chore(lib/runtime/wasmer): refactor Exec and exec methods (#2686)

- Remove nil storage check (temporary instances might not need it, and we should panic if this happens)
- Fix behavior for pointers and/or data lengths larger than the max int32 value
- Only use `Exec` instead of both directly wrapping `exec`
- Inline single/2-lines functions content in `exec`: `malloc`, `clear`, `store`, `load`
- Add sentinel errors and error wrappings
- Add named returns

Author: qdm12

dot/rpc/websocket_test.go

@@ -50,8 +50,10 @@ var testCalls = []struct {
 		expected: []byte(`{"jsonrpc":"2.0","result":3,"id":5}` + "\n")},
 	{
 		call: []byte(`{"jsonrpc":"2.0","method":"author_submitAndWatchExtrinsic","params":["0x010203"],"id":6}`),
-		expected: []byte(`{"jsonrpc":"2.0","error":{"code":null,"message":"Failed to call the ` +
-			"`" + `TaggedTransactionQueue_validate_transaction` + "`" + ` exported function."},"id":6}` + "\n")},
+		expected: []byte(`{"jsonrpc":"2.0","error":{"code":null,` +
+			`"message":"running runtime function: Failed to call the ` +
+			"`" + `TaggedTransactionQueue_validate_transaction` + "`" +
+			` exported function."},"id":6}` + "\n")},
 	{
 		call:     []byte(`{"jsonrpc":"2.0","method":"state_subscribeRuntimeVersion","params":[],"id":7}`),
 		expected: []byte(`{"jsonrpc":"2.0","result":6,"id":7}` + "\n")},

lib/runtime/errors.go

@@ -19,6 +19,3 @@ var ErrInvalidTransaction = &json2.Error{Code: 1010, Message: "Invalid Transacti
 // ErrUnknownTransaction is returned if the call to runtime function
 // TaggedTransactionQueueValidateTransaction fails with value of [1, 1, x]
 var ErrUnknownTransaction = &json2.Error{Code: 1011, Message: "Unknown Transaction Validity"}
-
-// ErrNilStorage is returned when the runtime context storage isn't set
-var ErrNilStorage = errors.New("runtime context storage is nil")

lib/runtime/wasmer/exports.go

@@ -16,7 +16,7 @@ import (
 // ValidateTransaction runs the extrinsic through the runtime function
 // TaggedTransactionQueue_validate_transaction and returns *Validity
 func (in *Instance) ValidateTransaction(e types.Extrinsic) (*transaction.Validity, error) {
-	ret, err := in.exec(runtime.TaggedTransactionQueueValidateTransaction, e)
+	ret, err := in.Exec(runtime.TaggedTransactionQueueValidateTransaction, e)
 	if err != nil {
 		return nil, err
 	}
@@ -33,7 +33,7 @@ func (in *Instance) ValidateTransaction(e types.Extrinsic) (*transaction.Validit
 
 // Version calls runtime function Core_Version
 func (in *Instance) Version() (runtime.Version, error) {
-	res, err := in.exec(runtime.CoreVersion, []byte{})
+	res, err := in.Exec(runtime.CoreVersion, []byte{})
 	if err != nil {
 		return nil, err
 	}
@@ -56,12 +56,12 @@ func (in *Instance) Version() (runtime.Version, error) {
 
 // Metadata calls runtime function Metadata_metadata
 func (in *Instance) Metadata() ([]byte, error) {
-	return in.exec(runtime.Metadata, []byte{})
+	return in.Exec(runtime.Metadata, []byte{})
 }
 
 // BabeConfiguration gets the configuration data for BABE from the runtime
 func (in *Instance) BabeConfiguration() (*types.BabeConfiguration, error) {
-	data, err := in.exec(runtime.BabeAPIConfiguration, []byte{})
+	data, err := in.Exec(runtime.BabeAPIConfiguration, []byte{})
 	if err != nil {
 		return nil, err
 	}
@@ -77,7 +77,7 @@ func (in *Instance) BabeConfiguration() (*types.BabeConfiguration, error) {
 
