// TestGetData tests the MsgGetData API.
func TestGetData(t *testing.T) {
	pver := btcwire.ProtocolVersion

	// Ensure the command is expected value.
	wantCmd := "getdata"
	msg := btcwire.NewMsgGetData()
	if cmd := msg.Command(); cmd != wantCmd {
		t.Errorf("NewMsgGetData: wrong command - got %v want %v",
			cmd, wantCmd)
	}

	// Ensure max payload is expected value for latest protocol version.
	// Num inventory vectors (varInt) + max allowed inventory vectors.
	wantPayload := uint32(1800009)
	maxPayload := msg.MaxPayloadLength(pver)
	if maxPayload != wantPayload {
		t.Errorf("MaxPayloadLength: wrong max payload length for "+
			"protocol version %d - got %v, want %v", pver,
			maxPayload, wantPayload)
	}

	// Ensure inventory vectors are added properly.
	hash := btcwire.ShaHash{}
	iv := btcwire.NewInvVect(btcwire.InvTypeBlock, &hash)
	err := msg.AddInvVect(iv)
	if err != nil {
		t.Errorf("AddInvVect: %v", err)
	}
	if msg.InvList[0] != iv {
		t.Errorf("AddInvVect: wrong invvect added - got %v, want %v",
			spew.Sprint(msg.InvList[0]), spew.Sprint(iv))
	}

	// Ensure adding more than the max allowed inventory vectors per
	// message returns an error.
	for i := 0; i < btcwire.MaxInvPerMsg; i++ {
		err = msg.AddInvVect(iv)
	}
	if err == nil {
		t.Errorf("AddInvVect: expected error on too many inventory " +
			"vectors not received")
	}

	// Ensure creating the message with a size hint larger than the max
	// works as expected.
	msg = btcwire.NewMsgGetDataSizeHint(btcwire.MaxInvPerMsg + 1)
	wantCap := btcwire.MaxInvPerMsg
	if cap(msg.InvList) != wantCap {
		t.Errorf("NewMsgGetDataSizeHint: wrong cap for size hint - "+
			"got %v, want %v", cap(msg.InvList), wantCap)
	}

	return
}

// handleInvMsg handles inv messages from all peers.
// We examine the inventory advertised by the remote peer and act accordingly.
func (b *blockManager) handleInvMsg(imsg *invMsg) {
	// Ignore invs from peers that aren't the sync if we are not current.
	// Helps prevent fetching a mass of orphans.
	if imsg.peer != b.syncPeer && !b.current() {
		return
	}

	// Attempt to find the final block in the inventory list.  There may
	// not be one.
	lastBlock := -1
	invVects := imsg.inv.InvList
	for i := len(invVects) - 1; i >= 0; i-- {
		if invVects[i].Type == btcwire.InvTypeBlock {
			lastBlock = i
			break
		}
	}

	// Request the advertised inventory if we don't already have it.  Also,
	// request parent blocks of orphans if we receive one we already have.
	// Finally, attempt to detect potential stalls due to long side chains
	// we already have and request more blocks to prevent them.
	chain := b.blockChain
	for i, iv := range invVects {
		// Ignore unsupported inventory types.
		if iv.Type != btcwire.InvTypeBlock && iv.Type != btcwire.InvTypeTx {
			continue
		}

		// Add the inventory to the cache of known inventory
		// for the peer.
		imsg.peer.AddKnownInventory(iv)

		// Ignore inventory when we're in headers-first mode.
		if b.headersFirstMode {
			continue
		}

