config.go

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//版权所有（c）2013-2017 BTCSuite开发者
//此源代码的使用由ISC控制
//可以在许可文件中找到的许可证。

package main

import (
	"bufio"
	"crypto/rand"
	"encoding/base64"
	"errors"
	"fmt"
	"io"
	"net"
	"os"
	"path/filepath"
	"runtime"
	"sort"
	"strconv"
	"strings"
	"time"

	"github.com/btcsuite/btcd/blockchain"
	"github.com/btcsuite/btcd/chaincfg"
	"github.com/btcsuite/btcd/chaincfg/chainhash"
	"github.com/btcsuite/btcd/connmgr"
	"github.com/btcsuite/btcd/database"
	_ "github.com/btcsuite/btcd/database/ffldb"
	"github.com/btcsuite/btcd/mempool"
	"github.com/btcsuite/btcd/peer"
	"github.com/btcsuite/btcutil"
	"github.com/btcsuite/go-socks/socks"
	flags "github.com/jessevdk/go-flags"
)

const (
	defaultConfigFilename        = "btcd.conf"
	defaultDataDirname           = "data"
	defaultLogLevel              = "info"
	defaultLogDirname            = "logs"
	defaultLogFilename           = "btcd.log"
	defaultMaxPeers              = 125
	defaultBanDuration           = time.Hour * 24
	defaultBanThreshold          = 100
	defaultConnectTimeout        = time.Second * 30
	defaultMaxRPCClients         = 10
	defaultMaxRPCWebsockets      = 25
	defaultMaxRPCConcurrentReqs  = 20
	defaultDbType                = "ffldb"
	defaultFreeTxRelayLimit      = 15.0
	defaultTrickleInterval       = peer.DefaultTrickleInterval
	defaultBlockMinSize          = 0
	defaultBlockMaxSize          = 750000
	defaultBlockMinWeight        = 0
	defaultBlockMaxWeight        = 3000000
	blockMaxSizeMin              = 1000
	blockMaxSizeMax              = blockchain.MaxBlockBaseSize - 1000
	blockMaxWeightMin            = 4000
	blockMaxWeightMax            = blockchain.MaxBlockWeight - 4000
	defaultGenerate              = false
	defaultMaxOrphanTransactions = 100
	defaultMaxOrphanTxSize       = 100000
	defaultSigCacheMaxSize       = 100000
	sampleConfigFilename         = "sample-btcd.conf"
	defaultTxIndex               = false
	defaultAddrIndex             = false
)

var (
	defaultHomeDir     = btcutil.AppDataDir("btcd", false)
	defaultConfigFile  = filepath.Join(defaultHomeDir, defaultConfigFilename)
	defaultDataDir     = filepath.Join(defaultHomeDir, defaultDataDirname)
	knownDbTypes       = database.SupportedDrivers()
	defaultRPCKeyFile  = filepath.Join(defaultHomeDir, "rpc.key")
	defaultRPCCertFile = filepath.Join(defaultHomeDir, "rpc.cert")
	defaultLogDir      = filepath.Join(defaultHomeDir, defaultLogDirname)
)

//runservicecommand仅在Windows上设置为实函数。它被使用
//解析和执行通过-s标志指定的服务命令。
var runServiceCommand func(string) error

//minint32是一个帮助函数，返回至少两个uint32。
//这样就避免了数学导入和强制转换为浮点。
func minUint32(a, b uint32) uint32 {
	if a < b {
		return a
	}
	return b
}

