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Remove multihash from Swarm bzz:// for Feeds (#18175)

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This commit is contained in:
Javier Peletier 2018-11-26 16:10:22 +01:00 committed by Anton Evangelatov
parent 0699287440
commit 2714e8f091
7 changed files with 167 additions and 226 deletions
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6
cmd/swarm/swarm-smoke/feed_upload_and_sync.go
View File

@ -16,7 +16,6 @@ import (
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/swarm/multihash"
"github.com/ethereum/go-ethereum/swarm/storage/feed"
colorable "github.com/mattn/go-colorable"
"github.com/pborman/uuid"
@ -36,7 +35,7 @@ func cliFeedUploadAndSync(c *cli.Context) error {
generateEndpoints(scheme, cluster, from, to)
log.Info("generating and uploading MRUs to " + endpoints[0] + " and syncing")
log.Info("generating and uploading feeds to " + endpoints[0] + " and syncing")
// create a random private key to sign updates with and derive the address
pkFile, err := ioutil.TempFile("", "swarm-feed-smoke-test")
@ -218,8 +217,7 @@ func cliFeedUploadAndSync(c *cli.Context) error {
if err != nil {
return err
}
multihashHex := hexutil.Encode(multihash.ToMultihash(hashBytes))
multihashHex := hexutil.Encode(hashBytes)
fileHash, err := digest(f)
if err != nil {
return err

1
swarm/OWNERS
View File

@ -7,7 +7,6 @@ swarm
├── fuse ────────────────── @jmozah, @holisticode
├── grafana_dashboards ──── @nonsense
├── metrics ─────────────── @nonsense, @holisticode
├── multihash ───────────── @nolash
├── network ─────────────── ethersphere
│ ├── bitvector ───────── @zelig, @janos, @gbalint
│ ├── priorityqueue ───── @zelig, @janos, @gbalint

25
swarm/api/api.go
View File

@ -42,7 +42,6 @@ import (
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/swarm/log"
"github.com/ethereum/go-ethereum/swarm/multihash"
"github.com/ethereum/go-ethereum/swarm/spancontext"
"github.com/ethereum/go-ethereum/swarm/storage"
"github.com/ethereum/go-ethereum/swarm/storage/feed"
@ -417,7 +416,7 @@ func (a *API) Get(ctx context.Context, decrypt DecryptFunc, manifestAddr storage
return reader, mimeType, status, nil, err
}
// get the data of the update
_, rsrcData, err := a.feed.GetContent(entry.Feed)
_, contentAddr, err := a.feed.GetContent(entry.Feed)
if err != nil {
apiGetNotFound.Inc(1)
status = http.StatusNotFound
@ -425,23 +424,23 @@ func (a *API) Get(ctx context.Context, decrypt DecryptFunc, manifestAddr storage
return reader, mimeType, status, nil, err
}
// extract multihash
decodedMultihash, err := multihash.FromMultihash(rsrcData)
if err != nil {
// extract content hash
if len(contentAddr) != storage.AddressLength {
apiGetInvalid.Inc(1)
status = http.StatusUnprocessableEntity
log.Warn("invalid multihash in feed update", "err", err)
return reader, mimeType, status, nil, err
errorMessage := fmt.Sprintf("invalid swarm hash in feed update. Expected %d bytes. Got %d", storage.AddressLength, len(contentAddr))
log.Warn(errorMessage)
return reader, mimeType, status, nil, errors.New(errorMessage)
}
manifestAddr = storage.Address(decodedMultihash)
log.Trace("feed update contains multihash", "key", manifestAddr)
manifestAddr = storage.Address(contentAddr)
log.Trace("feed update contains swarm hash", "key", manifestAddr)
// get the manifest the multihash digest points to
// get the manifest the swarm hash points to
trie, err := loadManifest(ctx, a.fileStore, manifestAddr, nil, NOOPDecrypt)
if err != nil {
apiGetNotFound.Inc(1)
status = http.StatusNotFound
log.Warn(fmt.Sprintf("loadManifestTrie (feed update multihash) error: %v", err))
log.Warn(fmt.Sprintf("loadManifestTrie (feed update) error: %v", err))
return reader, mimeType, status, nil, err
}
@ -451,8 +450,8 @@ func (a *API) Get(ctx context.Context, decrypt DecryptFunc, manifestAddr storage
if entry == nil {
status = http.StatusNotFound
apiGetNotFound.Inc(1)
err = fmt.Errorf("manifest (feed update multihash) entry for '%s' not found", path)
log.Trace("manifest (feed update multihash) entry not found", "key", manifestAddr, "path", path)
err = fmt.Errorf("manifest (feed update) entry for '%s' not found", path)
log.Trace("manifest (feed update) entry not found", "key", manifestAddr, "path", path)
return reader, mimeType, status, nil, err
}
}

