// realMain is the real main function for the utility.  It is necessary to work
// around the fact that deferred functions do not run when os.Exit() is called.
func realMain() error {
	// Load configuration and parse command line.
	tcfg, _, err := loadConfig()
	if err != nil {
		return err
	}
	cfg = tcfg

	// Setup logging.
	backendLogger := btclog.NewDefaultBackendLogger()
	defer backendLogger.Flush()
	log = btclog.NewSubsystemLogger(backendLogger, "")
	database.UseLogger(btclog.NewSubsystemLogger(backendLogger, "BCDB: "))
	blockchain.UseLogger(btclog.NewSubsystemLogger(backendLogger, "CHAN: "))
	indexers.UseLogger(btclog.NewSubsystemLogger(backendLogger, "INDX: "))

	// Load the block database.
	db, err := loadBlockDB()
	if err != nil {
		log.Errorf("Failed to load database: %v", err)
		return err
	}
	defer db.Close()

	fi, err := os.Open(cfg.InFile)
	if err != nil {
		log.Errorf("Failed to open file %v: %v", cfg.InFile, err)
		return err
	}
	defer fi.Close()

	// Create a block importer for the database and input file and start it.
	// The done channel returned from start will contain an error if
	// anything went wrong.
	importer, err := newBlockImporter(db, fi)
	if err != nil {
		log.Errorf("Failed create block importer: %v", err)
		return err
	}

	// Perform the import asynchronously.  This allows blocks to be
	// processed and read in parallel.  The results channel returned from
	// Import contains the statistics about the import including an error
	// if something went wrong.
	log.Info("Starting import")
	resultsChan := importer.Import()
	results := <-resultsChan
	if results.err != nil {
		log.Errorf("%v", results.err)
		return results.err
	}

	log.Infof("Processed a total of %d blocks (%d imported, %d already "+
		"known) in %v", results.blocksProcessed, results.blocksImported,
		results.blocksProcessed-results.blocksImported, results.duration)

	return nil
}

// realMain is the real main function for the utility.  It is necessary to work
// around the fact that deferred functions do not run when os.Exit() is called.
func realMain() error {
	// Setup logging.
	backendLogger := btclog.NewDefaultBackendLogger()
	defer backendLogger.Flush()
	log = btclog.NewSubsystemLogger(backendLogger, "")
	dbLog := btclog.NewSubsystemLogger(backendLogger, "BCDB: ")
	dbLog.SetLevel(btclog.DebugLvl)
	database.UseLogger(dbLog)

	// Setup the parser options and commands.
	appName := filepath.Base(os.Args[0])
	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
	parserFlags := flags.Options(flags.HelpFlag | flags.PassDoubleDash)
	parser := flags.NewNamedParser(appName, parserFlags)
	parser.AddGroup("Global Options", "", cfg)
	parser.AddCommand("insecureimport",
		"Insecurely import bulk block data from bootstrap.dat",
		"Insecurely import bulk block data from bootstrap.dat.  "+
			"WARNING: This is NOT secure because it does NOT "+
			"verify chain rules.  It is only provided for testing "+
			"purposes.", &importCfg)
	parser.AddCommand("loadheaders",
		"Time how long to load headers for all blocks in the database",
		"", &headersCfg)
	parser.AddCommand("fetchblock",
		"Fetch the specific block hash from the database", "",
		&fetchBlockCfg)
	parser.AddCommand("fetchblockregion",
		"Fetch the specified block region from the database", "",
		&blockRegionCfg)

	// Parse command line and invoke the Execute function for the specified
	// command.
	if _, err := parser.Parse(); err != nil {
		if e, ok := err.(*flags.Error); ok && e.Type == flags.ErrHelp {
			parser.WriteHelp(os.Stderr)
		} else {
			log.Error(err)
		}

		return err
	}

	return nil
}

// setLogLevel sets the logging level for provided subsystem.  Invalid
// subsystems are ignored.  Uninitialized subsystems are dynamically created as
// needed.
func setLogLevel(subsystemID string, logLevel string) {
	// Ignore invalid subsystems.
	logger, ok := subsystemLoggers[subsystemID]
	if !ok {
		return
	}

	// Default to info if the log level is invalid.
	level, ok := btclog.LogLevelFromString(logLevel)
	if !ok {
		level = btclog.InfoLvl
	}

	// Create new logger for the subsystem if needed.
	if logger == btclog.Disabled {
		logger = btclog.NewSubsystemLogger(backendLog, subsystemID+": ")
		useLogger(subsystemID, logger)
	}
	logger.SetLevel(level)
}

func main() {
	cfg := config{
		DbType:  "leveldb",
		DataDir: defaultDataDir,
	}
	parser := flags.NewParser(&cfg, flags.Default)
	_, err := parser.Parse()
	if err != nil {
		if e, ok := err.(*flags.Error); !ok || e.Type != flags.ErrHelp {
			parser.WriteHelp(os.Stderr)
		}
		return
	}

	backendLogger := btclog.NewDefaultBackendLogger()
	defer backendLogger.Flush()
	log = btclog.NewSubsystemLogger(backendLogger, "")
	database.UseLogger(log)