//config定义btcd的配置选项。
//
//有关配置加载过程的详细信息，请参阅loadconfig。
type config struct {
	ShowVersion          bool          `short:"V" long:"version" description:"Display version information and exit"`
	ConfigFile           string        `short:"C" long:"configfile" description:"Path to configuration file"`
	DataDir              string        `short:"b" long:"datadir" description:"Directory to store data"`
	LogDir               string        `long:"logdir" description:"Directory to log output."`
	AddPeers             []string      `short:"a" long:"addpeer" description:"Add a peer to connect with at startup"`
	ConnectPeers         []string      `long:"connect" description:"Connect only to the specified peers at startup"`
	DisableListen        bool          `long:"nolisten" description:"Disable listening for incoming connections -- NOTE: Listening is automatically disabled if the --connect or --proxy options are used without also specifying listen interfaces via --listen"`
	Listeners            []string      `long:"listen" description:"Add an interface/port to listen for connections (default all interfaces port: 8333, testnet: 18333)"`
	MaxPeers             int           `long:"maxpeers" description:"Max number of inbound and outbound peers"`
	DisableBanning       bool          `long:"nobanning" description:"Disable banning of misbehaving peers"`
	BanDuration          time.Duration `long:"banduration" description:"How long to ban misbehaving peers.  Valid time units are {s, m, h}.  Minimum 1 second"`
	BanThreshold         uint32        `long:"banthreshold" description:"Maximum allowed ban score before disconnecting and banning misbehaving peers."`
	Whitelists           []string      `long:"whitelist" description:"Add an IP network or IP that will not be banned. (eg. 192.168.1.0/24 or ::1)"`
	RPCUser              string        `short:"u" long:"rpcuser" description:"Username for RPC connections"`
	RPCPass              string        `short:"P" long:"rpcpass" default-mask:"-" description:"Password for RPC connections"`
	RPCLimitUser         string        `long:"rpclimituser" description:"Username for limited RPC connections"`
	RPCLimitPass         string        `long:"rpclimitpass" default-mask:"-" description:"Password for limited RPC connections"`
	RPCListeners         []string      `long:"rpclisten" description:"Add an interface/port to listen for RPC connections (default port: 8334, testnet: 18334)"`
	RPCCert              string        `long:"rpccert" description:"File containing the certificate file"`
	RPCKey               string        `long:"rpckey" description:"File containing the certificate key"`
	RPCMaxClients        int           `long:"rpcmaxclients" description:"Max number of RPC clients for standard connections"`
	RPCMaxWebsockets     int           `long:"rpcmaxwebsockets" description:"Max number of RPC websocket connections"`
	RPCMaxConcurrentReqs int           `long:"rpcmaxconcurrentreqs" description:"Max number of concurrent RPC requests that may be processed concurrently"`
	RPCQuirks            bool          `long:"rpcquirks" description:"Mirror some JSON-RPC quirks of Bitcoin Core -- NOTE: Discouraged unless interoperability issues need to be worked around"`
	DisableRPC           bool          `long:"norpc" description:"Disable built-in RPC server -- NOTE: The RPC server is disabled by default if no rpcuser/rpcpass or rpclimituser/rpclimitpass is specified"`
	DisableTLS           bool          `long:"notls" description:"Disable TLS for the RPC server -- NOTE: This is only allowed if the RPC server is bound to localhost"`
	DisableDNSSeed       bool          `long:"nodnsseed" description:"Disable DNS seeding for peers"`
	ExternalIPs          []string      `long:"externalip" description:"Add an ip to the list of local addresses we claim to listen on to peers"`
	Proxy                string        `long:"proxy" description:"Connect via SOCKS5 proxy (eg. 127.0.0.1:9050)"`
	ProxyUser            string        `long:"proxyuser" description:"Username for proxy server"`
	ProxyPass            string        `long:"proxypass" default-mask:"-" description:"Password for proxy server"`
	OnionProxy           string        `long:"onion" description:"Connect to tor hidden services via SOCKS5 proxy (eg. 127.0.0.1:9050)"`
	OnionProxyUser       string        `long:"onionuser" description:"Username for onion proxy server"`
	OnionProxyPass       string        `long:"onionpass" default-mask:"-" description:"Password for onion proxy server"`
	NoOnion              bool          `long:"noonion" description:"Disable connecting to tor hidden services"`
	TorIsolation         bool          `long:"torisolation" description:"Enable Tor stream isolation by randomizing user credentials for each connection."`
	TestNet3             bool          `long:"testnet" description:"Use the test network"`
	RegressionTest       bool          `long:"regtest" description:"Use the regression test network"`
	SimNet               bool          `long:"simnet" description:"Use the simulation test network"`
	AddCheckpoints       []string      `long:"addcheckpoint" description:"Add a custom checkpoint.  Format: '<height>:<hash>'"`
	DisableCheckpoints   bool          `long:"nocheckpoints" description:"Disable built-in checkpoints.  Don't do this unless you know what you're doing."`
	DbType               string        `long:"dbtype" description:"Database backend to use for the Block Chain"`
	Profile              string        `long:"profile" description:"Enable HTTP profiling on given port -- NOTE port must be between 1024 and 65536"`
	CPUProfile           string        `long:"cpuprofile" description:"Write CPU profile to the specified file"`
	DebugLevel           string        `short:"d" long:"debuglevel" description:"Logging level for all subsystems {trace, debug, info, warn, error, critical} -- You may also specify <subsystem>=<level>,<subsystem2>=<level>,... to set the log level for individual subsystems -- Use show to list available subsystems"`
	Upnp                 bool          `long:"upnp" description:"Use UPnP to map our listening port outside of NAT"`
	MinRelayTxFee        float64       `long:"minrelaytxfee" description:"The minimum transaction fee in BTC/kB to be considered a non-zero fee."`
	FreeTxRelayLimit     float64       `long:"limitfreerelay" description:"Limit relay of transactions with no transaction fee to the given amount in thousands of bytes per minute"`
	NoRelayPriority      bool          `long:"norelaypriority" description:"Do not require free or low-fee transactions to have high priority for relaying"`
	TrickleInterval      time.Duration `long:"trickleinterval" description:"Minimum time between attempts to send new inventory to a connected peer"`
	MaxOrphanTxs         int           `long:"maxorphantx" description:"Max number of orphan transactions to keep in memory"`
	Generate             bool          `long:"generate" description:"Generate (mine) bitcoins using the CPU"`
	MiningAddrs          []string      `long:"miningaddr" description:"Add the specified payment address to the list of addresses to use for generated blocks -- At least one address is required if the generate option is set"`
	BlockMinSize         uint32        `long:"blockminsize" description:"Mininum block size in bytes to be used when creating a block"`
	BlockMaxSize         uint32        `long:"blockmaxsize" description:"Maximum block size in bytes to be used when creating a block"`
	BlockMinWeight       uint32        `long:"blockminweight" description:"Mininum block weight to be used when creating a block"`
	BlockMaxWeight       uint32        `long:"blockmaxweight" description:"Maximum block weight to be used when creating a block"`
	BlockPrioritySize    uint32        `long:"blockprioritysize" description:"Size in bytes for high-priority/low-fee transactions when creating a block"`
	UserAgentComments    []string      `long:"uacomment" description:"Comment to add to the user agent -- See BIP 14 for more information."`
	NoPeerBloomFilters   bool          `long:"nopeerbloomfilters" description:"Disable bloom filtering support"`
	NoCFilters           bool          `long:"nocfilters" description:"Disable committed filtering (CF) support"`
	DropCfIndex          bool          `long:"dropcfindex" description:"Deletes the index used for committed filtering (CF) support from the database on start up and then exits."`
	SigCacheMaxSize      uint          `long:"sigcachemaxsize" description:"The maximum number of entries in the signature verification cache"`
	BlocksOnly           bool          `long:"blocksonly" description:"Do not accept transactions from remote peers."`
	TxIndex              bool          `long:"txindex" description:"Maintain a full hash-based transaction index which makes all transactions available via the getrawtransaction RPC"`
	DropTxIndex          bool          `long:"droptxindex" description:"Deletes the hash-based transaction index from the database on start up and then exits."`
	AddrIndex            bool          `long:"addrindex" description:"Maintain a full address-based transaction index which makes the searchrawtransactions RPC available"`
	DropAddrIndex        bool          `long:"dropaddrindex" description:"Deletes the address-based transaction index from the database on start up and then exits."`
	RelayNonStd          bool          `long:"relaynonstd" description:"Relay non-standard transactions regardless of the default settings for the active network."`
	RejectNonStd         bool          `long:"rejectnonstd" description:"Reject non-standard transactions regardless of the default settings for the active network."`
	lookup               func(string) ([]net.IP, error)
	oniondial            func(string, string, time.Duration) (net.Conn, error)
	dial                 func(string, string, time.Duration) (net.Conn, error)
	addCheckpoints       []chaincfg.Checkpoint
	miningAddrs          []btcutil.Address
	minRelayTxFee        btcutil.Amount
	whitelists           []*net.IPNet
}