112
swarm/api/client/client_test.go
View File

@ -25,13 +25,13 @@ import (
"sort"
"testing"
"github.com/ethereum/go-ethereum/swarm/storage"
"github.com/ethereum/go-ethereum/swarm/storage/feed/lookup"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/swarm/api"
swarmhttp "github.com/ethereum/go-ethereum/swarm/api/http"
"github.com/ethereum/go-ethereum/swarm/multihash"
"github.com/ethereum/go-ethereum/swarm/storage/feed"
)
@ -368,58 +368,99 @@ func newTestSigner() (*feed.GenericSigner, error) {
return feed.NewGenericSigner(privKey), nil
}
// test the transparent resolving of multihash feed updates with bzz:// scheme
// Test the transparent resolving of feed updates with bzz:// scheme
//
// first upload data, and store the multihash to the resulting manifest in a feed update
// retrieving the update with the multihash should return the manifest pointing directly to the data
// First upload data to bzz:, and store the Swarm hash to the resulting manifest in a feed update.
// This effectively uses a feed to store a pointer to content rather than the content itself
// Retrieving the update with the Swarm hash should return the manifest pointing directly to the data
// and raw retrieve of that hash should return the data
func TestClientCreateFeedMultihash(t *testing.T) {
func TestClientBzzWithFeed(t *testing.T) {
signer, _ := newTestSigner()
// Initialize a Swarm test server
srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
client := NewClient(srv.URL)
swarmClient := NewClient(srv.URL)
defer srv.Close()
// add the data our multihash aliased manifest will point to
databytes := []byte("bar")
// put together some data for our test:
dataBytes := []byte(`
//
// Create some data our manifest will point to. Data that could be very big and wouldn't fit in a feed update.
// So what we are going to do is upload it to Swarm bzz:// and obtain a **manifest hash** pointing to it:
//
// MANIFEST HASH --> DATA
//
// Then, we store that **manifest hash** into a Swarm Feed update. Once we have done this,
// we can use the **feed manifest hash** in bzz:// instead, this way: bzz://feed-manifest-hash.
//
// FEED MANIFEST HASH --> MANIFEST HASH --> DATA
//
// Given that we can update the feed at any time with a new **manifest hash** but the **feed manifest hash**
// stays constant, we have effectively created a fixed address to changing content. (Applause)
//
// FEED MANIFEST HASH (the same) --> MANIFEST HASH(2) --> DATA(2)
//
`)
swarmHash, err := client.UploadRaw(bytes.NewReader(databytes), int64(len(databytes)), false)
if err != nil {
t.Fatalf("Error uploading raw test data: %s", err)
// Create a virtual File out of memory containing the above data
f := &File{
ReadCloser: ioutil.NopCloser(bytes.NewReader(dataBytes)),
ManifestEntry: api.ManifestEntry{
ContentType: "text/plain",
Mode: 0660,
Size: int64(len(dataBytes)),
},
}
s := common.FromHex(swarmHash)
mh := multihash.ToMultihash(s)
// upload data to bzz:// and retrieve the content-addressed manifest hash, hex-encoded.
manifestAddressHex, err := swarmClient.Upload(f, "", false)
if err != nil {
t.Fatalf("Error creating manifest: %s", err)
}
// our feed topic
topic, _ := feed.NewTopic("foo.eth", nil)
// convert the hex-encoded manifest hash to a 32-byte slice
