Craetes a function to get the max size for abi.Argumetns, given any outermost slices have N elements

core/services/relay/evm/codec_entry.go

@@ -17,12 +17,12 @@ type CodecEntry struct {
 	nativeType  reflect.Type
 }
 
-func (info *CodecEntry) Init() error {
-	if info.checkedType != nil {
+func (entry *CodecEntry) Init() error {
+	if entry.checkedType != nil {
 		return nil
 	}
 
-	args := UnwrapArgs(info.Args)
+	args := UnwrapArgs(entry.Args)
 	argLen := len(args)
 	native := make([]reflect.StructField, argLen)
 	checked := make([]reflect.StructField, argLen)
@@ -32,8 +32,8 @@ func (info *CodecEntry) Init() error {
 		if err != nil {
 			return err
 		}
-		info.nativeType = nativeArg
-		info.checkedType = checkedArg
+		entry.nativeType = nativeArg
+		entry.checkedType = checkedArg
 		return nil
 	}
 
@@ -49,11 +49,18 @@ func (info *CodecEntry) Init() error {
 		checked[i] = reflect.StructField{Name: name, Type: checkedArg, Tag: tag}
 	}
 
-	info.nativeType = reflect.StructOf(native)
-	info.checkedType = reflect.StructOf(checked)
+	entry.nativeType = reflect.StructOf(native)
+	entry.checkedType = reflect.StructOf(checked)
 	return nil
 }
 
+func (entry *CodecEntry) GetMaxSize(n int) (int, error) {
+	if entry == nil {
+		return 0, commontypes.ErrInvalidType
+	}
+	return GetMaxSize(n, entry.Args)
+}
+
 func UnwrapArgs(args abi.Arguments) abi.Arguments {
 	// Unwrap an unnamed tuple so that callers don't need to wrap it
 	// Eg: If you have struct Foo { ... } and return an unnamed Foo, you should be able ot decode to a go Foo{} directly

core/services/relay/evm/size_helper.go

@@ -0,0 +1,65 @@
+package evm
+
+import (
+	"github.com/ethereum/go-ethereum/accounts/abi"
+
+	commontypes "github.com/smartcontractkit/chainlink-common/pkg/types"
+)
+
+func GetMaxSize(n int, args abi.Arguments) (int, error) {
+	size := 0
+	for _, arg := range args {
+		tmp := arg.Type
+		argSize, _, err := getTypeSize(n, &tmp, true, false)
+		if err != nil {
+			return 0, err
+		}
+		size += argSize
+	}
+
+	return size, nil
+}
+
+func getTypeSize(n int, t *abi.Type, dynamicTypeAllowed bool, isNested bool) (int, bool, error) {
+	// See https://docs.soliditylang.org/en/latest/abi-spec.html#formal-specification-of-the-encoding
+	switch t.T {
+	case abi.ArrayTy:
+		elmSize, _, err := getTypeSize(n, t.Elem, false, true)
+		return t.Size * elmSize, false, err
+	case abi.SliceTy:
+		if !dynamicTypeAllowed {
+			return 0, false, commontypes.ErrInvalidType
+		}
+		elmSize, _, err := getTypeSize(n, t.Elem, false, true)
+		return 32 /*header*/ + 32 /*footer*/ + elmSize*n, true, err
+	case abi.BytesTy, abi.StringTy:
+		if !dynamicTypeAllowed {
+			return 0, false, commontypes.ErrInvalidType
+		}
+		totalSize := (n + 31) / 32 * 32 // strings and bytes are padded to 32 bytes
+		return 32 /*header*/ + 32 /*footer*/ + totalSize, true, nil
+	case abi.TupleTy:
+		// No header or footer, because if the tuple is dynamically sized we would need to know the inner slice sizes
+		// so it would return error for that element.
+		size := 0
+		dynamic := false
+		for _, elm := range t.TupleElems {
+			argSize, dynamicArg, err := getTypeSize(n, elm, !isNested, true)
+			if err != nil {
+				return 0, false, err
+			}
+			dynamic = dynamic || dynamicArg
+			size += argSize
+		}
+
+		if dynamic {
+			// offset for the element needs to be included there are dynamic elements
+			size += 32
+		}
+
+		return size, dynamic, nil
+	default:
+		// types are padded to 32 bytes
+		return 32, false, nil
+	}
+}

