cmd/block: add selection of multihash parameters to block put command

License: MIT
Signed-off-by: Jeromy <why@ipfs.io>

core/commands/block.go

@@ -117,6 +117,8 @@ It reads from stdin, and <key> is a base58 encoded multihash.
 	},
 	Options: []cmds.Option{
 		cmds.StringOption("format", "f", "cid format for blocks to be created with.").Default("v0"),
+		cmds.StringOption("mhtype", "multihash hash function").Default("sha2-256"),
+		cmds.IntOption("mhlen", "multihash hash length").Default(-1),
 	},
 	Run: func(req cmds.Request, res cmds.Response) {
 		n, err := req.InvocContext().GetNode()
@@ -143,11 +145,10 @@ It reads from stdin, and <key> is a base58 encoded multihash.
 			return
 		}
 
-		format, _, _ := req.Option("format").String()
 		var pref cid.Prefix
-		pref.MhType = mh.SHA2_256
-		pref.MhLength = -1
 		pref.Version = 1
+
+		format, _, _ := req.Option("format").String()
 		switch format {
 		case "cbor":
 			pref.Codec = cid.DagCBOR
@@ -163,6 +164,21 @@ It reads from stdin, and <key> is a base58 encoded multihash.
 			return
 		}
 
+		mhtype, _, _ := req.Option("mhtype").String()
+		mhtval, ok := mh.Names[mhtype]
+		if !ok {
+			res.SetError(fmt.Errorf("unrecognized multihash function: %s", mhtype), cmds.ErrNormal)
+			return
+		}
+		pref.MhType = mhtval
+
+		mhlen, _, err := req.Option("mhlen").Int()
+		if err != nil {
+			res.SetError(err, cmds.ErrNormal)
+			return
+		}
+		pref.MhLength = mhlen
+
 		bcid, err := pref.Sum(data)
 		if err != nil {
 			res.SetError(err, cmds.ErrNormal)

test/sharness/t0050-block.sh

@@ -184,6 +184,19 @@ test_expect_success "block get output looks right" '
 	test_cmp pb_block_out ../t0051-object-data/testPut.pb
 '
 
+test_expect_success "can set multihash type and length on block put" '
+	HASH=$(echo "foooo" | ipfs block put --format=raw --mhtype=sha3 --mhlen=16)
+'
+
+test_expect_success "output looks good" '
+	test "z25ScPysKoxJBcPxczn9NvuHiZU5" = "$HASH"
+'
+
+test_expect_success "can read block with different hash" '
+	ipfs block get $HASH > blk_get_out &&
+	echo "foooo" > blk_get_exp &&
+	test_cmp blk_get_exp blk_get_out
+'
 #
 # Misc tests
 #