// fetchTxDataByLoc returns several pieces of data regarding the given tx
// located by the block/offset/size location
func (db *LevelDb) fetchTxDataByLoc(blkHeight int32, txOff int, txLen int, txspent []byte) (rtx *wire.MsgTx, rblksha *wire.ShaHash, rheight int32, rtxspent []byte, err error) {
	var blksha *wire.ShaHash
	var blkbuf []byte

	blksha, blkbuf, err = db.getBlkByHeight(blkHeight)
	if err != nil {
		if err == leveldb.ErrNotFound {
			err = database.ErrTxShaMissing
		}
		return
	}

	//log.Trace("transaction %v is at block %v %v txoff %v, txlen %v\n",
	//	txsha, blksha, blkHeight, txOff, txLen)

	if len(blkbuf) < txOff+txLen {
		err = database.ErrTxShaMissing
		return
	}
	rbuf := bytes.NewReader(blkbuf[txOff : txOff+txLen])

	var tx wire.MsgTx
	err = tx.Deserialize(rbuf)
	if err != nil {
		log.Warnf("unable to decode tx block %v %v txoff %v txlen %v",
			blkHeight, blksha, txOff, txLen)
		return
	}

	return &tx, blksha, blkHeight, txspent, nil
}

// calcPriority returns a transaction priority given a transaction and the sum
// of each of its input values multiplied by their age (# of confirmations).
// Thus, the final formula for the priority is:
// sum(inputValue * inputAge) / adjustedTxSize
func calcPriority(tx *wire.MsgTx, txStore blockchain.TxStore, nextBlockHeight int32) float64 {
	// In order to encourage spending multiple old unspent transaction
	// outputs thereby reducing the total set, don't count the constant
	// overhead for each input as well as enough bytes of the signature
	// script to cover a pay-to-script-hash redemption with a compressed
	// pubkey.  This makes additional inputs free by boosting the priority
	// of the transaction accordingly.  No more incentive is given to avoid
	// encouraging gaming future transactions through the use of junk
	// outputs.  This is the same logic used in the reference
	// implementation.
	//
	// The constant overhead for a txin is 41 bytes since the previous
	// outpoint is 36 bytes + 4 bytes for the sequence + 1 byte the
	// signature script length.
	//
	// A compressed pubkey pay-to-script-hash redemption with a maximum len
	// signature is of the form:
	// [OP_DATA_73 <73-byte sig> + OP_DATA_35 + {OP_DATA_33
	// <33 byte compresed pubkey> + OP_CHECKSIG}]
	//
	// Thus 1 + 73 + 1 + 1 + 33 + 1 = 110
	overhead := 0
	for _, txIn := range tx.TxIn {
		// Max inputs + size can't possibly overflow here.
		overhead += 41 + minInt(110, len(txIn.SignatureScript))
	}

	serializedTxSize := tx.SerializeSize()
	if overhead >= serializedTxSize {
		return 0.0
	}

	inputValueAge := calcInputValueAge(tx, txStore, nextBlockHeight)
	return inputValueAge / float64(serializedTxSize-overhead)
}

// TestTxSerializeErrors performs negative tests against wire encode and decode
// of MsgTx to confirm error paths work correctly.
func TestTxSerializeErrors(t *testing.T) {
	tests := []struct {
		in       *wire.MsgTx // Value to encode
		buf      []byte      // Serialized data
		max      int         // Max size of fixed buffer to induce errors
		writeErr error       // Expected write error
		readErr  error       // Expected read error
	}{
		// Force error in version.
		{multiTx, multiTxEncoded, 0, io.ErrShortWrite, io.EOF},
		// Force error in number of transaction inputs.
		{multiTx, multiTxEncoded, 4, io.ErrShortWrite, io.EOF},
		// Force error in transaction input previous block hash.
		{multiTx, multiTxEncoded, 5, io.ErrShortWrite, io.EOF},
		// Force error in transaction input previous block output index.
		{multiTx, multiTxEncoded, 37, io.ErrShortWrite, io.EOF},
		// Force error in transaction input signature script length.
		{multiTx, multiTxEncoded, 41, io.ErrShortWrite, io.EOF},
		// Force error in transaction input signature script.
		{multiTx, multiTxEncoded, 42, io.ErrShortWrite, io.EOF},
		// Force error in transaction input sequence.
		{multiTx, multiTxEncoded, 49, io.ErrShortWrite, io.EOF},
		// Force error in number of transaction outputs.
		{multiTx, multiTxEncoded, 53, io.ErrShortWrite, io.EOF},
		// Force error in transaction output value.
		{multiTx, multiTxEncoded, 54, io.ErrShortWrite, io.EOF},
		// Force error in transaction output pk script length.
		{multiTx, multiTxEncoded, 62, io.ErrShortWrite, io.EOF},
		// Force error in transaction output pk script.
		{multiTx, multiTxEncoded, 63, io.ErrShortWrite, io.EOF},
		// Force error in transaction output lock time.
		{multiTx, multiTxEncoded, 206, io.ErrShortWrite, io.EOF},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Serialize the transaction.
		w := newFixedWriter(test.max)
		err := test.in.Serialize(w)
		if err != test.writeErr {
			t.Errorf("Serialize #%d wrong error got: %v, want: %v",
				i, err, test.writeErr)
			continue
		}

