeExpected = map[string]struct{}{
+		"a":   {},
+		"b":   {},
+		"c":   {},
+		"c/d": {},
+		"c/e": {},
+	}
+)
+
+func TestPut(t *testing.T) {
+	ctx := context.Background()
+	_, api, err := makeAPI(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+
+	res, err := api.Dag().Put(ctx, strings.NewReader(`"Hello"`))
+	if err != nil {
+		t.Error(err)
+	}
+
+	if res.Cid().String() != "zdpuAqckYF3ToF3gcJNxPZXmnmGuXd3gxHCXhq81HGxBejEvv" {
+		t.Errorf("got wrong cid: %s", res.Cid().String())
+	}
+}
+
+func TestPutWithHash(t *testing.T) {
+	ctx := context.Background()
+	_, api, err := makeAPI(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+
+	res, err := api.Dag().Put(ctx, strings.NewReader(`"Hello"`), api.Dag().WithHash(mh.ID, -1))
+	if err != nil {
+		t.Error(err)
+	}
+
+	if res.Cid().String() != "z5hRLNd2sv4z1c" {
+		t.Errorf("got wrong cid: %s", res.Cid().String())
+	}
+}
+
+func TestPath(t *testing.T) {
+	ctx := context.Background()
+	_, api, err := makeAPI(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+
+	sub, err := api.Dag().Put(ctx, strings.NewReader(`"foo"`))
+	if err != nil {
+		t.Error(err)
+	}
+
+	res, err := api.Dag().Put(ctx, strings.NewReader(`{"lnk": {"/": "`+sub.Cid().String()+`"}}`))
+	if err != nil {
+		t.Error(err)
+	}
+
+	p, err := coreapi.ParsePath(path.Join(res.Cid().String(), "lnk"))
+	if err != nil {
+		t.Error(err)
+	}
+
+	nd, err := api.Dag().Get(ctx, p)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if nd.Cid().String() != sub.Cid().String() {
+		t.Errorf("got unexpected cid %s, expected %s", nd.Cid().String(), sub.Cid().String())
+	}
+}
+
+func TestTree(t *testing.T) {
+	ctx := context.Background()
+	_, api, err := makeAPI(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+
+	c, err := api.Dag().Put(ctx, strings.NewReader(`{"a": 123, "b": "foo", "c": {"d": 321, "e": 111}}`))
+	if err != nil {
+		t.Error(err)
+	}
+
+	res, err := api.Dag().Get(ctx, c)
+	if err != nil {
+		t.Error(err)
+	}
+
+	lst := res.Tree("", -1)
+	if len(lst) != len(treeExpected) {
+		t.Errorf("tree length of %d doesn't match expected %d", len(lst), len(treeExpected))
+	}
+
+	for _, ent := range lst {
+		if _, ok := treeExpected[ent]; !ok {
+			t.Errorf("unexpected tree entry %s", ent)
+		}
+	}
+}

core/coreapi/interface/interface.go

@@ -7,6 +7,8 @@ import (
 	"errors"
 	"io"
 
+	options "github.com/ipfs/go-ipfs/core/coreapi/interface/options"
+
 	ipld "gx/ipfs/QmNwUEK7QbwSqyKBu3mMtToo8SUc6wQJ7gdZq4gGGJqfnf/go-ipld-format"
 	cid "gx/ipfs/QmeSrf6pzut73u6zLQkRFQ3ygt3k6XFT2kjdYP8Tnkwwyg/go-cid"
 )
@@ -34,6 +36,7 @@ type Reader interface {
 type CoreAPI interface {
 	// Unixfs returns an implementation of Unixfs API
 	Unixfs() UnixfsAPI
+	Dag() DagAPI
 
 	// ResolvePath resolves the path using Unixfs resolver
 	ResolvePath(context.Context, Path) (Path, error)
@@ -55,6 +58,38 @@ type UnixfsAPI interface {
 	Ls(context.Context, Path) ([]*Link, error)
 }
 