manifestAddress := common.FromHex(manifestAddressHex)
createRequest := feed.NewFirstRequest(topic)
if len(manifestAddress) != storage.AddressLength {
t.Fatalf("Something went wrong. Got a hash of an unexpected length. Expected %d bytes. Got %d", storage.AddressLength, len(manifestAddress))
}
createRequest.SetData(mh)
if err := createRequest.Sign(signer); err != nil {
// Now create a **feed manifest**. For that, we need a topic:
topic, _ := feed.NewTopic("interesting topic indeed", nil)
// Build a feed request to update data
request := feed.NewFirstRequest(topic)
// Put the 32-byte address of the manifest into the feed update
request.SetData(manifestAddress)
// Sign the update
if err := request.Sign(signer); err != nil {
t.Fatalf("Error signing update: %s", err)
}
feedManifestHash, err := client.CreateFeedWithManifest(createRequest)
// Publish the update and at the same time request a **feed manifest** to be created
feedManifestAddressHex, err := swarmClient.CreateFeedWithManifest(request)
if err != nil {
t.Fatalf("Error creating feed manifest: %s", err)
}
correctManifestAddrHex := "bb056a5264c295c2b0f613c8409b9c87ce9d71576ace02458160df4cc894210b"
if feedManifestHash != correctManifestAddrHex {
t.Fatalf("Response feed manifest mismatch, expected '%s', got '%s'", correctManifestAddrHex, feedManifestHash)
// Check we have received the exact **feed manifest** to be expected
// given the topic and user signing the updates:
correctFeedManifestAddrHex := "747c402e5b9dc715a25a4393147512167bab018a007fad7cdcd9adc7fce1ced2"
if feedManifestAddressHex != correctFeedManifestAddrHex {
t.Fatalf("Response feed manifest mismatch, expected '%s', got '%s'", correctFeedManifestAddrHex, feedManifestAddressHex)
}
// Check we get a not found error when trying to get feed updates with a made-up manifest
_, err = client.QueryFeed(nil, "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb")
_, err = swarmClient.QueryFeed(nil, "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb")
if err != ErrNoFeedUpdatesFound {
t.Fatalf("Expected to receive ErrNoFeedUpdatesFound error. Got: %s", err)
}
reader, err := client.QueryFeed(nil, correctManifestAddrHex)
// If we query the feed directly we should get **manifest hash** back:
reader, err := swarmClient.QueryFeed(nil, correctFeedManifestAddrHex)
if err != nil {
t.Fatalf("Error retrieving feed updates: %s", err)
}
@ -428,10 +469,27 @@ func TestClientCreateFeedMultihash(t *testing.T) {
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(mh, gotData) {
t.Fatalf("Expected: %v, got %v", mh, gotData)
//Check that indeed the **manifest hash** is retrieved
if !bytes.Equal(manifestAddress, gotData) {
t.Fatalf("Expected: %v, got %v", manifestAddress, gotData)
}
// Now the final test we were looking for: Use bzz://<feed-manifest> and that should resolve all manifests
// and return the original data directly:
f, err = swarmClient.Download(feedManifestAddressHex, "")
if err != nil {
t.Fatal(err)
}
gotData, err = ioutil.ReadAll(f)
if err != nil {
t.Fatal(err)
}
// Check that we get back the original data:
if !bytes.Equal(dataBytes, gotData) {
t.Fatalf("Expected: %v, got %v", manifestAddress, gotData)
}
}
// TestClientCreateUpdateFeed will check that feeds can be created and updated via the HTTP client.

