// createDB creates a new db instance and returns a teardown function the caller
// should invoke when done testing to clean up.  The close flag indicates
// whether or not the teardown function should sync and close the database
// during teardown.
func createDB(dbType, dbName string, close bool) (database.Db, func(), error) {
	// Handle memory database specially since it doesn't need the disk
	// specific handling.
	if dbType == "memdb" {
		db, err := database.CreateDB(dbType)
		if err != nil {
			return nil, nil, fmt.Errorf("error creating db: %v", err)
		}

		// Setup a teardown function for cleaning up.  This function is
		// returned to the caller to be invoked when it is done testing.
		teardown := func() {
			if close {
				db.Close()
			}
		}

		return db, teardown, nil
	}

	// Create the root directory for test databases.
	if !fileExists(testDbRoot) {
		if err := os.MkdirAll(testDbRoot, 0700); err != nil {
			err := fmt.Errorf("unable to create test db "+
				"root: %v", err)
			return nil, nil, err
		}
	}

	// Create a new database to store the accepted blocks into.
	dbPath := filepath.Join(testDbRoot, dbName)
	_ = os.RemoveAll(dbPath)
	db, err := database.CreateDB(dbType, dbPath)
	if err != nil {
		return nil, nil, fmt.Errorf("error creating db: %v", err)
	}

	// Setup a teardown function for cleaning up.  This function is
	// returned to the caller to be invoked when it is done testing.
	teardown := func() {
		dbVersionPath := filepath.Join(testDbRoot, dbName+".ver")
		if close {
			db.Sync()
			db.Close()
		}
		os.RemoveAll(dbPath)
		os.Remove(dbVersionPath)
		os.RemoveAll(testDbRoot)
	}

	return db, teardown, nil
}

func setUpTestDb(t *testing.T, dbname string) (*testDb, error) {
	// Ignore db remove errors since it means we didn't have an old one.
	dbnamever := dbname + ".ver"
	_ = os.RemoveAll(dbname)
	_ = os.RemoveAll(dbnamever)
	db, err := database.CreateDB("leveldb", dbname)
	if err != nil {
		return nil, err
	}

	testdatafile := filepath.Join("..", "testdata", "blocks1-256.bz2")
	blocks, err := loadBlocks(t, testdatafile)
	if err != nil {
		return nil, err
	}

	cleanUp := func() {
		db.Close()
		os.RemoveAll(dbname)
		os.RemoveAll(dbnamever)
	}

	return &testDb{
		db:          db,
		blocks:      blocks,
		dbName:      dbname,
		dbNameVer:   dbnamever,
		cleanUpFunc: cleanUp,
	}, nil
}

// This example demonstrates creating a new database and inserting the genesis
// block into it.
func ExampleCreateDB() {
	// Notice in these example imports that the memdb driver is loaded.
	// Ordinarily this would be whatever driver(s) your application
	// requires.
	// import (
	//	"github.com/btcsuite/btcd/database"
	// 	_ "github.com/btcsuite/btcd/database/memdb"
	// )

	// Create a database and schedule it to be closed on exit.  This example
	// uses a memory-only database to avoid needing to write anything to
	// the disk.  Typically, you would specify a persistent database driver
	// such as "leveldb" and give it a database name as the second
	// parameter.
	db, err := database.CreateDB("memdb")
	if err != nil {
		fmt.Println(err)
		return
	}
	defer db.Close()

	// Insert the main network genesis block.
	genesis := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	newHeight, err := db.InsertBlock(genesis)
	if err != nil {
		fmt.Println(err)
		return
	}

	fmt.Println("New height:", newHeight)

	// Output:
	// New height: 0
}

// setupBlockDB loads (or creates when needed) the block database taking into
// account the selected database backend.  It also contains additional logic
// such warning the user if there are multiple databases which consume space on
// the file system and ensuring the regression test database is clean when in
// regression test mode.
func setupBlockDB() (database.Db, error) {
	// The memdb backend does not have a file path associated with it, so
	// handle it uniquely.  We also don't want to worry about the multiple
	// database type warnings when running with the memory database.
	if cfg.DbType == "memdb" {
		btcdLog.Infof("Creating block database in memory.")
		db, err := database.CreateDB(cfg.DbType)
		if err != nil {
			return nil, err
		}
		return db, nil
	}

	warnMultipeDBs()

