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1 files changed, 226 insertions, 0 deletions

diff --git a/accounts/abi/reflect.go b/accounts/abi/reflect.go
new file mode 100644
index 0000000..73ca8fa
--- /dev/null
+++ b/accounts/abi/reflect.go
@@ -0,0 +1,226 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// indirect recursively dereferences the value until it either gets the value
+// or finds a big.Int
+func indirect(v reflect.Value) reflect.Value {
+	if v.Kind() == reflect.Ptr && v.Elem().Type() != derefbigT {
+		return indirect(v.Elem())
+	}
+	return v
+}
+
+// indirectInterfaceOrPtr recursively dereferences the value until value is not interface.
+func indirectInterfaceOrPtr(v reflect.Value) reflect.Value {
+	if (v.Kind() == reflect.Interface || v.Kind() == reflect.Ptr) && v.Elem().IsValid() {
+		return indirect(v.Elem())
+	}
+	return v
+}
+
+// reflectIntKind returns the reflect using the given size and
+// unsignedness.
+func reflectIntKindAndType(unsigned bool, size int) (reflect.Kind, reflect.Type) {
+	switch size {
+	case 8:
+		if unsigned {
+			return reflect.Uint8, uint8T
+		}
+		return reflect.Int8, int8T
+	case 16:
+		if unsigned {
+			return reflect.Uint16, uint16T
+		}
+		return reflect.Int16, int16T
+	case 32:
+		if unsigned {
+			return reflect.Uint32, uint32T
+		}
+		return reflect.Int32, int32T
+	case 64:
+		if unsigned {
+			return reflect.Uint64, uint64T
+		}
+		return reflect.Int64, int64T
+	}
+	return reflect.Ptr, bigT
+}
+
+// mustArrayToBytesSlice creates a new byte slice with the exact same size as value
+// and copies the bytes in value to the new slice.
+func mustArrayToByteSlice(value reflect.Value) reflect.Value {
+	slice := reflect.MakeSlice(reflect.TypeOf([]byte{}), value.Len(), value.Len())
+	reflect.Copy(slice, value)
+	return slice
+}
+
+// set attempts to assign src to dst by either setting, copying or otherwise.
+//
+// set is a bit more lenient when it comes to assignment and doesn't force an as
+// strict ruleset as bare `reflect` does.
+func set(dst, src reflect.Value) error {
+	dstType, srcType := dst.Type(), src.Type()
+	switch {
+	case dstType.Kind() == reflect.Interface && dst.Elem().IsValid():
+		return set(dst.Elem(), src)
+	case dstType.Kind() == reflect.Ptr && dstType.Elem() != derefbigT:
+		return set(dst.Elem(), src)
+	case srcType.AssignableTo(dstType) && dst.CanSet():
+		dst.Set(src)
+	case dstType.Kind() == reflect.Slice && srcType.Kind() == reflect.Slice:
+		return setSlice(dst, src)
+	default:
+		return fmt.Errorf("abi: cannot unmarshal %v in to %v", src.Type(), dst.Type())
+	}
+	return nil
+}
+
+// setSlice attempts to assign src to dst when slices are not assignable by default
+// e.g. src: [][]byte -> dst: [][15]byte
+func setSlice(dst, src reflect.Value) error {
+	slice := reflect.MakeSlice(dst.Type(), src.Len(), src.Len())
+	for i := 0; i < src.Len(); i++ {
+		v := src.Index(i)
+		reflect.Copy(slice.Index(i), v)
+	}
+
+	dst.Set(slice)
+	return nil
+}
+
+// requireAssignable assures that `dest` is a pointer and it's not an interface.