104
swarm/api/http/server_test.go
View File

@ -45,7 +45,6 @@ import (
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/swarm/api"
swarm "github.com/ethereum/go-ethereum/swarm/api/client"
"github.com/ethereum/go-ethereum/swarm/multihash"
"github.com/ethereum/go-ethereum/swarm/storage"
"github.com/ethereum/go-ethereum/swarm/storage/feed"
"github.com/ethereum/go-ethereum/swarm/testutil"
@ -69,60 +68,91 @@ func newTestSigner() (*feed.GenericSigner, error) {
return feed.NewGenericSigner(privKey), nil
}
// test the transparent resolving of multihash-containing feed updates with bzz:// scheme
// Test the transparent resolving of feed updates with bzz:// scheme
//
// first upload data, and store the multihash to the resulting manifest in a feed update
// retrieving the update with the multihash should return the manifest pointing directly to the data
// First upload data to bzz:, and store the Swarm hash to the resulting manifest in a feed update.
// This effectively uses a feed to store a pointer to content rather than the content itself
// Retrieving the update with the Swarm hash should return the manifest pointing directly to the data
// and raw retrieve of that hash should return the data
func TestBzzFeedMultihash(t *testing.T) {
func TestBzzWithFeed(t *testing.T) {
signer, _ := newTestSigner()
// Initialize Swarm test server
srv := NewTestSwarmServer(t, serverFunc, nil)
defer srv.Close()
// add the data our multihash aliased manifest will point to
databytes := "bar"
testBzzUrl := fmt.Sprintf("%s/bzz:/", srv.URL)
resp, err := http.Post(testBzzUrl, "text/plain", bytes.NewReader([]byte(databytes)))
// put together some data for our test:
dataBytes := []byte(`
//
// Create some data our manifest will point to. Data that could be very big and wouldn't fit in a feed update.
// So what we are going to do is upload it to Swarm bzz:// and obtain a **manifest hash** pointing to it:
//
// MANIFEST HASH --> DATA
//
// Then, we store that **manifest hash** into a Swarm Feed update. Once we have done this,
// we can use the **feed manifest hash** in bzz:// instead, this way: bzz://feed-manifest-hash.
//
// FEED MANIFEST HASH --> MANIFEST HASH --> DATA
//
// Given that we can update the feed at any time with a new **manifest hash** but the **feed manifest hash**
// stays constant, we have effectively created a fixed address to changing content. (Applause)
//
// FEED MANIFEST HASH (the same) --> MANIFEST HASH(2) --> DATA(2) ...
//
`)
// POST data to bzz and get back a content-addressed **manifest hash** pointing to it.
resp, err := http.Post(fmt.Sprintf("%s/bzz:/", srv.URL), "text/plain", bytes.NewReader([]byte(dataBytes)))
if err != nil {
t.Fatal(err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
t.Fatalf("err %s", resp.Status)
}
b, err := ioutil.ReadAll(resp.Body)
manifestAddressHex, err := ioutil.ReadAll(resp.Body)
if err != nil {
t.Fatal(err)
}
s := common.FromHex(string(b))
mh := multihash.ToMultihash(s)
log.Info("added data", "manifest", string(b), "data", common.ToHex(mh))
manifestAddress := common.FromHex(string(manifestAddressHex))
topic, _ := feed.NewTopic("foo.eth", nil)
log.Info("added data", "manifest", string(manifestAddressHex))
// At this point we have uploaded the data and have a manifest pointing to it
// Now store that manifest address in a feed update.
// We also want a feed manifest, so we can use it to refer to the feed.
// First, create a topic for our feed:
topic, _ := feed.NewTopic("interesting topic indeed", nil)
// Create a feed update request:
updateRequest := feed.NewFirstRequest(topic)
updateRequest.SetData(mh)
// Store the **manifest address** as data into the feed update.
updateRequest.SetData(manifestAddress)
// Sign the update
