path: root/core/types/bloom9.go

package types

import (
    "math/big"

    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/state"
)

func CreateBloom(receipts Receipts) []byte {
    bin := new(big.Int)
    for _, receipt := range receipts {
        bin.Or(bin, LogsBloom(receipt.logs))
    }

    return ethutil.LeftPadBytes(bin.Bytes(), 64)
}

func LogsBloom(logs state.Logs) *big.Int {
    bin := new(big.Int)
    for _, log := range logs {
        data := make([][]byte, len(log.Topics())+1)
        data[0] = log.Address()

        for i, topic := range log.Topics() {
            data[i+1] = topic
        }

        for _, b := range data {
            bin.Or(bin, ethutil.BigD(bloom9(crypto.Sha3(b)).Bytes()))
        }
    }

    return bin
}

func bloom9(b []byte) *big.Int {
    r := new(big.Int)
    for _, i := range []int{0, 2, 4} {
        t := big.NewInt(1)
        b := uint(b[i+1]) + 256*(uint(b[i])&1)
        r.Or(r, t.Lsh(t, b))
    }

    return r
}

func BloomLookup(bin, topic []byte) bool {
    bloom := ethutil.BigD(bin)
    cmp := bloom9(crypto.Sha3(topic))

    return bloom.And(bloom, cmp).Cmp(cmp) == 0
}