github.com/linapex/ethereum-dpos-chinese@v0.0.0-20190316121959-b78b3a4a1ece/cmd/geth/chaincmd.go

//<developer>
//    <name>linapex 曹一峰</name>
//    <email>linapex@163.com</email>
//    <wx>superexc</wx>
//    <qqgroup>128148617</qqgroup>
//    <url>https://jsq.ink</url>
//    <role>pku engineer</role>
//    <date>2019-03-16 12:09:28</date>
//</624342590950477824>


package main

import (
	"encoding/json"
	"fmt"
	"os"
	"runtime"
	"strconv"
	"sync/atomic"
	"time"

	"github.com/ethereum/go-ethereum/cmd/utils"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/console"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/state"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/eth/downloader"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/event"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/trie"
	"github.com/syndtr/goleveldb/leveldb/util"
	"gopkg.in/urfave/cli.v1"
)

var (
	initCommand = cli.Command{
		Action:    utils.MigrateFlags(initGenesis),
		Name:      "init",
		Usage:     "Bootstrap and initialize a new genesis block",
		ArgsUsage: "<genesisPath>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
The init command initializes a new genesis block and definition for the network.
This is a destructive action and changes the network in which you will be
participating.

It expects the genesis file as argument.`,
	}
	importCommand = cli.Command{
		Action:    utils.MigrateFlags(importChain),
		Name:      "import",
		Usage:     "Import a blockchain file",
		ArgsUsage: "<filename> (<filename 2> ... <filename N>) ",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.CacheFlag,
			utils.SyncModeFlag,
			utils.GCModeFlag,
			utils.CacheDatabaseFlag,
			utils.CacheGCFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
The import command imports blocks from an RLP-encoded form. The form can be one file
with several RLP-encoded blocks, or several files can be used.

If only one file is used, import error will result in failure. If several files are used,
processing will proceed even if an individual RLP-file import failure occurs.`,
	}
	exportCommand = cli.Command{
		Action:    utils.MigrateFlags(exportChain),
		Name:      "export",
		Usage:     "Export blockchain into file",
		ArgsUsage: "<filename> [<blockNumFirst> <blockNumLast>]",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.CacheFlag,
			utils.SyncModeFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
Requires a first argument of the file to write to.
Optional second and third arguments control the first and
last block to write. In this mode, the file will be appended
if already existing. If the file ends with .gz, the output will
be gzipped.`,
	}
	importPreimagesCommand = cli.Command{
		Action:    utils.MigrateFlags(importPreimages),
		Name:      "import-preimages",
		Usage:     "Import the preimage database from an RLP stream",
		ArgsUsage: "<datafile>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.CacheFlag,
			utils.SyncModeFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
	The import-preimages command imports hash preimages from an RLP encoded stream.`,
	}
	exportPreimagesCommand = cli.Command{
		Action:    utils.MigrateFlags(exportPreimages),
		Name:      "export-preimages",
		Usage:     "Export the preimage database into an RLP stream",
		ArgsUsage: "<dumpfile>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.CacheFlag,
			utils.SyncModeFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
The export-preimages command export hash preimages to an RLP encoded stream`,
	}
	copydbCommand = cli.Command{
		Action:    utils.MigrateFlags(copyDb),
		Name:      "copydb",
		Usage:     "Create a local chain from a target chaindata folder",
		ArgsUsage: "<sourceChaindataDir>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.CacheFlag,
			utils.SyncModeFlag,
			utils.FakePoWFlag,
			utils.TestnetFlag,
			utils.RinkebyFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
The first argument must be the directory containing the blockchain to download from`,
	}
	removedbCommand = cli.Command{
		Action:    utils.MigrateFlags(removeDB),
		Name:      "removedb",
		Usage:     "Remove blockchain and state databases",
		ArgsUsage: " ",
		Flags: []cli.Flag{
			utils.DataDirFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
Remove blockchain and state databases`,
	}
	dumpCommand = cli.Command{
		Action:    utils.MigrateFlags(dump),
		Name:      "dump",
		Usage:     "Dump a specific block from storage",
		ArgsUsage: "[<blockHash> | <blockNum>]...",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.CacheFlag,
			utils.SyncModeFlag,
		},
		Category: "BLOCKCHAIN COMMANDS",
		Description: `
The arguments are interpreted as block numbers or hashes.
Use "ethereum dump 0" to dump the genesis block.`,
	}
)

