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author | Bas van Kervel <bas@ethdev.com> | 2015-10-15 22:07:19 +0800 |
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committer | Bas van Kervel <bas@ethdev.com> | 2015-12-14 23:34:05 +0800 |
commit | eae81465c1c815c317cd30e4de6bdf4d59df2340 (patch) | |
tree | b6f4b7787967a58416171adb79fd12ac29d89577 /eth/filters | |
parent | 8db9d44ca9fb6baf406256cae491c475de2f4989 (diff) | |
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rpc: new RPC implementation with pub/sub support
Diffstat (limited to 'eth/filters')
-rw-r--r-- | eth/filters/api.go | 575 |
1 files changed, 575 insertions, 0 deletions
diff --git a/eth/filters/api.go b/eth/filters/api.go new file mode 100644 index 000000000..411d8e5a3 --- /dev/null +++ b/eth/filters/api.go @@ -0,0 +1,575 @@ +// Copyright 2015 The go-ethereum Authors +// This file is part of go-ethereum. +// +// go-ethereum is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// go-ethereum 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 General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>. + +package filters + +import ( + "sync" + "time" + + "crypto/rand" + "encoding/hex" + "errors" + + "encoding/json" + "fmt" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/core/types" + "github.com/ethereum/go-ethereum/core/vm" + "github.com/ethereum/go-ethereum/ethdb" + "github.com/ethereum/go-ethereum/event" + rpc "github.com/ethereum/go-ethereum/rpc/v2" +) + +var ( + filterTickerTime = 5 * time.Minute +) + +// byte will be inferred +const ( + unknownFilterTy = iota + blockFilterTy + transactionFilterTy + logFilterTy +) + +// PublicFilterAPI offers support to create and manage filters. This will allow externa clients to retrieve various +// information related to the Ethereum protocol such als blocks, transactions and logs. +type PublicFilterAPI struct { + mux *event.TypeMux + + quit chan struct{} + chainDb ethdb.Database + + filterManager *FilterSystem + + filterMapMu sync.RWMutex + filterMapping map[string]int // maps between filter internal filter identifiers and external filter identifiers + + logMu sync.RWMutex + logQueue map[int]*logQueue + + blockMu sync.RWMutex + blockQueue map[int]*hashQueue + + transactionMu sync.RWMutex + transactionQueue map[int]*hashQueue + + transactMu sync.Mutex +} + +// NewPublicFilterAPI returns a new PublicFilterAPI instance. +func NewPublicFilterAPI(chainDb ethdb.Database, mux *event.TypeMux) *PublicFilterAPI { + svc := &PublicFilterAPI{ + mux: mux, + chainDb: chainDb, + filterManager: NewFilterSystem(mux), + filterMapping: make(map[string]int), + logQueue: make(map[int]*logQueue), + blockQueue: make(map[int]*hashQueue), + transactionQueue: make(map[int]*hashQueue), + } + go svc.start() + return svc +} + +// Stop quits the work loop. +func (s *PublicFilterAPI) Stop() { + close(s.quit) +} + +// start the work loop, wait and process events. +func (s *PublicFilterAPI) start() { + timer := time.NewTicker(2 * time.Second) + defer timer.Stop() +done: + for { + select { + case <-timer.C: + s.logMu.Lock() + for id, filter := range s.logQueue { + if time.Since(filter.timeout) > filterTickerTime { + s.filterManager.Remove(id) + delete(s.logQueue, id) + } + } + s.logMu.Unlock() + + s.blockMu.Lock() + for id, filter := range s.blockQueue { + if time.Since(filter.timeout) > filterTickerTime { + s.filterManager.Remove(id) + delete(s.blockQueue, id) + } + } + s.blockMu.Unlock() + + s.transactionMu.Lock() + for id, filter := range s.transactionQueue { + if time.Since(filter.timeout) > filterTickerTime { + s.filterManager.Remove(id) + delete(s.transactionQueue, id) + } + } + s.transactionMu.Unlock() + case <-s.quit: + break done + } + } + +} + +// NewBlockFilter create a new filter that returns blocks that