		// Deserialize the transaction.
		var tx wire.MsgTx
		r := newFixedReader(test.max, test.buf)
		err = tx.Deserialize(r)
		if err != test.readErr {
			t.Errorf("Deserialize #%d wrong error got: %v, want: %v",
				i, err, test.readErr)
			continue
		}
	}
}

func newCoinBase(outputValues ...int64) *wire.MsgTx {
	tx := wire.MsgTx{
		TxIn: []*wire.TxIn{
			&wire.TxIn{
				PreviousOutPoint: wire.OutPoint{Index: ^uint32(0)},
			},
		},
	}
	for _, val := range outputValues {
		tx.TxOut = append(tx.TxOut, &wire.TxOut{Value: val})
	}
	return &tx
}

func spendOutput(txHash *wire.ShaHash, index uint32, outputValues ...int64) *wire.MsgTx {
	tx := wire.MsgTx{
		TxIn: []*wire.TxIn{
			&wire.TxIn{
				PreviousOutPoint: wire.OutPoint{Hash: *txHash, Index: index},
			},
		},
	}
	for _, val := range outputValues {
		tx.TxOut = append(tx.TxOut, &wire.TxOut{Value: val})
	}
	return &tx
}

// addChange adds a new output with the given amount and address, and
// randomizes the index (and returns it) of the newly added output.
func addChange(msgtx *wire.MsgTx, change coinutil.Amount, changeAddr coinutil.Address) (int, error) {
	pkScript, err := txscript.PayToAddrScript(changeAddr)
	if err != nil {
		return 0, fmt.Errorf("cannot create txout script: %s", err)
	}
	msgtx.AddTxOut(wire.NewTxOut(int64(change), pkScript))

	// Randomize index of the change output.
	rng := badrand.New(badrand.NewSource(time.Now().UnixNano()))
	r := rng.Int31n(int32(len(msgtx.TxOut))) // random index
	c := len(msgtx.TxOut) - 1                // change index
	msgtx.TxOut[r], msgtx.TxOut[c] = msgtx.TxOut[c], msgtx.TxOut[r]
	return int(r), nil
}

// NewTxFromReader returns a new instance of a bitcoin transaction given a
// Reader to deserialize the transaction.  See Tx.
func NewTxFromReader(r io.Reader) (*Tx, error) {
	// Deserialize the bytes into a MsgTx.
	var msgTx wire.MsgTx
	err := msgTx.Deserialize(r)
	if err != nil {
		return nil, err
	}

	t := Tx{
		msgTx:   &msgTx,
		txIndex: TxIndexUnknown,
	}
	return &t, nil
}

// NewTxRecordFromMsgTx creates a new transaction record that may be inserted
// into the store.
func NewTxRecordFromMsgTx(msgTx *wire.MsgTx, received time.Time) (*TxRecord, error) {
	buf := bytes.NewBuffer(make([]byte, 0, msgTx.SerializeSize()))
	err := msgTx.Serialize(buf)
	if err != nil {
		str := "failed to serialize transaction"
		return nil, storeError(ErrInput, str, err)
	}
	rec := &TxRecord{
		MsgTx:        *msgTx,
		Received:     received,
		SerializedTx: buf.Bytes(),
	}
	copy(rec.Hash[:], wire.DoubleSha256(rec.SerializedTx))
	return rec, nil
}

func equalTxs(t *testing.T, got, exp *wire.MsgTx) {
	var bufGot, bufExp bytes.Buffer
	err := got.Serialize(&bufGot)
	if err != nil {
		t.Fatal(err)
	}
	err = exp.Serialize(&bufExp)
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(bufGot.Bytes(), bufExp.Bytes()) {
		t.Errorf("Found unexpected wire.MsgTx:")
		t.Errorf("Got: %v", got)
		t.Errorf("Expected: %v", exp)
	}
}