//initGenesis将初始化给定的JSON格式genesis文件，并将其写为
//如果它不能成功的话，它将很难阻止（也就是说，创世记）。
func initGenesis(ctx *cli.Context) error {
//确保我们有一个有效的Genesis JSON
	genesisPath := ctx.Args().First()
	if len(genesisPath) == 0 {
		utils.Fatalf("Must supply path to genesis JSON file")
	}
	file, err := os.Open(genesisPath)
	if err != nil {
		utils.Fatalf("Failed to read genesis file: %v", err)
	}
	defer file.Close()

	genesis := new(core.Genesis)
	if err := json.NewDecoder(file).Decode(genesis); err != nil {
		utils.Fatalf("invalid genesis file: %v", err)
	}
//打开初始化完整数据库和轻型数据库
	stack := makeFullNode(ctx)
	for _, name := range []string{"chaindata", "lightchaindata"} {
		chaindb, err := stack.OpenDatabase(name, 0, 0)
		if err != nil {
			utils.Fatalf("Failed to open database: %v", err)
		}
		_, hash, err := core.SetupGenesisBlock(chaindb, genesis)
		if err != nil {
			utils.Fatalf("Failed to write genesis block: %v", err)
		}
		log.Info("Successfully wrote genesis state", "database", name, "hash", hash)
	}
	return nil
}

func importChain(ctx *cli.Context) error {
	if len(ctx.Args()) < 1 {
		utils.Fatalf("This command requires an argument.")
	}
	stack := makeFullNode(ctx)
	chain, chainDb := utils.MakeChain(ctx, stack)
	defer chainDb.Close()

//开始定期收集内存配置文件
	var peakMemAlloc, peakMemSys uint64
	go func() {
		stats := new(runtime.MemStats)
		for {
			runtime.ReadMemStats(stats)
			if atomic.LoadUint64(&peakMemAlloc) < stats.Alloc {
				atomic.StoreUint64(&peakMemAlloc, stats.Alloc)
			}
			if atomic.LoadUint64(&peakMemSys) < stats.Sys {
				atomic.StoreUint64(&peakMemSys, stats.Sys)
			}
			time.Sleep(5 * time.Second)
		}
	}()
//导入链
	start := time.Now()

	if len(ctx.Args()) == 1 {
		if err := utils.ImportChain(chain, ctx.Args().First()); err != nil {
			log.Error("Import error", "err", err)
		}
	} else {
		for _, arg := range ctx.Args() {
			if err := utils.ImportChain(chain, arg); err != nil {
				log.Error("Import error", "file", arg, "err", err)
			}
		}
	}
	chain.Stop()
	fmt.Printf("Import done in %v.\n\n", time.Since(start))

//输出预压缩状态，主要是查看导入垃圾
	db := chainDb.(*ethdb.LDBDatabase)

	stats, err := db.LDB().GetProperty("leveldb.stats")
	if err != nil {
		utils.Fatalf("Failed to read database stats: %v", err)
	}
	fmt.Println(stats)

	ioStats, err := db.LDB().GetProperty("leveldb.iostats")
	if err != nil {
		utils.Fatalf("Failed to read database iostats: %v", err)
	}
	fmt.Println(ioStats)

	fmt.Printf("Trie cache misses:  %d\n", trie.CacheMisses())
	fmt.Printf("Trie cache unloads: %d\n\n", trie.CacheUnloads())

