add built-in CCF contract with encode function

Author: turbolent

cmd/cmd.go

@@ -26,6 +26,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/onflow/cadence"
 	"github.com/onflow/cadence/activations"
 	"github.com/onflow/cadence/ast"
 	"github.com/onflow/cadence/common"
@@ -433,6 +434,17 @@ func (h *StandardLibraryHandler) IsContractBeingAdded(common.AddressLocation) bo
 	return false
 }
 
+func (h *StandardLibraryHandler) ExportValue(
+	_ interpreter.Value,
+	_ *interpreter.Interpreter,
+	_ interpreter.LocationRange,
+) (
+	cadence.Value,
+	error,
+) {
+	return nil, goerrors.New("exporting values is not supported in this environment")
+}
+
 func formatLocationRange(locationRange interpreter.LocationRange) string {
 	var builder strings.Builder
 	if locationRange.Location != nil {

common/computationkind.go

@@ -142,4 +142,6 @@ const (
 	// RLP
 	ComputationKindSTDLIBRLPDecodeString
 	ComputationKindSTDLIBRLPDecodeList
+	// CCF
+	ComputationKindSTDLIBCCFEncode
 )

runtime/environment.go

@@ -146,6 +146,7 @@ var _ stdlib.BLSPoPVerifier = &interpreterEnvironment{}
 var _ stdlib.BLSPublicKeyAggregator = &interpreterEnvironment{}
 var _ stdlib.BLSSignatureAggregator = &interpreterEnvironment{}
 var _ stdlib.Hasher = &interpreterEnvironment{}
+var _ stdlib.Exporter = &interpreterEnvironment{}
 var _ ArgumentDecoder = &interpreterEnvironment{}
 var _ common.MemoryGauge = &interpreterEnvironment{}
 
@@ -1426,3 +1427,18 @@ func (e *interpreterEnvironment) newValidateAccountCapabilitiesPublishHandler()
 		return ok, err
 	}
 }
+
+func (e *interpreterEnvironment) ExportValue(
+	value interpreter.Value,
+	interpreter *interpreter.Interpreter,
+	locationRange interpreter.LocationRange,
+) (
+	cadence.Value,
+	error,
+) {
+	return ExportValue(
+		value,
+		interpreter,
+		locationRange,
+	)
+}

stdlib/builtin.go

@@ -36,6 +36,7 @@ type StandardLibraryHandler interface {
 	BLSPublicKeyAggregator
 	BLSSignatureAggregator
 	Hasher
+	Exporter
 }
 
 func DefaultStandardLibraryValues(handler StandardLibraryHandler) []StandardLibraryValue {
@@ -54,6 +55,7 @@ func DefaultStandardLibraryValues(handler StandardLibraryHandler) []StandardLibr
 		NewPublicKeyConstructor(handler),
 		NewBLSContract(nil, handler),
 		NewHashAlgorithmConstructor(handler),
+		NewCCFContract(nil, handler),
 	}
 }
 

stdlib/ccf.cdc

@@ -0,0 +1,7 @@
+access(all)
+contract CCF {
+    /// Encodes an encodable value to CCF.
+    /// Returns nil if the value cannot be encoded.
+    access(all)
+    view fun encode(_ input: &Any): [UInt8]?
+}