// addOutputs adds the given address/amount pairs as outputs to msgtx,
// returning their total amount.
func addOutputs(msgtx *wire.MsgTx, pairs map[string]coinutil.Amount, chainParams *chaincfg.Params) (coinutil.Amount, error) {
	var minAmount coinutil.Amount
	for addrStr, amt := range pairs {
		if amt <= 0 {
			return minAmount, ErrNonPositiveAmount
		}
		minAmount += amt
		addr, err := coinutil.DecodeAddress(addrStr, chainParams)
		if err != nil {
			return minAmount, fmt.Errorf("cannot decode address: %s", err)
		}

		// Add output to spend amt to addr.
		pkScript, err := txscript.PayToAddrScript(addr)
		if err != nil {
			return minAmount, fmt.Errorf("cannot create txout script: %s", err)
		}
		txout := wire.NewTxOut(int64(amt), pkScript)
		msgtx.AddTxOut(txout)
	}
	return minAmount, nil
}

// TestTxSerialize tests MsgTx serialize and deserialize.
func TestTxSerialize(t *testing.T) {
	noTx := wire.NewMsgTx()
	noTx.Version = 1
	noTxEncoded := []byte{
		0x01, 0x00, 0x00, 0x00, // Version
		0x00,                   // Varint for number of input transactions
		0x00,                   // Varint for number of output transactions
		0x00, 0x00, 0x00, 0x00, // Lock time
	}

	tests := []struct {
		in           *wire.MsgTx // Message to encode
		out          *wire.MsgTx // Expected decoded message
		buf          []byte      // Serialized data
		pkScriptLocs []int       // Expected output script locations
	}{
		// No transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
			nil,
		},

		// Multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
			multiTxPkScriptLocs,
		},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Serialize the transaction.
		var buf bytes.Buffer
		err := test.in.Serialize(&buf)
		if err != nil {
			t.Errorf("Serialize #%d error %v", i, err)
			continue
		}
		if !bytes.Equal(buf.Bytes(), test.buf) {
			t.Errorf("Serialize #%d\n got: %s want: %s", i,
				spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
			continue
		}

		// Deserialize the transaction.
		var tx wire.MsgTx
		rbuf := bytes.NewReader(test.buf)
		err = tx.Deserialize(rbuf)
		if err != nil {
			t.Errorf("Deserialize #%d error %v", i, err)
			continue
		}
		if !reflect.DeepEqual(&tx, test.out) {
			t.Errorf("Deserialize #%d\n got: %s want: %s", i,
				spew.Sdump(&tx), spew.Sdump(test.out))
			continue
		}

		// Ensure the public key script locations are accurate.
		pkScriptLocs := test.in.PkScriptLocs()
		if !reflect.DeepEqual(pkScriptLocs, test.pkScriptLocs) {
			t.Errorf("PkScriptLocs #%d\n got: %s want: %s", i,
				spew.Sdump(pkScriptLocs),
				spew.Sdump(test.pkScriptLocs))
			continue
		}
		for j, loc := range pkScriptLocs {
			wantPkScript := test.in.TxOut[j].PkScript
			gotPkScript := test.buf[loc : loc+len(wantPkScript)]
			if !bytes.Equal(gotPkScript, wantPkScript) {
				t.Errorf("PkScriptLocs #%d:%d\n unexpected "+
					"script got: %s want: %s", i, j,
					spew.Sdump(gotPkScript),
					spew.Sdump(wantPkScript))
			}
		}
	}
}

// TestTxWireErrors performs negative tests against wire encode and decode
// of MsgTx to confirm error paths work correctly.
func TestTxWireErrors(t *testing.T) {
	// Use protocol version 60002 specifically here instead of the latest
	// because the test data is using bytes encoded with that protocol
	// version.
	pver := uint32(60002)

	tests := []struct {
		in       *wire.MsgTx // 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
	}{
		// Force error in version.
		{multiTx, multiTxEncoded, pver, 0, io.ErrShortWrite, io.EOF},
		// Force error in number of transaction inputs.
		{multiTx, multiTxEncoded, pver, 4, io.ErrShortWrite, io.EOF},
		// Force error in transaction input previous block hash.
		{multiTx, multiTxEncoded, pver, 5, io.ErrShortWrite, io.EOF},
		// Force error in transaction input previous block output index.
		{multiTx, multiTxEncoded, pver, 37, io.ErrShortWrite, io.EOF},
		// Force error in transaction input signature script length.
		{multiTx, multiTxEncoded, pver, 41, io.ErrShortWrite, io.EOF},
		// Force error in transaction input signature script.
		{multiTx, multiTxEncoded, pver, 42, io.ErrShortWrite, io.EOF},
		// Force error in transaction input sequence.
		{multiTx, multiTxEncoded, pver, 49, io.ErrShortWrite, io.EOF},
		// Force error in number of transaction outputs.
		{multiTx, multiTxEncoded, pver, 53, io.ErrShortWrite, io.EOF},
		// Force error in transaction output value.
		{multiTx, multiTxEncoded, pver, 54, io.ErrShortWrite, io.EOF},
		// Force error in transaction output pk script length.
		{multiTx, multiTxEncoded, pver, 62, io.ErrShortWrite, io.EOF},
		// Force error in transaction output pk script.
		{multiTx, multiTxEncoded, pver, 63, io.ErrShortWrite, io.EOF},
		// Force error in transaction output lock time.
		{multiTx, multiTxEncoded, pver, 206, io.ErrShortWrite, io.EOF},
	}