		// Request the inventory if we don't already have it.
		haveInv, err := b.haveInventory(iv)
		if err != nil {
			bmgrLog.Warnf("Unexpected failure when checking for "+
				"existing inventory during inv message "+
				"processing: %v", err)
			continue
		}
		if !haveInv {
			// Add it to the request queue.
			imsg.peer.requestQueue.PushBack(iv)
			continue
		}

		if iv.Type == btcwire.InvTypeBlock {
			// The block is an orphan block that we already have.
			// When the existing orphan was processed, it requested
			// the missing parent blocks.  When this scenario
			// happens, it means there were more blocks missing
			// than are allowed into a single inventory message.  As
			// a result, once this peer requested the final
			// advertised block, the remote peer noticed and is now
			// resending the orphan block as an available block
			// to signal there are more missing blocks that need to
			// be requested.
			if chain.IsKnownOrphan(&iv.Hash) {
				// Request blocks starting at the latest known
				// up to the root of the orphan that just came
				// in.
				orphanRoot := chain.GetOrphanRoot(&iv.Hash)
				locator, err := chain.LatestBlockLocator()
				if err != nil {
					bmgrLog.Errorf("PEER: Failed to get block "+
						"locator for the latest block: "+
						"%v", err)
					continue
				}
				imsg.peer.PushGetBlocksMsg(locator, orphanRoot)
				continue
			}

			// We already have the final block advertised by this
			// inventory message, so force a request for more.  This
			// should only happen if we're on a really long side
			// chain.
			if i == lastBlock {
				// Request blocks after this one up to the
				// final one the remote peer knows about (zero
				// stop hash).
				locator := chain.BlockLocatorFromHash(&iv.Hash)
				imsg.peer.PushGetBlocksMsg(locator, &zeroHash)
			}
		}
	}

	// Request as much as possible at once.  Anything that won't fit into
	// the request will be requested on the next inv message.
	numRequested := 0
	gdmsg := btcwire.NewMsgGetData()
	requestQueue := imsg.peer.requestQueue
//.........这里部分代码省略.........

// TestGetDataWire tests the MsgGetData wire encode and decode for various
// numbers of inventory vectors and protocol versions.
func TestGetDataWire(t *testing.T) {
	// Block 203707 hash.
	hashStr := "3264bc2ac36a60840790ba1d475d01367e7c723da941069e9dc"
	blockHash, err := btcwire.NewShaHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewShaHashFromStr: %v", err)
	}

	// Transation 1 of Block 203707 hash.
	hashStr = "d28a3dc7392bf00a9855ee93dd9a81eff82a2c4fe57fbd42cfe71b487accfaf0"
	txHash, err := btcwire.NewShaHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewShaHashFromStr: %v", err)
	}

	iv := btcwire.NewInvVect(btcwire.InvVect_Block, blockHash)
	iv2 := btcwire.NewInvVect(btcwire.InvVect_Tx, txHash)

	// Empty MsgGetData message.
	NoInv := btcwire.NewMsgGetData()
	NoInvEncoded := []byte{
		0x00, // Varint for number of inventory vectors
	}

	// MsgGetData message with multiple inventory vectors.
	MultiInv := btcwire.NewMsgGetData()
	MultiInv.AddInvVect(iv)
	MultiInv.AddInvVect(iv2)
	MultiInvEncoded := []byte{
		0x02,                   // Varint for number of inv vectors
		0x02, 0x00, 0x00, 0x00, // InvVect_Block
		0xdc, 0xe9, 0x69, 0x10, 0x94, 0xda, 0x23, 0xc7,
		0xe7, 0x67, 0x13, 0xd0, 0x75, 0xd4, 0xa1, 0x0b,
		0x79, 0x40, 0x08, 0xa6, 0x36, 0xac, 0xc2, 0x4b,
		0x26, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Block 203707 hash
		0x01, 0x00, 0x00, 0x00, // InvVect_Tx
		0xf0, 0xfa, 0xcc, 0x7a, 0x48, 0x1b, 0xe7, 0xcf,
		0x42, 0xbd, 0x7f, 0xe5, 0x4f, 0x2c, 0x2a, 0xf8,
		0xef, 0x81, 0x9a, 0xdd, 0x93, 0xee, 0x55, 0x98,
		0x0a, 0xf0, 0x2b, 0x39, 0xc7, 0x3d, 0x8a, 0xd2, // Tx 1 of block 203707 hash
	}

	tests := []struct {
		in   *btcwire.MsgGetData // Message to encode
		out  *btcwire.MsgGetData // Expected decoded message
		buf  []byte              // Wire encoding
		pver uint32              // Protocol version for wire encoding
	}{
		// Latest protocol version with no inv vectors.
		{
			NoInv,
			NoInv,
			NoInvEncoded,
			btcwire.ProtocolVersion,
		},