stdlib/ccf.go

@@ -0,0 +1,113 @@
+/*
+ * Cadence - The resource-oriented smart contract programming language
+ *
+ * Copyright Flow Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package stdlib
+
+//go:generate go run ../sema/gen -p stdlib ccf.cdc ccf.gen.go
+
+import (
+	"github.com/onflow/cadence"
+	"github.com/onflow/cadence/common"
+	"github.com/onflow/cadence/encoding/ccf"
+	"github.com/onflow/cadence/errors"
+	"github.com/onflow/cadence/interpreter"
+)
+
+type Exporter interface {
+	ExportValue(
+		value interpreter.Value,
+		interpreter *interpreter.Interpreter,
+		locationRange interpreter.LocationRange,
+	) (
+		cadence.Value,
+		error,
+	)
+}
+
+type CCFContractHandler interface {
+	Exporter
+}
+
+// newCCFEncodeFunction creates a new host function that encodes a value using the CCF encoding format.
+func newCCFEncodeFunction(
+	gauge common.MemoryGauge,
+	handler CCFContractHandler,
+) *interpreter.HostFunctionValue {
+	return interpreter.NewStaticHostFunctionValue(
+		gauge,
+		CCFTypeEncodeFunctionType,
+		func(invocation interpreter.Invocation) interpreter.Value {
+			inter := invocation.Interpreter
+			locationRange := invocation.LocationRange
+
+			referenceValue, ok := invocation.Arguments[0].(interpreter.ReferenceValue)
+			if !ok {
+				panic(errors.NewUnreachableError())
+			}
+
+			referencedValue := referenceValue.ReferencedValue(inter, locationRange, true)
+			if referencedValue == nil {
+				return interpreter.Nil
+			}
+
+			exportedValue, err := handler.ExportValue(*referencedValue, inter, locationRange)
+			if err != nil {
+				return interpreter.Nil
+			}
+
+			encoded, err := ccf.Encode(exportedValue)
+			if err != nil {
+				return interpreter.Nil
+			}
+
+			res := interpreter.ByteSliceToByteArrayValue(inter, encoded)
+
+			return interpreter.NewSomeValueNonCopying(inter, res)
+		},
+	)
+}
+
+var CCFTypeStaticType = interpreter.ConvertSemaToStaticType(nil, CCFType)
+
+func NewCCFContract(
+	gauge common.MemoryGauge,
+	handler CCFContractHandler,
+) StandardLibraryValue {
+
+	ccfContractFields := map[string]interpreter.Value{
+		CCFTypeEncodeFunctionName: newCCFEncodeFunction(gauge, handler),
+	}
+
+	var ccfContractValue = interpreter.NewSimpleCompositeValue(
+		gauge,
+		CCFType.ID(),
+		CCFTypeStaticType,
+		nil,
+		ccfContractFields,
+		nil,
+		nil,
+		nil,
+	)
+
+	return StandardLibraryValue{
+		Name:  CCFTypeName,
+		Type:  CCFType,
+		Value: ccfContractValue,
+		Kind:  common.DeclarationKindContract,
+	}
+}

tests/ccf_test.go

@@ -0,0 +1,106 @@
+/*
+ * Cadence - The resource-oriented smart contract programming language
+ *
+ * Copyright Flow Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package tests
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/onflow/cadence"
+	"github.com/onflow/cadence/common"
+	. "github.com/onflow/cadence/runtime"
+	. "github.com/onflow/cadence/tests/runtime_utils"
+)
+
+func TestRuntimeCCFEncodeStruct(t *testing.T) {
+
+	t.Parallel()
+
+	type testCase struct {
+		name   string
+		value  string
+		output []byte
+	}
+
+	tests := []testCase{
+		{
+			name:   "String",
+			value:  `"test"`,
+			output: []byte{0xd8, 0x82, 0x82, 0xd8, 0x89, 0x1, 0x64, 0x74, 0x65, 0x73, 0x74},
+		},
+		{
+			name:   "Bool",
+			value:  `true`,
+			output: []byte{0xd8, 0x82, 0x82, 0xd8, 0x89, 0x0, 0xf5},
+		},
+		{
+			name:   "function",
+			value:  `fun (): Int { return 1 }`,
+			output: []byte{0xd8, 0x82, 0x82, 0xd8, 0x89, 0x18, 0x33, 0x84, 0x80, 0x80, 0xd8, 0xb9, 0x4, 0x0},
+		},
+	}
+
+	test := func(test testCase) {
+		t.Run(test.name, func(t *testing.T) {
+
+			t.Parallel()
+
+			runtime := NewTestInterpreterRuntime()
+
+			runtimeInterface := &TestRuntimeInterface{
+				Storage: NewTestLedger(nil, nil),
+			}
+
+			script := []byte(fmt.Sprintf(
+				`
+                  access(all) fun main(): [UInt8]? {
+                      let value = %s
+                      return CCF.encode(&value as &AnyStruct)
+                  }
+                `,
+				test.value,
+			))
+
+			result, err := runtime.ExecuteScript(
+				Script{
+					Source: script,
+				},
+				Context{
+					Interface: runtimeInterface,
+					Location:  common.ScriptLocation{},
+				},
+			)
+			require.NoError(t, err)
+
+			assert.Equal(t,
+				cadence.NewOptional(
+					cadence.ByteSliceToByteArray(test.output),
+				),
+				result,
+			)
+		})
+	}
+
+	for _, testCase := range tests {
+		test(testCase)
+	}
+}

values.go

@@ -1436,6 +1436,19 @@ func (v Array) String() string {
 	return format.Array(values)
 }
 
+var ByteArrayType = NewVariableSizedArrayType(PrimitiveType(interpreter.PrimitiveStaticTypeUInt8))
+
+// ByteSliceToByteArray converts a byte slice to a Cadence byte array of type [UInt8].
+func ByteSliceToByteArray(b []byte) Array {
+	values := make([]Value, len(b))
+
+	for i, v := range b {
+		values[i] = UInt8(v)
+	}
+
+	return NewArray(values).WithType(ByteArrayType)
+}
+
 // Dictionary
 
 type Dictionary struct {