	// The database name is based on the database type.
	dbPath := blockDbPath(cfg.DbType)

	// The regression test is special in that it needs a clean database for
	// each run, so remove it now if it already exists.
	removeRegressionDB(dbPath)

	btcdLog.Infof("Loading block database from '%s'", dbPath)
	db, err := database.OpenDB(cfg.DbType, dbPath)
	if err != nil {
		// Return the error if it's not because the database
		// doesn't exist.
		if err != database.ErrDbDoesNotExist {
			return nil, err
		}

		// Create the db if it does not exist.
		err = os.MkdirAll(cfg.DataDir, 0700)
		if err != nil {
			return nil, err
		}
		db, err = database.CreateDB(cfg.DbType, dbPath)
		if err != nil {
			return nil, err
		}
	}

	return db, nil
}

// exampleLoadDB is used in the example to elide the setup code.
func exampleLoadDB() (database.Db, error) {
	db, err := database.CreateDB("memdb")
	if err != nil {
		return nil, err
	}

	// Insert the main network genesis block.
	genesis := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	_, err = db.InsertBlock(genesis)
	if err != nil {
		return nil, err
	}

	return db, err
}

// This example demonstrates how to create a new chain instance and use
// ProcessBlock to attempt to attempt add a block to the chain.  As the package
// overview documentation describes, this includes all of the Bitcoin consensus
// rules.  This example intentionally attempts to insert a duplicate genesis
// block to illustrate how an invalid block is handled.
func ExampleBlockChain_ProcessBlock() {
	// Create a new database to store the accepted blocks into.  Typically
	// this would be opening an existing database and would not use memdb
	// which is a memory-only database backend, but we create a new db
	// here so this is a complete working example.
	db, err := database.CreateDB("memdb")
	if err != nil {
		fmt.Printf("Failed to create database: %v\n", err)
		return
	}
	defer db.Close()

	// Insert the main network genesis block.  This is part of the initial
	// database setup.  Like above, this typically would not be needed when
	// opening an existing database.
	genesisBlock := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	_, err = db.InsertBlock(genesisBlock)
	if err != nil {
		fmt.Printf("Failed to insert genesis block: %v\n", err)
		return
	}

	// Create a new BlockChain instance without an initialized signature
	// verification cache, using the underlying database for the main
	// bitcoin network and ignore notifications.
	chain := blockchain.New(db, &chaincfg.MainNetParams, nil, nil)

	// Create a new median time source that is required by the upcoming
	// call to ProcessBlock.  Ordinarily this would also add time values
	// obtained from other peers on the network so the local time is
	// adjusted to be in agreement with other peers.
	timeSource := blockchain.NewMedianTime()

	// Process a block.  For this example, we are going to intentionally
	// cause an error by trying to process the genesis block which already
	// exists.
	isOrphan, err := chain.ProcessBlock(genesisBlock, timeSource, blockchain.BFNone)
	if err != nil {
		fmt.Printf("Failed to process block: %v\n", err)
		return
	}
	fmt.Printf("Block accepted. Is it an orphan?: %v", isOrphan)

	// Output:
	// Failed to process block: already have block 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f
}

func TestEmptyDB(t *testing.T) {

	dbname := "tstdbempty"
	dbnamever := dbname + ".ver"
	_ = os.RemoveAll(dbname)
	_ = os.RemoveAll(dbnamever)
	db, err := database.CreateDB("leveldb", dbname)
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer os.RemoveAll(dbname)
	defer os.RemoveAll(dbnamever)

	sha, height, err := db.NewestSha()
	if !sha.IsEqual(&wire.ShaHash{}) {
		t.Errorf("sha not zero hash")
	}
	if height != -1 {
		t.Errorf("height not -1 %v", height)
	}

	// This is a reopen test
	if err := db.Close(); err != nil {
		t.Errorf("Close: unexpected error: %v", err)
	}

	db, err = database.OpenDB("leveldb", dbname)
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("Close: unexpected error: %v", err)
		}
	}()

	sha, height, err = db.NewestSha()
	if !sha.IsEqual(&wire.ShaHash{}) {
		t.Errorf("sha not zero hash")
	}
	if height != -1 {
		t.Errorf("height not -1 %v", height)
	}
}