are included into the canonical chain. +func (s *PublicFilterAPI) NewBlockFilter() (string, error) { + externalId, err := newFilterId() + if err != nil { + return "", err + } + + s.blockMu.Lock() + filter := New(s.chainDb) + id := s.filterManager.Add(filter) + s.blockQueue[id] = &hashQueue{timeout: time.Now()} + + filter.BlockCallback = func(block *types.Block, logs vm.Logs) { + s.blockMu.Lock() + defer s.blockMu.Unlock() + + if queue := s.blockQueue[id]; queue != nil { + queue.add(block.Hash()) + } + } + + defer s.blockMu.Unlock() + + s.filterMapMu.Lock() + s.filterMapping[externalId] = id + s.filterMapMu.Unlock() + + return externalId, nil +} + +// NewPendingTransactionFilter creates a filter that returns new pending transactions. +func (s *PublicFilterAPI) NewPendingTransactionFilter() (string, error) { + externalId, err := newFilterId() + if err != nil { + return "", err + } + + s.transactionMu.Lock() + defer s.transactionMu.Unlock() + + filter := New(s.chainDb) + id := s.filterManager.Add(filter) + s.transactionQueue[id] = &hashQueue{timeout: time.Now()} + + filter.TransactionCallback = func(tx *types.Transaction) { + s.transactionMu.Lock() + defer s.transactionMu.Unlock() + + if queue := s.transactionQueue[id]; queue != nil { + queue.add(tx.Hash()) + } + } + + s.filterMapMu.Lock() + s.filterMapping[externalId] = id + s.filterMapMu.Unlock() + + return externalId, nil +} + +// newLogFilter creates a new log filter. +func (s *PublicFilterAPI) newLogFilter(earliest, latest int64, addresses []common.Address, topics [][]common.Hash) int { + s.logMu.Lock() + defer s.logMu.Unlock() + + filter := New(s.chainDb) + id := s.filterManager.Add(filter) + s.logQueue[id] = &logQueue{timeout: time.Now()} + + filter.SetBeginBlock(earliest) + filter.SetEndBlock(latest) + filter.SetAddresses(addresses) + filter.SetTopics(topics) + filter.LogsCallback = func(logs vm.Logs) { + s.logMu.Lock() + defer s.logMu.Unlock() + + if queue := s.logQueue[id]; queue != nil { + queue.add(logs...) + } + } + + return id +} + +// NewFilterArgs represents a request to create a new filter. +type NewFilterArgs struct { + FromBlock rpc.BlockNumber + ToBlock rpc.BlockNumber + Addresses []common.Address + Topics [][]common.Hash +} + +func (args *NewFilterArgs) UnmarshalJSON(data []byte) error { + type input struct { + From *rpc.BlockNumber `json:"fromBlock"` + ToBlock *rpc.BlockNumber `json:"toBlock"` + Addresses interface{} `json:"address"` + Topics interface{} `json:"topics"` + } + + var raw input + if err := json.Unmarshal(data, &raw); err != nil { + return err + } + + if raw.From == nil { + args.FromBlock = rpc.LatestBlockNumber + } else { + args.FromBlock = *raw.From + } + + if raw.ToBlock == nil { + args.ToBlock = rpc.LatestBlockNumber + } else { + args.ToBlock = *raw.ToBlock + } + + args.Addresses = []common.Address{} + + if raw.Addresses != nil { + // raw.Address can contain a single address or an array of addresses + var addresses []common.Address + + if strAddrs, ok := raw.Addresses.([]interface{}); ok { + for i, addr := range strAddrs { + if strAddr, ok := addr.(string); ok { + if len(strAddr) >= 2 && strAddr[0] == '0' && (strAddr[1] == 'x' || strAddr[1] == 'X') { + strAddr = strAddr[2:] + } + if decAddr, err := hex.DecodeString(strAddr); err == nil { + addresses = append(addresses, common.BytesToAddress(decAddr)) + } else { + fmt.Errorf("invalid address given") + } + } else { + return fmt.Errorf("invalid address on index %d", i) + } + } + } else if singleAddr, ok := raw.Addresses.