diff options
Diffstat (limited to 'core/types/json.go')
-rw-r--r-- | core/types/json.go | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/core/types/json.go b/core/types/json.go new file mode 100644 index 000000000..403e79899 --- /dev/null +++ b/core/types/json.go @@ -0,0 +1,87 @@ +// 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 types + +import ( + "encoding/hex" + "fmt" + "math/big" +) + +// JSON unmarshaling utilities. + +type hexBytes []byte + +func (b *hexBytes) UnmarshalJSON(input []byte) error { + if len(input) < 2 || input[0] != '"' || input[len(input)-1] != '"' { + return fmt.Errorf("cannot unmarshal non-string into hexBytes") + } + input = input[1 : len(input)-1] + if len(input) < 2 || input[0] != '0' || input[1] != 'x' { + return fmt.Errorf("missing 0x prefix in hexBytes input %q", input) + } + dec := make(hexBytes, (len(input)-2)/2) + if _, err := hex.Decode(dec, input[2:]); err != nil { + return err + } + *b = dec + return nil +} + +type hexBig big.Int + +func (b *hexBig) UnmarshalJSON(input []byte) error { + raw, err := checkHexNumber(input) + if err != nil { + return err + } + dec, ok := new(big.Int).SetString(string(raw), 16) + if !ok { + return fmt.Errorf("invalid hex number") + } + *b = (hexBig)(*dec) + return nil +} + +type hexUint64 uint64 + +func (b *hexUint64) UnmarshalJSON(input []byte) error { + raw, err := checkHexNumber(input) + if err != nil { + return err + } + _, err = fmt.Sscanf(string(raw), "%x", b) + return err +} + +func checkHexNumber(input []byte) (raw []byte, err error) { + if len(input) < 2 || input[0] != '"' || input[len(input)-1] != '"' { + return nil, fmt.Errorf("cannot unmarshal non-string into hex number") + } + input = input[1 : len(input)-1] + if len(input) < 2 || input[0] != '0' || input[1] != 'x' { + return nil, fmt.Errorf("missing 0x prefix in hex number input %q", input) + } + if len(input) == 2 { + return nil, fmt.Errorf("empty hex number") + } + raw = input[2:] + if len(raw)%2 != 0 { + raw = append([]byte{'0'}, raw...) + } + return raw, nil +} |