// TestCreateOpenUnsupported ensures that attempting to create or open an
// unsupported database type is handled properly.
func TestCreateOpenUnsupported(t *testing.T) {
	// Ensure creating a database with an unsupported type fails with the
	// expected error.
	dbType := "unsupported"
	_, err := database.CreateDB(dbType, "unsupportedcreatetest")
	if err != database.ErrDbUnknownType {
		t.Errorf("TestCreateOpenUnsupported: expected error not "+
			"received - got: %v, want %v", err, database.ErrDbUnknownType)
		return
	}

	// Ensure opening a database with the new type fails with the expected
	// error.
	_, err = database.OpenDB(dbType, "unsupportedopentest")
	if err != database.ErrDbUnknownType {
		t.Errorf("TestCreateOpenUnsupported: expected error not "+
			"received - got: %v, want %v", err, database.ErrDbUnknownType)
		return
	}
}

// TestCreateOpenFail ensures that errors which occur while opening or closing
// a database are handled properly.
func TestCreateOpenFail(t *testing.T) {
	// bogusCreateDB is a function which acts as a bogus create and open
	// driver function that intentionally returns a failure which can be
	// detected.
	dbType := "createopenfail"
	openError := fmt.Errorf("failed to create or open database for "+
		"database type [%v]", dbType)
	bogusCreateDB := func(args ...interface{}) (database.Db, error) {
		return nil, openError
	}

	// Create and add driver that intentionally fails when created or opened
	// to ensure errors on database open and create are handled properly.
	driver := database.DriverDB{
		DbType:   dbType,
		CreateDB: bogusCreateDB,
		OpenDB:   bogusCreateDB,
	}
	database.AddDBDriver(driver)

	// Ensure creating a database with the new type fails with the expected
	// error.
	_, err := database.CreateDB(dbType, "createfailtest")
	if err != openError {
		t.Errorf("TestCreateOpenFail: expected error not received - "+
			"got: %v, want %v", err, openError)
		return
	}

	// Ensure opening a database with the new type fails with the expected
	// error.
	_, err = database.OpenDB(dbType, "openfailtest")
	if err != openError {
		t.Errorf("TestCreateOpenFail: expected error not received - "+
			"got: %v, want %v", err, openError)
		return
	}
}

// loadBlockDB opens the block database and returns a handle to it.
func loadBlockDB() (database.Db, error) {
	// The database name is based on the database type.
	dbName := blockDbNamePrefix + "_" + cfg.DbType
	if cfg.DbType == "sqlite" {
		dbName = dbName + ".db"
	}
	dbPath := filepath.Join(cfg.DataDir, dbName)

	log.Infof("Loading block database from '%s'", dbPath)
	db, err := database.OpenDB(cfg.DbType, dbPath)
	if err != nil {
		// Return the error if it's not because the database doesn't
		// exist.
		if err != database.ErrDbDoesNotExist {
			return nil, err
		}

		// Create the db if it does not exist.
		err = os.MkdirAll(cfg.DataDir, 0700)
		if err != nil {
			return nil, err
		}
		db, err = database.CreateDB(cfg.DbType, dbPath)
		if err != nil {
			return nil, err
		}
	}

	// Get the latest block height from the database.
	_, height, err := db.NewestSha()
	if err != nil {
		db.Close()
		return nil, err
	}

	log.Infof("Block database loaded with block height %d", height)
	return db, nil
}

// chainSetup is used to create a new db and chain instance with the genesis
// block already inserted.  In addition to the new chain instnce, it returns
// a teardown function the caller should invoke when done testing to clean up.
func chainSetup(dbName string) (*blockchain.BlockChain, func(), error) {
	if !isSupportedDbType(testDbType) {
		return nil, nil, fmt.Errorf("unsupported db type %v", testDbType)
	}

	// Handle memory database specially since it doesn't need the disk
	// specific handling.
	var db database.Db
	var teardown func()
	if testDbType == "memdb" {
		ndb, err := database.CreateDB(testDbType)
		if err != nil {
			return nil, nil, fmt.Errorf("error creating db: %v", err)
		}
		db = ndb

		// Setup a teardown function for cleaning up.  This function is
		// returned to the caller to be invoked when it is done testing.
		teardown = func() {
			db.Close()
		}
	} else {
		// Create the root directory for test databases.
		if !fileExists(testDbRoot) {
			if err := os.MkdirAll(testDbRoot, 0700); err != nil {
				err := fmt.Errorf("unable to create test db "+
					"root: %v", err)
				return nil, nil, err
			}
		}