	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 err != test.writeErr {
			t.Errorf("BtcEncode #%d wrong error got: %v, want: %v",
				i, err, test.writeErr)
			continue
		}

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

// TestTxWire tests the MsgTx wire encode and decode for various numbers
// of transaction inputs and outputs and protocol versions.
func TestTxWire(t *testing.T) {
	// Empty tx message.
	noTx := wire.NewMsgTx()
	noTx.Version = 1
	noTxEncoded := []byte{
		0x01, 0x00, 0x00, 0x00, // Version
		0x00,                   // Varint for number of input transactions
		0x00,                   // Varint for number of output transactions
		0x00, 0x00, 0x00, 0x00, // Lock time
	}

	tests := []struct {
		in   *wire.MsgTx // Message to encode
		out  *wire.MsgTx // Expected decoded message
		buf  []byte      // Wire encoding
		pver uint32      // Protocol version for wire encoding
	}{
		// Latest protocol version with no transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
			wire.ProtocolVersion,
		},

		// Latest protocol version with multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
			wire.ProtocolVersion,
		},

		// Protocol version BIP0035Version with no transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
			wire.BIP0035Version,
		},

		// Protocol version BIP0035Version with multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
			wire.BIP0035Version,
		},

		// Protocol version BIP0031Version with no transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
			wire.BIP0031Version,
		},

		// Protocol version BIP0031Version with multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
			wire.BIP0031Version,
		},

		// Protocol version NetAddressTimeVersion with no transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
			wire.NetAddressTimeVersion,
		},

		// Protocol version NetAddressTimeVersion with multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
			wire.NetAddressTimeVersion,
		},

		// Protocol version MultipleAddressVersion with no transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
			wire.MultipleAddressVersion,
		},

		// Protocol version MultipleAddressVersion with multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
			wire.MultipleAddressVersion,
		},
	}

//.........这里部分代码省略.........

// InsertBlock inserts raw block and transaction data from a block into the
// database.  The first block inserted into the database will be treated as the
// genesis block.  Every subsequent block insert requires the referenced parent
// block to already exist.
func (db *LevelDb) InsertBlock(block *coinutil.Block) (height int32, rerr error) {
	db.dbLock.Lock()
	defer db.dbLock.Unlock()
	defer func() {
		if rerr == nil {
			rerr = db.processBatches()
		} else {
			db.lBatch().Reset()
		}
	}()

	blocksha := block.Sha()
	mblock := block.MsgBlock()
	rawMsg, err := block.Bytes()
	if err != nil {
		log.Warnf("Failed to obtain raw block sha %v", blocksha)
		return 0, err
	}
	txloc, err := block.TxLoc()
	if err != nil {
		log.Warnf("Failed to obtain raw block sha %v", blocksha)
		return 0, err
	}

	// Insert block into database
	newheight, err := db.insertBlockData(blocksha, &mblock.Header.PrevBlock,
		rawMsg)
	if err != nil {
		log.Warnf("Failed to insert block %v %v %v", blocksha,
			&mblock.Header.PrevBlock, err)
		return 0, err
	}

	// At least two blocks in the long past were generated by faulty
	// miners, the sha of the transaction exists in a previous block,
	// detect this condition and 'accept' the block.
	for txidx, tx := range mblock.Transactions {
		txsha, err := block.TxSha(txidx)
		if err != nil {
			log.Warnf("failed to compute tx name block %v idx %v err %v", blocksha, txidx, err)
			return 0, err
		}
		spentbuflen := (len(tx.TxOut) + 7) / 8
		spentbuf := make([]byte, spentbuflen, spentbuflen)
		if len(tx.TxOut)%8 != 0 {
			for i := uint(len(tx.TxOut) % 8); i < 8; i++ {
				spentbuf[spentbuflen-1] |= (byte(1) << i)
			}
		}

		err = db.insertTx(txsha, newheight, txloc[txidx].TxStart, txloc[txidx].TxLen, spentbuf)
		if err != nil {
			log.Warnf("block %v idx %v failed to insert tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
			return 0, err
		}