 // GrandpaAuthorities returns the genesis authorities from the runtime
 func (in *Instance) GrandpaAuthorities() ([]types.Authority, error) {
-	ret, err := in.exec(runtime.GrandpaAuthorities, []byte{})
+	ret, err := in.Exec(runtime.GrandpaAuthorities, []byte{})
 	if err != nil {
 		return nil, err
 	}
@@ -98,23 +98,23 @@ func (in *Instance) InitializeBlock(header *types.Header) error {
 		return fmt.Errorf("cannot encode header: %w", err)
 	}
 
-	_, err = in.exec(runtime.CoreInitializeBlock, encodedHeader)
+	_, err = in.Exec(runtime.CoreInitializeBlock, encodedHeader)
 	return err
 }
 
 // InherentExtrinsics calls runtime API function BlockBuilder_inherent_extrinsics
 func (in *Instance) InherentExtrinsics(data []byte) ([]byte, error) {
-	return in.exec(runtime.BlockBuilderInherentExtrinsics, data)
+	return in.Exec(runtime.BlockBuilderInherentExtrinsics, data)
 }
 
 // ApplyExtrinsic calls runtime API function BlockBuilder_apply_extrinsic
 func (in *Instance) ApplyExtrinsic(data types.Extrinsic) ([]byte, error) {
-	return in.exec(runtime.BlockBuilderApplyExtrinsic, data)
+	return in.Exec(runtime.BlockBuilderApplyExtrinsic, data)
 }
 
 // FinalizeBlock calls runtime API function BlockBuilder_finalize_block
 func (in *Instance) FinalizeBlock() (*types.Header, error) {
-	data, err := in.exec(runtime.BlockBuilderFinalizeBlock, []byte{})
+	data, err := in.Exec(runtime.BlockBuilderFinalizeBlock, []byte{})
 	if err != nil {
 		return nil, err
 	}
@@ -161,7 +161,7 @@ func (in *Instance) ExecuteBlock(block *types.Block) ([]byte, error) {
 
 // DecodeSessionKeys decodes the given public session keys. Returns a list of raw public keys including their key type.
 func (in *Instance) DecodeSessionKeys(enc []byte) ([]byte, error) {
-	return in.exec(runtime.DecodeSessionKeys, enc)
+	return in.Exec(runtime.DecodeSessionKeys, enc)
 }
 
 // PaymentQueryInfo returns information of a given extrinsic
@@ -171,7 +171,7 @@ func (in *Instance) PaymentQueryInfo(ext []byte) (*types.TransactionPaymentQuery
 		return nil, err
 	}
 
-	resBytes, err := in.exec(runtime.TransactionPaymentAPIQueryInfo, append(ext, encLen...))
+	resBytes, err := in.Exec(runtime.TransactionPaymentAPIQueryInfo, append(ext, encLen...))
 	if err != nil {
 		return nil, err
 	}

lib/runtime/wasmer/exports_test.go

@@ -5,7 +5,6 @@ package wasmer
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"math/big"
 	"os"
@@ -1022,15 +1021,14 @@ func TestInstance_DecodeSessionKeys(t *testing.T) {
 
 func TestInstance_PaymentQueryInfo(t *testing.T) {
 	tests := []struct {
-		extB   []byte
-		ext    string
-		err    error
-		expect *types.TransactionPaymentQueryInfo
+		extB       []byte
+		ext        string
+		errMessage string
+		expect     *types.TransactionPaymentQueryInfo
 	}{
 		{
 			// Was made with @polkadot/api on https://github.com/danforbes/polkadot-js-scripts/tree/create-signed-tx
 			ext: "0xd1018400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d01bc2b6e35929aabd5b8bc4e5b0168c9bee59e2bb9d6098769f6683ecf73e44c776652d947a270d59f3d37eb9f9c8c17ec1b4cc473f2f9928ffdeef0f3abd43e85d502000000012844616e20466f72626573", //nolint:lll
-			err: nil,
 			expect: &types.TransactionPaymentQueryInfo{
 				Weight: 1973000,
 				Class:  0,
@@ -1043,12 +1041,14 @@ func TestInstance_PaymentQueryInfo(t *testing.T) {
 		{
 			// incomplete extrinsic
 			ext: "0x4ccde39a5684e7a56da23b22d4d9fbadb023baa19c56495432884d0640000000000000000000000000000000",
-			err: errors.New("Failed to call the `TransactionPaymentApi_query_info` exported function."), //nolint:revive
+			errMessage: "running runtime function: " +
+				"Failed to call the `TransactionPaymentApi_query_info` exported function.",
 		},
 		{
 			// incomplete extrinsic
 			extB: nil,
-			err:  errors.New("Failed to call the `TransactionPaymentApi_query_info` exported function."), //nolint:revive
+			errMessage: "running runtime function: " +
+				"Failed to call the `TransactionPaymentApi_query_info` exported function.",
 		},
 	}
 