		// Create a new database to store the accepted blocks into.
		dbPath := filepath.Join(testDbRoot, dbName)
		_ = os.RemoveAll(dbPath)
		ndb, err := database.CreateDB(testDbType, dbPath)
		if err != nil {
			return nil, nil, fmt.Errorf("error creating db: %v", err)
		}
		db = ndb

		// Setup a teardown function for cleaning up.  This function is
		// returned to the caller to be invoked when it is done testing.
		teardown = func() {
			dbVersionPath := filepath.Join(testDbRoot, dbName+".ver")
			db.Sync()
			db.Close()
			os.RemoveAll(dbPath)
			os.Remove(dbVersionPath)
			os.RemoveAll(testDbRoot)
		}
	}

	// Insert the main network genesis block.  This is part of the initial
	// database setup.
	genesisBlock := btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock)
	_, err := db.InsertBlock(genesisBlock)
	if err != nil {
		teardown()
		err := fmt.Errorf("failed to insert genesis block: %v", err)
		return nil, nil, err
	}

	chain := blockchain.New(db, &chaincfg.MainNetParams, nil)
	return chain, teardown, nil
}

// insert every block in the test chain
// after each insert, fetch all the tx affected by the latest
// block and verify that the the tx is spent/unspent
// new tx should be fully unspent, referenced tx should have
// the associated txout set to spent.
func testUnspentInsert(t *testing.T) {
	// Ignore db remove errors since it means we didn't have an old one.
	dbname := fmt.Sprintf("tstdbuspnt1")
	dbnamever := dbname + ".ver"
	_ = os.RemoveAll(dbname)
	_ = os.RemoveAll(dbnamever)
	db, err := database.CreateDB("leveldb", dbname)
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer os.RemoveAll(dbname)
	defer os.RemoveAll(dbnamever)
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("Close: unexpected error: %v", err)
		}
	}()

	blocks := loadblocks(t)
endtest:
	for height := int64(0); height < int64(len(blocks)); height++ {

		block := blocks[height]
		// look up inputs to this tx
		mblock := block.MsgBlock()
		var txneededList []*wire.ShaHash
		var txlookupList []*wire.ShaHash
		var txOutList []*wire.ShaHash
		var txInList []*wire.OutPoint
		for _, tx := range mblock.Transactions {
			for _, txin := range tx.TxIn {
				if txin.PreviousOutPoint.Index == uint32(4294967295) {
					continue
				}
				origintxsha := &txin.PreviousOutPoint.Hash

				txInList = append(txInList, &txin.PreviousOutPoint)
				txneededList = append(txneededList, origintxsha)
				txlookupList = append(txlookupList, origintxsha)

				exists, err := db.ExistsTxSha(origintxsha)
				if err != nil {
					t.Errorf("ExistsTxSha: unexpected error %v ", err)
				}
				if !exists {
					t.Errorf("referenced tx not found %v ", origintxsha)
				}
			}
			txshaname := tx.TxSha()
			txlookupList = append(txlookupList, &txshaname)
			txOutList = append(txOutList, &txshaname)
		}

		txneededmap := map[wire.ShaHash]*database.TxListReply{}
		txlist := db.FetchUnSpentTxByShaList(txneededList)
		for _, txe := range txlist {
			if txe.Err != nil {
				t.Errorf("tx list fetch failed %v err %v ", txe.Sha, txe.Err)
				break endtest
			}
			txneededmap[*txe.Sha] = txe
		}
		for _, spend := range txInList {
			itxe := txneededmap[spend.Hash]
			if itxe.TxSpent[spend.Index] == true {
				t.Errorf("txin %v:%v is already spent", spend.Hash, spend.Index)
			}
		}

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

		txlookupmap := map[wire.ShaHash]*database.TxListReply{}
		txlist = db.FetchTxByShaList(txlookupList)
		for _, txe := range txlist {
			if txe.Err != nil {
				t.Errorf("tx list fetch failed %v err %v ", txe.Sha, txe.Err)
				break endtest
			}
			txlookupmap[*txe.Sha] = txe
		}
		for _, spend := range txInList {
			itxe := txlookupmap[spend.Hash]
			if itxe.TxSpent[spend.Index] == false {
				t.Errorf("txin %v:%v is unspent %v", spend.Hash, spend.Index, itxe.TxSpent)
			}
		}
//.........这里部分代码省略.........