		// Some old blocks contain duplicate transactions
		// Attempt to cleanly bypass this problem by marking the
		// first as fully spent.
		// http://blockexplorer.com/b/91812 dup in 91842
		// http://blockexplorer.com/b/91722 dup in 91880
		if newheight == 91812 {
			dupsha, err := wire.NewShaHashFromStr("d5d27987d2a3dfc724e359870c6644b40e497bdc0589a033220fe15429d88599")
			if err != nil {
				panic("invalid sha string in source")
			}
			if txsha.IsEqual(dupsha) {
				// marking TxOut[0] as spent
				po := wire.NewOutPoint(dupsha, 0)
				txI := wire.NewTxIn(po, []byte("garbage"))

				var spendtx wire.MsgTx
				spendtx.AddTxIn(txI)
				err = db.doSpend(&spendtx)
				if err != nil {
					log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
				}
			}
		}
		if newheight == 91722 {
			dupsha, err := wire.NewShaHashFromStr("e3bf3d07d4b0375638d5f1db5255fe07ba2c4cb067cd81b84ee974b6585fb468")
			if err != nil {
				panic("invalid sha string in source")
			}
			if txsha.IsEqual(dupsha) {
				// marking TxOut[0] as spent
				po := wire.NewOutPoint(dupsha, 0)
				txI := wire.NewTxIn(po, []byte("garbage"))

				var spendtx wire.MsgTx
				spendtx.AddTxIn(txI)
				err = db.doSpend(&spendtx)
				if err != nil {
					log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
				}
			}
//.........这里部分代码省略.........

// loadTxStore returns a transaction store loaded from a file.
func loadTxStore(filename string) (blockchain.TxStore, error) {
	// The txstore file format is:
	// <num tx data entries> <tx length> <serialized tx> <blk height>
	// <num spent bits> <spent bits>
	//
	// All num and length fields are little-endian uint32s.  The spent bits
	// field is padded to a byte boundary.

	filename = filepath.Join("testdata/", filename)
	fi, err := os.Open(filename)
	if err != nil {
		return nil, err
	}

	// Choose read based on whether the file is compressed or not.
	var r io.Reader
	if strings.HasSuffix(filename, ".bz2") {
		r = bzip2.NewReader(fi)
	} else {
		r = fi
	}
	defer fi.Close()

	// Num of transaction store objects.
	var numItems uint32
	if err := binary.Read(r, binary.LittleEndian, &numItems); err != nil {
		return nil, err
	}

	txStore := make(blockchain.TxStore)
	var uintBuf uint32
	for height := uint32(0); height < numItems; height++ {
		txD := blockchain.TxData{}

		// Serialized transaction length.
		err = binary.Read(r, binary.LittleEndian, &uintBuf)
		if err != nil {
			return nil, err
		}
		serializedTxLen := uintBuf
		if serializedTxLen > wire.MaxBlockPayload {
			return nil, fmt.Errorf("Read serialized transaction "+
				"length of %d is larger max allowed %d",
				serializedTxLen, wire.MaxBlockPayload)
		}

		// Transaction.
		var msgTx wire.MsgTx
		err = msgTx.Deserialize(r)
		if err != nil {
			return nil, err
		}
		txD.Tx = coinutil.NewTx(&msgTx)

		// Transaction hash.
		txHash := msgTx.TxSha()
		txD.Hash = &txHash

		// Block height the transaction came from.
		err = binary.Read(r, binary.LittleEndian, &uintBuf)
		if err != nil {
			return nil, err
		}
		txD.BlockHeight = int32(uintBuf)

		// Num spent bits.
		err = binary.Read(r, binary.LittleEndian, &uintBuf)
		if err != nil {
			return nil, err
		}
		numSpentBits := uintBuf
		numSpentBytes := numSpentBits / 8
		if numSpentBits%8 != 0 {
			numSpentBytes++
		}

		// Packed spent bytes.
		spentBytes := make([]byte, numSpentBytes)
		_, err = io.ReadFull(r, spentBytes)
		if err != nil {
			return nil, err
		}

		// Populate spent data based on spent bits.
		txD.Spent = make([]bool, numSpentBits)
		for byteNum, spentByte := range spentBytes {
			for bit := 0; bit < 8; bit++ {
				if uint32((byteNum*8)+bit) < numSpentBits {
					if spentByte&(1<<uint(bit)) != 0 {
						txD.Spent[(byteNum*8)+bit] = true
					}
				}
			}
		}

		txStore[*txD.Hash] = &txD
	}

	return txStore, nil
//.........这里部分代码省略.........

