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author | obscuren <geffobscura@gmail.com> | 2014-02-15 06:56:09 +0800 |
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committer | obscuren <geffobscura@gmail.com> | 2014-02-15 06:56:09 +0800 |
commit | f6d1bfe45bf3709d7bad40bf563b5c09228622e3 (patch) | |
tree | df48311a5a494c66c74dcd51f1056cc699f01507 /ethutil/rlp.go | |
parent | c2fb9f06ad018d01ce335c82b3542de16045a32d (diff) | |
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The great merge
Diffstat (limited to 'ethutil/rlp.go')
-rw-r--r-- | ethutil/rlp.go | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/ethutil/rlp.go b/ethutil/rlp.go new file mode 100644 index 000000000..0f88933b3 --- /dev/null +++ b/ethutil/rlp.go @@ -0,0 +1,418 @@ +package ethutil + +import ( + "bytes" + _ "encoding/binary" + "fmt" + _ "log" + _ "math" + "math/big" + "reflect" +) + +/////////////////////////////////////// +type EthEncoder interface { + EncodeData(rlpData interface{}) []byte +} +type EthDecoder interface { + Get(idx int) *RlpValue +} + +////////////////////////////////////// + +type RlpEncoder struct { + rlpData []byte +} + +func NewRlpEncoder() *RlpEncoder { + encoder := &RlpEncoder{} + + return encoder +} +func (coder *RlpEncoder) EncodeData(rlpData interface{}) []byte { + return Encode(rlpData) +} + +// Data rlpValueutes are returned by the rlp decoder. The data rlpValueutes represents +// one item within the rlp data structure. It's responsible for all the casting +// It always returns something rlpValueid +type RlpValue struct { + Value interface{} + kind reflect.Value +} + +func (rlpValue *RlpValue) String() string { + return fmt.Sprintf("%q", rlpValue.Value) +} + +func Conv(rlpValue interface{}) *RlpValue { + return &RlpValue{Value: rlpValue, kind: reflect.ValueOf(rlpValue)} +} + +func NewRlpValue(rlpValue interface{}) *RlpValue { + return &RlpValue{Value: rlpValue} +} + +func (rlpValue *RlpValue) Type() reflect.Kind { + return reflect.TypeOf(rlpValue.Value).Kind() +} + +func (rlpValue *RlpValue) IsNil() bool { + return rlpValue.Value == nil +} + +func (rlpValue *RlpValue) Length() int { + //return rlpValue.kind.Len() + if data, ok := rlpValue.Value.([]interface{}); ok { + return len(data) + } + + return 0 +} + +func (rlpValue *RlpValue) AsRaw() interface{} { + return rlpValue.Value +} + +func (rlpValue *RlpValue) AsUint() uint64 { + if Value, ok := rlpValue.Value.(uint8); ok { + return uint64(Value) + } else if Value, ok := rlpValue.Value.(uint16); ok { + return uint64(Value) + } else if Value, ok := rlpValue.Value.(uint32); ok { + return uint64(Value) + } else if Value, ok := rlpValue.Value.(uint64); ok { + return Value + } + + return 0 +} + +func (rlpValue *RlpValue) AsByte() byte { + if Value, ok := rlpValue.Value.(byte); ok { + return Value + } + + return 0x0 +} + +func (rlpValue *RlpValue) AsBigInt() *big.Int { + if a, ok := rlpValue.Value.([]byte); ok { + b := new(big.Int) + b.SetBytes(a) + return b + } + + return big.NewInt(0) +} + +func (rlpValue *RlpValue) AsString() string { + if a, ok := rlpValue.Value.([]byte); ok { + return string(a) + } else if a, ok := rlpValue.Value.