func Test_dupTx(t *testing.T) {

	// Ignore db remove errors since it means we didn't have an old one.
	dbname := fmt.Sprintf("tstdbdup0")
	dbnamever := dbname + ".ver"
	_ = os.RemoveAll(dbname)
	_ = os.RemoveAll(dbnamever)
	db, err := database.CreateDB("leveldb", dbname)
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	defer os.RemoveAll(dbname)
	defer os.RemoveAll(dbnamever)
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("Close: unexpected error: %v", err)
		}
	}()

	testdatafile := filepath.Join("testdata", "blocks1-256.bz2")
	blocks, err := loadBlocks(t, testdatafile)
	if err != nil {
		t.Errorf("Unable to load blocks from test data for: %v",
			err)
		return
	}

	var lastSha *wire.ShaHash

	// Populate with the fisrt 256 blocks, so we have blocks to 'mess with'
	err = nil
out:
	for height := int64(0); height < int64(len(blocks)); height++ {
		block := blocks[height]

		// except for NoVerify which does not allow lookups check inputs
		mblock := block.MsgBlock()
		var txneededList []*wire.ShaHash
		for _, tx := range mblock.Transactions {
			for _, txin := range tx.TxIn {
				if txin.PreviousOutPoint.Index == uint32(4294967295) {
					continue
				}
				origintxsha := &txin.PreviousOutPoint.Hash
				txneededList = append(txneededList, origintxsha)

				exists, err := db.ExistsTxSha(origintxsha)
				if err != nil {
					t.Errorf("ExistsTxSha: unexpected error %v ", err)
				}
				if !exists {
					t.Errorf("referenced tx not found %v ", origintxsha)
				}

				_, err = db.FetchTxBySha(origintxsha)
				if err != nil {
					t.Errorf("referenced tx not found %v err %v ", origintxsha, err)
				}
			}
		}
		txlist := db.FetchUnSpentTxByShaList(txneededList)
		for _, txe := range txlist {
			if txe.Err != nil {
				t.Errorf("tx list fetch failed %v err %v ", txe.Sha, txe.Err)
				break out
			}
		}

		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
//.........这里部分代码省略.........

// TestClosed ensure calling the interface functions on a closed database
// returns appropriate errors for the interface functions that return errors
// and does not panic or otherwise misbehave for functions which do not return
// errors.
func TestClosed(t *testing.T) {
	db, err := database.CreateDB("memdb")
	if err != nil {
		t.Errorf("Failed to open test database %v", err)
		return
	}
	_, err = db.InsertBlock(btcutil.NewBlock(chaincfg.MainNetParams.GenesisBlock))
	if err != nil {
		t.Errorf("InsertBlock: %v", err)
	}
	if err := db.Close(); err != nil {
		t.Errorf("Close: unexpected error %v", err)
	}

	genesisHash := chaincfg.MainNetParams.GenesisHash
	if err := db.DropAfterBlockBySha(genesisHash); err != memdb.ErrDbClosed {
		t.Errorf("DropAfterBlockBySha: unexpected error %v", err)
	}

	if _, err := db.ExistsSha(genesisHash); err != memdb.ErrDbClosed {
		t.Errorf("ExistsSha: Unexpected error: %v", err)
	}

	if _, err := db.FetchBlockBySha(genesisHash); err != memdb.ErrDbClosed {
		t.Errorf("FetchBlockBySha: unexpected error %v", err)
	}

	if _, err := db.FetchBlockShaByHeight(0); err != memdb.ErrDbClosed {
		t.Errorf("FetchBlockShaByHeight: unexpected error %v", err)
	}

	if _, err := db.FetchHeightRange(0, 1); err != memdb.ErrDbClosed {
		t.Errorf("FetchHeightRange: unexpected error %v", err)
	}

	genesisCoinbaseTx := chaincfg.MainNetParams.GenesisBlock.Transactions[0]
	coinbaseHash, err := genesisCoinbaseTx.TxSha()
	if err != nil {
		t.Errorf("TxSha: unexpected error %v", err)
	}
	if _, err := db.ExistsTxSha(&coinbaseHash); err != memdb.ErrDbClosed {
		t.Errorf("ExistsTxSha: unexpected error %v", err)
	}

