// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// go-ethereum 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 core
import (
"math"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
)
type AccountChange struct {
Address, StateAddress []byte
}
// Filtering interface
type Filter struct {
eth Backend
earliest int64
latest int64
skip int
address []common.Address
max int
topics [][]common.Hash
BlockCallback func(*types.Block, state.Logs)
TransactionCallback func(*types.Transaction)
LogsCallback func(state.Logs)
}
// Create a new filter which uses a bloom filter on blocks to figure out whether a particular block
// is interesting or not.
func NewFilter(eth Backend) *Filter {
return &Filter{eth: eth}
}
// Set the earliest and latest block for filtering.
// -1 = latest block (i.e., the current block)
// hash = particular hash from-to
func (self *Filter) SetEarliestBlock(earliest int64) {
self.earliest = earliest
}
func (self *Filter) SetLatestBlock(latest int64) {
self.latest = latest
}
func (self *Filter) SetAddress(addr []common.Address) {
self.address = addr
}
func (self *Filter) SetTopics(topics [][]common.Hash) {
self.topics = topics
}
func (self *Filter) SetMax(max int) {
self.max = max
}
func (self *Filter) SetSkip(skip int) {
self.skip = skip
}
// Run filters logs with the current parameters set
func (self *Filter) Find() state.Logs {
earliestBlock := self.eth.ChainManager().CurrentBlock()
var earliestBlockNo uint64 = uint64(self.earliest)
if self.earliest == -1 {
earliestBlockNo = earliestBlock.NumberU64()
}
var latestBlockNo uint64 = uint64(self.latest)
if self.latest == -1 {
latestBlockNo = earliestBlock.NumberU64()
}
var (
logs state.Logs
block = self.eth.ChainManager().GetBlockByNumber(latestBlockNo)
)
done:
for i := 0; block != nil; i++ {
// Quit on latest
switch {
case block.NumberU64() == 0:
break done
case block.NumberU64() < earliestBlockNo:
break done
case self.max <= len(logs):
break done
}
// Use bloom filtering to see if this block is interesting given the
// current parameters
if self.bloomFilter(block) {
// Get the logs of the block
unfiltered, err := self.eth.BlockProcessor().GetLogs(block)
if err != nil {
chainlogger.Warnln("err: filter get logs ", err)
break
}
logs = append(logs, self.FilterLogs(unfiltered)...)
}
block = self.eth.ChainManager().GetBlock(block.ParentHash())
}
skip := int(math.Min(float64(len(logs)), float64(self.skip)))
return logs[skip:]
}
func includes(addresses []common.Address, a common.Address) bool {
for _, addr := range addresses {
if addr != a {
return false
}
}
return true
}
func (self *Filter) FilterLogs(logs state.Logs) state.Logs {
var ret state.Logs
// Filter the logs for interesting stuff
Logs:
for _, log := range logs {
if len(self.address) > 0 && !includes(self.address, log.Address) {
continue
}
logTopics := make([]common.Hash, len(self.topics))
copy(logTopics, log.Topics)
// If the to filtered topics is greater than the amount of topics in
// logs, skip.
if len(self.topics) > len(log.Topics) {
continue Logs
}
for i, topics := range self.topics {
var match bool
for _, topic := range topics {
// common.Hash{} is a match all (wildcard)
if (topic == common.Hash{}) || log.Topics[i] == topic {
match = true
break
}
}
if !match {
continue Logs
}
}
ret = append(ret, log)
}
return ret
}
func (self *Filter) bloomFilter(block *types.Block) bool {
if len(self.address) > 0 {
var included bool
for _, addr := range self.address {
if types.BloomLookup(block.Bloom(), addr) {
included = true
break
}
}
if !included {
return false
}
}
for _, sub := range self.topics {
var included bool
for _, topic := range sub {
if (topic == common.Hash{}) || types.BloomLookup(block.Bloom(), topic) {
included = true
break
}
}
if !included {
return false
}
}
return true
}