path: root/core/types/bloom9.go

// 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"
    "github.com/ethereum/go-ethereum/core/vm"
    "github.com/ethereum/go-ethereum/crypto"
)

type bytesBacked interface {
    Bytes() []byte
}

const bloomLength = 256

type Bloom [bloomLength]byte

func BytesToBloom(b []byte) Bloom {
    var bloom Bloom
    bloom.SetBytes(b)
    return bloom
}

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[bloomLength-len(d):], d)
}

func (b *Bloom) Add(d *big.Int) {
    bin := new(big.Int).SetBytes(b[:])
    bin.Or(bin, bloom9(d.Bytes()))
    b.SetBytes(bin.Bytes())
}

func (b Bloom) Big() *big.Int {
    return common.Bytes2Big(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(common.BytesToBig(test))
}

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 vm.Logs) *big.Int {
    bin := new(big.Int)
    for _, log := range logs {
        data := make([]common.Hash, len(log.Topics))
        bin.Or(bin, bloom9(log.Address.Bytes()))

        for i, topic := range log.Topics {
            data[i] = topic
        }

        for _, b := range data {
            bin.Or(bin, bloom9(b[:]))
        }
    }

    return bin
}

func bloom9(b []byte) *big.Int {
    b = crypto.Sha3(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
}