rpc: add getstate RPC handler

docs/rpc.md

@@ -54,6 +54,7 @@ which would yield the response:
 | `getproof` |
 | `getrawmempool` |
 | `getrawtransaction` |
+| `getstate` |
 | `getstateheight` |
 | `getstateroot` |
 | `getstorage` |

pkg/core/blockchainer/state_root.go

@@ -13,6 +13,7 @@ type StateRoot interface {
 	CurrentLocalHeight() uint32
 	CurrentLocalStateRoot() util.Uint256
 	CurrentValidatedHeight() uint32
+	GetState(root util.Uint256, key []byte) ([]byte, error)
 	GetStateProof(root util.Uint256, key []byte) ([][]byte, error)
 	GetStateRoot(height uint32) (*state.MPTRoot, error)
 	GetStateValidators(height uint32) keys.PublicKeys

pkg/core/helper_test.go

@@ -501,6 +501,20 @@ func initBasicChain(t *testing.T, bc *Blockchain) {
 	require.NoError(t, err)
 	checkResult(t, res, stackitem.Null{})
 
+	// Invoke `test_contract.go`: put new value with the same key to check `getstate` RPC call
+	script.Reset()
+	emit.AppCall(script.BinWriter, cHash, "putValue", callflag.All, "testkey", "newtestvalue")
+
+	txInv = transaction.New(script.Bytes(), 1*native.GASFactor)
+	txInv.Nonce = getNextNonce()
+	txInv.ValidUntilBlock = validUntilBlock
+	txInv.Signers = []transaction.Signer{{Account: priv0ScriptHash}}
+	require.NoError(t, addNetworkFee(bc, txInv, acc0))
+	require.NoError(t, acc0.SignTx(testchain.Network(), txInv))
+	b = bc.newBlock(txInv)
+	require.NoError(t, bc.AddBlock(b))
+	checkTxHalt(t, bc, txInv.Hash())
+
 	// Compile contract to test `invokescript` RPC call
 	_, _ = newDeployTx(t, bc, priv0ScriptHash, prefix+"invokescript_contract.go", "ContractForInvokescriptTest", nil)
 }

pkg/core/native/management.go

@@ -38,7 +38,7 @@ type Management struct {
 }
 
 const (
-	managementContractID = -1
+	ManagementContractID = -1
 
 	prefixContract = 8
 
@@ -55,15 +55,15 @@ var (
 	keyMinimumDeploymentFee = []byte{20}
 )
 
-// makeContractKey creates a key from account script hash.
-func makeContractKey(h util.Uint160) []byte {
+// MakeContractKey creates a key from account script hash.
+func MakeContractKey(h util.Uint160) []byte {
 	return makeUint160Key(prefixContract, h)
 }
 
 // newManagement creates new Management native contract.
 func newManagement() *Management {
 	var m = &Management{
-		ContractMD: *interop.NewContractMD(nativenames.Management, managementContractID),
+		ContractMD: *interop.NewContractMD(nativenames.Management, ManagementContractID),
 		contracts:  make(map[util.Uint160]*state.Contract),
 		nep17:      make(map[util.Uint160]struct{}),
 	}
@@ -156,7 +156,7 @@ func (m *Management) GetContract(d dao.DAO, hash util.Uint160) (*state.Contract,
 
 func (m *Management) getContractFromDAO(d dao.DAO, hash util.Uint160) (*state.Contract, error) {
 	contract := new(state.Contract)
-	key := makeContractKey(hash)
+	key := MakeContractKey(hash)
 	err := getConvertibleFromDAO(m.ID, d, key, contract)
 	if err != nil {
 		return nil, err
@@ -268,7 +268,7 @@ func (m *Management) markUpdated(h util.Uint160) {
 // It doesn't run _deploy method and doesn't emit notification.
 func (m *Management) Deploy(d dao.DAO, sender util.Uint160, neff *nef.File, manif *manifest.Manifest) (*state.Contract, error) {
 	h := state.CreateContractHash(sender, neff.Checksum, manif.Name)
-	key := makeContractKey(h)
+	key := MakeContractKey(h)
 	si := d.GetStorageItem(m.ID, key)
 	if si != nil {
 		return nil, errors.New("contract already exists")
@@ -382,7 +382,7 @@ func (m *Management) Destroy(d dao.DAO, hash util.Uint160) error {
 	if err != nil {
 		return err
 	}
-	key := makeContractKey(hash)
+	key := MakeContractKey(hash)
 	err = d.DeleteStorageItem(m.ID, key)
 	if err != nil {
 		return err
@@ -553,7 +553,7 @@ func (m *Management) Initialize(ic *interop.Context) error {
 
