cli: add dump-bin command

Dump blocks (starting with the genesis or specified block) to the
directory in binary format.

Signed-off-by: Ekaterina Pavlova <ekt@morphbits.io>

cli/server/dump_bin.go

@@ -0,0 +1,87 @@
+package server
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/nspcc-dev/neo-go/cli/cmdargs"
+	"github.com/nspcc-dev/neo-go/cli/options"
+	"github.com/nspcc-dev/neo-go/pkg/core/block"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/urfave/cli/v2"
+)
+
+func dumpBin(ctx *cli.Context) error {
+	if err := cmdargs.EnsureNone(ctx); err != nil {
+		return err
+	}
+	cfg, err := options.GetConfigFromContext(ctx)
+	if err != nil {
+		return cli.Exit(err, 1)
+	}
+	log, _, logCloser, err := options.HandleLoggingParams(ctx.Bool("debug"), cfg.ApplicationConfiguration)
+	if err != nil {
+		return cli.Exit(err, 1)
+	}
+	if logCloser != nil {
+		defer func() { _ = logCloser() }()
+	}
+	count := uint32(ctx.Uint("count"))
+	start := uint32(ctx.Uint("start"))
+
+	chain, prometheus, pprof, err := initBCWithMetrics(cfg, log)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		pprof.ShutDown()
+		prometheus.ShutDown()
+		chain.Close()
+	}()
+
+	blocksCount := chain.BlockHeight() + 1
+	if start+count > blocksCount {
+		return cli.Exit(fmt.Errorf("chain is not that high (%d) to dump %d blocks starting from %d", blocksCount-1, count, start), 1)
+	}
+	if count == 0 {
+		count = blocksCount - start
+	}
+
+	out := ctx.String("out")
+	if out == "" {
+		return cli.Exit("output directory is not specified", 1)
+	}
+	if _, err = os.Stat(out); os.IsNotExist(err) {
+		if err = os.MkdirAll(out, os.ModePerm); err != nil {
+			return cli.Exit(fmt.Sprintf("failed to create directory %s: %s", out, err), 1)
+		}
+	}
+	if err != nil {
+		return cli.Exit(fmt.Sprintf("failed to check directory %s: %s", out, err), 1)
+	}
+
+	for i := start; i < start+count; i++ {
+		blk, err := chain.GetBlock(chain.GetHeaderHash(i))
+		if err != nil {
+			return cli.Exit(fmt.Sprintf("failed to get block %d: %s", i, err), 1)
+		}
+		filePath := filepath.Join(out, fmt.Sprintf("block-%d.bin", i))
+		if err = saveBlockToFile(blk, filePath); err != nil {
+			return cli.Exit(fmt.Sprintf("failed to save block %d to file %s: %s", i, filePath, err), 1)
+		}
+	}
+	return nil
+}
+
+func saveBlockToFile(blk *block.Block, filePath string) error {
+	file, err := os.Create(filePath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	writer := io.NewBinWriterFromIO(file)
+	blk.EncodeBinary(writer)
+	return writer.Err
+}