core/services/relay/evm/size_helper_test.go

@@ -0,0 +1,263 @@
+package evm_test
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	commontypes "github.com/smartcontractkit/chainlink-common/pkg/types"
+
+	"github.com/smartcontractkit/chainlink/v2/core/services/relay/evm"
+)
+
+const anyNumElements = 10
+
+func TestGetMaxSize(t *testing.T) {
+	t.Run("Basic types all encode to 32 bytes", func(t *testing.T) {
+		args := abi.Arguments{
+			{Name: "I8", Type: mustType(t, "int8")},
+			{Name: "I80", Type: mustType(t, "int80")},
+			{Name: "I256", Type: mustType(t, "int256")},
+			{Name: "B3", Type: mustType(t, "bytes3")},
+			{Name: "B32", Type: mustType(t, "bytes32")},
+			{Name: "TF", Type: mustType(t, "bool")},
+		}
+
+		runSizeTest(t, anyNumElements, args, int8(9), big.NewInt(3), big.NewInt(200), [3]byte{1, 3, 4}, make32Bytes(1), true)
+	})
+
+	t.Run("Slices of basic types all encode to 32 bytes each + header and footer", func(t *testing.T) {
+		args := abi.Arguments{
+			{Name: "I8", Type: mustType(t, "int8[]")},
+			{Name: "I80", Type: mustType(t, "int80[]")},
+			{Name: "I256", Type: mustType(t, "int256[]")},
+			{Name: "B3", Type: mustType(t, "bytes3[]")},
+			{Name: "B32", Type: mustType(t, "bytes32[]")},
+			{Name: "TF", Type: mustType(t, "bool[]")},
+		}
+
+		i8 := []int8{9, 2, 1, 3, 5, 6, 2, 1, 2, 3}
+		i80 := []*big.Int{big.NewInt(9), big.NewInt(2), big.NewInt(1), big.NewInt(3), big.NewInt(5), big.NewInt(6), big.NewInt(2), big.NewInt(1), big.NewInt(2), big.NewInt(3)}
+		i256 := []*big.Int{big.NewInt(119), big.NewInt(112), big.NewInt(1), big.NewInt(3), big.NewInt(5), big.NewInt(6), big.NewInt(2), big.NewInt(1), big.NewInt(2), big.NewInt(3)}
+		b3 := [][3]byte{{1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}, {1, 2, 3}}
+		b32 := [][32]byte{make32Bytes(1), make32Bytes(2), make32Bytes(3), make32Bytes(4), make32Bytes(5), make32Bytes(6), make32Bytes(7), make32Bytes(8), make32Bytes(9), make32Bytes(10)}
+		tf := []bool{true, false, true, false, true, false, true, false, true, false}
+		runSizeTest(t, anyNumElements, args, i8, i80, i256, b3, b32, tf)
+	})
+
+	t.Run("Arrays of basic types all encode to 32 bytes each", func(t *testing.T) {
+		args := abi.Arguments{
+			{Name: "I8", Type: mustType(t, "int8[3]")},
+			{Name: "I80", Type: mustType(t, "int80[3]")},
+			{Name: "I256", Type: mustType(t, "int256[3]")},
+			{Name: "B3", Type: mustType(t, "bytes3[3]")},
+			{Name: "B32", Type: mustType(t, "bytes32[3]")},
+			{Name: "TF", Type: mustType(t, "bool[3]")},
+		}
+
+		i8 := [3]int8{9, 2, 1}
+		i80 := [3]*big.Int{big.NewInt(9), big.NewInt(2), big.NewInt(1)}
+		i256 := [3]*big.Int{big.NewInt(119), big.NewInt(112), big.NewInt(1)}
+		b3 := [3][3]byte{{1, 2, 3}, {1, 2, 3}, {1, 2, 3}}
+		b32 := [3][32]byte{make32Bytes(1), make32Bytes(2), make32Bytes(3)}
+		tf := [3]bool{true, false, true}
+		runSizeTest(t, anyNumElements, args, i8, i80, i256, b3, b32, tf)
