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author | obscuren <geffobscura@gmail.com> | 2014-08-11 22:23:17 +0800 |
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committer | obscuren <geffobscura@gmail.com> | 2014-08-11 22:23:17 +0800 |
commit | 2e5d28c73f1d97865def3ffe8c7ad0a4819f15f3 (patch) | |
tree | 9bf393d0aef53672594274359b4e0f23e2a69d8d /ethchain/filter.go | |
parent | 42d2bc28affe9bbd8d57a5eb3deab804e5c4a206 (diff) | |
download | dexon-2e5d28c73f1d97865def3ffe8c7ad0a4819f15f3.tar.gz dexon-2e5d28c73f1d97865def3ffe8c7ad0a4819f15f3.tar.zst dexon-2e5d28c73f1d97865def3ffe8c7ad0a4819f15f3.zip |
Added bloom filter & block filter methods
Diffstat (limited to 'ethchain/filter.go')
-rw-r--r-- | ethchain/filter.go | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/ethchain/filter.go b/ethchain/filter.go new file mode 100644 index 000000000..c3b0a7f94 --- /dev/null +++ b/ethchain/filter.go @@ -0,0 +1,146 @@ +package ethchain + +import ( + "bytes" + "fmt" + + "github.com/ethereum/eth-go/ethstate" + "github.com/ethereum/eth-go/ethutil" +) + +// Filtering interface +type Filter struct { + eth EthManager + earliest []byte + latest []byte + skip int + from, to []byte + max int +} + +// 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} +} + +// 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 interface{}) { + e := ethutil.NewValue(earliest) + + // Check for -1 (latest) otherwise assume bytes + if e.Int() == -1 { + self.earliest = self.eth.BlockChain().CurrentBlock.Hash() + } else if e.Len() > 0 { + self.earliest = e.Bytes() + } else { + panic(fmt.Sprintf("earliest has to be either -1 or a valid hash: %v (%T)", e, e.Val)) + } +} + +func (self *Filter) SetLatestBlock(latest interface{}) { + l := ethutil.NewValue(latest) + + // Check for -1 (latest) otherwise assume bytes + if l.Int() == -1 { + self.latest = self.eth.BlockChain().CurrentBlock.Hash() + } else if l.Len() > 0 { + self.latest = l.Bytes() + } else { + panic(fmt.Sprintf("latest has to be either -1 or a valid hash: %v", l)) + } +} + +func (self *Filter) SetFrom(addr []byte) { + self.from = addr +} + +func (self *Filter) SetTo(addr []byte) { + 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 messages []*ethstate.Message + + block := self.eth.BlockChain().GetBlock(self.latest) + + // skip N blocks (useful for pagination) + if self.skip > 0 { + for i := 0; i < i; i++ { + block = self.eth.BlockChain().GetBlock(block.PrevHash) + } + } + + // Start block filtering + quit := false + for i := 1; !quit && block != nil; i++ { + // Mark last check + if self.max == i || (len(self.earliest) > 0 && bytes.Compare(block.Hash(), self.earliest) == 0) { + quit = true + } + + // 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 + } + + // Filter the messages for interesting stuff + for _, message := range msgs { + if len(self.to) > 0 && bytes.Compare(message.To, self.to) != 0 { + continue + } + + if len(self.from) > 0 && bytes.Compare(message.From, self.from) != 0 { + continue + } + + messages = append(messages, message) + } + } + + block = self.eth.BlockChain().GetBlock(block.PrevHash) + } + + 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 { + panic(err) + } + + bloom := NewBloomFilter(bin) + + if len(self.from) > 0 { + if !bloom.Search(self.from) { + return false + } + } + + if len(self.to) > 0 { + if !bloom.Search(self.to) { + return false + } + } + + return true +} |