Merge pull request #3687 from ipfs/feat/sub-obj-dag-get

Feat/sub obj dag get

core/commands/dag/dag.go

@@ -10,8 +10,8 @@ import (
 	path "github.com/ipfs/go-ipfs/path"
 
 	cid "gx/ipfs/QmV5gPoRsjN1Gid3LMdNZTyfCtP2DsvqEbMAmz82RmmiGk/go-cid"
-	ipldcbor "gx/ipfs/QmWcQMNruWC3wphK1L6zEcV4MZBJqfsNKSRFcuo4AsNk4k/go-ipld-cbor"
 	node "gx/ipfs/QmYDscK7dmdo2GZ9aumS8s5auUUAH5mR1jvj5pYhWusfK7/go-ipld-node"
+	ipldcbor "gx/ipfs/QmdaC21UyoyN3t9QdapHZfsaUo3mqVf5p4CEuFaYVFqwap/go-ipld-cbor"
 )
 
 var DagCmd = &cmds.Command{
@@ -137,13 +137,23 @@ var DagGetCmd = &cmds.Command{
 			return
 		}
 
-		obj, err := n.Resolver.ResolvePath(req.Context(), p)
+		obj, rem, err := n.Resolver.ResolveToLastNode(req.Context(), p)
 		if err != nil {
 			res.SetError(err, cmds.ErrNormal)
 			return
 		}
 
-		res.SetOutput(obj)
+		var out interface{} = obj
+		if len(rem) > 0 {
+			final, _, err := obj.Resolve(rem)
+			if err != nil {
+				res.SetError(err, cmds.ErrNormal)
+				return
+			}
+			out = final
+		}
+
+		res.SetOutput(out)
 	},
 }
 

merkledag/merkledag.go

@@ -13,8 +13,8 @@ import (
 
 	logging "gx/ipfs/QmSpJByNKFX1sCsHBEp3R73FL4NF6FnQTEGyNAXHm2GS52/go-log"
 	cid "gx/ipfs/QmV5gPoRsjN1Gid3LMdNZTyfCtP2DsvqEbMAmz82RmmiGk/go-cid"
-	ipldcbor "gx/ipfs/QmWcQMNruWC3wphK1L6zEcV4MZBJqfsNKSRFcuo4AsNk4k/go-ipld-cbor"
 	node "gx/ipfs/QmYDscK7dmdo2GZ9aumS8s5auUUAH5mR1jvj5pYhWusfK7/go-ipld-node"
+	ipldcbor "gx/ipfs/QmdaC21UyoyN3t9QdapHZfsaUo3mqVf5p4CEuFaYVFqwap/go-ipld-cbor"
 )
 
 var log = logging.Logger("merkledag")

package.json

@@ -267,9 +267,9 @@
     },
     {
       "author": "whyrusleeping",
-      "hash": "QmWcQMNruWC3wphK1L6zEcV4MZBJqfsNKSRFcuo4AsNk4k",
+      "hash": "QmdaC21UyoyN3t9QdapHZfsaUo3mqVf5p4CEuFaYVFqwap",
       "name": "go-ipld-cbor",
-      "version": "1.2.0"
+      "version": "1.2.1"
     },
     {
       "author": "lgierth",

path/resolver.go

@@ -73,6 +73,39 @@ func SplitAbsPath(fpath Path) (*cid.Cid, []string, error) {
 	return c, parts[1:], nil
 }
 
+func (r *Resolver) ResolveToLastNode(ctx context.Context, fpath Path) (node.Node, []string, error) {
+	c, p, err := SplitAbsPath(fpath)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	nd, err := r.DAG.Get(ctx, c)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	for len(p) > 0 {
+		val, rest, err := nd.Resolve(p)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		switch val := val.(type) {
+		case *node.Link:
+			next, err := val.GetNode(ctx, r.DAG)
+			if err != nil {
+				return nil, nil, err
+			}
+			nd = next
+			p = rest
+		default:
+			return nd, p, nil
+		}
+	}
+
+	return nd, nil, nil
+}
+
 // ResolvePath fetches the node for given path. It returns the last item
 // returned by ResolvePathComponents.
 func (s *Resolver) ResolvePath(ctx context.Context, fpath Path) (node.Node, error) {

test/sharness/t0053-dag.sh

@@ -22,7 +22,7 @@ test_expect_success "make a few test files" '
 '
 
 test_expect_success "make an ipld object in json" '
-	printf "{\"hello\":\"world\",\"cats\":[{\"/\":\"%s\"},{\"water\":{\"/\":\"%s\"}}],\"magic\":{\"/\":\"%s\"}}" $HASH1 $HASH2 $HASH3 > ipld_object
+	printf "{\"hello\":\"world\",\"cats\":[{\"/\":\"%s\"},{\"water\":{\"/\":\"%s\"}}],\"magic\":{\"/\":\"%s\"},\"sub\":{\"dict\":\"ionary\",\"beep\":[0,\"bop\"]}}" $HASH1 $HASH2 $HASH3 > ipld_object
 '
 
 test_dag_cmd() {
@@ -31,7 +31,7 @@ test_dag_cmd() {
 	'
 
 	test_expect_success "output looks correct" '
-		EXPHASH="zdpuAzn7KZcQmKJvpEM1DgHXaybVj7mRP4ZMrkW94taYEuZHp"
+		EXPHASH="zdpuAsXfkHapxohc8LtsCzYiAsy84ESqKRD8eWuY64tt9r2CE"
 		test $EXPHASH = $IPLDHASH
 	'
 
@@ -47,6 +47,27 @@ test_dag_cmd() {
 		test_cmp file3 out3
 	'
 
+	test_expect_success "resolving sub-objects works" '
+		ipfs dag get $IPLDHASH/hello > sub1 &&
+		ipfs dag get $IPLDHASH/sub > sub2 &&
+		ipfs dag get $IPLDHASH/sub/beep > sub3 &&
+		ipfs dag get $IPLDHASH/sub/beep/0 > sub4 &&
+		ipfs dag get $IPLDHASH/sub/beep/1 > sub5
+	'
+
+	test_expect_success "sub-objects look right" '
+		echo "\"world\"" > sub1_exp &&
+		test_cmp sub1_exp sub1 &&
+		echo "{\"beep\":[0,\"bop\"],\"dict\":\"ionary\"}" > sub2_exp &&
+		test_cmp sub2_exp sub2 &&
+		echo "[0,\"bop\"]" > sub3_exp &&
+		test_cmp sub3_exp sub3 &&
+		echo "0" > sub4_exp &&
+		test_cmp sub4_exp sub4 &&
+		echo "\"bop\"" > sub5_exp &&
+		test_cmp sub5_exp sub5
+	'
+
 	test_expect_success "can pin cbor object" '
 		ipfs pin add $EXPHASH
 	'