+	})
+
+	t.Run("Tuples are a sum of their elements", func(t *testing.T) {
+		tuple1 := []abi.ArgumentMarshaling{
+			{Name: "I8", Type: "int8"},
+			{Name: "I80", Type: "int80"},
+			{Name: "I256", Type: "int256"},
+			{Name: "B3", Type: "bytes3"},
+			{Name: "B32", Type: "bytes32"},
+			{Name: "TF", Type: "bool"},
+		}
+		t1, err := abi.NewType("tuple", "", tuple1)
+		require.NoError(t, err)
+
+		tuple2 := []abi.ArgumentMarshaling{
+			{Name: "I80", Type: "int80"},
+			{Name: "TF", Type: "bool"},
+		}
+		t2, err := abi.NewType("tuple", "", tuple2)
+		require.NoError(t, err)
+
+		args := abi.Arguments{
+			{Name: "t1", Type: t1},
+			{Name: "t2", Type: t2},
+		}
+		arg1 := struct {
+			I8   int8
+			I80  *big.Int
+			I256 *big.Int
+			B3   [3]byte
+			B32  [32]byte
+			TF   bool
+		}{
+			int8(9), big.NewInt(3), big.NewInt(200), [3]byte{1, 3, 4}, make32Bytes(1), true,
+		}
+
+		arg2 := struct {
+			I80 *big.Int
+			TF  bool
+		}{
+			big.NewInt(3), true,
+		}
+		runSizeTest(t, anyNumElements, args, arg1, arg2)
+	})
+
+	t.Run("Slices of tuples are a sum of their elements with header and footer", func(t *testing.T) {
+		tuple1 := []abi.ArgumentMarshaling{
+			{Name: "I80", Type: "int80"},
+			{Name: "TF", Type: "bool"},
+		}
+		t1, err := abi.NewType("tuple[]", "", tuple1)
+		require.NoError(t, err)
+
+		args := abi.Arguments{
+			{Name: "t1", Type: t1},
+		}
+		arg1 := []struct {
+			I80 *big.Int
+			TF  bool
+		}{
+			{big.NewInt(1), true},
+			{big.NewInt(2), true},
+			{big.NewInt(3), true},
+			{big.NewInt(4), false},
+			{big.NewInt(5), true},
+			{big.NewInt(6), true},
+			{big.NewInt(7), true},
+			{big.NewInt(8), false},
+			{big.NewInt(9), true},
+			{big.NewInt(10), true},
+		}
+		runSizeTest(t, anyNumElements, args, arg1)
+	})
+
+	t.Run("Arrays of tuples are a sum of their elements", func(t *testing.T) {
+		tuple1 := []abi.ArgumentMarshaling{
+			{Name: "I80", Type: "int80"},
+			{Name: "TF", Type: "bool"},
+		}
+		t1, err := abi.NewType("tuple[3]", "", tuple1)
+		require.NoError(t, err)
+
+		args := abi.Arguments{
+			{Name: "t1", Type: t1},
+		}
+		arg1 := []struct {
+			I80 *big.Int
+			TF  bool
+		}{
+			{big.NewInt(1), true},
+			{big.NewInt(2), true},
+			{big.NewInt(3), true},
+		}
+		runSizeTest(t, anyNumElements, args, arg1)
+
+	})
+
+	t.Run("Bytes pack themselves", func(t *testing.T) {
+		args := abi.Arguments{{Name: "B", Type: mustType(t, "bytes")}}
+		t.Run("No padding needed", func(t *testing.T) {
+			padded := []byte("12345789022345678903234567890412345678905123456789061234")
+			runSizeTest(t, 64, args, padded)
+		})
+		t.Run("Padding needed", func(t *testing.T) {
+			needsPadding := []byte("12345789022345678903234567890412345678905123456")
+			runSizeTest(t, 56, args, needsPadding)
+		})
+	})
+
+	t.Run("Strings pack themselves", func(t *testing.T) {