//打印导入使用的内存统计信息
	mem := new(runtime.MemStats)
	runtime.ReadMemStats(mem)

	fmt.Printf("Object memory: %.3f MB current, %.3f MB peak\n", float64(mem.Alloc)/1024/1024, float64(atomic.LoadUint64(&peakMemAlloc))/1024/1024)
	fmt.Printf("System memory: %.3f MB current, %.3f MB peak\n", float64(mem.Sys)/1024/1024, float64(atomic.LoadUint64(&peakMemSys))/1024/1024)
	fmt.Printf("Allocations:   %.3f million\n", float64(mem.Mallocs)/1000000)
	fmt.Printf("GC pause:      %v\n\n", time.Duration(mem.PauseTotalNs))

	if ctx.GlobalIsSet(utils.NoCompactionFlag.Name) {
		return nil
	}

//压缩整个数据库以更准确地测量磁盘IO并打印统计信息
	start = time.Now()
	fmt.Println("Compacting entire database...")
	if err = db.LDB().CompactRange(util.Range{}); err != nil {
		utils.Fatalf("Compaction failed: %v", err)
	}
	fmt.Printf("Compaction done in %v.\n\n", time.Since(start))

	stats, err = db.LDB().GetProperty("leveldb.stats")
	if err != nil {
		utils.Fatalf("Failed to read database stats: %v", err)
	}
	fmt.Println(stats)

	ioStats, err = db.LDB().GetProperty("leveldb.iostats")
	if err != nil {
		utils.Fatalf("Failed to read database iostats: %v", err)
	}
	fmt.Println(ioStats)

	return nil
}

func exportChain(ctx *cli.Context) error {
	if len(ctx.Args()) < 1 {
		utils.Fatalf("This command requires an argument.")
	}
	stack := makeFullNode(ctx)
	chain, _ := utils.MakeChain(ctx, stack)
	start := time.Now()

	var err error
	fp := ctx.Args().First()
	if len(ctx.Args()) < 3 {
		err = utils.ExportChain(chain, fp)
	} else {
//这可以改进为允许大于9223372036854775807的数字
		first, ferr := strconv.ParseInt(ctx.Args().Get(1), 10, 64)
		last, lerr := strconv.ParseInt(ctx.Args().Get(2), 10, 64)
		if ferr != nil || lerr != nil {
			utils.Fatalf("Export error in parsing parameters: block number not an integer\n")
		}
		if first < 0 || last < 0 {
			utils.Fatalf("Export error: block number must be greater than 0\n")
		}
		err = utils.ExportAppendChain(chain, fp, uint64(first), uint64(last))
	}

	if err != nil {
		utils.Fatalf("Export error: %v\n", err)
	}
	fmt.Printf("Export done in %v\n", time.Since(start))
	return nil
}

//importpreimages从指定文件导入preimage数据。
func importPreimages(ctx *cli.Context) error {
	if len(ctx.Args()) < 1 {
		utils.Fatalf("This command requires an argument.")
	}
	stack := makeFullNode(ctx)
	diskdb := utils.MakeChainDatabase(ctx, stack).(*ethdb.LDBDatabase)

	start := time.Now()
	if err := utils.ImportPreimages(diskdb, ctx.Args().First()); err != nil {
		utils.Fatalf("Export error: %v\n", err)
	}
	fmt.Printf("Export done in %v\n", time.Since(start))
	return nil
}

