cli: add db dump/restore commands

Dump given number of blocks (from the given offset) to file and restore them
from it. Fixes #436.

cli/server/server.go

@@ -9,6 +9,7 @@ import (
 	"github.com/CityOfZion/neo-go/config"
 	"github.com/CityOfZion/neo-go/pkg/core"
 	"github.com/CityOfZion/neo-go/pkg/core/storage"
+	"github.com/CityOfZion/neo-go/pkg/io"
 	"github.com/CityOfZion/neo-go/pkg/network"
 	"github.com/CityOfZion/neo-go/pkg/rpc"
 	"github.com/pkg/errors"
@@ -18,18 +19,63 @@ import (
 
 // NewCommands returns 'node' command.
 func NewCommands() []cli.Command {
-	return []cli.Command{{
-		Name:   "node",
-		Usage:  "start a NEO node",
-		Action: startServer,
-		Flags: []cli.Flag{
+	var cfgFlags = []cli.Flag{
 		cli.StringFlag{Name: "config-path"},
 		cli.BoolFlag{Name: "privnet, p"},
 		cli.BoolFlag{Name: "mainnet, m"},
 		cli.BoolFlag{Name: "testnet, t"},
 		cli.BoolFlag{Name: "debug, d"},
+	}
+	var cfgWithCountFlags = make([]cli.Flag, len(cfgFlags))
+	copy(cfgWithCountFlags, cfgFlags)
+	cfgWithCountFlags = append(cfgWithCountFlags,
+		cli.UintFlag{
+			Name:  "count, c",
+			Usage: "number of blocks to be processed (default or 0: all chain)",
 		},
-	}}
+		cli.UintFlag{
+			Name:  "skip, s",
+			Usage: "number of blocks to skip (default: 0)",
+		},
+	)
+	var cfgCountOutFlags = make([]cli.Flag, len(cfgWithCountFlags))
+	copy(cfgCountOutFlags, cfgWithCountFlags)
+	cfgCountOutFlags = append(cfgCountOutFlags, cli.StringFlag{
+		Name:  "out, o",
+		Usage: "Output file (stdout if not given)",
+	})
+	var cfgCountInFlags = make([]cli.Flag, len(cfgWithCountFlags))
+	copy(cfgCountInFlags, cfgWithCountFlags)
+	cfgCountInFlags = append(cfgCountInFlags, cli.StringFlag{
+		Name:  "in, i",
+		Usage: "Input file (stdin if not given)",
+	})
+	return []cli.Command{
+		{
+			Name:   "node",
+			Usage:  "start a NEO node",
+			Action: startServer,
+			Flags:  cfgFlags,
+		},
+		{
+			Name:  "db",
+			Usage: "database manipulations",
+			Subcommands: []cli.Command{
+				{
+					Name:   "dump",
+					Usage:  "dump blocks (starting with block #1) to the file",
+					Action: dumpDB,
+					Flags:  cfgCountOutFlags,
+				},
+				{
+					Name:   "restore",
+					Usage:  "restore blocks from the file",
+					Action: restoreDB,
+					Flags:  cfgCountInFlags,
+				},
+			},
+		},
+	}
 }
 
 func newGraceContext() context.Context {
@@ -43,26 +89,154 @@ func newGraceContext() context.Context {
 	return ctx
 }
 