// TestTxOverflowErrors performs tests to ensure deserializing transactions
// which are intentionally crafted to use large values for the variable number
// of inputs and outputs are handled properly.  This could otherwise potentially
// be used as an attack vector.
func TestTxOverflowErrors(t *testing.T) {
	// Use protocol version 70001 and transaction version 1 specifically
	// here instead of the latest values because the test data is using
	// bytes encoded with those versions.
	pver := uint32(70001)
	txVer := uint32(1)

	tests := []struct {
		buf     []byte // Wire encoding
		pver    uint32 // Protocol version for wire encoding
		version uint32 // Transaction version
		err     error  // Expected error
	}{
		// Transaction that claims to have ~uint64(0) inputs.
		{
			[]byte{
				0x00, 0x00, 0x00, 0x01, // Version
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0xff, // Varint for number of input transactions
			}, pver, txVer, &wire.MessageError{},
		},

		// Transaction that claims to have ~uint64(0) outputs.
		{
			[]byte{
				0x00, 0x00, 0x00, 0x01, // Version
				0x00, // Varint for number of input transactions
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0xff, // Varint for number of output transactions
			}, pver, txVer, &wire.MessageError{},
		},

		// Transaction that has an input with a signature script that
		// claims to have ~uint64(0) length.
		{
			[]byte{
				0x00, 0x00, 0x00, 0x01, // Version
				0x01, // Varint for number of input transactions
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Previous output hash
				0xff, 0xff, 0xff, 0xff, // Prevous output index
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0xff, // Varint for length of signature script
			}, pver, txVer, &wire.MessageError{},
		},

		// Transaction that has an output with a public key script
		// that claims to have ~uint64(0) length.
		{
			[]byte{
				0x00, 0x00, 0x00, 0x01, // Version
				0x01, // Varint for number of input transactions
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Previous output hash
				0xff, 0xff, 0xff, 0xff, // Prevous output index
				0x00,                   // Varint for length of signature script
				0xff, 0xff, 0xff, 0xff, // Sequence
				0x01,                                           // Varint for number of output transactions
				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Transaction amount
				0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
				0xff, // Varint for length of public key script
			}, pver, txVer, &wire.MessageError{},
		},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Decode from wire format.
		var msg wire.MsgTx
		r := bytes.NewReader(test.buf)
		err := msg.BtcDecode(r, test.pver)
		if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
				i, err, reflect.TypeOf(test.err))
			continue
		}

		// Decode from wire format.
		r = bytes.NewReader(test.buf)
		err = msg.Deserialize(r)
		if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
			t.Errorf("Deserialize #%d wrong error got: %v, want: %v",
				i, err, reflect.TypeOf(test.err))
			continue
		}
	}
}

// TestSort ensures the transaction sorting works according to the BIP.
func TestSort(t *testing.T) {
	tests := []struct {
		name         string
		hexFile      string
		isSorted     bool
		unsortedHash string
		sortedHash   string
	}{
		{
			name:         "first test case from BIPLI01 - sorts inputs only, based on hash",
			hexFile:      "li01-1.hex",
			isSorted:     false,
			unsortedHash: "0a6a357e2f7796444e02638749d9611c008b253fb55f5dc88b739b230ed0c4c3",
			sortedHash:   "839503cb611a3e3734bd521c608f881be2293ff77b7384057ab994c794fce623",
		},
		{
			name:         "second test case from BIPLI01 - already sorted",
			hexFile:      "li01-2.hex",
			isSorted:     true,
			unsortedHash: "28204cad1d7fc1d199e8ef4fa22f182de6258a3eaafe1bbe56ebdcacd3069a5f",
			sortedHash:   "28204cad1d7fc1d199e8ef4fa22f182de6258a3eaafe1bbe56ebdcacd3069a5f",
		},
		{
			name:         "block 100001 tx[1] - sorts outputs only, based on amount",
			hexFile:      "li01-3.hex",
			isSorted:     false,
			unsortedHash: "fbde5d03b027d2b9ba4cf5d4fecab9a99864df2637b25ea4cbcb1796ff6550ca",
			sortedHash:   "0a8c246c55f6b82f094d211f4f57167bf2ea4898741d218b09bdb2536fd8d13f",
		},
		{
			name:         "block 100001 tx[2] - sorts both inputs and outputs",
			hexFile:      "li01-4.hex",
			isSorted:     false,
			unsortedHash: "8131ffb0a2c945ecaf9b9063e59558784f9c3a74741ce6ae2a18d0571dac15bb",
			sortedHash:   "a3196553b928b0b6154b002fa9a1ce875adabc486fedaaaf4c17430fd4486329",
		},
		{
			name:         "block 100998 tx[6] - sorts outputs only, based on output script",
			hexFile:      "li01-5.hex",
			isSorted:     false,
			unsortedHash: "ff85e8fc92e71bbc217e3ea9a3bacb86b435e52b6df0b089d67302c293a2b81d",
			sortedHash:   "9a6c24746de024f77cac9b2138694f11101d1c66289261224ca52a25155a7c94",
		},
	}