//service options将守护进程的配置选项定义为上的服务
//窗户。
type serviceOptions struct {
	ServiceCommand string `short:"s" long:"service" description:"Service command {install, remove, start, stop}"`
}

//cleanandexpandpath扩展环境变量并在
//传递路径，清除结果并返回。
func cleanAndExpandPath(path string) string {
//将initial~扩展到操作系统特定的主目录。
	if strings.HasPrefix(path, "~") {
		homeDir := filepath.Dir(defaultHomeDir)
		path = strings.Replace(path, "~", homeDir, 1)
	}

//注意：os.expandenv不适用于Windows样式%variable%，
//但这些变量仍然可以通过posix样式的$variable进行扩展。
	return filepath.Clean(os.ExpandEnv(path))
}

//validLogLevel返回logLevel是否为有效的调试日志级别。
func validLogLevel(logLevel string) bool {
	switch logLevel {
	case "trace":
		fallthrough
	case "debug":
		fallthrough
	case "info":
		fallthrough
	case "warn":
		fallthrough
	case "error":
		fallthrough
	case "critical":
		return true
	}
	return false
}

//SupportedSubsystems返回受支持子系统的已排序切片
//日志记录目的。
func supportedSubsystems() []string {
//将子系统记录器映射键转换为切片。
	subsystems := make([]string, 0, len(subsystemLoggers))
	for subsysID := range subsystemLoggers {
		subsystems = append(subsystems, subsysID)
	}

//对子系统进行排序，以便稳定显示。
	sort.Strings(subsystems)
	return subsystems
}

//parsandsetdebuglevels尝试解析指定的调试级别并设置
//相应的水平。如果有任何错误
//无效。
func parseAndSetDebugLevels(debugLevel string) error {
//当指定的字符串没有任何delimter时，将其视为
//所有子系统的日志级别。
	if !strings.Contains(debugLevel, ",") && !strings.Contains(debugLevel, "=") {
//验证调试日志级别。
		if !validLogLevel(debugLevel) {
			str := "The specified debug level [%v] is invalid"
			return fmt.Errorf(str, debugLevel)
		}

//更改所有子系统的日志记录级别。
		setLogLevels(debugLevel)

		return nil
	}

//检测时将指定的字符串拆分为子系统/级别对
//发布并相应更新日志级别。
	for _, logLevelPair := range strings.Split(debugLevel, ",") {
		if !strings.Contains(logLevelPair, "=") {
			str := "The specified debug level contains an invalid " +
				"subsystem/level pair [%v]"
			return fmt.Errorf(str, logLevelPair)
		}

//提取指定的子系统和日志级别。
		fields := strings.Split(logLevelPair, "=")
		subsysID, logLevel := fields[0], fields[1]

//验证子系统。
		if _, exists := subsystemLoggers[subsysID]; !exists {
			str := "The specified subsystem [%v] is invalid -- " +
				"supported subsytems %v"
			return fmt.Errorf(str, subsysID, supportedSubsystems())
		}

//验证日志级别。
		if !validLogLevel(logLevel) {
			str := "The specified debug level [%v] is invalid"
			return fmt.Errorf(str, logLevel)
		}

		setLogLevel(subsysID, logLevel)
	}

	return nil
}

//validdbtype返回dbtype是否为受支持的数据库类型。
func validDbType(dbType string) bool {
	for _, knownType := range knownDbTypes {
		if dbType == knownType {
			return true
		}
	}

	return false
}

//removeduplicateAddresses返回一个新切片，其中包含所有重复项
//删除ADDR。
func removeDuplicateAddresses(addrs []string) []string {
	result := make([]string, 0, len(addrs))
	seen := map[string]struct{}{}
	for _, val := range addrs {
		if _, ok := seen[val]; !ok {
			result = append(result, val)
			seen[val] = struct{}{}
		}
	}
	return result
}

//normalizedAddress返回addr，并附加传递的默认端口if
//尚未指定端口。
func normalizeAddress(addr, defaultPort string) string {
	_, _, err := net.SplitHostPort(addr)
	if err != nil {
		return net.JoinHostPort(addr, defaultPort)
	}
	return addr
}

