// Copyright 2014 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 (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto"
)
type bytesBacked interface {
Bytes() []byte
}
const (
// BloomByteLength represents the number of bytes used in a header log bloom.
BloomByteLength = 256
// BloomBitLength represents the number of bits used in a header log bloom.
BloomBitLength = 8 * BloomByteLength
)
// Bloom represents a 2048 bit bloom filter.
type Bloom [BloomByteLength]byte
// BytesToBloom converts a byte slice to a bloom filter.
// It panics if b is not of suitable size.
func BytesToBloom(b []byte) Bloom {
var bloom Bloom
bloom.SetBytes(b)
return bloom
}
// SetBytes sets the content of b to the given bytes.
// It panics if d is not of suitable size.
func (b *Bloom) SetBytes(d []byte) {
if len(b) < len(d) {
panic(fmt.Sprintf("bloom bytes too big %d %d", len(b), len(d)))
}
copy(b[BloomByteLength-len(d):], d)
}
// Add adds d to the filter. Future calls of Test(d) will return true.
func (b *Bloom) Add(d *big.Int) {
bin := new(big.Int).SetBytes(b[:])
bin.Or(bin, bloom9(d.Bytes()))
b.SetBytes(bin.Bytes())
}
// Big converts b to a big integer.
func (b Bloom) Big() *big.Int {
return new(big.Int).SetBytes(b[:])
}
func (b Bloom) Bytes() []byte {
return b[:]
}
func (b Bloom) Test(test *big.Int) bool {
return BloomLookup(b, test)
}
func (b Bloom) TestBytes(test []byte) bool {
return b.Test(new(big.Int).SetBytes(test))
}
// MarshalText encodes b as a hex string with 0x prefix.
func (b Bloom) MarshalText() ([]byte, error) {
return hexutil.Bytes(b[:]).MarshalText()
}
// UnmarshalText b as a hex string with 0x prefix.
func (b *Bloom) UnmarshalText(input []byte) error {
return hexutil.UnmarshalFixedText("Bloom", input, b[:])
}
func CreateBloom(receipts Receipts) Bloom {
bin := new(big.Int)
for _, receipt := range receipts {
bin.Or(bin, LogsBloom(receipt.Logs))
}
return BytesToBloom(bin.Bytes())
}
func LogsBloom(logs []*Log) *big.Int {
bin := new(big.Int)
for _, log := range logs {
bin.Or(bin, bloom9(log.Address.Bytes()))
for _, b := range log.Topics {
bin.Or(bin, bloom9(b[:]))
}
}
return bin
}
func bloom9(b []byte) *big.Int {
b = crypto.Keccak256(b)
r := new(big.Int)
for i := 0; i < 6; i += 2 {
t := big.NewInt(1)
b := (uint(b[i+1]) + (uint(b[i]) << 8)) & 2047
r.Or(r, t.Lsh(t, b))
}
return r
}
var Bloom9 = bloom9
func BloomLookup(bin Bloom, topic bytesBacked) bool {
bloom := bin.Big()
cmp := bloom9(topic.Bytes())
return bloom.And(bloom, cmp).Cmp(cmp) == 0
}