plugeth/ethchain/filter.go
obscuren d2bb83833f Moved Filter's wrapping functions to their own util package. Fixes #61
* CLI ethereum should no longer require the Qt/QML package
2014-10-18 13:20:06 +02:00

207 lines
4.2 KiB
Go

package ethchain
import (
"bytes"
"fmt"
"math"
"github.com/ethereum/eth-go/ethstate"
)
type AccountChange struct {
Address, StateAddress []byte
}
// Filtering interface
type Filter struct {
eth EthManager
earliest int64
latest int64
skip int
from, to [][]byte
max int
Altered []AccountChange
BlockCallback func(*Block)
MessageCallback func(ethstate.Messages)
}
// 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 EthManager) *Filter {
return &Filter{eth: eth}
}
func (self *Filter) AddAltered(address, stateAddress []byte) {
self.Altered = append(self.Altered, AccountChange{address, stateAddress})
}
// 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) SetFrom(addr [][]byte) {
self.from = addr
}
func (self *Filter) AddFrom(addr []byte) {
self.from = append(self.from, addr)
}
func (self *Filter) SetTo(addr [][]byte) {
self.to = addr
}
func (self *Filter) AddTo(addr []byte) {
self.to = append(self.to, addr)
}
func (self *Filter) SetMax(max int) {
self.max = max
}
func (self *Filter) SetSkip(skip int) {
self.skip = skip
}
// Run filters messages with the current parameters set
func (self *Filter) Find() []*ethstate.Message {
var earliestBlockNo uint64 = uint64(self.earliest)
if self.earliest == -1 {
earliestBlockNo = self.eth.BlockChain().CurrentBlock.Number.Uint64()
}
var latestBlockNo uint64 = uint64(self.latest)
if self.latest == -1 {
latestBlockNo = self.eth.BlockChain().CurrentBlock.Number.Uint64()
}
var (
messages []*ethstate.Message
block = self.eth.BlockChain().GetBlockByNumber(latestBlockNo)
quit bool
)
for i := 0; !quit && block != nil; i++ {
// Quit on latest
switch {
case block.Number.Uint64() == earliestBlockNo:
quit = true
case self.max <= len(messages):
break
}
// Use bloom filtering to see if this block is interesting given the
// current parameters
if self.bloomFilter(block) {
// Get the messages of the block
msgs, err := self.eth.StateManager().GetMessages(block)
if err != nil {
chainlogger.Warnln("err: filter get messages ", err)
break
}
messages = append(messages, self.FilterMessages(msgs)...)
}
block = self.eth.BlockChain().GetBlock(block.PrevHash)
}
skip := int(math.Min(float64(len(messages)), float64(self.skip)))
return messages[skip:]
}
func includes(addresses [][]byte, a []byte) (found bool) {
for _, addr := range addresses {
if bytes.Compare(addr, a) == 0 {
return true
}
}
return
}
func (self *Filter) FilterMessages(msgs []*ethstate.Message) []*ethstate.Message {
var messages []*ethstate.Message
// Filter the messages for interesting stuff
for _, message := range msgs {
if len(self.to) > 0 && !includes(self.to, message.To) {
continue
}
if len(self.from) > 0 && !includes(self.from, message.From) {
continue
}
var match bool
if len(self.Altered) == 0 {
match = true
}
for _, accountChange := range self.Altered {
if len(accountChange.Address) > 0 && bytes.Compare(message.To, accountChange.Address) != 0 {
continue
}
if len(accountChange.StateAddress) > 0 && !includes(message.ChangedAddresses, accountChange.StateAddress) {
continue
}
match = true
break
}
if !match {
continue
}
messages = append(messages, message)
}
return messages
}
func (self *Filter) bloomFilter(block *Block) bool {
fk := append([]byte("bloom"), block.Hash()...)
bin, err := self.eth.Db().Get(fk)
if err != nil {
fmt.Println(err)
}
bloom := NewBloomFilter(bin)
var fromIncluded, toIncluded bool
if len(self.from) > 0 {
for _, from := range self.from {
if bloom.Search(from) {
fromIncluded = true
break
}
}
} else {
fromIncluded = true
}
if len(self.to) > 0 {
for _, to := range self.to {
if bloom.Search(to) {
toIncluded = true
break
}
}
} else {
toIncluded = true
}
return fromIncluded && toIncluded
}