ipld-eth-server/pkg/watch/service.go

509 lines
18 KiB
Go

// VulcanizeDB
// Copyright © 2019 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program 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 Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package watch
import (
"fmt"
"sync"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
ethnode "github.com/ethereum/go-ethereum/node"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/rpc"
log "github.com/sirupsen/logrus"
"github.com/vulcanize/ipfs-blockchain-watcher/pkg/builders"
"github.com/vulcanize/ipfs-blockchain-watcher/pkg/node"
"github.com/vulcanize/ipfs-blockchain-watcher/pkg/postgres"
"github.com/vulcanize/ipfs-blockchain-watcher/pkg/shared"
)
const (
PayloadChanBufferSize = 2000
)
// Watcher is the top level interface for streaming, converting to IPLDs, publishing,
// and indexing all chain data; screening this data; and serving it up to subscribed clients
// This service is compatible with the Ethereum service interface (node.Service)
type Watcher interface {
// APIs(), Protocols(), Start() and Stop()
ethnode.Service
// Data processing event loop
Sync(wg *sync.WaitGroup, forwardPayloadChan chan<- shared.ConvertedData) error
// Pub-Sub handling event loop
Serve(wg *sync.WaitGroup, screenAndServePayload <-chan shared.ConvertedData)
// