Golang util.NewTimeSeededRand函數代碼示例

func TestCallbacksWork(t *testing.T) {
	fake := new(FakeStream)

	var sent int64
	var recv int64

	sentCB := func(n int64, proto protocol.ID, p peer.ID) {
		sent += n
	}

	recvCB := func(n int64, proto protocol.ID, p peer.ID) {
		recv += n
	}

	ms := newMeteredStream(fake, protocol.ID("TEST"), peer.ID("PEER"), recvCB, sentCB)

	toWrite := int64(100000)
	toRead := int64(100000)

	fake.ReadBuf = io.LimitReader(u.NewTimeSeededRand(), toRead)
	writeData := io.LimitReader(u.NewTimeSeededRand(), toWrite)

	n, err := io.Copy(ms, writeData)
	if err != nil {
		t.Fatal(err)
	}

	if n != toWrite {
		t.Fatal("incorrect write amount")
	}

	if toWrite != sent {
		t.Fatal("incorrectly reported writes", toWrite, sent)
	}

	n, err = io.Copy(ioutil.Discard, ms)
	if err != nil {
		t.Fatal(err)
	}

	if n != toRead {
		t.Fatal("incorrect read amount")
	}

	if toRead != recv {
		t.Fatal("incorrectly reported reads")
	}
}

func TestBalancedDag(t *testing.T) {
	ds := mdtest.Mock()
	buf := make([]byte, 10000)
	u.NewTimeSeededRand().Read(buf)
	r := bytes.NewReader(buf)

	nd, err := BuildDagFromReader(ds, chunk.DefaultSplitter(r), nil)
	if err != nil {
		t.Fatal(err)
	}

	dr, err := uio.NewDagReader(context.Background(), nd, ds)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(dr)
	if err != nil {
		t.Fatal(err)
	}

	if !bytes.Equal(out, buf) {
		t.Fatal("bad read")
	}
}

func TestRabinChunking(t *testing.T) {
	data := make([]byte, 1024*1024*16)
	util.NewTimeSeededRand().Read(data)

	r := NewRabin(bytes.NewReader(data), 1024*256)

	var chunks [][]byte

	for {
		chunk, err := r.NextBytes()
		if err != nil {
			if err == io.EOF {
				break
			}
			t.Fatal(err)
		}

		chunks = append(chunks, chunk)
	}

	fmt.Printf("average block size: %d\n", len(data)/len(chunks))

	unchunked := bytes.Join(chunks, nil)
	if !bytes.Equal(unchunked, data) {
		fmt.Printf("%d %d\n", len(unchunked), len(data))
		t.Fatal("data was chunked incorrectly")
	}
}

func randNode() (*merkledag.Node, key.Key) {
	node := new(merkledag.Node)
	node.Data = make([]byte, 32)
	util.NewTimeSeededRand().Read(node.Data)
	k, _ := node.Key()
	return node, k
}

func randBuf(t *testing.T, size int) []byte {
	buf := make([]byte, size)
	if _, err := u.NewTimeSeededRand().Read(buf); err != nil {
		t.Fatal("failed to read enough randomness")
	}
	return buf
}

func testFileConsistency(t *testing.T, bs chunk.SplitterGen, nbytes int) {
	should := make([]byte, nbytes)
	u.NewTimeSeededRand().Read(should)

	read := bytes.NewReader(should)
	ds := mdtest.Mock()
	nd, err := buildTestDag(ds, bs(read))
	if err != nil {
		t.Fatal(err)
	}

	r, err := uio.NewDagReader(context.Background(), nd, ds)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(r)
	if err != nil {
		t.Fatal(err)
	}

	err = arrComp(out, should)
	if err != nil {
		t.Fatal(err)
	}
}

func TestBuilderConsistency(t *testing.T) {
	nbytes := 100000
	buf := new(bytes.Buffer)
	io.CopyN(buf, u.NewTimeSeededRand(), int64(nbytes))
	should := dup(buf.Bytes())
	dagserv := mdtest.Mock()
	nd, err := buildTestDag(dagserv, chunk.DefaultSplitter(buf))
	if err != nil {
		t.Fatal(err)
	}
	r, err := uio.NewDagReader(context.Background(), nd, dagserv)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(r)
	if err != nil {
		t.Fatal(err)
	}

	err = arrComp(out, should)
	if err != nil {
		t.Fatal(err)
	}
}

func randNode() (*mdag.Node, key.Key) {
	nd := new(mdag.Node)
	nd.Data = make([]byte, 32)
	util.NewTimeSeededRand().Read(nd.Data)
	k, _ := nd.Key()
	return nd, k
}

func BenchmarkDagmodWrite(b *testing.B) {
	b.StopTimer()
	dserv, pins := getMockDagServ(b)
	_, n := getNode(b, dserv, 0, pins)
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	wrsize := 4096