//exportpreimages以流式方式将preimage数据转储到指定的JSON文件。
func exportPreimages(ctx *cli.Context) error {
	if len(ctx.Args()) < 1 {
		utils.Fatalf("This command requires an argument.")
	}
	stack := makeFullNode(ctx)
	diskdb := utils.MakeChainDatabase(ctx, stack).(*ethdb.LDBDatabase)

	start := time.Now()
	if err := utils.ExportPreimages(diskdb, ctx.Args().First()); err != nil {
		utils.Fatalf("Export error: %v\n", err)
	}
	fmt.Printf("Export done in %v\n", time.Since(start))
	return nil
}

func copyDb(ctx *cli.Context) error {
//确保我们有一个要复制的源链目录
	if len(ctx.Args()) != 1 {
		utils.Fatalf("Source chaindata directory path argument missing")
	}
//初始化要同步到的运行节点的新链
	stack := makeFullNode(ctx)
	chain, chainDb := utils.MakeChain(ctx, stack)

	syncmode := *utils.GlobalTextMarshaler(ctx, utils.SyncModeFlag.Name).(*downloader.SyncMode)
	dl := downloader.New(syncmode, chainDb, new(event.TypeMux), chain, nil, nil)

//创建源对等点以满足来自
	db, err := ethdb.NewLDBDatabase(ctx.Args().First(), ctx.GlobalInt(utils.CacheFlag.Name), 256)
	if err != nil {
		return err
	}
	hc, err := core.NewHeaderChain(db, chain.Config(), chain.Engine(), func() bool { return false })
	if err != nil {
		return err
	}
	peer := downloader.NewFakePeer("local", db, hc, dl)
	if err = dl.RegisterPeer("local", 63, peer); err != nil {
		return err
	}
//与模拟对等机同步
	start := time.Now()

	currentHeader := hc.CurrentHeader()
	if err = dl.Synchronise("local", currentHeader.Hash(), hc.GetTd(currentHeader.Hash(), currentHeader.Number.Uint64()), syncmode); err != nil {
		return err
	}
	for dl.Synchronising() {
		time.Sleep(10 * time.Millisecond)
	}
	fmt.Printf("Database copy done in %v\n", time.Since(start))

//压缩整个数据库以消除任何同步开销
	start = time.Now()
	fmt.Println("Compacting entire database...")
	if err = chainDb.(*ethdb.LDBDatabase).LDB().CompactRange(util.Range{}); err != nil {
		utils.Fatalf("Compaction failed: %v", err)
	}
	fmt.Printf("Compaction done in %v.\n\n", time.Since(start))

	return nil
}

func removeDB(ctx *cli.Context) error {
	stack, _ := makeConfigNode(ctx)

	for _, name := range []string{"chaindata", "lightchaindata"} {
//首先确保数据库存在
		logger := log.New("database", name)

		dbdir := stack.ResolvePath(name)
		if !common.FileExist(dbdir) {
			logger.Info("Database doesn't exist, skipping", "path", dbdir)
			continue
		}
//确认删除并执行
		fmt.Println(dbdir)
		confirm, err := console.Stdin.PromptConfirm("Remove this database?")
		switch {
		case err != nil:
			utils.Fatalf("%v", err)
		case !confirm:
			logger.Warn("Database deletion aborted")
		default:
			start := time.Now()
			os.RemoveAll(dbdir)
			logger.Info("Database successfully deleted", "elapsed", common.PrettyDuration(time.Since(start)))
		}
	}
	return nil
}

func dump(ctx *cli.Context) error {
	stack := makeFullNode(ctx)
	chain, chainDb := utils.MakeChain(ctx, stack)
	for _, arg := range ctx.Args() {
		var block *types.Block
		if hashish(arg) {
			block = chain.GetBlockByHash(common.HexToHash(arg))
		} else {
			num, _ := strconv.Atoi(arg)
			block = chain.GetBlockByNumber(uint64(num))
		}
		if block == nil {
			fmt.Println("{}")
			utils.Fatalf("block not found")
		} else {
			state, err := state.New(block.Root(), state.NewDatabase(chainDb))
			if err != nil {
				utils.Fatalf("could not create new state: %v", err)
			}
			fmt.Printf("%s\n", state.Dump())
		}
	}
	chainDb.Close()
	return nil
}

//对于看起来像哈希的字符串，hashish返回true。
func hashish(x string) bool {
	_, err := strconv.Atoi(x)
	return err != nil
}