+// DagAPI specifies the interface to IPLD
+type DagAPI interface {
+	// Put inserts data using specified format and input encoding.
+	// Unless used with WithCodec or WithHash, the defaults "dag-cbor" and
+	// "sha256" are used.
+	Put(ctx context.Context, src io.Reader, opts ...options.DagPutOption) (Path, error)
+
+	// WithInputEnc is an option for Put which specifies the input encoding of the
+	// data. Default is "json", most formats/codecs support "raw"
+	WithInputEnc(enc string) options.DagPutOption
+
+	// WithCodec is an option for Put which specifies the multicodec to use to
+	// serialize the object. Default is cid.DagCBOR (0x71)
+	WithCodec(codec uint64) options.DagPutOption
+
+	// WithHash is an option for Put which specifies the multihash settings to use
+	// when hashing the object. Default is based on the codec used
+	// (mh.SHA2_256 (0x12) for DagCBOR). If mhLen is set to -1, default length for
+	// the hash will be used
+	WithHash(mhType uint64, mhLen int) options.DagPutOption
+
+	// Get attempts to resolve and get the node specified by the path
+	Get(ctx context.Context, path Path) (Node, error)
+
+	// Tree returns list of paths within a node specified by the path.
+	Tree(ctx context.Context, path Path, opts ...options.DagTreeOption) ([]Path, error)
+
+	// WithDepth is an option for Tree which specifies maximum depth of the
+	// returned tree. Default is -1 (no depth limit)
+	WithDepth(depth int) options.DagTreeOption
+}
+
 // type ObjectAPI interface {
 // 	New() (cid.Cid, Object)
 // 	Get(string) (Object, error)

core/coreapi/interface/options/dag.go

@@ -0,0 +1,83 @@
+package options
+
+import (
+	"math"
+
+	cid "gx/ipfs/QmeSrf6pzut73u6zLQkRFQ3ygt3k6XFT2kjdYP8Tnkwwyg/go-cid"
+)
+
+type DagPutSettings struct {
+	InputEnc string
+	Codec    uint64
+	MhType   uint64
+	MhLength int
+}
+
+type DagTreeSettings struct {
+	Depth int
+}
+
+type DagPutOption func(*DagPutSettings) error
+type DagTreeOption func(*DagTreeSettings) error
+
+func DagPutOptions(opts ...DagPutOption) (*DagPutSettings, error) {
+	options := &DagPutSettings{
+		InputEnc: "json",
+		Codec:    cid.DagCBOR,
+		MhType:   math.MaxUint64,
+		MhLength: -1,
+	}
+
+	for _, opt := range opts {
+		err := opt(options)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return options, nil
+}
+
+func DagTreeOptions(opts ...DagTreeOption) (*DagTreeSettings, error) {
+	options := &DagTreeSettings{
+		Depth: -1,
+	}
+
+	for _, opt := range opts {
+		err := opt(options)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return options, nil
+}
+
+type DagOptions struct{}
+
+func (api *DagOptions) WithInputEnc(enc string) DagPutOption {
+	return func(settings *DagPutSettings) error {
+		settings.InputEnc = enc
+		return nil
+	}
+}
+
+func (api *DagOptions) WithCodec(codec uint64) DagPutOption {
+	return func(settings *DagPutSettings) error {
+		settings.Codec = codec
+		return nil
+	}
+}
+
+func (api *DagOptions) WithHash(mhType uint64, mhLen int) DagPutOption {
+	return func(settings *DagPutSettings) error {
+		settings.MhType = mhType
+		settings.MhLength = mhLen
+		return nil
+	}
+}
+
+func (api *DagOptions) WithDepth(depth int) DagTreeOption {
+	return func(settings *DagTreeSettings) error {
+		settings.Depth = depth
+		return nil
+	}
+}