(string); ok { + return a + } else { + //panic(fmt.Sprintf("not string %T: %v", rlpValue.Value, rlpValue.Value)) + } + + return "" +} + +func (rlpValue *RlpValue) AsBytes() []byte { + if a, ok := rlpValue.Value.([]byte); ok { + return a + } + + return make([]byte, 0) +} + +func (rlpValue *RlpValue) AsSlice() []interface{} { + if d, ok := rlpValue.Value.([]interface{}); ok { + return d + } + + return []interface{}{} +} + +func (rlpValue *RlpValue) AsSliceFrom(from int) *RlpValue { + slice := rlpValue.AsSlice() + + return NewRlpValue(slice[from:]) +} + +func (rlpValue *RlpValue) AsSliceTo(to int) *RlpValue { + slice := rlpValue.AsSlice() + + return NewRlpValue(slice[:to]) +} + +func (rlpValue *RlpValue) AsSliceFromTo(from, to int) *RlpValue { + slice := rlpValue.AsSlice() + + return NewRlpValue(slice[from:to]) +} + +// Threat the rlpValueute as a slice +func (rlpValue *RlpValue) Get(idx int) *RlpValue { + if d, ok := rlpValue.Value.([]interface{}); ok { + // Guard for oob + if len(d) <= idx { + return NewRlpValue(nil) + } + + if idx < 0 { + panic("negative idx for Rlp Get") + } + + return NewRlpValue(d[idx]) + } + + // If this wasn't a slice you probably shouldn't be using this function + return NewRlpValue(nil) +} + +func (rlpValue *RlpValue) Cmp(o *RlpValue) bool { + return reflect.DeepEqual(rlpValue.Value, o.Value) +} + +func (rlpValue *RlpValue) Encode() []byte { + return Encode(rlpValue.Value) +} + +func NewRlpValueFromBytes(rlpData []byte) *RlpValue { + if len(rlpData) != 0 { + data, _ := Decode(rlpData, 0) + return NewRlpValue(data) + } + + return NewRlpValue(nil) +} + +// RlpValue value setters +// An empty rlp value is always a list +func EmptyRlpValue() *RlpValue { + return NewRlpValue([]interface{}{}) +} + +func (rlpValue *RlpValue) AppendList() *RlpValue { + list := EmptyRlpValue() + rlpValue.Value = append(rlpValue.AsSlice(), list) + + return list +} + +func (rlpValue *RlpValue) Append(v interface{}) *RlpValue { + rlpValue.Value = append(rlpValue.AsSlice(), v) + + return rlpValue +} + +/* +func FromBin(data []byte) uint64 { + if len(data) == 0 { + return 0 + } + + return FromBin(data[:len(data)-1])*256 + uint64(data[len(data)-1]) +} +*/ + +const ( + RlpEmptyList = 0x80 + RlpEmptyStr = 0x40 +) + +func Char(c []byte) int { + if len(c) > 0 { + return int(c[0]) + } + + return 0 +} + +func DecodeWithReader(reader *bytes.Buffer) interface{} { + var slice []interface{} + + // Read the next byte + char := Char(reader.Next(1)) + switch { + case char == 0: + return nil + case char <= 0x7c: + return char + + case char <= 0xb7: + return reader.Next(int(char - 0x80)) + + case char <= 0xbf: + buff := bytes.NewReader(reader.Next(int(char - 0xb8))) + length := ReadVarint(buff) + + return reader.Next(int(length)) + + case char <= 0xf7: + length := int(char - 0xc0) + for i := 0; i < length; i++ { + obj := DecodeWithReader(reader) + if obj != nil { + slice = append(slice, obj) + } else { + break + } + } + + return slice + + } + + return slice +} + +// TODO Use a bytes.Buffer instead of a raw byte slice. +// Cleaner code, and use draining instead of seeking the next bytes to read +func Decode(data []byte, pos