	dagmod, err := NewDagModifier(ctx, n, dserv, pins, sizeSplitterGen(512))
	if err != nil {
		b.Fatal(err)
	}

	buf := make([]byte, b.N*wrsize)
	u.NewTimeSeededRand().Read(buf)
	b.StartTimer()
	b.SetBytes(int64(wrsize))
	for i := 0; i < b.N; i++ {
		n, err := dagmod.Write(buf[i*wrsize : (i+1)*wrsize])
		if err != nil {
			b.Fatal(err)
		}
		if n != wrsize {
			b.Fatal("Wrote bad size")
		}
	}
}

func TestIndirectBlocks(t *testing.T) {
	splitter := chunk.SizeSplitterGen(512)
	nbytes := 1024 * 1024
	buf := make([]byte, nbytes)
	u.NewTimeSeededRand().Read(buf)

	read := bytes.NewReader(buf)

	ds := mdtest.Mock()
	dag, err := buildTestDag(ds, splitter(read))
	if err != nil {
		t.Fatal(err)
	}

	reader, err := uio.NewDagReader(context.Background(), dag, ds)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(reader)
	if err != nil {
		t.Fatal(err)
	}

	if !bytes.Equal(out, buf) {
		t.Fatal("Not equal!")
	}
}

func TestSeekEndSingleBlockFile(t *testing.T) {
	nbytes := int64(100)
	should := make([]byte, nbytes)
	u.NewTimeSeededRand().Read(should)

	read := bytes.NewReader(should)
	ds := mdtest.Mock()
	nd, err := buildTestDag(ds, chunk.NewSizeSplitter(read, 5000))
	if err != nil {
		t.Fatal(err)
	}

	rs, err := uio.NewDagReader(context.Background(), nd, ds)
	if err != nil {
		t.Fatal(err)
	}

	seeked, err := rs.Seek(0, os.SEEK_END)
	if err != nil {
		t.Fatal(err)
	}
	if seeked != nbytes {
		t.Fatal("Failed to seek to end")
	}
}

// RandPeerID generates random "valid" peer IDs. it does not NEED to generate
// keys because it is as if we lost the key right away. fine to read randomness
// and hash it. to generate proper keys and corresponding PeerID, use:
//  sk, pk, _ := testutil.RandKeyPair()
//  id, _ := peer.IDFromPublicKey(pk)
func RandPeerID() (peer.ID, error) {
	buf := make([]byte, 16)
	if _, err := io.ReadFull(u.NewTimeSeededRand(), buf); err != nil {
		return "", err
	}
	h := u.Hash(buf)
	return peer.ID(h), nil
}

func RandTestBogusPrivateKey() (TestBogusPrivateKey, error) {
	r := u.NewTimeSeededRand()
	k := make([]byte, 5)
	if _, err := io.ReadFull(r, k); err != nil {
		return nil, err
	}
	return TestBogusPrivateKey(k), nil
}

func getTrickleDag(t testing.TB, size int64, blksize int64) (*dag.Node, dag.DAGService) {
	ds := mdtest.Mock()
	r := io.LimitReader(u.NewTimeSeededRand(), size)
	nd, err := BuildTrickleDagFromReader(ds, chunk.NewSizeSplitter(r, blksize), nil)
	if err != nil {
		t.Fatal(err)
	}
	return nd, ds
}

func TestMetadata(t *testing.T) {
	ctx := context.Background()
	// Make some random node
	ds := getDagserv(t)
	data := make([]byte, 1000)
	u.NewTimeSeededRand().Read(data)
	r := bytes.NewReader(data)
	nd, err := importer.BuildDagFromReader(ds, chunk.DefaultSplitter(r), nil)
	if err != nil {
		t.Fatal(err)
	}

	k, err := nd.Key()
	if err != nil {
		t.Fatal(err)
	}

	m := new(ft.Metadata)
	m.MimeType = "THIS IS A TEST"

	// Such effort, many compromise
	ipfsnode := &core.IpfsNode{DAG: ds}

	mdk, err := AddMetadataTo(ipfsnode, k.B58String(), m)
	if err != nil {
		t.Fatal(err)
	}

	rec, err := Metadata(ipfsnode, mdk)
	if err != nil {
		t.Fatal(err)
	}
	if rec.MimeType != m.MimeType {
		t.Fatalf("something went wrong in conversion: '%s' != '%s'", rec.MimeType, m.MimeType)
	}

	retnode, err := ds.Get(ctx, key.B58KeyDecode(mdk))
	if err != nil {
		t.Fatal(err)
	}

	ndr, err := uio.NewDagReader(ctx, retnode, ds)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(ndr)
	if err != nil {
		t.Fatal(err)
	}

	if !bytes.Equal(out, data) {
		t.Fatal("read incorrect data")
	}
}