vm: add 'storage' VM CLI command to dump storage items

Another nice one, very useful for debugging.

cli/vm/cli.go

@@ -17,6 +17,7 @@ import (
 
 	"github.com/chzyer/readline"
 	"github.com/kballard/go-shellquote"
+	"github.com/nspcc-dev/neo-go/cli/flags"
 	"github.com/nspcc-dev/neo-go/pkg/compiler"
 	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/core"
@@ -54,8 +55,9 @@ const (
 
 // Various flag names.
 const (
-	verboseFlagFullName  = "verbose"
-	historicFlagFullName = "historic"
+	verboseFlagFullName   = "verbose"
+	historicFlagFullName  = "historic"
+	backwardsFlagFullName = "backwards"
 )
 
 var historicFlag = cli.IntFlag{
@@ -267,6 +269,32 @@ Example:
 > env -v`,
 		Action: handleEnv,
 	},
+	{
+		Name: "storage",
+		Usage: "Dump storage of the contract with the specified hash, address or ID as is at the current stage of script invocation. " +
+			"Can be used if no script is loaded. " +
+			"Hex-encoded storage items prefix may be specified (empty by default to return the whole set of storage items). " +
+			"If seek prefix is not empty, then it's trimmed from the resulting keys." +
+			"Items are sorted. Backwards seek direction may be specified (false by default, which means forwards storage seek direction).",
+		UsageText: `storage <hash-or-address-or-id> [<prefix>] [--backwards]`,
+		Flags: []cli.Flag{
+			cli.BoolFlag{
+				Name:  backwardsFlagFullName + ",b",
+				Usage: "Backwards traversal direction",
+			},
+		},
+		Description: `storage <hash-or-address-or-id> <prefix> --backwards
+
+Dump storage of the contract with the specified hash, address or ID as is at the current stage of script invocation.
+Can be used if no script is loaded.
+Hex-encoded storage items prefix may be specified (empty by default to return the whole set of storage items).
+If seek prefix is not empty, then it's trimmed from the resulting keys.
+Items are sorted. Backwards seek direction may be specified (false by default, which means forwards storage seek direction).
+
+Example:
+> storage 0x0000000009070e030d0f0e020d0c06050e030c02 030e --backwards`,
+		Action: handleStorage,
+	},
 }
 
 var completer *readline.PrefixCompleter
@@ -871,6 +899,50 @@ func handleEnv(c *cli.Context) error {
 	return nil
 }
 
+func handleStorage(c *cli.Context) error {
+	if !c.Args().Present() {
+		return errors.New("contract hash, address or ID is mandatory argument")
+	}
+	hashOrID := c.Args().Get(0)
+	var (
+		id        int32
+		ic        = getInteropContextFromContext(c.App)
+		prefix    []byte
+		backwards bool
+	)
+	h, err := flags.ParseAddress(hashOrID)
+	if err != nil {
+		i, err := strconv.Atoi(hashOrID)
+		if err != nil {
+			return fmt.Errorf("failed to parse contract hash, address or ID: %w", err)
+		}
+		id = int32(i)
+	} else {
+		cs, err := ic.GetContract(h)
+		if err != nil {
+			return fmt.Errorf("contract %s not found: %w", h.StringLE(), err)
+		}
+		id = cs.ID
+	}
+	if c.NArg() > 1 {
+		prefix, err = hex.DecodeString(c.Args().Get(1))
+		if err != nil {
+			return fmt.Errorf("failed to decode prefix from hex: %w", err)
+		}
+	}
+	if c.Bool(backwardsFlagFullName) {
+		backwards = true
+	}
+	ic.DAO.Seek(id, storage.SeekRange{
+		Prefix:    prefix,
+		Backwards: backwards,
+	}, func(k, v []byte) bool {
+		fmt.Fprintf(c.App.Writer, "%s: %v\n", hex.EncodeToString(k), hex.EncodeToString(v))
+		return true
+	})
+	return nil
+}
+
 func dumpEvents(app *cli.App) (string, error) {
 	ic := getInteropContextFromContext(app)
 	if len(ic.Notifications) == 0 {

cli/vm/cli_test.go

@@ -221,6 +221,12 @@ func (e *executor) checkEvents(t *testing.T, isKeywordExpected bool, events ...s
 	require.NoError(t, err)
 }
 
+func (e *executor) checkStorage(t *testing.T, kvs ...storage.KeyValue) {
+	for _, kv := range kvs {
+		e.checkNextLine(t, fmt.Sprintf("%s: %s", hex.EncodeToString(kv.Key), hex.EncodeToString(kv.Value)))
+	}
+}
+
 func (e *executor) checkSlot(t *testing.T, items ...interface{}) {
 	d := json.NewDecoder(e.out)
 	var actual interface{}
@@ -849,3 +855,28 @@ func TestEnv(t *testing.T) {
 		e.checkNextLine(t, "Node config:") // Do not check exact node config.
 	})
 }
+
+func TestDumpStorage(t *testing.T) {
+	e := newTestVMClIWithState(t)
+
+	h, err := e.cli.chain.GetContractScriptHash(1) // examples/storage/storage.go
+	require.NoError(t, err)
+	expected := []storage.KeyValue{
+		{Key: []byte{1}, Value: []byte{2}},
+		{Key: []byte{2}, Value: []byte{2}},
+	}
+	e.runProg(t,
+		"storage "+h.StringLE(),
+		"storage 0x"+h.StringLE(),
+		"storage "+address.Uint160ToString(h),
+		"storage 1",
+		"storage 1 "+hex.EncodeToString(expected[0].Key),
+		"storage 1 --backwards",
+	)
+	e.checkStorage(t, expected...)
+	e.checkStorage(t, expected...)
+	e.checkStorage(t, expected...)
+	e.checkStorage(t, expected...)
+	e.checkStorage(t, storage.KeyValue{Key: nil, Value: []byte{2}}) // empty key because search prefix is trimmed
+	e.checkStorage(t, expected[1], expected[0])
+}