Golang io.NewDagReader函数代码示例

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 (s *Node) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {

	k, err := s.Nd.Key()
	if err != nil {
		return err
	}

	// setup our logging event
	lm := make(lgbl.DeferredMap)
	lm["fs"] = "ipfs"
	lm["key"] = func() interface{} { return k.Pretty() }
	lm["req_offset"] = req.Offset
	lm["req_size"] = req.Size
	defer log.EventBegin(ctx, "fuseRead", lm).Done()

	r, err := uio.NewDagReader(ctx, s.Nd, s.Ipfs.DAG)
	if err != nil {
		return err
	}
	o, err := r.Seek(req.Offset, os.SEEK_SET)
	lm["res_offset"] = o
	if err != nil {
		return err
	}

	buf := resp.Data[:min(req.Size, int(int64(r.Size())-req.Offset))]
	n, err := io.ReadFull(r, buf)
	if err != nil && err != io.EOF {
		return err
	}
	resp.Data = resp.Data[:n]
	lm["res_size"] = n
	return nil // may be non-nil / not succeeded
}

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 TestSeekingConsistency(t *testing.T) {
	nbytes := int64(128 * 1024)
	ds := mdtest.Mock()
	nd, should := getTestDag(t, ds, nbytes, 500)

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

	out := make([]byte, nbytes)

	for coff := nbytes - 4096; coff >= 0; coff -= 4096 {
		t.Log(coff)
		n, err := rs.Seek(coff, os.SEEK_SET)
		if err != nil {
			t.Fatal(err)
		}
		if n != coff {
			t.Fatal("wasnt able to seek to the right position")
		}
		nread, err := rs.Read(out[coff : coff+4096])
		if err != nil {
			t.Fatal(err)
		}
		if nread != 4096 {
			t.Fatal("didnt read the correct number of bytes")
		}
	}

	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 (dm *DagModifier) readPrep() error {
	err := dm.Sync()
	if err != nil {
		return err
	}

	if dm.read == nil {
		ctx, cancel := context.WithCancel(dm.ctx)
		dr, err := uio.NewDagReader(ctx, dm.curNode, dm.dagserv)
		if err != nil {
			return err
		}

		i, err := dr.Seek(int64(dm.curWrOff), os.SEEK_SET)
		if err != nil {
			return err
		}

		if i != int64(dm.curWrOff) {
			return ErrSeekFail
		}

		dm.readCancel = cancel
		dm.read = dr
	}

	return nil
}

func TestSeekToAlmostBegin(t *testing.T) {
	ds := mdtest.Mock()
	nd, should := getTestDag(t, ds, 10*1024, 500)

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

	n, err := io.CopyN(ioutil.Discard, rs, 1024*4)
	if err != nil {
		t.Fatal(err)
	}
	if n != 4096 {
		t.Fatal("Copy didnt copy enough bytes")
	}

	seeked, err := rs.Seek(1, os.SEEK_SET)
	if err != nil {
		t.Fatal(err)
	}
	if seeked != 1 {
		t.Fatal("Failed to seek to almost beginning")
	}

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

	err = arrComp(out, should[1:])
	if err != nil {
		t.Fatal(err)
	}
}

func TestSeekingBasic(t *testing.T) {
	nbytes := int64(10 * 1024)
	ds := mdtest.Mock()
	nd, should := getTestDag(t, ds, nbytes, 500)

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

	start := int64(4000)
	n, err := rs.Seek(start, os.SEEK_SET)
	if err != nil {
		t.Fatal(err)
	}
	if n != start {
		t.Fatal("Failed to seek to correct offset")
	}

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

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

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 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")
	}
}

func Cat(n *core.IpfsNode, pstr string) (*uio.DagReader, error) {
	p := path.FromString(pstr)
	dagNode, err := n.Resolver.ResolvePath(n.Context(), p)
	if err != nil {
		return nil, err
	}
	return uio.NewDagReader(n.Context(), dagNode, n.DAG)
}

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")
	}
}

func TestMultiWrite(t *testing.T) {
	dserv, pins := getMockDagServ(t)
	_, n := getNode(t, dserv, 0, pins)

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

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

	data := make([]byte, 4000)
	u.NewTimeSeededRand().Read(data)

	for i := 0; i < len(data); i++ {
		n, err := dagmod.WriteAt(data[i:i+1], int64(i))
		if err != nil {
			t.Fatal(err)
		}
		if n != 1 {
			t.Fatal("Somehow wrote the wrong number of bytes! (n != 1)")
		}

		size, err := dagmod.Size()
		if err != nil {
			t.Fatal(err)
		}

		if size != int64(i+1) {
			t.Fatal("Size was reported incorrectly")
		}
	}
	nd, err := dagmod.GetNode()
	if err != nil {
		t.Fatal(err)
	}

	read, err := uio.NewDagReader(context.Background(), nd, dserv)
	if err != nil {
		t.Fatal(err)
	}
	rbuf, err := ioutil.ReadAll(read)
	if err != nil {
		t.Fatal(err)
	}

	err = arrComp(rbuf, data)
	if err != nil {
		t.Fatal(err)
	}
}

// This test appends one byte at a time to an empty file
func TestMultipleAppends(t *testing.T) {
	ds := mdtest.Mock()

	// TODO: fix small size appends and make this number bigger
	nbytes := int64(1000)
	should := make([]byte, nbytes)
	u.NewTimeSeededRand().Read(should)

	read := bytes.NewReader(nil)
	nd, err := buildTestDag(ds, chunk.NewSizeSplitter(read, 500))
	if err != nil {
		t.Fatal(err)
	}

	dbp := &h.DagBuilderParams{
		Dagserv:  ds,
		Maxlinks: 4,
	}

	spl := chunk.SizeSplitterGen(500)

	ctx := context.Background()
	for i := 0; i < len(should); i++ {
		blks, errs := chunk.Chan(spl(bytes.NewReader(should[i : i+1])))

		nnode, err := TrickleAppend(ctx, nd, dbp.New(blks, errs))
		if err != nil {
			t.Fatal(err)
		}

		err = VerifyTrickleDagStructure(nnode, ds, dbp.Maxlinks, layerRepeat)
		if err != nil {
			t.Fatal(err)
		}

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

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

		err = arrComp(out, should[:i+1])
		if err != nil {
			t.Fatal(err)
		}
	}
}

func runReadBench(b *testing.B, nd *dag.Node, ds dag.DAGService) {
	for i := 0; i < b.N; i++ {
		ctx, cancel := context.WithCancel(context.Background())
		read, err := uio.NewDagReader(ctx, nd, ds)
		if err != nil {
			b.Fatal(err)
		}

		_, err = read.WriteTo(ioutil.Discard)
		if err != nil && err != io.EOF {
			b.Fatal(err)
		}
		cancel()
	}
}