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author | Guillaume Ballet <gballet@gmail.com> | 2018-05-14 20:47:31 +0800 |
---|---|---|
committer | GitHub <noreply@github.com> | 2018-05-14 20:47:31 +0800 |
commit | 247b5f03690b47fdcb862c9a1173365cbdd9d279 (patch) | |
tree | 582b47762aa978c12caa63e55ae9dc8cc9136aa1 /accounts | |
parent | 49ec4f0cd1f4d4c84c13ccd8d920d56112d7268a (diff) | |
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accounts/abi: allow abi: tags when unpacking structs
Go code users can now tag event struct members with `abi:` to specify in what fields the event will be de-serialized.
See PR #16648 for details.
Diffstat (limited to 'accounts')
-rw-r--r-- | accounts/abi/argument.go | 44 | ||||
-rw-r--r-- | accounts/abi/event_test.go | 81 | ||||
-rw-r--r-- | accounts/abi/reflect.go | 104 |
3 files changed, 194 insertions, 35 deletions
diff --git a/accounts/abi/argument.go b/accounts/abi/argument.go index 512d8fdfa..93b513c34 100644 --- a/accounts/abi/argument.go +++ b/accounts/abi/argument.go @@ -111,9 +111,14 @@ func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interfa if err := requireUnpackKind(value, typ, kind, arguments); err != nil { return err } - // If the output interface is a struct, make sure names don't collide + + // If the interface is a struct, get of abi->struct_field mapping + + var abi2struct map[string]string if kind == reflect.Struct { - if err := requireUniqueStructFieldNames(arguments); err != nil { + var err error + abi2struct, err = mapAbiToStructFields(arguments, value) + if err != nil { return err } } @@ -123,9 +128,10 @@ func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interfa switch kind { case reflect.Struct: - err := unpackStruct(value, reflectValue, arg) - if err != nil { - return err + if structField, ok := abi2struct[arg.Name]; ok { + if err := set(value.FieldByName(structField), reflectValue, arg); err != nil { + return err + } } case reflect.Slice, reflect.Array: if value.Len() < i { @@ -151,17 +157,22 @@ func (arguments Arguments) unpackAtomic(v interface{}, marshalledValues []interf if len(marshalledValues) != 1 { return fmt.Errorf("abi: wrong length, expected single value, got %d", len(marshalledValues)) } + elem := reflect.ValueOf(v).Elem() kind := elem.Kind() reflectValue := reflect.ValueOf(marshalledValues[0]) + var abi2struct map[string]string if kind == reflect.Struct { - //make sure names don't collide - if err := requireUniqueStructFieldNames(arguments); err != nil { + var err error + if abi2struct, err = mapAbiToStructFields(arguments, elem); err != nil { return err } - - return unpackStruct(elem, reflectValue, arguments[0]) + arg := arguments.NonIndexed()[0] + if structField, ok := abi2struct[arg.Name]; ok { + return set(elem.FieldByName(structField), reflectValue, arg) + } + return nil } return set(elem, reflectValue, arguments.NonIndexed()[0]) @@ -277,18 +288,3 @@ func capitalise(input string) string { } return strings.ToUpper(input[:1]) + input[1:] } - -//unpackStruct extracts each argument into its corresponding struct field -func unpackStruct(value, reflectValue reflect.Value, arg Argument) error { - name := capitalise(arg.Name) - typ := value.Type() - for j := 0; j < typ.NumField(); j++ { - // TODO read tags: `abi:"fieldName"` - if typ.Field(j).Name == name { - if err := set(value.Field(j), reflectValue, arg); err != nil { - return err - } - } - } - return nil -} diff --git a/accounts/abi/event_test.go b/accounts/abi/event_test.go index cca61e433..3bfdd7c0a 100644 --- a/accounts/abi/event_test.go +++ b/accounts/abi/event_test.go @@ -58,12 +58,28 @@ var jsonEventPledge = []byte(`{ "type": "event" }`) +var jsonEventMixedCase = []byte(`{ + "anonymous": false, + "inputs": [{ + "indexed": false, "name": "value", "type": "uint256" + }, { + "indexed": false, "name": "_value", "type": "uint256" + }, { + "indexed": false, "name": "Value", "type": "uint256" + }], + "name": "MixedCase", + "type": "event" + }`) + // 1000000 var transferData1 = "00000000000000000000000000000000000000000000000000000000000f4240" // "0x00Ce0d46d924CC8437c806721496599FC3FFA268", 2218516807680, "usd" var pledgeData1 = "00000000000000000000000000ce0d46d924cc8437c806721496599fc3ffa2680000000000000000000000000000000000000000000000000000020489e800007573640000000000000000000000000000000000000000000000000000000000" +// 1000000,2218516807680,1000001 +var mixedCaseData1 = "00000000000000000000000000000000000000000000000000000000000f42400000000000000000000000000000000000000000000000000000020489e8000000000000000000000000000000000000000000000000000000000000000f4241" + func TestEventId(t *testing.T) { var table = []struct { definition string @@ -121,6 +137,27 @@ func TestEventTupleUnpack(t *testing.T) { Value *big.Int } + type EventTransferWithTag struct { + // this is valid because `value` is not exportable, + // so value is only unmarshalled into `Value1`. + value *big.Int + Value1 *big.Int `abi:"value"` + } + + type BadEventTransferWithSameFieldAndTag struct { + Value *big.Int + Value1 *big.Int `abi:"value"` + } + + type BadEventTransferWithDuplicatedTag struct { + Value1 *big.Int `abi:"value"` + Value2 *big.Int `abi:"value"` + } + + type BadEventTransferWithEmptyTag struct { + Value *big.Int `abi:""` + } + type EventPledge struct { Who common.Address Wad *big.Int @@ -133,9 +170,16 @@ func TestEventTupleUnpack(t *testing.T) { Currency [3]byte } + type EventMixedCase struct { + Value1 *big.Int `abi:"value"` + Value2 *big.Int `abi:"_value"` + Value3 *big.Int `abi:"Value"` + } + bigint := new(big.Int) bigintExpected := big.NewInt(1000000) bigintExpected2 := big.NewInt(2218516807680) + bigintExpected3 := big.NewInt(1000001) addr := common.HexToAddress("0x00Ce0d46d924CC8437c806721496599FC3FFA268") var testCases = []struct { data string @@ -159,6 +203,34 @@ func TestEventTupleUnpack(t *testing.T) { "", "Can unpack ERC20 Transfer event into slice", }, { + transferData1, + &EventTransferWithTag{}, + &EventTransferWithTag{Value1: bigintExpected}, + jsonEventTransfer, + "", + "Can unpack ERC20 Transfer event into structure with abi: tag", + }, { + transferData1, + &BadEventTransferWithDuplicatedTag{}, + &BadEventTransferWithDuplicatedTag{}, + jsonEventTransfer, + "struct: abi tag in 'Value2' already mapped", + "Can not unpack ERC20 Transfer event with duplicated abi tag", + }, { + transferData1, + &BadEventTransferWithSameFieldAndTag{}, + &BadEventTransferWithSameFieldAndTag{}, + jsonEventTransfer, + "abi: multiple variables maps to the same abi field 'value'", + "Can not unpack ERC20 Transfer event with a field and a tag mapping to the same abi variable", + }, { + transferData1, + &BadEventTransferWithEmptyTag{}, + &BadEventTransferWithEmptyTag{}, + jsonEventTransfer, + "struct: abi tag in 'Value' is empty", + "Can not unpack ERC20 Transfer event with an empty tag", + }, { pledgeData1, &EventPledge{}, &EventPledge{ @@ -216,6 +288,13 @@ func TestEventTupleUnpack(t *testing.T) { jsonEventPledge, "abi: cannot unmarshal tuple into map[string]interface {}", "Can not unpack Pledge event into map", + }, { + mixedCaseData1, + &EventMixedCase{}, + &EventMixedCase{Value1: bigintExpected, Value2: bigintExpected2, Value3: bigintExpected3}, + jsonEventMixedCase, + "", + "Can unpack abi variables with mixed case", }} for _, tc := range testCases { @@ -227,7 +306,7 @@ func TestEventTupleUnpack(t *testing.T) { assert.Nil(err, "Should be able to unpack event data.") assert.Equal(tc.expected, tc.dest, tc.name) } else { - assert.EqualError(err, tc.error) + assert.EqualError(err, tc.error, tc.name) } }) } diff --git a/accounts/abi/reflect.go b/accounts/abi/reflect.go index 5620a7084..0193517a4 100644 --- a/accounts/abi/reflect.go +++ b/accounts/abi/reflect.go @@ -19,6 +19,7 @@ package abi import ( "fmt" "reflect" + "strings" ) // indirect recursively dereferences the value until it either gets the value @@ -111,18 +112,101 @@ func requireUnpackKind(v reflect.Value, t reflect.Type, k reflect.Kind, return nil } -// requireUniqueStructFieldNames makes sure field names don't collide -func requireUniqueStructFieldNames(args Arguments) error { - exists := make(map[string]bool) +// mapAbiToStringField maps abi to struct fields. +// first round: for each Exportable field that contains a `abi:""` tag +// and this field name exists in the arguments, pair them together. +// second round: for each argument field 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. +func mapAbiToStructFields(args Arguments, 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 _, abiField := range args.NonIndexed() { + if abiField.Name == tagName { + if abi2struct[abiField.Name] != "" { + return nil, fmt.Errorf("struct: abi tag in '%s' already mapped", structFieldName) + } + // pair them + abi2struct[abiField.Name] = structFieldName + struct2abi[structFieldName] = abiField.Name + 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 _, arg := range args { - field := capitalise(arg.Name) - if field == "" { - return fmt.Errorf("abi: purely underscored output cannot unpack to struct") + + abiFieldName := arg.Name + structFieldName := capitalise(abiFieldName) + + if structFieldName == "" { + return nil, fmt.Errorf("abi: purely underscored output cannot unpack to struct") } - if exists[field] { - return fmt.Errorf("abi: multiple outputs mapping to the same struct field '%s'", field) + + // 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[abiFieldName] != "" { + if abi2struct[abiFieldName] != structFieldName && + struct2abi[structFieldName] == "" && + value.FieldByName(structFieldName).IsValid() { + return nil, fmt.Errorf("abi: multiple variables maps to the same abi field '%s'", abiFieldName) + } + continue } - exists[field] = true + + // 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[abiFieldName] = structFieldName + struct2abi[structFieldName] = abiFieldName + } else { + // not paired, but annotate as used, to detect cases like + // abi : [ { "name": "value" }, { "name": "_value" } ] + // struct { Value *big.Int } + struct2abi[structFieldName] = abiFieldName + } + } - return nil + + return abi2struct, nil } |