From cdc1c837f736321c3c59245c723820f9e560e173 Mon Sep 17 00:00:00 2001
From: Kevin Atkinson <k@kevina.org>
Date: Fri, 12 May 2017 15:06:08 -0400
Subject: [PATCH] adder: add support for specifying the hash function

License: MIT
Signed-off-by: Kevin Atkinson <k@kevina.org>
---
 core/commands/add.go               | 18 ++++++++++++++++++
 test/sharness/t0040-add-and-cat.sh | 13 +++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/core/commands/add.go b/core/commands/add.go
index a16817db9353..7a6b61003403 100644
--- a/core/commands/add.go
+++ b/core/commands/add.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 
 	bstore "github.com/ipfs/go-ipfs/blocks/blockstore"
 	blockservice "github.com/ipfs/go-ipfs/blockservice"
@@ -17,6 +18,7 @@ import (
 	mfs "github.com/ipfs/go-ipfs/mfs"
 	ft "github.com/ipfs/go-ipfs/unixfs"
 
+	mh "gx/ipfs/QmVGtdTZdTFaLsaj2RwdVG8jcjNNcp1DE914DKZ2kHmXHw/go-multihash"
 	u "gx/ipfs/QmWbjfz3u6HkAdPh34dgPchGbQjob6LXLhAeCGii2TX69n/go-ipfs-util"
 	"gx/ipfs/QmeWjRodbcZFKe5tMN7poEx3izym6osrLSnTLf9UjJZBbs/pb"
 )
@@ -39,6 +41,7 @@ const (
 	noCopyOptionName      = "nocopy"
 	fstoreCacheOptionName = "fscache"
 	cidVersionOptionName  = "cid-version"
+	hashOptionName        = "hash"
 )
 
 const adderOutChanSize = 8
@@ -90,6 +93,7 @@ You can now refer to the added file in a gateway, like so:
 		cmds.BoolOption(noCopyOptionName, "Add the file using filestore. (experimental)"),
 		cmds.BoolOption(fstoreCacheOptionName, "Check the filestore for pre-existing blocks. (experimental)"),
 		cmds.IntOption(cidVersionOptionName, "Cid version. Non-zero value will change default of 'raw-leaves' to true. (experimental)").Default(0),
+		cmds.StringOption(hashOptionName, "Hash function to use. Will set Cid version to 1 if used. (experimental)").Default("sha2-256"),
 	},
 	PreRun: func(req cmds.Request) error {
 		quiet, _, _ := req.Option(quietOptionName).Bool()
@@ -164,6 +168,7 @@ You can now refer to the added file in a gateway, like so:
 		nocopy, _, _ := req.Option(noCopyOptionName).Bool()
 		fscache, _, _ := req.Option(fstoreCacheOptionName).Bool()
 		cidVer, _, _ := req.Option(cidVersionOptionName).Int()
+		hashFunStr, hfset, _ := req.Option(hashOptionName).String()
 
 		if nocopy && !cfg.Experimental.FilestoreEnabled {
 			res.SetError(errors.New("filestore is not enabled, see https://git.io/vy4XN"),
@@ -180,6 +185,10 @@ You can now refer to the added file in a gateway, like so:
 			return
 		}
 
+		if hfset && cidVer == 0 {
+			cidVer = 1
+		}
+
 		if cidVer >= 1 && !rbset {
 			rawblks = true
 		}
@@ -190,6 +199,15 @@ You can now refer to the added file in a gateway, like so:
 			return
 		}
 
+		hashFunCode, ok := mh.Names[strings.ToLower(hashFunStr)]
+		if !ok {
+			res.SetError(fmt.Errorf("unrecognized hash function: %s", strings.ToLower(hashFunStr)), cmds.ErrNormal)
+			return
+		}
+
+		prefix.MhType = hashFunCode
+		prefix.MhLength = -1
+
 		if hash {
 			nilnode, err := core.NewNode(n.Context(), &core.BuildCfg{
 				//TODO: need this to be true or all files
diff --git a/test/sharness/t0040-add-and-cat.sh b/test/sharness/t0040-add-and-cat.sh
index 4b2d636a4805..5f9c703cf2e3 100755
--- a/test/sharness/t0040-add-and-cat.sh
+++ b/test/sharness/t0040-add-and-cat.sh
@@ -403,6 +403,10 @@ MARS="zdj7WWx6fGNrNGkdpkuTAxCjKbQ1pPtarqA6VQhedhLTZu34J"
 VENUS="zdj7WbB1BUF8WejmVpQCmMLd1RbPnxJtvAj1Lep6eTmXRFbrz"
 add_directory '--cid-version=1 --raw-leaves=false'
 
+#PLANETS="???"
+#MARS="???"
+#VENUS="???"
+#add_directory '--hash=blake2b-256'
 
 test_expect_success "'ipfs add -rn' succeeds" '
 	mkdir -p mountdir/moons/jupiter &&
@@ -446,6 +450,15 @@ test_add_cat_5MB --cid-version=1 "zdj7WiiaedqVBXjX4SNqx3jfuZideDqdLYnDzCDJ66JDMK
 # format (i.e. not raw)
 test_add_cat_5MB '--cid-version=1 --raw-leaves=false' "zdj7WfgEsj897BBZj2mcfsRLhaPZcCixPV2G7DkWgF1Wdr64P"
 
+# note: --hash=blake2b-256 implies --cid-version=1 which implies --raw-leaves=true
+# the specified hash represents the leaf nodes stored as raw leaves and
+# encoded with the blake2b-256 hash funtion
+test_add_cat_5MB '--hash=blake2b-256' "zDMZof1kuxn7ebvKyvmkYLPvocSvFYxxAWT1yQBN1wWiXXr7w5mY"
+
+# the specified hash represents the leaf nodes stored as protoful nodes and
+# encoded with the blake2b-256 hash funtion
+test_add_cat_5MB '--hash=blake2b-256 --raw-leaves=false' "zDMZof1krz3SFTyhboRyWZyUP2qNgVdn9wjtaX211aHJ8WgeyT9v"
+
 test_add_cat_expensive "" "QmU9SWAPPmNEKZB8umYMmjYvN7VyHqABNvdA6GUi4MMEz3"
 
 # note: the specified hash implies that internal nodes are stored