//normalizeadresss返回一个新切片，其中包含所有传递的对等地址
//使用给定的默认端口进行规范化，并删除所有重复项。
func normalizeAddresses(addrs []string, defaultPort string) []string {
	for i, addr := range addrs {
		addrs[i] = normalizeAddress(addr, defaultPort)
	}

	return removeDuplicateAddresses(addrs)
}

//newcheckpointfromstr以“<height>：<hash>”格式分析检查点。
func newCheckpointFromStr(checkpoint string) (chaincfg.Checkpoint, error) {
	parts := strings.Split(checkpoint, ":")
	if len(parts) != 2 {
		return chaincfg.Checkpoint{}, fmt.Errorf("unable to parse "+
			"checkpoint %q -- use the syntax <height>:<hash>",
			checkpoint)
	}

	height, err := strconv.ParseInt(parts[0], 10, 32)
	if err != nil {
		return chaincfg.Checkpoint{}, fmt.Errorf("unable to parse "+
			"checkpoint %q due to malformed height", checkpoint)
	}

	if len(parts[1]) == 0 {
		return chaincfg.Checkpoint{}, fmt.Errorf("unable to parse "+
			"checkpoint %q due to missing hash", checkpoint)
	}
	hash, err := chainhash.NewHashFromStr(parts[1])
	if err != nil {
		return chaincfg.Checkpoint{}, fmt.Errorf("unable to parse "+
			"checkpoint %q due to malformed hash", checkpoint)
	}

	return chaincfg.Checkpoint{
		Height: int32(height),
		Hash:   hash,
	}, nil
}

//ParseCheckpoints检查检查点字符串的有效语法
//（'<height>：<hash>'）并将其解析为chaincfg.checkpoint实例。
func parseCheckpoints(checkpointStrings []string) ([]chaincfg.Checkpoint, error) {
	if len(checkpointStrings) == 0 {
		return nil, nil
	}
	checkpoints := make([]chaincfg.Checkpoint, len(checkpointStrings))
	for i, cpString := range checkpointStrings {
		checkpoint, err := newCheckpointFromStr(cpString)
		if err != nil {
			return nil, err
		}
		checkpoints[i] = checkpoint
	}
	return checkpoints, nil
}

//filesexists报告命名文件或目录是否存在。
func fileExists(name string) bool {
	if _, err := os.Stat(name); err != nil {
		if os.IsNotExist(err) {
			return false
		}
	}
	return true
}

//NewConfigParser返回新的命令行标志分析器。
func newConfigParser(cfg *config, so *serviceOptions, options flags.Options) *flags.Parser {
	parser := flags.NewParser(cfg, options)
	if runtime.GOOS == "windows" {
		parser.AddGroup("Service Options", "Service Options", so)
	}
	return parser
}

//loadconfig使用配置文件和命令初始化并分析配置
//行选项。
//
//配置过程如下：
//1）从具有健全设置的默认配置开始
//2）预分析命令行以检查备用配置文件
//3）使用任何指定选项加载配置文件覆盖默认值
//4）解析cli选项并覆盖/添加任何指定选项
//
//以上结果导致btcd在没有任何配置设置的情况下正常工作。
//同时仍允许用户使用配置文件和
//命令行选项。命令行选项始终优先。
func loadConfig() (*config, []string, error) {
//默认配置。
	cfg := config{
		ConfigFile:           defaultConfigFile,
		DebugLevel:           defaultLogLevel,
		MaxPeers:             defaultMaxPeers,
		BanDuration:          defaultBanDuration,
		BanThreshold:         defaultBanThreshold,
		RPCMaxClients:        defaultMaxRPCClients,
		RPCMaxWebsockets:     defaultMaxRPCWebsockets,
		RPCMaxConcurrentReqs: defaultMaxRPCConcurrentReqs,
		DataDir:              defaultDataDir,
		LogDir:               defaultLogDir,
		DbType:               defaultDbType,
		RPCKey:               defaultRPCKeyFile,
		RPCCert:              defaultRPCCertFile,
		MinRelayTxFee:        mempool.DefaultMinRelayTxFee.ToBTC(),
		FreeTxRelayLimit:     defaultFreeTxRelayLimit,
		TrickleInterval:      defaultTrickleInterval,
		BlockMinSize:         defaultBlockMinSize,
		BlockMaxSize:         defaultBlockMaxSize,
		BlockMinWeight:       defaultBlockMinWeight,
		BlockMaxWeight:       defaultBlockMaxWeight,
		BlockPrioritySize:    mempool.DefaultBlockPrioritySize,
		MaxOrphanTxs:         defaultMaxOrphanTransactions,
		SigCacheMaxSize:      defaultSigCacheMaxSize,
		Generate:             defaultGenerate,
		TxIndex:              defaultTxIndex,
		AddrIndex:            defaultAddrIndex,
	}

//仅在Windows上添加的服务选项。
	serviceOpts := serviceOptions{}

//预分析命令行选项，以查看是否有其他配置
//指定了文件或版本标志。除了
//此处可以忽略帮助消息错误，因为它们将被
//下面的最终分析。
	preCfg := cfg
	preParser := newConfigParser(&preCfg, &serviceOpts, flags.HelpFlag)
	_, err := preParser.Parse()
	if err != nil {
		if e, ok := err.(*flags.Error); ok && e.Type == flags.ErrHelp {
			fmt.Fprintln(os.Stderr, err)
			return nil, nil, err
		}
	}

//显示版本，如果指定了版本标志，则退出。
	appName := filepath.Base(os.Args[0])
	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
	usageMessage := fmt.Sprintf("Use %s -h to show usage", appName)
	if preCfg.ShowVersion {
		fmt.Println(appName, "version", version())
		os.Exit(0)
	}

//执行服务命令并退出（如果指定）。无效服务
//命令显示适当的错误。仅在Windows上运行
//如果不在Windows上，runservicecommand函数将为nil。
	if serviceOpts.ServiceCommand != "" && runServiceCommand != nil {
		err := runServiceCommand(serviceOpts.ServiceCommand)
		if err != nil {
			fmt.Fprintln(os.Stderr, err)
		}
		os.Exit(0)
	}