 // PutContractState saves given contract state into given DAO.
 func (m *Management) PutContractState(d dao.DAO, cs *state.Contract) error {
-	key := makeContractKey(cs.Hash)
+	key := MakeContractKey(cs.Hash)
 	if err := putConvertibleToDAO(m.ID, d, key, cs); err != nil {
 		return err
 	}

pkg/core/stateroot/module.go

@@ -55,6 +55,12 @@ func NewModule(bc blockchainer.Blockchainer, log *zap.Logger, s *storage.MemCach
 	}
 }
 
+// GetState returns value at the specified key fom the MPT with the specified root.
+func (s *Module) GetState(root util.Uint256, key []byte) ([]byte, error) {
+	tr := mpt.NewTrie(mpt.NewHashNode(root), false, storage.NewMemCachedStore(s.Store))
+	return tr.Get(key)
+}
+
 // GetStateProof returns proof of having key in the MPT with the specified root.
 func (s *Module) GetStateProof(root util.Uint256, key []byte) ([][]byte, error) {
 	tr := mpt.NewTrie(mpt.NewHashNode(root), false, storage.NewMemCachedStore(s.Store))

pkg/core/statesync_test.go

@@ -285,7 +285,6 @@ func TestStateSyncModule_RestoreBasicChain(t *testing.T) {
 	// make spout chain higher that latest state sync point
 	require.NoError(t, bcSpout.AddBlock(bcSpout.newBlock()))
 	require.NoError(t, bcSpout.AddBlock(bcSpout.newBlock()))
-	require.NoError(t, bcSpout.AddBlock(bcSpout.newBlock()))
 	require.Equal(t, uint32(stateSyncPoint+2), bcSpout.BlockHeight())
 
 	boltCfg := func(c *config.Config) {

pkg/rpc/client/rpc.go

@@ -374,6 +374,19 @@ func (c *Client) GetRawTransactionVerbose(hash util.Uint256) (*result.Transactio
 	return resp, nil
 }
 
+// GetState returns historical contract storage item state by the given stateroot,
+// historical contract hash and historical item key.
+func (c *Client) GetState(stateroot util.Uint256, historicalContractHash util.Uint160, historicalKey []byte) ([]byte, error) {
+	var (
+		params = request.NewRawParams(stateroot.StringLE(), historicalContractHash.StringLE(), historicalKey)
+		resp   []byte
+	)
+	if err := c.performRequest("getstate", params, &resp); err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
 // GetStateHeight returns current validated and local node state height.
 func (c *Client) GetStateHeight() (*result.StateHeight, error) {
 	var (

pkg/rpc/client/rpc_test.go

@@ -675,6 +675,20 @@ var rpcClientTestCases = map[string][]rpcClientTestCase{
 			},
 		},
 	},
+	"getstate": {
+		{
+			name: "positive",
+			invoke: func(c *Client) (interface{}, error) {
+				root, _ := util.Uint256DecodeStringLE("252e9d73d49c95c7618d40650da504e05183a1b2eed0685e42c360413c329170")
+				cHash, _ := util.Uint160DecodeStringLE("5c9e40a12055c6b9e3f72271c9779958c842135d")
+				return c.GetState(root, cHash, []byte("testkey"))
+			},
+			serverResponse: `{"id":1,"jsonrpc":"2.0","result":"dGVzdHZhbHVl"}`,
+			result: func(c *Client) interface{} {
+				return []byte("testvalue")
+			},
+		},
+	},
 	"getstateheight": {
 		{
 			name: "positive",

pkg/rpc/server/server.go

@@ -24,6 +24,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/fee"
 	"github.com/nspcc-dev/neo-go/pkg/core/mempoolevent"
 	"github.com/nspcc-dev/neo-go/pkg/core/mpt"
+	"github.com/nspcc-dev/neo-go/pkg/core/native"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
@@ -44,6 +45,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 	"go.uber.org/zap"
 )
 