	for _, test := range tests {
		// Load and deserialize the test transaction.
		filePath := filepath.Join("testdata", test.hexFile)
		txHexBytes, err := ioutil.ReadFile(filePath)
		if err != nil {
			t.Errorf("ReadFile (%s): failed to read test file: %v",
				test.name, err)
			continue
		}
		txBytes, err := hex.DecodeString(string(txHexBytes))
		if err != nil {
			t.Errorf("DecodeString (%s): failed to decode tx: %v",
				test.name, err)
			continue
		}
		var tx wire.MsgTx
		err = tx.Deserialize(bytes.NewReader(txBytes))
		if err != nil {
			t.Errorf("Deserialize (%s): unexpected error %v",
				test.name, err)
			continue
		}

		// Ensure the sort order of the original transaction matches the
		// expected value.
		if got := txsort.IsSorted(&tx); got != test.isSorted {
			t.Errorf("IsSorted (%s): sort does not match "+
				"expected - got %v, want %v", test.name, got,
				test.isSorted)
			continue
		}

		// Sort the transaction and ensure the resulting hash is the
		// expected value.
		sortedTx := txsort.Sort(&tx)
		if got := sortedTx.TxSha().String(); got != test.sortedHash {
			t.Errorf("Sort (%s): sorted hash does not match "+
				"expected - got %v, want %v", test.name, got,
				test.sortedHash)
			continue
		}

		// Ensure the original transaction is not modified.
		if got := tx.TxSha().String(); got != test.unsortedHash {
			t.Errorf("Sort (%s): unsorted hash does not match "+
				"expected - got %v, want %v", test.name, got,
				test.unsortedHash)
			continue
		}

		// Now sort the transaction using the mutable version and ensure
		// the resulting hash is the expected value.
		txsort.InPlaceSort(&tx)
		if got := tx.TxSha().String(); got != test.sortedHash {
//.........这里部分代码省略.........

// Sort returns a new transaction with the inputs and outputs sorted based on
// BIP LI01.  The passed transaction is not modified and the new transaction
// might have a different hash if any sorting was done.
func Sort(tx *wire.MsgTx) *wire.MsgTx {
	txCopy := tx.Copy()
	sort.Sort(sortableInputSlice(txCopy.TxIn))
	sort.Sort(sortableOutputSlice(txCopy.TxOut))
	return txCopy
}

// calcSignatureHash will, given a script and hash type for the current script
// engine instance, calculate the signature hash to be used for signing and
// verification.
func calcSignatureHash(script []parsedOpcode, hashType SigHashType, tx *wire.MsgTx, idx int) []byte {
	// The SigHashSingle signature type signs only the corresponding input
	// and output (the output with the same index number as the input).
	//
	// Since transactions can have more inputs than outputs, this means it
	// is improper to use SigHashSingle on input indices that don't have a
	// corresponding output.
	//
	// A bug in the original Satoshi client implementation means specifying
	// an index that is out of range results in a signature hash of 1 (as a
	// uint256 little endian).  The original intent appeared to be to
	// indicate failure, but unfortunately, it was never checked and thus is
	// treated as the actual signature hash.  This buggy behavior is now
	// part of the consensus and a hard fork would be required to fix it.
	//
	// Due to this, care must be taken by software that creates transactions
	// which make use of SigHashSingle because it can lead to an extremely
	// dangerous situation where the invalid inputs will end up signing a
	// hash of 1.  This in turn presents an opportunity for attackers to
	// cleverly construct transactions which can steal those coins provided
	// they can reuse signatures.
	if hashType&sigHashMask == SigHashSingle && idx >= len(tx.TxOut) {
		var hash wire.ShaHash
		hash[0] = 0x01
		return hash[:]
	}

	// Remove all instances of OP_CODESEPARATOR from the script.
	script = removeOpcode(script, OP_CODESEPARATOR)