//从文件加载附加配置。
	var configFileError error
	parser := newConfigParser(&cfg, &serviceOpts, flags.Default)
	if !(preCfg.RegressionTest || preCfg.SimNet) || preCfg.ConfigFile !=
		defaultConfigFile {

		if _, err := os.Stat(preCfg.ConfigFile); os.IsNotExist(err) {
			err := createDefaultConfigFile(preCfg.ConfigFile)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Error creating a "+
					"default config file: %v\n", err)
			}
		}

		err := flags.NewIniParser(parser).ParseFile(preCfg.ConfigFile)
		if err != nil {
			if _, ok := err.(*os.PathError); !ok {
				fmt.Fprintf(os.Stderr, "Error parsing config "+
					"file: %v\n", err)
				fmt.Fprintln(os.Stderr, usageMessage)
				return nil, nil, err
			}
			configFileError = err
		}
	}

//在回归测试模式下，不要从配置文件添加对等。
	if preCfg.RegressionTest && len(cfg.AddPeers) > 0 {
		cfg.AddPeers = nil
	}

//再次分析命令行选项以确保它们优先。
	remainingArgs, err := parser.Parse()
	if err != nil {
		if e, ok := err.(*flags.Error); !ok || e.Type != flags.ErrHelp {
			fmt.Fprintln(os.Stderr, usageMessage)
		}
		return nil, nil, err
	}

//如果主目录不存在，则创建它。
	funcName := "loadConfig"
	err = os.MkdirAll(defaultHomeDir, 0700)
	if err != nil {
//如果是因为符号链接
//链接到不存在的目录（可能是因为
//它没有安装）。
		if e, ok := err.(*os.PathError); ok && os.IsExist(err) {
			if link, lerr := os.Readlink(e.Path); lerr == nil {
				str := "is symlink %s -> %s mounted?"
				err = fmt.Errorf(str, e.Path, link)
			}
		}

		str := "%s: Failed to create home directory: %v"
		err := fmt.Errorf(str, funcName, err)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

//无法同时选择多个网络。
	numNets := 0
//计数传递的网络标志数；分配活动的网络参数
//当我们在那里的时候
	if cfg.TestNet3 {
		numNets++
		activeNetParams = &testNet3Params
	}
	if cfg.RegressionTest {
		numNets++
		activeNetParams = &regressionNetParams
	}
	if cfg.SimNet {
		numNets++
//同时禁用模拟测试网络上的DNS种子设定。
		activeNetParams = &simNetParams
		cfg.DisableDNSSeed = true
	}
	if numNets > 1 {
		str := "%s: The testnet, regtest, segnet, and simnet params " +
			"can't be used together -- choose one of the four"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//设置中继非标准事务的默认策略
//根据活动网络的默认值。集合
//配置值优先于
//选定的网络。
	relayNonStd := activeNetParams.RelayNonStdTxs
	switch {
	case cfg.RelayNonStd && cfg.RejectNonStd:
		str := "%s: rejectnonstd and relaynonstd cannot be used " +
			"together -- choose only one"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	case cfg.RejectNonStd:
		relayNonStd = false
	case cfg.RelayNonStd:
		relayNonStd = true
	}
	cfg.RelayNonStd = relayNonStd

//将网络类型附加到数据目录中，使其具有“名称空间”
//每个网络。除了块数据库，还有其他
//保存到磁盘上的数据块，如地址管理器状态。
//所有数据都是特定于一个网络的，因此名称间隔数据目录
//意味着每个单独的序列化数据不必
//担心更改每个网络的名称等等。
	cfg.DataDir = cleanAndExpandPath(cfg.DataDir)
	cfg.DataDir = filepath.Join(cfg.DataDir, netName(activeNetParams))

//将网络类型附加到日志目录中，使其具有“名称空间”
//与数据目录的方式相同。
	cfg.LogDir = cleanAndExpandPath(cfg.LogDir)
	cfg.LogDir = filepath.Join(cfg.LogDir, netName(activeNetParams))

//列出支持的子系统并退出的特殊显示命令。
	if cfg.DebugLevel == "show" {
		fmt.Println("Supported subsystems", supportedSubsystems())
		os.Exit(0)
	}

//初始化日志旋转。日志旋转初始化后，
//可以使用记录器变量。
	initLogRotator(filepath.Join(cfg.LogDir, defaultLogFilename))

//分析、验证和设置调试日志级别。
	if err := parseAndSetDebugLevels(cfg.DebugLevel); err != nil {
		err := fmt.Errorf("%s: %v", funcName, err.Error())
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//验证数据库类型。
	if !validDbType(cfg.DbType) {
		str := "%s: The specified database type [%v] is invalid -- " +
			"supported types %v"
		err := fmt.Errorf(str, funcName, cfg.DbType, knownDbTypes)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//验证配置文件端口号
	if cfg.Profile != "" {
		profilePort, err := strconv.Atoi(cfg.Profile)
		if err != nil || profilePort < 1024 || profilePort > 65535 {
			str := "%s: The profile port must be between 1024 and 65535"
			err := fmt.Errorf(str, funcName)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}
	}

//禁止时间太短。
	if cfg.BanDuration < time.Second {
		str := "%s: The banduration option may not be less than 1s -- parsed [%v]"
		err := fmt.Errorf(str, funcName, cfg.BanDuration)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//验证任何给定的白名单IP地址和网络。
	if len(cfg.Whitelists) > 0 {
		var ip net.IP
		cfg.whitelists = make([]*net.IPNet, 0, len(cfg.Whitelists))

		for _, addr := range cfg.Whitelists {
			_, ipnet, err := net.ParseCIDR(addr)
			if err != nil {
				ip = net.ParseIP(addr)
				if ip == nil {
					str := "%s: The whitelist value of '%s' is invalid"
					err = fmt.Errorf(str, funcName, addr)
					fmt.Fprintln(os.Stderr, err)
					fmt.Fprintln(os.Stderr, usageMessage)
					return nil, nil, err
				}
				var bits int
				if ip.To4() == nil {
//IPv6
					bits = 128
				} else {
					bits = 32
				}
				ipnet = &net.IPNet{
					IP:   ip,
					Mask: net.CIDRMask(bits, bits),
				}
			}
			cfg.whitelists = append(cfg.whitelists, ipnet)
		}
	}