		// Latest protocol version with multiple inv vectors.
		{
			MultiInv,
			MultiInv,
			MultiInvEncoded,
			btcwire.ProtocolVersion,
		},

		// Protocol version BIP0035Version no inv vectors.
		{
			NoInv,
			NoInv,
			NoInvEncoded,
			btcwire.BIP0035Version,
		},

		// Protocol version BIP0035Version with multiple inv vectors.
		{
			MultiInv,
			MultiInv,
			MultiInvEncoded,
			btcwire.BIP0035Version,
		},

		// Protocol version BIP0031Version no inv vectors.
		{
			NoInv,
			NoInv,
			NoInvEncoded,
			btcwire.BIP0031Version,
		},

		// Protocol version BIP0031Version with multiple inv vectors.
		{
			MultiInv,
			MultiInv,
			MultiInvEncoded,
			btcwire.BIP0031Version,
		},

		// Protocol version NetAddressTimeVersion no inv vectors.
		{
//.........这里部分代码省略.........

// TestGetDataWireErrors performs negative tests against wire encode and decode
// of MsgGetData to confirm error paths work correctly.
func TestGetDataWireErrors(t *testing.T) {
	pver := btcwire.ProtocolVersion
	btcwireErr := &btcwire.MessageError{}

	// Block 203707 hash.
	hashStr := "3264bc2ac36a60840790ba1d475d01367e7c723da941069e9dc"
	blockHash, err := btcwire.NewShaHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewShaHashFromStr: %v", err)
	}

	iv := btcwire.NewInvVect(btcwire.InvVect_Block, blockHash)

	// Base message used to induce errors.
	baseGetData := btcwire.NewMsgGetData()
	baseGetData.AddInvVect(iv)
	baseGetDataEncoded := []byte{
		0x02,                   // Varint for number of inv vectors
		0x02, 0x00, 0x00, 0x00, // InvVect_Block
		0xdc, 0xe9, 0x69, 0x10, 0x94, 0xda, 0x23, 0xc7,
		0xe7, 0x67, 0x13, 0xd0, 0x75, 0xd4, 0xa1, 0x0b,
		0x79, 0x40, 0x08, 0xa6, 0x36, 0xac, 0xc2, 0x4b,
		0x26, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Block 203707 hash
	}

	// Message that forces an error by having more than the max allowed inv
	// vectors.
	maxGetData := btcwire.NewMsgGetData()
	for i := 0; i < btcwire.MaxInvPerMsg; i++ {
		maxGetData.AddInvVect(iv)
	}
	maxGetData.InvList = append(maxGetData.InvList, iv)
	maxGetDataEncoded := []byte{
		0xfd, 0x51, 0xc3, // Varint for number of inv vectors (50001)
	}

	tests := []struct {
		in       *btcwire.MsgGetData // Value to encode
		buf      []byte              // Wire encoding
		pver     uint32              // Protocol version for wire encoding
		max      int                 // Max size of fixed buffer to induce errors
		writeErr error               // Expected write error
		readErr  error               // Expected read error
	}{
		// Latest protocol version with intentional read/write errors.
		// Force error in inventory vector count
		{baseGetData, baseGetDataEncoded, pver, 0, io.ErrShortWrite, io.EOF},
		// Force error in inventory list.
		{baseGetData, baseGetDataEncoded, pver, 1, io.ErrShortWrite, io.EOF},
		// Force error with greater than max inventory vectors.
		{maxGetData, maxGetDataEncoded, pver, 3, btcwireErr, btcwireErr},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode to wire format.
		w := newFixedWriter(test.max)
		err := test.in.BtcEncode(w, test.pver)
		if reflect.TypeOf(err) != reflect.TypeOf(test.writeErr) {
			t.Errorf("BtcEncode #%d wrong error got: %v, want: %v",
				i, err, test.writeErr)
			continue
		}