(string); ok { + if len(singleAddr) >= 2 && singleAddr[0] == '0' && (singleAddr[1] == 'x' || singleAddr[1] == 'X') { + singleAddr = singleAddr[2:] + } + if decAddr, err := hex.DecodeString(singleAddr); err == nil { + addresses = append(addresses, common.BytesToAddress(decAddr)) + } else { + fmt.Errorf("invalid address given") + } + } else { + errors.New("invalid address(es) given") + } + args.Addresses = addresses + } + + topicConverter := func(raw string) (common.Hash, error) { + if len(raw) == 0 { + return common.Hash{}, nil + } + + if len(raw) >= 2 && raw[0] == '0' && (raw[1] == 'x' || raw[1] == 'X') { + raw = raw[2:] + } + + if decAddr, err := hex.DecodeString(raw); err == nil { + return common.BytesToHash(decAddr), nil + } + + return common.Hash{}, errors.New("invalid topic given") + } + + // topics is an array consisting of strings or arrays of strings + if raw.Topics != nil { + topics, ok := raw.Topics.([]interface{}) + if ok { + parsedTopics := make([][]common.Hash, len(topics)) + for i, topic := range topics { + if topic == nil { + parsedTopics[i] = []common.Hash{common.StringToHash("")} + } else if strTopic, ok := topic.(string); ok { + if t, err := topicConverter(strTopic); err != nil { + return fmt.Errorf("invalid topic on index %d", i) + } else { + parsedTopics[i] = []common.Hash{t} + } + } else if arrTopic, ok := topic.([]interface{}); ok { + parsedTopics[i] = make([]common.Hash, len(arrTopic)) + for j := 0; j < len(parsedTopics[i]); i++ { + if arrTopic[j] == nil { + parsedTopics[i][j] = common.StringToHash("") + } else if str, ok := arrTopic[j].(string); ok { + if t, err := topicConverter(str); err != nil { + return fmt.Errorf("invalid topic on index %d", i) + } else { + parsedTopics[i] = []common.Hash{t} + } + } else { + fmt.Errorf("topic[%d][%d] not a string", i, j) + } + } + } else { + return fmt.Errorf("topic[%d] invalid", i) + } + } + args.Topics = parsedTopics + } + } + + return nil +} + +// NewFilter creates a new filter and returns the filter id. It can be uses to retrieve logs. +func (s *PublicFilterAPI) NewFilter(args NewFilterArgs) (string, error) { + externalId, err := newFilterId() + if err != nil { + return "", err + } + + var id int + if len(args.Addresses) > 0 { + id = s.newLogFilter(args.FromBlock.Int64(), args.ToBlock.Int64(), args.Addresses, args.Topics) + } else { + id = s.newLogFilter(args.FromBlock.Int64(), args.ToBlock.Int64(), nil, args.Topics) + } + + s.filterMapMu.Lock() + s.filterMapping[externalId] = id + s.filterMapMu.Unlock() + + return externalId, nil +} + +// GetLogs returns the logs matching the given argument. +func (s *PublicFilterAPI) GetLogs(args NewFilterArgs) vm.Logs { + filter := New(s.chainDb) + filter.SetBeginBlock(args.FromBlock.Int64()) + filter.SetEndBlock(args.ToBlock.Int64()) + filter.SetAddresses(args.Addresses) + filter.SetTopics(args.Topics) + + return returnLogs(filter.Find()) +} + +// UninstallFilter removes the filter with the given filter id. +func (s *PublicFilterAPI) UninstallFilter(filterId string) bool { + s.filterMapMu.Lock() + defer s.filterMapMu.Unlock() + + id, ok := s.filterMapping[filterId] + if !ok { + return false + } + + defer s.filterManager.Remove(id) + delete(s.filterMapping, filterId) + + if _, ok := s.logQueue[id]; ok { + s.logMu.Lock() + defer s.logMu.Unlock() + delete(s.logQueue, id) + return true + } + if _, ok := s.blockQueue[id]; ok { + s.blockMu.Lock() + defer s.blockMu.Unlock() + delete(s.blockQueue, id) + return true + } + if _, ok := s.transactionQueue[id]; ok { + s.transactionMu.Lock() + defer s.transactionMu.Unlock() + delete(s.transactionQueue, id) + return true + } + + return false +} + +// getFilterType is a helper utility that determine the type of filter for the given filter id. +func (s *PublicFilterAPI) getFilterType(id int) byte { + if _, ok := s.blockQueue[id]; ok { + return blockFilterTy + } else if _, ok := s.transactionQueue[id]; ok { + return transactionFilterTy + } else if _, ok := s.logQueue[id]; ok { + return logFilterTy + } + + return unknownFilterTy +} + +// blockFilterChanged