//--addpeer和--connect不要混合使用。
	if len(cfg.AddPeers) > 0 && len(cfg.ConnectPeers) > 0 {
		str := "%s: the --addpeer and --connect options can not be " +
			"mixed"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//--proxy或--connect without--listen禁用侦听。
	if (cfg.Proxy != "" || len(cfg.ConnectPeers) > 0) &&
		len(cfg.Listeners) == 0 {
		cfg.DisableListen = true
	}

//连接意味着没有DNS种子设定。
	if len(cfg.ConnectPeers) > 0 {
		cfg.DisableDNSSeed = true
	}

//如果未指定，则添加默认侦听器。默认值
//侦听器是网络侦听端口上的所有地址
//我们要接通。
	if len(cfg.Listeners) == 0 {
		cfg.Listeners = []string{
			net.JoinHostPort("", activeNetParams.DefaultPort),
		}
	}

//检查以确保受限用户和管理员用户没有相同的用户名
	if cfg.RPCUser == cfg.RPCLimitUser && cfg.RPCUser != "" {
		str := "%s: --rpcuser and --rpclimituser must not specify the " +
			"same username"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//检查以确保受限用户和管理员用户没有相同的密码
	if cfg.RPCPass == cfg.RPCLimitPass && cfg.RPCPass != "" {
		str := "%s: --rpcpass and --rpclimitpass must not specify the " +
			"same password"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//如果未提供用户名或密码，则禁用RPC服务器。
	if (cfg.RPCUser == "" || cfg.RPCPass == "") &&
		(cfg.RPCLimitUser == "" || cfg.RPCLimitPass == "") {
		cfg.DisableRPC = true
	}

	if cfg.DisableRPC {
		btcdLog.Infof("RPC service is disabled")
	}

//默认的RPC只在本地主机上侦听。
	if !cfg.DisableRPC && len(cfg.RPCListeners) == 0 {
		addrs, err := net.LookupHost("localhost")
		if err != nil {
			return nil, nil, err
		}
		cfg.RPCListeners = make([]string, 0, len(addrs))
		for _, addr := range addrs {
			addr = net.JoinHostPort(addr, activeNetParams.rpcPort)
			cfg.RPCListeners = append(cfg.RPCListeners, addr)
		}
	}

	if cfg.RPCMaxConcurrentReqs < 0 {
		str := "%s: The rpcmaxwebsocketconcurrentrequests option may " +
			"not be less than 0 -- parsed [%d]"
		err := fmt.Errorf(str, funcName, cfg.RPCMaxConcurrentReqs)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//验证minrelaytxfee。
	cfg.minRelayTxFee, err = btcutil.NewAmount(cfg.MinRelayTxFee)
	if err != nil {
		str := "%s: invalid minrelaytxfee: %v"
		err := fmt.Errorf(str, funcName, err)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//将最大块大小限制为正常值。
	if cfg.BlockMaxSize < blockMaxSizeMin || cfg.BlockMaxSize >
		blockMaxSizeMax {

		str := "%s: The blockmaxsize option must be in between %d " +
			"and %d -- parsed [%d]"
		err := fmt.Errorf(str, funcName, blockMaxSizeMin,
			blockMaxSizeMax, cfg.BlockMaxSize)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//将最大块重量限制为正常值。
	if cfg.BlockMaxWeight < blockMaxWeightMin ||
		cfg.BlockMaxWeight > blockMaxWeightMax {

		str := "%s: The blockmaxweight option must be in between %d " +
			"and %d -- parsed [%d]"
		err := fmt.Errorf(str, funcName, blockMaxWeightMin,
			blockMaxWeightMax, cfg.BlockMaxWeight)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//将最大孤立计数限制为正常值。
	if cfg.MaxOrphanTxs < 0 {
		str := "%s: The maxorphantx option may not be less than 0 " +
			"-- parsed [%d]"
		err := fmt.Errorf(str, funcName, cfg.MaxOrphanTxs)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//将块优先级和最小块大小限制为最大块大小。
	cfg.BlockPrioritySize = minUint32(cfg.BlockPrioritySize, cfg.BlockMaxSize)
	cfg.BlockMinSize = minUint32(cfg.BlockMinSize, cfg.BlockMaxSize)
	cfg.BlockMinWeight = minUint32(cfg.BlockMinWeight, cfg.BlockMaxWeight)

	switch {
//如果未设置最大块大小，但最大权重为，则我们将
//将最大块大小的限制设置为安全限制，以便重量
//优先。
	case cfg.BlockMaxSize == defaultBlockMaxSize &&
		cfg.BlockMaxWeight != defaultBlockMaxWeight:

		cfg.BlockMaxSize = blockchain.MaxBlockBaseSize - 1000

//如果未设置最大块重，但块大小为，则我们将
//根据最大块大小值相应缩放设定的权重。
	case cfg.BlockMaxSize != defaultBlockMaxSize &&
		cfg.BlockMaxWeight == defaultBlockMaxWeight:

		cfg.BlockMaxWeight = cfg.BlockMaxSize * blockchain.WitnessScaleFactor
	}

//在用户代理注释中查找非法字符。
	for _, uaComment := range cfg.UserAgentComments {
		if strings.ContainsAny(uaComment, "/:()") {
			err := fmt.Errorf("%s: The following characters must not "+
				"appear in user agent comments: '/', ':', '(', ')'",
				funcName)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}
	}