if err := updateRequest.Sign(signer); err != nil {
t.Fatal(err)
}
log.Info("added data", "manifest", string(b), "data", common.ToHex(mh))
log.Info("added data", "data", common.ToHex(manifestAddress))
testUrl, err := url.Parse(fmt.Sprintf("%s/bzz-feed:/", srv.URL))
// Build the feed update http request:
feedUpdateURL, err := url.Parse(fmt.Sprintf("%s/bzz-feed:/", srv.URL))
if err != nil {
t.Fatal(err)
}
query := testUrl.Query()
query := feedUpdateURL.Query()
body := updateRequest.AppendValues(query) // this adds all query parameters and returns the data to be posted
query.Set("manifest", "1") // indicate we want a manifest back
testUrl.RawQuery = query.Encode()
query.Set("manifest", "1") // indicate we want a feed manifest back
feedUpdateURL.RawQuery = query.Encode()
// create the multihash update
resp, err = http.Post(testUrl.String(), "application/octet-stream", bytes.NewReader(body))
// submit the feed update request to Swarm
resp, err = http.Post(feedUpdateURL.String(), "application/octet-stream", bytes.NewReader(body))
if err != nil {
t.Fatal(err)
}
@ -130,24 +160,25 @@ func TestBzzFeedMultihash(t *testing.T) {
if resp.StatusCode != http.StatusOK {
t.Fatalf("err %s", resp.Status)
}
b, err = ioutil.ReadAll(resp.Body)
feedManifestAddressHex, err := ioutil.ReadAll(resp.Body)
if err != nil {
t.Fatal(err)
}
rsrcResp := &storage.Address{}
err = json.Unmarshal(b, rsrcResp)
feedManifestAddress := &storage.Address{}
err = json.Unmarshal(feedManifestAddressHex, feedManifestAddress)
if err != nil {
t.Fatalf("data %s could not be unmarshaled: %v", b, err)
t.Fatalf("data %s could not be unmarshaled: %v", feedManifestAddressHex, err)
}
correctManifestAddrHex := "bb056a5264c295c2b0f613c8409b9c87ce9d71576ace02458160df4cc894210b"
if rsrcResp.Hex() != correctManifestAddrHex {
t.Fatalf("Response feed manifest address mismatch, expected '%s', got '%s'", correctManifestAddrHex, rsrcResp.Hex())
correctManifestAddrHex := "747c402e5b9dc715a25a4393147512167bab018a007fad7cdcd9adc7fce1ced2"
if feedManifestAddress.Hex() != correctManifestAddrHex {
t.Fatalf("Response feed manifest address mismatch, expected '%s', got '%s'", correctManifestAddrHex, feedManifestAddress.Hex())
}
// get bzz manifest transparent feed update resolve
testBzzUrl = fmt.Sprintf("%s/bzz:/%s", srv.URL, rsrcResp)
resp, err = http.Get(testBzzUrl)
getBzzURL := fmt.Sprintf("%s/bzz:/%s", srv.URL, feedManifestAddress)
resp, err = http.Get(getBzzURL)
if err != nil {
t.Fatal(err)
}
@ -155,12 +186,12 @@ func TestBzzFeedMultihash(t *testing.T) {
if resp.StatusCode != http.StatusOK {
t.Fatalf("err %s", resp.Status)
}
b, err = ioutil.ReadAll(resp.Body)
retrievedData, err := ioutil.ReadAll(resp.Body)
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(b, []byte(databytes)) {
t.Fatalf("retrieved data mismatch, expected %x, got %x", databytes, b)
if !bytes.Equal(retrievedData, []byte(dataBytes)) {
t.Fatalf("retrieved data mismatch, expected %x, got %x", dataBytes, retrievedData)
}
}
@ -245,7 +276,8 @@ func TestBzzFeed(t *testing.T) {
t.Fatalf("Expected manifest Feed '%s', got '%s'", correctFeedHex, manifest.Entries[0].Feed.Hex())
}
// get bzz manifest transparent feed update resolve
// take the chance to have bzz: crash on resolving a feed update that does not contain
// a swarm hash:
testBzzUrl := fmt.Sprintf("%s/bzz:/%s", srv.URL, rsrcResp)
resp, err = http.Get(testBzzUrl)
if err != nil {
@ -253,7 +285,7 @@ func TestBzzFeed(t *testing.T) {
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusOK {
t.Fatal("Expected error status since feed update does not contain multihash. Received 200 OK")
t.Fatal("Expected error status since feed update does not contain a Swarm hash. Received 200 OK")
}
_, err = ioutil.ReadAll(resp.Body)
if err != nil {