@@ -1066,11 +1066,11 @@ func TestInstance_PaymentQueryInfo(t *testing.T) {
 		ins := NewTestInstance(t, runtime.NODE_RUNTIME)
 		info, err := ins.PaymentQueryInfo(extBytes)
 
-		if test.err != nil {
-			require.Error(t, err)
-			require.Equal(t, err.Error(), test.err.Error())
+		if test.errMessage != "" {
+			assert.EqualError(t, err, test.errMessage)
 			continue
 		}
+		require.NoError(t, err)
 
 		fmt.Println(info.PartialFee.String())
 		fmt.Println(test.expect.PartialFee.String())

lib/runtime/wasmer/imports_test.go

@@ -41,8 +41,9 @@ func Test_ext_offchain_timestamp_version_1(t *testing.T) {
 	res, err := runtimeFunc(0, 0)
 	require.NoError(t, err)
 
-	offset, length := runtime.Int64ToPointerAndSize(res.ToI64())
-	data := inst.load(offset, length)
+	outputPtr, outputLength := runtime.Int64ToPointerAndSize(res.ToI64())
+	memory := inst.vm.Memory.Data()
+	data := memory[outputPtr : outputPtr+outputLength]
 	var timestamp int64
 	err = scale.Unmarshal(data, &timestamp)
 	require.NoError(t, err)
@@ -718,10 +719,12 @@ func Test_ext_crypto_ed25519_generate_version_1(t *testing.T) {
 	// we manually store and call the runtime function here since inst.exec assumes
 	// the data returned from the function is a pointer-size, but for ext_crypto_ed25519_generate_version_1,
 	// it's just a pointer
-	ptr, err := inst.malloc(uint32(len(params)))
+	ptr, err := inst.ctx.Allocator.Allocate(uint32(len(params)))
 	require.NoError(t, err)
 
-	inst.store(params, int32(ptr))
+	memory := inst.vm.Memory.Data()
+	copy(memory[ptr:ptr+uint32(len(params))], params)
+
 	dataLen := int32(len(params))
 
 	runtimeFunc, ok := inst.vm.Exports["rtm_ext_crypto_ed25519_generate_version_1"]
@@ -921,15 +924,15 @@ func Test_ext_crypto_ecdsa_verify_version_2_Table(t *testing.T) {
 			key: []byte{132, 2, 39, 55, 134, 131, 142, 43, 100, 63, 134, 96, 14, 253, 15, 222, 119, 154, 110, 188, 20, 159, 62, 125, 42, 59, 127, 19, 16, 0, 161, 236, 109}, //nolint:lll
 			err: wasmer.NewExportedFunctionError(
 				"rtm_ext_crypto_ecdsa_verify_version_2",
-				"Failed to call the `%s` exported function."),
+				"running runtime function: Failed to call the `%s` exported function."),
 		},
 		"invalid message": {
 			sig: []byte{5, 1, 187, 179, 88, 183, 46, 115, 242, 32, 9, 54, 141, 207, 44, 15, 238, 42, 217, 196, 111, 173, 239, 204, 128, 93, 49, 179, 137, 150, 162, 125, 226, 225, 28, 145, 122, 127, 15, 154, 185, 11, 3, 66, 27, 187, 204, 242, 107, 68, 26, 111, 245, 30, 115, 141, 85, 74, 158, 211, 161, 217, 43, 151, 120, 125, 1}, //nolint:lll
 			msg: []byte{48, 72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100},
 			key: []byte{132, 2, 39, 206, 55, 134, 131, 142, 43, 100, 63, 134, 96, 14, 253, 15, 222, 119, 154, 110, 188, 20, 159, 62, 125, 42, 59, 127, 19, 16, 0, 161, 236, 109}, //nolint:lll
 			err: wasmer.NewExportedFunctionError(
 				"rtm_ext_crypto_ecdsa_verify_version_2",
-				"Failed to call the `%s` exported function."),
+				"running runtime function: Failed to call the `%s` exported function."),
 		},
 	}
 	for name, tc := range testCases {
@@ -1592,7 +1595,8 @@ func Test_ext_default_child_storage_storage_kill_version_3(t *testing.T) {
 			key:      []byte(`fakekey`),
 			limit:    optLimit2,
 			expected: []byte{0, 0, 0, 0, 0},
-			errMsg:   "Failed to call the `rtm_ext_default_child_storage_storage_kill_version_3` exported function.",
+			errMsg: "running runtime function: " +
+				"Failed to call the `rtm_ext_default_child_storage_storage_kill_version_3` exported function.",
 		},
 		{key: testChildKey, limit: optLimit2, expected: []byte{1, 2, 0, 0, 0}},
 		{key: testChildKey, limit: nil, expected: []byte{0, 1, 0, 0, 0}},