//--txtindex和--droptxindex不混合。
	if cfg.TxIndex && cfg.DropTxIndex {
		err := fmt.Errorf("%s: the --txindex and --droptxindex "+
			"options may  not be activated at the same time",
			funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//--addrindex和--dropaddrindex不混合。
	if cfg.AddrIndex && cfg.DropAddrIndex {
		err := fmt.Errorf("%s: the --addrindex and --dropaddrindex "+
			"options may not be activated at the same time",
			funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//--addrindex和--droptxindex不混合。
	if cfg.AddrIndex && cfg.DropTxIndex {
		err := fmt.Errorf("%s: the --addrindex and --droptxindex "+
			"options may not be activated at the same time "+
			"because the address index relies on the transaction "+
			"index",
			funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//检查挖掘地址是否有效并保存已分析的版本。
	cfg.miningAddrs = make([]btcutil.Address, 0, len(cfg.MiningAddrs))
	for _, strAddr := range cfg.MiningAddrs {
		addr, err := btcutil.DecodeAddress(strAddr, activeNetParams.Params)
		if err != nil {
			str := "%s: mining address '%s' failed to decode: %v"
			err := fmt.Errorf(str, funcName, strAddr, err)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}
		if !addr.IsForNet(activeNetParams.Params) {
			str := "%s: mining address '%s' is on the wrong network"
			err := fmt.Errorf(str, funcName, strAddr)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}
		cfg.miningAddrs = append(cfg.miningAddrs, addr)
	}

//当generate标志为
//集合。
	if cfg.Generate && len(cfg.MiningAddrs) == 0 {
		str := "%s: the generate flag is set, but there are no mining " +
			"addresses specified "
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//如果需要，将默认端口添加到所有侦听器地址并删除
//重复地址。
	cfg.Listeners = normalizeAddresses(cfg.Listeners,
		activeNetParams.DefaultPort)

//如果需要，将默认端口添加到所有RPC侦听器地址，然后删除
//重复地址。
	cfg.RPCListeners = normalizeAddresses(cfg.RPCListeners,
		activeNetParams.rpcPort)

//Only allow TLS to be disabled if the RPC is bound to localhost
//地址。
	if !cfg.DisableRPC && cfg.DisableTLS {
		allowedTLSListeners := map[string]struct{}{
			"localhost": {},
			"127.0.0.1": {},
			"::1":       {},
		}
		for _, addr := range cfg.RPCListeners {
			host, _, err := net.SplitHostPort(addr)
			if err != nil {
				str := "%s: RPC listen interface '%s' is " +
					"invalid: %v"
				err := fmt.Errorf(str, funcName, addr, err)
				fmt.Fprintln(os.Stderr, err)
				fmt.Fprintln(os.Stderr, usageMessage)
				return nil, nil, err
			}
			if _, ok := allowedTLSListeners[host]; !ok {
				str := "%s: the --notls option may not be used " +
					"when binding RPC to non localhost " +
					"addresses: %s"
				err := fmt.Errorf(str, funcName, addr)
				fmt.Fprintln(os.Stderr, err)
				fmt.Fprintln(os.Stderr, usageMessage)
				return nil, nil, err
			}
		}
	}

//如果需要，将默认端口添加到所有添加的对等地址，然后删除
//重复地址。
	cfg.AddPeers = normalizeAddresses(cfg.AddPeers,
		activeNetParams.DefaultPort)
	cfg.ConnectPeers = normalizeAddresses(cfg.ConnectPeers,
		activeNetParams.DefaultPort)

//——诺尼翁和——洋葱不能混合。
	if cfg.NoOnion && cfg.OnionProxy != "" {
		err := fmt.Errorf("%s: the --noonion and --onion options may "+
			"not be activated at the same time", funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//检查检查检查点是否有语法错误。
	cfg.addCheckpoints, err = parseCheckpoints(cfg.AddCheckpoints)
	if err != nil {
		str := "%s: Error parsing checkpoints: %v"
		err := fmt.Errorf(str, funcName, err)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//Tor stream isolation requires either proxy or onion proxy to be set.
	if cfg.TorIsolation && cfg.Proxy == "" && cfg.OnionProxy == "" {
		str := "%s: Tor stream isolation requires either proxy or " +
			"onionproxy to be set"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

//根据设置拨号和DNS解析（查找）功能
//指定的选项。默认值是使用标准
//NET.DialTimeout函数以及系统DNS解析程序。当A
//已指定代理，拨号功能设置为特定于代理
//拨号功能和查找设置为使用TOR（除非-nooion是
//在这种情况下指定使用系统DNS解析程序）。
	cfg.dial = net.DialTimeout
	cfg.lookup = net.LookupIP
	if cfg.Proxy != "" {
		_, _, err := net.SplitHostPort(cfg.Proxy)
		if err != nil {
			str := "%s: Proxy address '%s' is invalid: %v"
			err := fmt.Errorf(str, funcName, cfg.Proxy, err)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}

//Tor隔离标志表示代理凭据将被重写
//除非在这种情况下还配置了洋葱代理
//那个将被覆盖。
		torIsolation := false
		if cfg.TorIsolation && cfg.OnionProxy == "" &&
			(cfg.ProxyUser != "" || cfg.ProxyPass != "") {

			torIsolation = true
			fmt.Fprintln(os.Stderr, "Tor isolation set -- "+
				"overriding specified proxy user credentials")
		}

		proxy := &socks.Proxy{
			Addr:         cfg.Proxy,
			Username:     cfg.ProxyUser,
			Password:     cfg.ProxyPass,
			TorIsolation: torIsolation,
		}
		cfg.dial = proxy.DialTimeout