+func requireAssignable(dst, src reflect.Value) error {
+	if dst.Kind() != reflect.Ptr && dst.Kind() != reflect.Interface {
+		return fmt.Errorf("abi: cannot unmarshal %v into %v", src.Type(), dst.Type())
+	}
+	return nil
+}
+
+// requireUnpackKind verifies preconditions for unpacking `args` into `kind`
+func requireUnpackKind(v reflect.Value, t reflect.Type, k reflect.Kind,
+	args Arguments) error {
+
+	switch k {
+	case reflect.Struct:
+	case reflect.Slice, reflect.Array:
+		if minLen := args.LengthNonIndexed(); v.Len() < minLen {
+			return fmt.Errorf("abi: insufficient number of elements in the list/array for unpack, want %d, got %d",
+				minLen, v.Len())
+		}
+	default:
+		return fmt.Errorf("abi: cannot unmarshal tuple into %v", t)
+	}
+	return nil
+}
+
+// mapArgNamesToStructFields maps a slice of argument names to struct fields.
+// first round: for each Exportable field that contains a `abi:""` tag
+//   and this field name exists in the given argument name list, pair them together.
+// second round: for each argument name that has not been already linked,
+//   find what variable is expected to be mapped into, if it exists and has not been
+//   used, pair them.
+// Note this function assumes the given value is a struct value.
+func mapArgNamesToStructFields(argNames []string, value reflect.Value) (map[string]string, error) {
+	typ := value.Type()
+
+	abi2struct := make(map[string]string)
+	struct2abi := make(map[string]string)
+
+	// first round ~~~
+	for i := 0; i < typ.NumField(); i++ {
+		structFieldName := typ.Field(i).Name
+
+		// skip private struct fields.
+		if structFieldName[:1] != strings.ToUpper(structFieldName[:1]) {
+			continue
+		}
+		// skip fields that have no abi:"" tag.
+		var ok bool
+		var tagName string
+		if tagName, ok = typ.Field(i).Tag.Lookup("abi"); !ok {
+			continue
+		}
+		// check if tag is empty.
+		if tagName == "" {
+			return nil, fmt.Errorf("struct: abi tag in '%s' is empty", structFieldName)
+		}
+		// check which argument field matches with the abi tag.
+		found := false
+		for _, arg := range argNames {
+			if arg == tagName {
+				if abi2struct[arg] != "" {
+					return nil, fmt.Errorf("struct: abi tag in '%s' already mapped", structFieldName)
+				}
+				// pair them
+				abi2struct[arg] = structFieldName
+				struct2abi[structFieldName] = arg
+				found = true
+			}
+		}
+		// check if this tag has been mapped.
+		if !found {
+			return nil, fmt.Errorf("struct: abi tag '%s' defined but not found in abi", tagName)
+		}
+	}
+
+	// second round ~~~
+	for _, argName := range argNames {
+
+		structFieldName := ToCamelCase(argName)
+
+		if structFieldName == "" {
+			return nil, fmt.Errorf("abi: purely underscored output cannot unpack to struct")
+		}
+
+		// this abi has already been paired, skip it... unless there exists another, yet unassigned
+		// struct field with the same field name. If so, raise an error:
+		//    abi: [ { "name": "value" } ]
+		//    struct { Value  *big.Int , Value1 *big.Int `abi:"value"`}
+		if abi2struct[argName] != "" {
+			if abi2struct[argName] != structFieldName &&
+				struct2abi[structFieldName] == "" &&
+				value.FieldByName(structFieldName).IsValid() {
+				return nil, fmt.Errorf("abi: multiple variables maps to the same abi field '%s'", argName)
+			}
+			continue
+		}
+
+		// return an error if this struct field has already been paired.
+		if struct2abi[structFieldName] != "" {
+			return nil, fmt.Errorf("abi: multiple outputs mapping to the same struct field '%s'", structFieldName)
+		}
+
+		if value.FieldByName(structFieldName).IsValid() {
+			// pair them
+			abi2struct[argName] = structFieldName
+			struct2abi[structFieldName] = argName
+		} else {
+			// not paired, but annotate as used, to detect cases like
+			//   abi : [ { "name": "value" }, { "name": "_value" } ]
+			//   struct { Value *big.Int }
+			struct2abi[structFieldName] = argName
+		}
+	}
+	return abi2struct, nil
+}