	// Make a deep copy of the transaction, zeroing out the script for all
	// inputs that are not currently being processed.
	txCopy := tx.Copy()
	for i := range txCopy.TxIn {
		if i == idx {
			// UnparseScript cannot fail here because removeOpcode
			// above only returns a valid script.
			sigScript, _ := unparseScript(script)
			txCopy.TxIn[idx].SignatureScript = sigScript
		} else {
			txCopy.TxIn[i].SignatureScript = nil
		}
	}

	switch hashType & sigHashMask {
	case SigHashNone:
		txCopy.TxOut = txCopy.TxOut[0:0] // Empty slice.
		for i := range txCopy.TxIn {
			if i != idx {
				txCopy.TxIn[i].Sequence = 0
			}
		}

	case SigHashSingle:
		// Resize output array to up to and including requested index.
		txCopy.TxOut = txCopy.TxOut[:idx+1]

		// All but current output get zeroed out.
		for i := 0; i < idx; i++ {
			txCopy.TxOut[i].Value = -1
			txCopy.TxOut[i].PkScript = nil
		}

		// Sequence on all other inputs is 0, too.
		for i := range txCopy.TxIn {
			if i != idx {
				txCopy.TxIn[i].Sequence = 0
			}
		}

	default:
		// Consensus treats undefined hashtypes like normal SigHashAll
		// for purposes of hash generation.
		fallthrough
	case SigHashOld:
		fallthrough
	case SigHashAll:
		// Nothing special here.
	}
	if hashType&SigHashAnyOneCanPay != 0 {
		txCopy.TxIn = txCopy.TxIn[idx : idx+1]
		idx = 0
	}

	// The final hash is the double sha256 of both the serialized modified
	// transaction and the hash type (encoded as a 4-byte little-endian
	// value) appended.
	var wbuf bytes.Buffer
	txCopy.Serialize(&wbuf)
	binary.Write(&wbuf, binary.LittleEndian, hashType)
	return wire.DoubleSha256(wbuf.Bytes())
}

//.........这里部分代码省略.........

		newheight, err := db.InsertBlock(block)
		if err != nil {
			t.Errorf("failed to insert block %v err %v", height, err)
			break out
		}
		if newheight != height {
			t.Errorf("height mismatch expect %v returned %v", height, newheight)
			break out
		}

		newSha, blkid, err := db.NewestSha()
		if err != nil {
			t.Errorf("failed to obtain latest sha %v %v", height, err)
		}

		if blkid != height {
			t.Errorf("height doe not match latest block height %v %v %v", blkid, height, err)
		}

		blkSha := block.Sha()
		if *newSha != *blkSha {
			t.Errorf("Newest block sha does not match freshly inserted one %v %v %v ", newSha, blkSha, err)
		}
		lastSha = blkSha
	}

	// generate a new block based on the last sha
	// these block are not verified, so there are a bunch of garbage fields
	// in the 'generated' block.

	var bh wire.BlockHeader

	bh.Version = 2
	bh.PrevBlock = *lastSha
	// Bits, Nonce are not filled in

	mblk := wire.NewMsgBlock(&bh)

	hash, _ := wire.NewShaHashFromStr("df2b060fa2e5e9c8ed5eaf6a45c13753ec8c63282b2688322eba40cd98ea067a")

	po := wire.NewOutPoint(hash, 0)
	txI := wire.NewTxIn(po, []byte("garbage"))
	txO := wire.NewTxOut(50000000, []byte("garbageout"))

	var tx wire.MsgTx
	tx.AddTxIn(txI)
	tx.AddTxOut(txO)

	mblk.AddTransaction(&tx)

	blk := coinutil.NewBlock(mblk)

	fetchList := []*wire.ShaHash{hash}
	listReply := db.FetchUnSpentTxByShaList(fetchList)
	for _, lr := range listReply {
		if lr.Err != nil {
			t.Errorf("sha %v spent %v err %v\n", lr.Sha,
				lr.TxSpent, lr.Err)
		}
	}

	_, err = db.InsertBlock(blk)
	if err != nil {
		t.Errorf("failed to insert phony block %v", err)
	}

	// ok, did it 'spend' the tx ?

	listReply = db.FetchUnSpentTxByShaList(fetchList)
	for _, lr := range listReply {
		if lr.Err != database.ErrTxShaMissing {
			t.Errorf("sha %v spent %v err %v\n", lr.Sha,
				lr.TxSpent, lr.Err)
		}
	}

	txlist := blk.Transactions()
	for _, tx := range txlist {
		txsha := tx.Sha()
		txReply, err := db.FetchTxBySha(txsha)
		if err != nil {
			t.Errorf("fully spent lookup %v err %v\n", hash, err)
		} else {
			for _, lr := range txReply {
				if lr.Err != nil {
					t.Errorf("stx %v spent %v err %v\n", lr.Sha,
						lr.TxSpent, lr.Err)
				}
			}
		}
	}

	t.Logf("Dropping block")

	err = db.DropAfterBlockBySha(lastSha)
	if err != nil {
		t.Errorf("failed to drop spending block %v", err)
	}
}