lib/runtime/wasmer/instance.go

@@ -264,67 +264,45 @@ func (in *Instance) Stop() {
 	}
 }
 
-// Store func
-func (in *Instance) store(data []byte, location int32) {
-	mem := in.vm.Memory.Data()
-	copy(mem[location:location+int32(len(data))], data)
-}
-
-// Load load
-func (in *Instance) load(location, length int32) []byte {
-	mem := in.vm.Memory.Data()
-	return mem[location : location+length]
-}
+var (
+	ErrInstanceIsStopped      = errors.New("instance is stopped")
+	ErrExportFunctionNotFound = errors.New("export function not found")
+)
 
 // Exec calls the given function with the given data
-func (in *Instance) Exec(function string, data []byte) ([]byte, error) {
-	return in.exec(function, data)
-}
-
-// Exec func
-func (in *Instance) exec(function string, data []byte) ([]byte, error) {
-	if in.ctx.Storage == nil {
-		return nil, runtime.ErrNilStorage
-	}
-
+func (in *Instance) Exec(function string, data []byte) (result []byte, err error) {
 	in.Lock()
 	defer in.Unlock()
 
 	if in.isClosed {
-		return nil, errors.New("instance is stopped")
+		return nil, ErrInstanceIsStopped
 	}
 
-	ptr, err := in.malloc(uint32(len(data)))
+	dataLength := uint32(len(data))
+	inputPtr, err := in.ctx.Allocator.Allocate(dataLength)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("allocating input memory: %w", err)
 	}
 
-	defer in.clear()
+	defer in.ctx.Allocator.Clear()
 
 	// Store the data into memory
-	in.store(data, int32(ptr))
-	datalen := int32(len(data))
+	memory := in.vm.Memory.Data()
+	copy(memory[inputPtr:inputPtr+dataLength], data)
 
 	runtimeFunc, ok := in.vm.Exports[function]
 	if !ok {
-		return nil, fmt.Errorf("could not find exported function %s", function)
+		return nil, fmt.Errorf("%w: %s", ErrExportFunctionNotFound, function)
 	}
 
-	res, err := runtimeFunc(int32(ptr), datalen)
+	wasmValue, err := runtimeFunc(int32(inputPtr), int32(dataLength))
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("running runtime function: %w", err)
 	}
 
-	offset, length := runtime.Int64ToPointerAndSize(res.ToI64())
-	return in.load(offset, length), nil
-}
-
-func (in *Instance) malloc(size uint32) (uint32, error) {
-	return in.ctx.Allocator.Allocate(size)
-}
-
-func (in *Instance) clear() {
-	in.ctx.Allocator.Clear()
+	outputPtr, outputLength := runtime.Int64ToPointerAndSize(wasmValue.ToI64())
+	memory = in.vm.Memory.Data() // call Data() again to get larger slice
+	return memory[outputPtr : outputPtr+outputLength], nil
 }
 
 // NodeStorage to get reference to runtime node service

lib/runtime/wasmer/instance_test.go

@@ -20,10 +20,10 @@ func TestConcurrentRuntimeCalls(t *testing.T) {
 
 	// execute 2 concurrent calls to the runtime
 	go func() {
-		_, _ = instance.exec(runtime.CoreVersion, []byte{})
+		_, _ = instance.Exec(runtime.CoreVersion, []byte{})
 	}()
 	go func() {
-		_, _ = instance.exec(runtime.CoreVersion, []byte{})
+		_, _ = instance.Exec(runtime.CoreVersion, []byte{})
 	}()
 }