github.com/immesys/bw2bc@v1.1.0/core/types/bloom9.go (about)

     1  // Copyright 2014 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package types
    18  
    19  import (
    20  	"math/big"
    21  
    22  	"github.com/ethereum/go-ethereum/common"
    23  	"github.com/ethereum/go-ethereum/core/state"
    24  	"github.com/ethereum/go-ethereum/crypto"
    25  )
    26  
    27  type bytesBacked interface {
    28  	Bytes() []byte
    29  }
    30  
    31  func CreateBloom(receipts Receipts) Bloom {
    32  	bin := new(big.Int)
    33  	for _, receipt := range receipts {
    34  		bin.Or(bin, LogsBloom(receipt.logs))
    35  	}
    36  
    37  	return BytesToBloom(bin.Bytes())
    38  }
    39  
    40  func LogsBloom(logs state.Logs) *big.Int {
    41  	bin := new(big.Int)
    42  	for _, log := range logs {
    43  		data := make([]common.Hash, len(log.Topics))
    44  		bin.Or(bin, bloom9(log.Address.Bytes()))
    45  
    46  		for i, topic := range log.Topics {
    47  			data[i] = topic
    48  		}
    49  
    50  		for _, b := range data {
    51  			bin.Or(bin, bloom9(b[:]))
    52  		}
    53  	}
    54  
    55  	return bin
    56  }
    57  
    58  func bloom9(b []byte) *big.Int {
    59  	b = crypto.Sha3(b[:])
    60  
    61  	r := new(big.Int)
    62  
    63  	for i := 0; i < 6; i += 2 {
    64  		t := big.NewInt(1)
    65  		b := (uint(b[i+1]) + (uint(b[i]) << 8)) & 2047
    66  		r.Or(r, t.Lsh(t, b))
    67  	}
    68  
    69  	return r
    70  }
    71  
    72  var Bloom9 = bloom9
    73  
    74  func BloomLookup(bin Bloom, topic bytesBacked) bool {
    75  	bloom := bin.Big()
    76  	cmp := bloom9(topic.Bytes()[:])
    77  
    78  	return bloom.And(bloom, cmp).Cmp(cmp) == 0
    79  }