returns a collection of block hashes for the block filter with the given id. +func (s *PublicFilterAPI) blockFilterChanged(id int) []common.Hash { + s.blockMu.Lock() + defer s.blockMu.Unlock() + + if s.blockQueue[id] != nil { + return s.blockQueue[id].get() + } + return nil +} + +// transactionFilterChanged returns a collection of transaction hashes for the pending +// transaction filter with the given id. +func (s *PublicFilterAPI) transactionFilterChanged(id int) []common.Hash { + s.blockMu.Lock() + defer s.blockMu.Unlock() + + if s.transactionQueue[id] != nil { + return s.transactionQueue[id].get() + } + return nil +} + +// logFilterChanged returns a collection of logs for the log filter with the given id. +func (s *PublicFilterAPI) logFilterChanged(id int) vm.Logs { + s.logMu.Lock() + defer s.logMu.Unlock() + + if s.logQueue[id] != nil { + return s.logQueue[id].get() + } + return nil +} + +// GetFilterLogs returns the logs for the filter with the given id. +func (s *PublicFilterAPI) GetFilterLogs(filterId string) vm.Logs { + id, ok := s.filterMapping[filterId] + if !ok { + return returnLogs(nil) + } + + if filter := s.filterManager.Get(id); filter != nil { + return returnLogs(filter.Find()) + } + + return returnLogs(nil) +} + +// GetFilterChanges returns the logs for the filter with the given id since last time is was called. +// This can be used for polling. +func (s *PublicFilterAPI) GetFilterChanges(filterId string) interface{} { + s.filterMapMu.Lock() + id, ok := s.filterMapping[filterId] + s.filterMapMu.Unlock() + + if !ok { // filter not found + return []interface{}{} + } + + switch s.getFilterType(id) { + case blockFilterTy: + return returnHashes(s.blockFilterChanged(id)) + case transactionFilterTy: + return returnHashes(s.transactionFilterChanged(id)) + case logFilterTy: + return returnLogs(s.logFilterChanged(id)) + } + + return []interface{}{} +} + +type logQueue struct { + mu sync.Mutex + + logs vm.Logs + timeout time.Time + id int +} + +func (l *logQueue) add(logs ...*vm.Log) { + l.mu.Lock() + defer l.mu.Unlock() + + l.logs = append(l.logs, logs...) +} + +func (l *logQueue) get() vm.Logs { + l.mu.Lock() + defer l.mu.Unlock() + + l.timeout = time.Now() + tmp := l.logs + l.logs = nil + return tmp +} + +type hashQueue struct { + mu sync.Mutex + + hashes []common.Hash + timeout time.Time + id int +} + +func (l *hashQueue) add(hashes ...common.Hash) { + l.mu.Lock() + defer l.mu.Unlock() + + l.hashes = append(l.hashes, hashes...) +} + +func (l *hashQueue) get() []common.Hash { + l.mu.Lock() + defer l.mu.Unlock() + + l.timeout = time.Now() + tmp := l.hashes + l.hashes = nil + return tmp +} + +// newFilterId generates a new random filter identifier that can be exposed to the outer world. By publishing random +// identifiers it is not feasible for DApp's to guess filter id's for other DApp's and uninstall or poll for them +// causing the affected DApp to miss data. +func newFilterId() (string, error) { + var subid [16]byte + n, _ := rand.Read(subid[:]) + if n != 16 { + return "", errors.New("Unable to generate filter id") + } + return "0x" + hex.EncodeToString(subid[:]), nil +} + +// returnLogs is a helper that will return an empty logs array case the given logs is nil, otherwise is will return the +// given logs. The RPC interfaces defines that always an array is returned. +func returnLogs(logs vm.Logs) vm.Logs { + if logs == nil { + return vm.Logs{} + } + return logs +} + +// returnHashes is a helper that will return an empty hash array case the given hash array is nil, otherwise is will +// return the given hashes. The RPC interfaces defines that always an array is returned. +func returnHashes(hashes []common.Hash) []common.Hash { + if hashes == nil { + return []common.Hash{} + } + return hashes +} |