rpc: new RPC implementation with pub/sub support

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
+}