@@ -118,6 +120,7 @@ var rpcHandlers = map[string]func(*Server, request.Params) (interface{}, *respon
 	"getproof":               (*Server).getProof,
 	"getrawmempool":          (*Server).getRawMempool,
 	"getrawtransaction":      (*Server).getrawtransaction,
+	"getstate":               (*Server).getState,
 	"getstateheight":         (*Server).getStateHeight,
 	"getstateroot":           (*Server).getStateRoot,
 	"getstorage":             (*Server).getStorage,
@@ -1026,6 +1029,46 @@ func (s *Server) verifyProof(ps request.Params) (interface{}, *response.Error) {
 	return vp, nil
 }
 
+func (s *Server) getState(ps request.Params) (interface{}, *response.Error) {
+	root, err := ps.Value(0).GetUint256()
+	if err != nil {
+		return nil, response.WrapErrorWithData(response.ErrInvalidParams, errors.New("invalid stateroot"))
+	}
+	if s.chain.GetConfig().KeepOnlyLatestState {
+		curr, err := s.chain.GetStateModule().GetStateRoot(s.chain.BlockHeight())
+		if err != nil {
+			return nil, response.NewInternalServerError("failed to get current stateroot", err)
+		}
+		if !curr.Root.Equals(root) {
+			return nil, response.NewInvalidRequestError("'getstate' is not supported for old states", errKeepOnlyLatestState)
+		}
+	}
+	csHash, err := ps.Value(1).GetUint160FromHex()
+	if err != nil {
+		return nil, response.WrapErrorWithData(response.ErrInvalidParams, errors.New("invalid contract hash"))
+	}
+	key, err := ps.Value(2).GetBytesBase64()
+	if err != nil {
+		return nil, response.WrapErrorWithData(response.ErrInvalidParams, errors.New("invalid key"))
+	}
+	csKey := makeStorageKey(native.ManagementContractID, native.MakeContractKey(csHash))
+	csBytes, err := s.chain.GetStateModule().GetState(root, csKey)
+	if err != nil {
+		return nil, response.NewInternalServerError("failed to get historical contract state", err)
+	}
+	contract := new(state.Contract)
+	err = stackitem.DeserializeConvertible(csBytes, contract)
+	if err != nil {
+		return nil, response.NewInternalServerError("failed to deserialize historical contract state", err)
+	}
+	sKey := makeStorageKey(contract.ID, key)
+	res, err := s.chain.GetStateModule().GetState(root, sKey)
+	if err != nil {
+		return nil, response.NewInternalServerError("failed to get historical item state", err)
+	}
+	return res, nil
+}
+
 func (s *Server) getStateHeight(_ request.Params) (interface{}, *response.Error) {
 	var height = s.chain.BlockHeight()
 	var stateHeight = s.chain.GetStateModule().CurrentValidatedHeight()

pkg/rpc/server/server_test.go

@@ -55,7 +55,7 @@ type rpcTestCase struct {
 }
 
 const testContractHash = "5c9e40a12055c6b9e3f72271c9779958c842135d"
-const deploymentTxHash = "fefc10d2f7e323282cb50838174b68979b1794c1e5131f2b4737acbc5dde5932"
+const deploymentTxHash = "cb17eac9594d7ffa318545ab36e3227eedf30b4d13d76d3b49c94243fb3b2bde"
 const genesisBlockHash = "0f8fb4e17d2ab9f3097af75ca7fd16064160fb8043db94909e00dd4e257b9dc4"
 