-func startServer(ctx *cli.Context) error {
-	net := config.ModePrivNet
+// getConfigFromContext looks at path and mode flags in the given config and
+// returns appropriate config.
+func getConfigFromContext(ctx *cli.Context) (config.Config, error) {
+	var net = config.ModePrivNet
 	if ctx.Bool("testnet") {
 		net = config.ModeTestNet
 	}
 	if ctx.Bool("mainnet") {
 		net = config.ModeMainNet
 	}
-
-	grace, cancel := context.WithCancel(newGraceContext())
-	defer cancel()
-
 	configPath := "./config"
 	if argCp := ctx.String("config-path"); argCp != "" {
 		configPath = argCp
 	}
-	cfg, err := config.Load(configPath, net)
+	return config.Load(configPath, net)
+}
+
+// handleLoggingParams enables debugging output is that's requested by the user.
+func handleLoggingParams(ctx *cli.Context) {
+	if ctx.Bool("debug") {
+		log.SetLevel(log.DebugLevel)
+	}
+}
+
+func getCountAndSkipFromContext(ctx *cli.Context) (uint32, uint32) {
+	count := uint32(ctx.Uint("count"))
+	skip := uint32(ctx.Uint("skip"))
+	return count, skip
+}
+
+func dumpDB(ctx *cli.Context) error {
+	cfg, err := getConfigFromContext(ctx)
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
+	handleLoggingParams(ctx)
+	count, skip := getCountAndSkipFromContext(ctx)
+
+	var outStream = os.Stdout
+	if out := ctx.String("out"); out != "" {
+		outStream, err = os.Create(out)
+		if err != nil {
+			return cli.NewExitError(err, 1)
+		}
+	}
+	defer outStream.Close()
+	writer := io.NewBinWriterFromIO(outStream)
+
+	grace, cancel := context.WithCancel(newGraceContext())
+	defer cancel()
+
+	chain, err := initBlockChain(cfg)
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	go chain.Run(grace)
+
+	chainHeight := chain.BlockHeight()
+	if skip+count > chainHeight {
+		return cli.NewExitError(fmt.Errorf("chain is not that high (%d) to dump %d blocks starting from %d", chainHeight, count, skip), 1)
+	}
+	if count == 0 {
+		count = chainHeight - skip
+	}
+	writer.WriteLE(count)
+	for i := skip + 1; i <= count; i++ {
+		bh := chain.GetHeaderHash(int(i))
+		b, err := chain.GetBlock(bh)
+		if err != nil {
+			return cli.NewExitError(fmt.Errorf("failed to get block %d: %s", i, err), 1)
+		}
+		b.EncodeBinary(writer)
+		if writer.Err != nil {
+			return cli.NewExitError(err, 1)
+		}
+	}
+	return nil
+}
+func restoreDB(ctx *cli.Context) error {
+	cfg, err := getConfigFromContext(ctx)
+	if err != nil {
+		return err
+	}
+	handleLoggingParams(ctx)
+	count, skip := getCountAndSkipFromContext(ctx)
+
+	var inStream = os.Stdin
+	if in := ctx.String("in"); in != "" {
+		inStream, err = os.Open(in)
+		if err != nil {
+			return cli.NewExitError(err, 1)
+		}
+	}
+	defer inStream.Close()
+	reader := io.NewBinReaderFromIO(inStream)
+
+	grace, cancel := context.WithCancel(newGraceContext())
+	defer cancel()
+
+	chain, err := initBlockChain(cfg)
+	if err != nil {
+		return err
+	}
+	go chain.Run(grace)
+
+	var allBlocks uint32
+	reader.ReadLE(&allBlocks)
+	if reader.Err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	if skip+count > allBlocks {
+		return cli.NewExitError(fmt.Errorf("input file has only %d blocks, can't read %d starting from %d", allBlocks, count, skip), 1)
+	}
+	if count == 0 {
+		count = allBlocks
+	}
+	i := uint32(0)
+	for ; i < skip; i++ {
+		b := &core.Block{}
+		b.DecodeBinary(reader)
+		if reader.Err != nil {
+			return cli.NewExitError(err, 1)
+		}
+	}
+	for ; i < count; i++ {
+		b := &core.Block{}
+		b.DecodeBinary(reader)
+		if reader.Err != nil {
+			return cli.NewExitError(err, 1)
+		}
+		err := chain.AddBlock(b)
+		if err != nil {
+			return cli.NewExitError(fmt.Errorf("failed to add block %d: %s", i, err), 1)
+		}
+	}
+
+	return nil
+}
+
+func startServer(ctx *cli.Context) error {
+	cfg, err := getConfigFromContext(ctx)
+	if err != nil {
+		return err
+	}
+	handleLoggingParams(ctx)
+
+	grace, cancel := context.WithCancel(newGraceContext())
+	defer cancel()
 
 	serverConfig := network.NewServerConfig(cfg)
 
@@ -71,10 +245,6 @@ func startServer(ctx *cli.Context) error {
 		return err
 	}
 
-	if ctx.Bool("debug") {
-		log.SetLevel(log.DebugLevel)
-	}
-
 	server := network.NewServer(serverConfig, chain)
 	rpcServer := rpc.NewServer(chain, cfg.ApplicationConfiguration.RPCPort, server)
 	errChan := make(chan error)