Merge pull request #982 from nspcc-dev/neo3/protocol/getblockdata

protocol: implement getblockdata p2p command

pkg/network/payload/getblockdata.go

@@ -0,0 +1,39 @@
+package payload
+
+import (
+	"errors"
+
+	"github.com/nspcc-dev/neo-go/pkg/io"
+)
+
+// maximum number of blocks to query about
+const maxBlockCount = 500
+
+// GetBlockData payload
+type GetBlockData struct {
+	IndexStart uint32
+	Count      uint16
+}
+
+// NewGetBlockData returns GetBlockData payload with specified start index and count
+func NewGetBlockData(indexStart uint32, count uint16) *GetBlockData {
+	return &GetBlockData{
+		IndexStart: indexStart,
+		Count:      count,
+	}
+}
+
+// DecodeBinary implements Serializable interface.
+func (d *GetBlockData) DecodeBinary(br *io.BinReader) {
+	d.IndexStart = br.ReadU32LE()
+	d.Count = br.ReadU16LE()
+	if d.Count == 0 || d.Count > maxBlockCount {
+		br.Err = errors.New("invalid block count")
+	}
+}
+
+// EncodeBinary implements Serializable interface.
+func (d *GetBlockData) EncodeBinary(bw *io.BinWriter) {
+	bw.WriteU32LE(d.IndexStart)
+	bw.WriteU16LE(d.Count)
+}

pkg/network/payload/getblockdata_test.go

@@ -0,0 +1,25 @@
+package payload
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/internal/testserdes"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetBlockDataEncodeDecode(t *testing.T) {
+	d := NewGetBlockData(123, 100)
+	testserdes.EncodeDecodeBinary(t, d, new(GetBlockData))
+
+	// invalid block count
+	d = NewGetBlockData(5, 0)
+	data, err := testserdes.EncodeBinary(d)
+	require.NoError(t, err)
+	require.Error(t, testserdes.DecodeBinary(data, new(GetBlockData)))
+
+	// invalid block count
+	d = NewGetBlockData(5, maxBlockCount+1)
+	data, err = testserdes.EncodeBinary(d)
+	require.NoError(t, err)
+	require.Error(t, testserdes.DecodeBinary(data, new(GetBlockData)))
+}