 const verifyContractHash = "f68822e4ecd93de334bdf1f7c409eda3431bcbd0"
@@ -316,6 +316,38 @@ var rpcTestCases = map[string][]rpcTestCase{
 			fail:   true,
 		},
 	},
+	"getstate": {
+		{
+			name:   "no params",
+			params: `[]`,
+			fail:   true,
+		},
+		{
+			name:   "invalid root",
+			params: `["0xabcdef"]`,
+			fail:   true,
+		},
+		{
+			name:   "invalid contract",
+			params: `["0000000000000000000000000000000000000000000000000000000000000000", "0xabcdef"]`,
+			fail:   true,
+		},
+		{
+			name:   "invalid key",
+			params: `["0000000000000000000000000000000000000000000000000000000000000000", "` + testContractHash + `", "notabase64%"]`,
+			fail:   true,
+		},
+		{
+			name:   "unknown contract",
+			params: `["0000000000000000000000000000000000000000000000000000000000000000", "0000000000000000000000000000000000000000", "QQ=="]`,
+			fail:   true,
+		},
+		{
+			name:   "unknown root/item",
+			params: `["0000000000000000000000000000000000000000000000000000000000000000", "` + testContractHash + `", "QQ=="]`,
+			fail:   true,
+		},
+	},
 	"getstateheight": {
 		{
 			name:   "positive",
@@ -347,7 +379,7 @@ var rpcTestCases = map[string][]rpcTestCase{
 			name:   "positive",
 			params: fmt.Sprintf(`["%s", "dGVzdGtleQ=="]`, testContractHash),
 			result: func(e *executor) interface{} {
-				v := base64.StdEncoding.EncodeToString([]byte("testvalue"))
+				v := base64.StdEncoding.EncodeToString([]byte("newtestvalue"))
 				return &v
 			},
 		},
@@ -650,7 +682,7 @@ var rpcTestCases = map[string][]rpcTestCase{
 				require.True(t, ok)
 				expected := result.UnclaimedGas{
 					Address:   testchain.MultisigScriptHash(),
-					Unclaimed: *big.NewInt(7500),
+					Unclaimed: *big.NewInt(8000),
 				}
 				assert.Equal(t, expected, *actual)
 			},
@@ -1387,6 +1419,31 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 		t.Run("ByHeight", func(t *testing.T) { testRoot(t, strconv.FormatInt(5, 10)) })
 		t.Run("ByHash", func(t *testing.T) { testRoot(t, `"`+chain.GetHeaderHash(5).StringLE()+`"`) })
 	})
+	t.Run("getstate", func(t *testing.T) {
+		testGetState := func(t *testing.T, p string, expected string) {
+			rpc := fmt.Sprintf(`{"jsonrpc": "2.0", "id": 1, "method": "getstate", "params": [%s]}`, p)
+			body := doRPCCall(rpc, httpSrv.URL, t)
+			rawRes := checkErrGetResult(t, body, false)
+
+			var actual string
+			require.NoError(t, json.Unmarshal(rawRes, &actual))
+			require.Equal(t, expected, actual)
+		}
+		t.Run("good: historical state", func(t *testing.T) {
+			root, err := e.chain.GetStateModule().GetStateRoot(4)
+			require.NoError(t, err)
+			// `testkey`-`testvalue` pair was put to the contract storage at block #3
+			params := fmt.Sprintf(`"%s", "%s", "%s"`, root.Root.StringLE(), testContractHash, base64.StdEncoding.EncodeToString([]byte("testkey")))
+			testGetState(t, params, base64.StdEncoding.EncodeToString([]byte("testvalue")))
+		})
+		t.Run("good: fresh state", func(t *testing.T) {
+			root, err := e.chain.GetStateModule().GetStateRoot(16)
+			require.NoError(t, err)
+			// `testkey`-`newtestvalue` pair was put to the contract storage at block #16
+			params := fmt.Sprintf(`"%s", "%s", "%s"`, root.Root.StringLE(), testContractHash, base64.StdEncoding.EncodeToString([]byte("testkey")))
+			testGetState(t, params, base64.StdEncoding.EncodeToString([]byte("newtestvalue")))
+		})
+	})
 
 	t.Run("getrawtransaction", func(t *testing.T) {
 		block, _ := chain.GetBlock(chain.GetHeaderHash(1))
@@ -1430,7 +1487,7 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 		require.NoErrorf(t, err, "could not parse response: %s", txOut)
 
 		assert.Equal(t, *block.Transactions[0], actual.Transaction)
-		assert.Equal(t, 16, actual.Confirmations)
+		assert.Equal(t, 17, actual.Confirmations)
 		assert.Equal(t, TXHash, actual.Transaction.Hash())
 	})
 