		// For errors which are not of type btcwire.MessageError, check
		// them for equality.
		if _, ok := err.(*btcwire.MessageError); !ok {
			if err != test.writeErr {
				t.Errorf("BtcEncode #%d wrong error got: %v, "+
					"want: %v", i, err, test.writeErr)
				continue
			}
		}

		// Decode from wire format.
		var msg btcwire.MsgGetData
		r := newFixedReader(test.max, test.buf)
		err = msg.BtcDecode(r, test.pver)
		if reflect.TypeOf(err) != reflect.TypeOf(test.readErr) {
			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
				i, err, test.readErr)
			continue
		}

		// For errors which are not of type btcwire.MessageError, check
		// them for equality.
		if _, ok := err.(*btcwire.MessageError); !ok {
			if err != test.readErr {
				t.Errorf("BtcDecode #%d wrong error got: %v, "+
					"want: %v", i, err, test.readErr)
				continue
			}
		}
	}
}

// TestMessage tests the Read/WriteMessage API.
func TestMessage(t *testing.T) {
	pver := btcwire.ProtocolVersion

	// Create the various types of messages to test.

	// MsgVersion.
	addrYou := &net.TCPAddr{IP: net.ParseIP("192.168.0.1"), Port: 8333}
	you, err := btcwire.NewNetAddress(addrYou, btcwire.SFNodeNetwork)
	if err != nil {
		t.Errorf("NewNetAddress: %v", err)
	}
	you.Timestamp = time.Time{} // Version message has zero value timestamp.
	addrMe := &net.TCPAddr{IP: net.ParseIP("127.0.0.1"), Port: 8333}
	me, err := btcwire.NewNetAddress(addrMe, btcwire.SFNodeNetwork)
	if err != nil {
		t.Errorf("NewNetAddress: %v", err)
	}
	me.Timestamp = time.Time{} // Version message has zero value timestamp.
	msgVersion := btcwire.NewMsgVersion(me, you, 123123, "/test:0.0.1/", 0)

	msgVerack := btcwire.NewMsgVerAck()
	msgGetAddr := btcwire.NewMsgGetAddr()
	msgAddr := btcwire.NewMsgAddr()
	msgGetBlocks := btcwire.NewMsgGetBlocks(&btcwire.ShaHash{})
	msgBlock := &blockOne
	msgInv := btcwire.NewMsgInv()
	msgGetData := btcwire.NewMsgGetData()
	msgNotFound := btcwire.NewMsgNotFound()
	msgTx := btcwire.NewMsgTx()
	msgPing := btcwire.NewMsgPing(123123)
	msgPong := btcwire.NewMsgPong(123123)
	msgGetHeaders := btcwire.NewMsgGetHeaders()
	msgHeaders := btcwire.NewMsgHeaders()
	msgAlert := btcwire.NewMsgAlert("payload", "signature")
	msgMemPool := btcwire.NewMsgMemPool()