uint64) (interface{}, uint64) { + /* + if pos > uint64(len(data)-1) { + log.Println(data) + log.Panicf("index out of range %d for data %q, l = %d", pos, data, len(data)) + } + */ + + var slice []interface{} + char := int(data[pos]) + switch { + case char <= 0x7f: + return data[pos], pos + 1 + + case char <= 0xb7: + b := uint64(data[pos]) - 0x80 + + return data[pos+1 : pos+1+b], pos + 1 + b + + case char <= 0xbf: + b := uint64(data[pos]) - 0xb7 + + b2 := ReadVarint(bytes.NewReader(data[pos+1 : pos+1+b])) + + return data[pos+1+b : pos+1+b+b2], pos + 1 + b + b2 + + case char <= 0xf7: + b := uint64(data[pos]) - 0xc0 + prevPos := pos + pos++ + for i := uint64(0); i < b; { + var obj interface{} + + // Get the next item in the data list and append it + obj, prevPos = Decode(data, pos) + slice = append(slice, obj) + + // Increment i by the amount bytes read in the previous + // read + i += (prevPos - pos) + pos = prevPos + } + return slice, pos + + case char <= 0xff: + l := uint64(data[pos]) - 0xf7 + //b := BigD(data[pos+1 : pos+1+l]).Uint64() + b := ReadVarint(bytes.NewReader(data[pos+1 : pos+1+l])) + + pos = pos + l + 1 + + prevPos := b + for i := uint64(0); i < uint64(b); { + var obj interface{} + + obj, prevPos = Decode(data, pos) + slice = append(slice, obj) + + i += (prevPos - pos) + pos = prevPos + } + return slice, pos + + default: + panic(fmt.Sprintf("byte not supported: %q", char)) + } + + return slice, 0 +} + +var ( + directRlp = big.NewInt(0x7f) + numberRlp = big.NewInt(0xb7) + zeroRlp = big.NewInt(0x0) +) + +func Encode(object interface{}) []byte { + var buff bytes.Buffer + + if object != nil { + switch t := object.(type) { + case *RlpValue: + buff.Write(Encode(t.AsRaw())) + // Code dup :-/ + case int: + buff.Write(Encode(big.NewInt(int64(t)))) + case uint: + buff.Write(Encode(big.NewInt(int64(t)))) + case int8: + buff.Write(Encode(big.NewInt(int64(t)))) + case int16: + buff.Write(Encode(big.NewInt(int64(t)))) + case int32: + buff.Write(Encode(big.NewInt(int64(t)))) + case int64: + buff.Write(Encode(big.NewInt(t))) + case uint16: + buff.Write(Encode(big.NewInt(int64(t)))) + case uint32: + buff.Write(Encode(big.NewInt(int64(t)))) + case uint64: + buff.Write(Encode(big.NewInt(int64(t)))) + case byte: + buff.Write(Encode(big.NewInt(int64(t)))) + case *big.Int: + buff.Write(Encode(t.Bytes())) + case []byte: + if len(t) == 1 && t[0] <= 0x7f { + buff.Write(t) + } else if len(t) < 56 { + buff.WriteByte(byte(len(t) + 0x80)) + buff.Write(t) + } else { + b := big.NewInt(int64(len(t))) + buff.WriteByte(byte(len(b.Bytes()) + 0xb7)) + buff.Write(b.Bytes()) + buff.Write(t) + } + case string: + buff.Write(Encode([]byte(t))) + case []interface{}: + // Inline function for writing the slice header + WriteSliceHeader := func(length int) { + if length < 56 { + buff.WriteByte(byte(length + 0xc0)) + } else { + b := big.NewInt(int64(length)) + buff.WriteByte(byte(len(b.Bytes()) + 0xf7)) + buff.Write(b.Bytes()) + } + } + + var b bytes.Buffer + for _, val := range t { + b.Write(Encode(val)) + } + WriteSliceHeader(len(b.Bytes())) + buff.Write(b.Bytes()) + } + } else { + // Empty list for nil + buff.WriteByte(0xc0) + } + + return buff.Bytes() +} |