@@ -1543,12 +1600,12 @@ func testRPCProtocol(t *testing.T, doRPCCall func(string, string, *testing.T) []
 			require.NoError(t, json.Unmarshal(res, actual))
 			checkNep17TransfersAux(t, e, actual, sent, rcvd)
 		}
-		t.Run("time frame only", func(t *testing.T) { testNEP17T(t, 4, 5, 0, 0, []int{9, 10, 11, 12}, []int{2, 3}) })
+		t.Run("time frame only", func(t *testing.T) { testNEP17T(t, 4, 5, 0, 0, []int{10, 11, 12, 13}, []int{2, 3}) })
 		t.Run("no res", func(t *testing.T) { testNEP17T(t, 100, 100, 0, 0, []int{}, []int{}) })
-		t.Run("limit", func(t *testing.T) { testNEP17T(t, 1, 7, 3, 0, []int{6, 7}, []int{1}) })
-		t.Run("limit 2", func(t *testing.T) { testNEP17T(t, 4, 5, 2, 0, []int{9}, []int{2}) })
-		t.Run("limit with page", func(t *testing.T) { testNEP17T(t, 1, 7, 3, 1, []int{8, 9}, []int{2}) })
-		t.Run("limit with page 2", func(t *testing.T) { testNEP17T(t, 1, 7, 3, 2, []int{10, 11}, []int{3}) })
+		t.Run("limit", func(t *testing.T) { testNEP17T(t, 1, 7, 3, 0, []int{7, 8}, []int{1}) })
+		t.Run("limit 2", func(t *testing.T) { testNEP17T(t, 4, 5, 2, 0, []int{10}, []int{2}) })
+		t.Run("limit with page", func(t *testing.T) { testNEP17T(t, 1, 7, 3, 1, []int{9, 10}, []int{2}) })
+		t.Run("limit with page 2", func(t *testing.T) { testNEP17T(t, 1, 7, 3, 2, []int{11, 12}, []int{3}) })
 	})
 }
 
@@ -1651,8 +1708,8 @@ func checkNep17Balances(t *testing.T, e *executor, acc interface{}) {
 			},
 			{
 				Asset:       e.chain.UtilityTokenHash(),
-				Amount:      "57898138260",
-				LastUpdated: 15,
+				Amount:      "57796933740",
+				LastUpdated: 16,
 			}},
 		Address: testchain.PrivateKeyByID(0).GetScriptHash().StringLE(),
 	}
@@ -1661,7 +1718,7 @@ func checkNep17Balances(t *testing.T, e *executor, acc interface{}) {
 }
 
 func checkNep17Transfers(t *testing.T, e *executor, acc interface{}) {
-	checkNep17TransfersAux(t, e, acc, []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14}, []int{0, 1, 2, 3, 4, 5, 6, 7})
+	checkNep17TransfersAux(t, e, acc, []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}, []int{0, 1, 2, 3, 4, 5, 6, 7})
 }
 
 func checkNep17TransfersAux(t *testing.T, e *executor, acc interface{}, sent, rcvd []int) {
@@ -1670,6 +1727,11 @@ func checkNep17TransfersAux(t *testing.T, e *executor, acc interface{}, sent, rc
 	rublesHash, err := util.Uint160DecodeStringLE(testContractHash)
 	require.NoError(t, err)
 
+	blockPutNewTestValue, err := e.chain.GetBlock(e.chain.GetHeaderHash(16)) // invoke `put` method of `test_contract.go` with `testkey`, `newtestvalue` args
+	require.NoError(t, err)
+	require.Equal(t, 1, len(blockPutNewTestValue.Transactions))
+	txPutNewTestValue := blockPutNewTestValue.Transactions[0]
+
 	blockSetRecord, err := e.chain.GetBlock(e.chain.GetHeaderHash(15)) // add type A record to `neo.com` domain via NNS
 	require.NoError(t, err)
 	require.Equal(t, 1, len(blockSetRecord.Transactions))
@@ -1746,6 +1808,14 @@ func checkNep17TransfersAux(t *testing.T, e *executor, acc interface{}, sent, rc
 	// duplicate the Server method.
 	expected := result.NEP17Transfers{
 		Sent: []result.NEP17Transfer{
+			{
+				Timestamp: blockPutNewTestValue.Timestamp,
+				Asset:     e.chain.UtilityTokenHash(),
+				Address:   "", // burn
+				Amount:    big.NewInt(txPutNewTestValue.SystemFee + txPutNewTestValue.NetworkFee).String(),
+				Index:     16,
+				TxHash:    blockPutNewTestValue.Hash(),
+			},
 			{
 				Timestamp: blockSetRecord.Timestamp,
 				Asset:     e.chain.UtilityTokenHash(),