//将代理视为TOR并通过它执行DNS解析
//除非设置了--noonion标志或
//配置了洋葱特定的代理。
		if !cfg.NoOnion && cfg.OnionProxy == "" {
			cfg.lookup = func(host string) ([]net.IP, error) {
				return connmgr.TorLookupIP(host, cfg.Proxy)
			}
		}
	}

//根据指定的选项设置洋葱地址拨号功能。
//默认为使用上面选择的相同拨号功能。然而，
//当指定了洋葱特定的代理时，洋葱地址拨号
//函数设置为在离开时使用特定于洋葱的代理
//正常拨号功能，如上所选。这允许。洋葱地址
//要通过不同于正常流量的代理路由的流量。
	if cfg.OnionProxy != "" {
		_, _, err := net.SplitHostPort(cfg.OnionProxy)
		if err != nil {
			str := "%s: Onion proxy address '%s' is invalid: %v"
			err := fmt.Errorf(str, funcName, cfg.OnionProxy, err)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}

//Tor隔离标志表示洋葱代理凭据将
//重写的
		if cfg.TorIsolation &&
			(cfg.OnionProxyUser != "" || cfg.OnionProxyPass != "") {
			fmt.Fprintln(os.Stderr, "Tor isolation set -- "+
				"overriding specified onionproxy user "+
				"credentials ")
		}

		cfg.oniondial = func(network, addr string, timeout time.Duration) (net.Conn, error) {
			proxy := &socks.Proxy{
				Addr:         cfg.OnionProxy,
				Username:     cfg.OnionProxyUser,
				Password:     cfg.OnionProxyPass,
				TorIsolation: cfg.TorIsolation,
			}
			return proxy.DialTimeout(network, addr, timeout)
		}

//在网桥模式下配置时（洋葱和代理都是
//配置），这意味着由--proxy配置的代理是
//不是Tor代理，因此重写DNS解析以使用
//洋葱专用代理。
		if cfg.Proxy != "" {
			cfg.lookup = func(host string) ([]net.IP, error) {
				return connmgr.TorLookupIP(host, cfg.OnionProxy)
			}
		}
	} else {
		cfg.oniondial = cfg.dial
	}

//指定--noonion表示洋葱地址拨号函数导致
//一个错误。
	if cfg.NoOnion {
		cfg.oniondial = func(a, b string, t time.Duration) (net.Conn, error) {
			return nil, errors.New("tor has been disabled")
		}
	}

//只有在所有其他配置为
//完成。This prevents the warning on help messages and invalid
//选项。注意，这应该在退货前直接进行。
	if configFileError != nil {
		btcdLog.Warnf("%v", configFileError)
	}

	return &cfg, remainingArgs, nil
}

//createfaultconfig将文件sample-btcd.conf复制到给定的目标路径，
//并用一些随机生成的RPC用户名和密码填充它。
func createDefaultConfigFile(destinationPath string) error {
//如果目标目录不存在，则创建该目录
	err := os.MkdirAll(filepath.Dir(destinationPath), 0700)
	if err != nil {
		return err
	}

//我们假设示例配置文件路径与二进制文件相同
	path, err := filepath.Abs(filepath.Dir(os.Args[0]))
	if err != nil {
		return err
	}
	sampleConfigPath := filepath.Join(path, sampleConfigFilename)

//我们生成一个随机的用户和密码
	randomBytes := make([]byte, 20)
	_, err = rand.Read(randomBytes)
	if err != nil {
		return err
	}
	generatedRPCUser := base64.StdEncoding.EncodeToString(randomBytes)

	_, err = rand.Read(randomBytes)
	if err != nil {
		return err
	}
	generatedRPCPass := base64.StdEncoding.EncodeToString(randomBytes)

	src, err := os.Open(sampleConfigPath)
	if err != nil {
		return err
	}
	defer src.Close()

	dest, err := os.OpenFile(destinationPath,
		os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
	if err != nil {
		return err
	}
	defer dest.Close()

//我们将示例配置文件中的每一行复制到目标，
//only replacing the two lines for rpcuser and rpcpass
	reader := bufio.NewReader(src)
	for err != io.EOF {
		var line string
		line, err = reader.ReadString('\n')
		if err != nil && err != io.EOF {
			return err
		}

		if strings.Contains(line, "rpcuser=") {
			line = "rpcuser=" + generatedRPCUser + "\n"
		} else if strings.Contains(line, "rpcpass=") {
			line = "rpcpass=" + generatedRPCPass + "\n"
		}

		if _, err := dest.WriteString(line); err != nil {
			return err
		}
	}

	return nil
}

//btcddial使用适当的
//拨号功能取决于地址和配置选项。为了
//example, .onion addresses will be dialed using the onion specific proxy if
//指定了一个，但将使用普通拨号功能（即
//是否可以使用代理）。
func btcdDial(addr net.Addr) (net.Conn, error) {
	if strings.Contains(addr.String(), ".onion:") {
		return cfg.oniondial(addr.Network(), addr.String(),
			defaultConnectTimeout)
	}
	return cfg.dial(addr.Network(), addr.String(), defaultConnectTimeout)
}

//btcdLookup使用正确的DNS查找解析给定主机的IP
//功能取决于配置选项。例如，地址将
//在指定--proxy标志时使用tor解析，除非--noonion
//还指定了正常情况下DNS解析器的使用情况。
//
//任何解析Tor地址（.洋葱）的尝试都将返回一个错误，因为它们
//不打算在TOR代理之外解决。
func btcdLookup(host string) ([]net.IP, error) {
	if strings.HasSuffix(host, ".onion") {
		return nil, fmt.Errorf("attempt to resolve tor address %s", host)
	}

	return cfg.lookup(host)
}