	if _, err := db.FetchTxBySha(genesisHash); err != memdb.ErrDbClosed {
		t.Errorf("FetchTxBySha: unexpected error %v", err)
	}

	requestHashes := []*wire.ShaHash{genesisHash}
	reply := db.FetchTxByShaList(requestHashes)
	if len(reply) != len(requestHashes) {
		t.Errorf("FetchUnSpentTxByShaList unexpected number of replies "+
			"got: %d, want: %d", len(reply), len(requestHashes))
	}
	for i, txLR := range reply {
		wantReply := &database.TxListReply{
			Sha: requestHashes[i],
			Err: memdb.ErrDbClosed,
		}
		if !reflect.DeepEqual(wantReply, txLR) {
			t.Errorf("FetchTxByShaList unexpected reply\ngot: %v\n"+
				"want: %v", txLR, wantReply)
		}
	}

	reply = db.FetchUnSpentTxByShaList(requestHashes)
	if len(reply) != len(requestHashes) {
		t.Errorf("FetchUnSpentTxByShaList unexpected number of replies "+
			"got: %d, want: %d", len(reply), len(requestHashes))
	}
	for i, txLR := range reply {
		wantReply := &database.TxListReply{
			Sha: requestHashes[i],
			Err: memdb.ErrDbClosed,
		}
		if !reflect.DeepEqual(wantReply, txLR) {
			t.Errorf("FetchUnSpentTxByShaList unexpected reply\n"+
				"got: %v\nwant: %v", txLR, wantReply)
		}
	}

	if _, _, err := db.NewestSha(); err != memdb.ErrDbClosed {
		t.Errorf("NewestSha: unexpected error %v", err)
	}

	if err := db.Sync(); err != memdb.ErrDbClosed {
		t.Errorf("Sync: unexpected error %v", err)
	}

	if err := db.RollbackClose(); err != memdb.ErrDbClosed {
		t.Errorf("RollbackClose: unexpected error %v", err)
	}

	if err := db.Close(); err != memdb.ErrDbClosed {
		t.Errorf("Close: unexpected error %v", err)
	}
//.........这里部分代码省略.........

func TestInsertData(t *testing.T) {
	// Ignore db remove errors since it means we didn't have an old one.
	dbname := fmt.Sprintf("tstdbdata1")
	dbnamever := dbname + ".ver"
	_ = os.RemoveAll(dbname)
	_ = os.RemoveAll(dbnamever)
	db, err := database.CreateDB("leveldb", dbname)
	if err != nil {
		t.Fatalf("Failed to open test database %v", err)
	}

	defer os.RemoveAll(dbname)
	defer os.RemoveAll(dbnamever)
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("Close: unexpected error: %v", err)
		}
	}()

	list, err := db.FetchTxsByData([]byte("dhaskj2"))
	if err != nil {
		t.Fatalf("Get data failed %v", err)
	}
	if len(list) != 0 {
		t.Errorf("Expected empty list, got length %d.", len(list))
	}

	txSha0, err := wire.NewShaHash([]byte("00001111222233334444555566667777"))
	if err != nil {
		t.Fatalf("Failed to set-up ShaHash %v", err)
	}
	txSha1, err := wire.NewShaHash([]byte("10001111222233334444555566667777"))
	if err != nil {
		t.Fatalf("Failed to set-up ShaHash %v", err)
	}
	err = db.InsertData([]byte("dhaskj1"), txSha0, 0)
	if err != nil {
		t.Fatalf("Insert data failed %v", err)
	}

	list, err = db.FetchTxsByData([]byte("dhaskj2"))
	if err != nil {
		t.Fatalf("Get data failed %v", err)
	}
	if len(list) != 0 {
		t.Errorf("Expected empty list, got length %d.", len(list))
	}

	err = db.InsertData([]byte("dhaskj2"), txSha0, 0)
	if err != nil {
		t.Fatalf("Insert data failed %v", err)
	}
	err = db.InsertData([]byte("dhaskj2"), txSha1, 0)
	if err != nil {
		t.Fatalf("Insert data failed %v", err)
	}

	list, err = db.FetchTxsByData([]byte("dhaskj2"))
	if err != nil {
		t.Fatalf("Get data failed %v", err)
	}
	if len(list) != 2 {
		t.Errorf("Expected list with 2 items, got %d.", len(list))
	}
}