	tests := []struct {
		in     btcwire.Message    // Value to encode
		out    btcwire.Message    // Expected decoded value
		pver   uint32             // Protocol version for wire encoding
		btcnet btcwire.BitcoinNet // Network to use for wire encoding
	}{
		{msgVersion, msgVersion, pver, btcwire.MainNet},
		{msgVerack, msgVerack, pver, btcwire.MainNet},
		{msgGetAddr, msgGetAddr, pver, btcwire.MainNet},
		{msgAddr, msgAddr, pver, btcwire.MainNet},
		{msgGetBlocks, msgGetBlocks, pver, btcwire.MainNet},
		{msgBlock, msgBlock, pver, btcwire.MainNet},
		{msgInv, msgInv, pver, btcwire.MainNet},
		{msgGetData, msgGetData, pver, btcwire.MainNet},
		{msgNotFound, msgNotFound, pver, btcwire.MainNet},
		{msgTx, msgTx, pver, btcwire.MainNet},
		{msgPing, msgPing, pver, btcwire.MainNet},
		{msgPong, msgPong, pver, btcwire.MainNet},
		{msgGetHeaders, msgGetHeaders, pver, btcwire.MainNet},
		{msgHeaders, msgHeaders, pver, btcwire.MainNet},
		{msgAlert, msgAlert, pver, btcwire.MainNet},
		{msgMemPool, msgMemPool, pver, btcwire.MainNet},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode to wire format.
		var buf bytes.Buffer
		err := btcwire.WriteMessage(&buf, test.in, test.pver, test.btcnet)
		if err != nil {
			t.Errorf("WriteMessage #%d error %v", i, err)
			continue
		}

		// Decode from wire format.
		rbuf := bytes.NewBuffer(buf.Bytes())
		msg, _, err := btcwire.ReadMessage(rbuf, test.pver, test.btcnet)
		if err != nil {
			t.Errorf("ReadMessage #%d error %v, msg %v", i, err,
				spew.Sdump(msg))
			continue
		}
		if !reflect.DeepEqual(msg, test.out) {
			t.Errorf("ReadMessage #%d\n got: %v want: %v", i,
				spew.Sdump(msg), spew.Sdump(test.out))
			continue
		}
	}
}

func nodeHandler(cfg TowerCfg, txStream chan<- *TxMeta, blockStream chan<- *btcwire.MsgBlock) {

	conn := setupConn(cfg.Addr, cfg.Logger)

	connparams := connParams{
		conn:    conn,
		pver:    btcwire.ProtocolVersion,
		btcnet:  cfg.Net,
		logger:  cfg.Logger,
		insetup: true,
	}

	read, write := composeConnOuts(connparams)

	// Initial handshake
	ver_m, _ := btcwire.NewMsgVersionFromConn(conn, genNonce(), int32(cfg.StartHeight))
	ver_m.AddUserAgent("Watchtower", "0.0.0")

	write(ver_m)

	// Wait for responses
	acked, responded := false, false
	for {
		var msg btcwire.Message
		msg = read()
		cfg.Logger.Println(msg.Command())
		switch msg := msg.(type) {
		case *btcwire.MsgVersion:
			responded = true
			ack := btcwire.NewMsgVerAck()
			nodeVer := uint32(msg.ProtocolVersion)
			if nodeVer < connparams.pver {
				connparams.pver = nodeVer
				read, write = composeConnOuts(connparams)
			}
			write(ack)
		case *btcwire.MsgVerAck:
			acked = true
		}
		if responded && acked {
			break
		}
	}

	// We are through the initial handshake, assume functional channel from here
	// on out. If there any errors with the pipe logger.Fatal gets called.
	connparams.insetup = false
	read, write = composeConnOuts(connparams)
	cfg.Logger.Println("Conn Negotiated")

	for {
		// If there are messages to send to peers send them. Otherwise, listen!
		select {
		case msg := <-cfg.MsgChan:
			write(msg)
		default:
			// listen for txs + blocks then push them into the appropriatestreams
			msg := read()
			switch msg := msg.(type) {
			case *btcwire.MsgInv:
				want := btcwire.NewMsgGetData()
				invVec := msg.InvList
				for i := range invVec {
					chunk := invVec[i]
					want.AddInvVect(chunk)
				}
				write(want)
			case *btcwire.MsgTx:
				var empt []byte // evaluates to nil
				meta := TxMeta{MsgTx: msg, BlockSha: empt, Time: time.Now()}
				txStream <- &meta
			case *btcwire.MsgBlock:
				blockStream <- msg
			case *btcwire.MsgPing:
				pong := btcwire.NewMsgPong(msg.Nonce)
				// More fun than anything...
				write(pong)
			}
		}
	}
}