92
swarm/multihash/multihash.go
View File

@ -1,92 +0,0 @@
// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package multihash
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
)
const (
defaultMultihashLength = 32
defaultMultihashTypeCode = 0x1b
)
var (
multihashTypeCode uint8
MultihashLength = defaultMultihashLength
)
func init() {
multihashTypeCode = defaultMultihashTypeCode
MultihashLength = defaultMultihashLength
}
// check if valid swarm multihash
func isSwarmMultihashType(code uint8) bool {
return code == multihashTypeCode
}
// GetMultihashLength returns the digest length of the provided multihash
// It will fail if the multihash is not a valid swarm mulithash
func GetMultihashLength(data []byte) (int, int, error) {
cursor := 0
typ, c := binary.Uvarint(data)
if c <= 0 {
return 0, 0, errors.New("unreadable hashtype field")
}
if !isSwarmMultihashType(uint8(typ)) {
return 0, 0, fmt.Errorf("hash code %x is not a swarm hashtype", typ)
}
cursor += c
hashlength, c := binary.Uvarint(data[cursor:])
if c <= 0 {
return 0, 0, errors.New("unreadable length field")
}
cursor += c
// we cheekily assume hashlength < maxint
inthashlength := int(hashlength)
if len(data[c:]) < inthashlength {
return 0, 0, errors.New("length mismatch")
}
return inthashlength, cursor, nil
}
// FromMulithash returns the digest portion of the multihash
// It will fail if the multihash is not a valid swarm multihash
func FromMultihash(data []byte) ([]byte, error) {
hashLength, _, err := GetMultihashLength(data)
if err != nil {
return nil, err
}
return data[len(data)-hashLength:], nil
}
// ToMulithash wraps the provided digest data with a swarm mulithash header
func ToMultihash(hashData []byte) []byte {
buf := bytes.NewBuffer(nil)
b := make([]byte, 8)
c := binary.PutUvarint(b, uint64(multihashTypeCode))
buf.Write(b[:c])
c = binary.PutUvarint(b, uint64(len(hashData)))
buf.Write(b[:c])
buf.Write(hashData)
return buf.Bytes()
}

53
swarm/multihash/multihash_test.go
View File

@ -1,53 +0,0 @@
// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package multihash
import (
"bytes"
"math/rand"
"testing"
)
// parse multihash, and check that invalid multihashes fail
func TestCheckMultihash(t *testing.T) {
hashbytes := make([]byte, 32)
c, err := rand.Read(hashbytes)
if err != nil {
t.Fatal(err)
} else if c < 32 {
t.Fatal("short read")
}
expected := ToMultihash(hashbytes)
l, hl, _ := GetMultihashLength(expected)
if l != 32 {
t.Fatalf("expected length %d, got %d", 32, l)
} else if hl != 2 {
t.Fatalf("expected header length %d, got %d", 2, hl)
}
if _, _, err := GetMultihashLength(expected[1:]); err == nil {
t.Fatal("expected failure on corrupt header")
}
if _, _, err := GetMultihashLength(expected[:len(expected)-2]); err == nil {
t.Fatal("expected failure on short content")
}
dh, _ := FromMultihash(expected)
if !bytes.Equal(dh, hashbytes) {
t.Fatalf("expected content hash %x, got %x", hashbytes, dh)
}
}