+		args := abi.Arguments{{Name: "B", Type: mustType(t, "string")}}
+		t.Run("No padding needed", func(t *testing.T) {
+			padded := "12345789022345678903234567890412345678905123456789061234"
+			runSizeTest(t, 64, args, padded)
+		})
+		t.Run("Padding needed", func(t *testing.T) {
+			needsPadding := "12345789022345678903234567890412345678905123456"
+			runSizeTest(t, 56, args, needsPadding)
+		})
+	})
+
+	t.Run("Nested dynamic types return errors", func(t *testing.T) {
+		t.Run("Slice in slice", func(t *testing.T) {
+			args := abi.Arguments{{Name: "B", Type: mustType(t, "int32[][]")}}
+			_, err := evm.GetMaxSize(anyNumElements, args)
+			assert.IsType(t, commontypes.ErrInvalidType, err)
+		})
+		t.Run("Slice in array", func(t *testing.T) {
+			args := abi.Arguments{{Name: "B", Type: mustType(t, "int32[][2]")}}
+			_, err := evm.GetMaxSize(anyNumElements, args)
+			assert.IsType(t, commontypes.ErrInvalidType, err)
+		})
+	})
+
+	t.Run("Slices in a top level tuple works as-if they are the sized element", func(t *testing.T) {
+		tuple1 := []abi.ArgumentMarshaling{
+			{Name: "I80", Type: "int80[]"},
+			{Name: "TF", Type: "bool[]"},
+		}
+		t1, err := abi.NewType("tuple", "", tuple1)
+		require.NoError(t, err)
+		args := abi.Arguments{{Name: "tuple", Type: t1}}
+
+		arg1 := struct {
+			I80 []*big.Int
+			TF  []bool
+		}{
+			I80: []*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3), big.NewInt(4), big.NewInt(5), big.NewInt(6), big.NewInt(7), big.NewInt(8), big.NewInt(9), big.NewInt(10)},
+			TF:  []bool{true, true, true, false, true, true, true, false, true, true},
+		}
+
+		runSizeTest(t, anyNumElements, args, arg1)
+	})
+
+	t.Run("Nested dynamic tuples return errors", func(t *testing.T) {
+		tuple1 := []abi.ArgumentMarshaling{
+			{Name: "I8", Type: "int8"},
+			{Name: "I80", Type: "int80"},
+			{Name: "I256", Type: "int256"},
+			{Name: "B3", Type: "bytes3"},
+			{Name: "B32", Type: "bytes32"},
+			{Name: "TF", Type: "bool[]"},
+		}
+
+		tuple2 := []abi.ArgumentMarshaling{
+			{Name: "I80", Type: "int80"},
+			{Name: "T1", Type: "tuple", Components: tuple1},
+		}
+		t2, err := abi.NewType("tuple", "", tuple2)
+		require.NoError(t, err)
+
+		args := abi.Arguments{{Name: "t2", Type: t2}}
+		_, err = evm.GetMaxSize(anyNumElements, args)
+		assert.IsType(t, commontypes.ErrInvalidType, err)
+	})
+}
+
+func runSizeTest(t *testing.T, n int, args abi.Arguments, params ...any) {
+
+	actual, err := evm.GetMaxSize(n, args)
+	require.NoError(t, err)
+
+	expected, err := args.Pack(params...)
+	require.NoError(t, err)
+	assert.Equal(t, len(expected), actual)
+}
+
+func mustType(t *testing.T, name string) abi.Type {
+	aType, err := abi.NewType(name, "", []abi.ArgumentMarshaling{})
+	require.NoError(t, err)
+	return aType
+}
+
+func make32Bytes(firstByte byte) [32]byte {
+	return [32]byte{firstByte, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3}
+}