	// Multiple networks can't be selected simultaneously.
	funcName := "main"
	numNets := 0
	// Count number of network flags passed; assign active network params
	// while we're at it
	if cfg.TestNet3 {
		numNets++
		activeNetParams = &chaincfg.TestNet3Params
	}
	if cfg.RegressionTest {
		numNets++
		activeNetParams = &chaincfg.RegressionNetParams
	}
	if cfg.SimNet {
		numNets++
		activeNetParams = &chaincfg.SimNetParams
	}
	if numNets > 1 {
		str := "%s: The testnet, regtest, and simnet params can't be " +
			"used together -- choose one of the three"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		parser.WriteHelp(os.Stderr)
		return
	}
	cfg.DataDir = filepath.Join(cfg.DataDir, netName(activeNetParams))

	blockDbNamePrefix := "blocks"
	dbName := blockDbNamePrefix + "_" + cfg.DbType
	if cfg.DbType == "sqlite" {
		dbName = dbName + ".db"
	}
	dbPath := filepath.Join(cfg.DataDir, dbName)

	log.Infof("loading db")
	db, err := database.OpenDB(cfg.DbType, dbPath)
	if err != nil {
		log.Warnf("db open failed: %v", err)
		return
	}
	defer db.Close()
	log.Infof("db load complete")

	_, height, err := db.NewestSha()
	log.Infof("loaded block height %v", height)

	sha, err := getSha(db, cfg.ShaString)
	if err != nil {
		log.Infof("Invalid block hash %v", cfg.ShaString)
		return
	}

	err = db.DropAfterBlockBySha(&sha)
	if err != nil {
		log.Warnf("failed %v", err)
	}

}

func main() {
	end := int64(-1)

	cfg := config{
		DbType:  "leveldb",
		DataDir: defaultDataDir,
	}
	parser := flags.NewParser(&cfg, flags.Default)
	_, err := parser.Parse()
	if err != nil {
		if e, ok := err.(*flags.Error); !ok || e.Type != flags.ErrHelp {
			parser.WriteHelp(os.Stderr)
		}
		return
	}

	backendLogger := btclog.NewDefaultBackendLogger()
	defer backendLogger.Flush()
	log = btclog.NewSubsystemLogger(backendLogger, "")
	database.UseLogger(log)

	// Multiple networks can't be selected simultaneously.
	funcName := "main"
	numNets := 0
	// Count number of network flags passed; assign active network params
	// while we're at it
	if cfg.TestNet {
		numNets++
		activeNetParams = &chaincfg.TestNetParams
	}
	if cfg.SimNet {
		numNets++
		activeNetParams = &chaincfg.SimNetParams
	}
	if numNets > 1 {
		str := "%s: The testnet, regtest, and simnet params can't be " +
			"used together -- choose one of the three"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		parser.WriteHelp(os.Stderr)
		return
	}
	cfg.DataDir = filepath.Join(cfg.DataDir, netName(activeNetParams))

	blockDbNamePrefix := "blocks"
	dbName := blockDbNamePrefix + "_" + cfg.DbType
	if cfg.DbType == "sqlite" {
		dbName = dbName + ".db"
	}
	dbPath := filepath.Join(cfg.DataDir, dbName)

	log.Infof("loading db %v", cfg.DbType)
	database, err := database.OpenDB(cfg.DbType, dbPath)
	if err != nil {
		log.Warnf("db open failed: %v", err)
		return
	}
	defer database.Close()
	log.Infof("db load complete")

	height, err := getHeight(database, cfg.ShaString)
	if err != nil {
		log.Infof("Invalid block %v", cfg.ShaString)
		return
	}
	if cfg.EShaString != "" {
		end, err = getHeight(database, cfg.EShaString)
		if err != nil {
			log.Infof("Invalid end block %v", cfg.EShaString)
			return
		}
	} else {
		end = height + 1
	}

	log.Infof("height %v end %v", height, end)

	var fo io.WriteCloser
	if cfg.OutFile != "" {
		fo, err = os.Create(cfg.OutFile)
		if err != nil {
			log.Warnf("failed to open file %v, err %v", cfg.OutFile, err)
		}
		defer func() {
			if err := fo.Close(); err != nil {
				log.Warn("failed to close file %v %v", cfg.OutFile, err)
			}
		}()
	}

	for ; height < end; height++ {
		if cfg.Progress && height%int64(1) == 0 {
			log.Infof("Processing block %v", height)
		}
		err = DumpBlock(database, height, fo, cfg.RawBlock, cfg.FmtBlock, cfg.ShowTx)
		if err != nil {
			break
		}
	}
	if cfg.Progress {
//.........这里部分代码省略.........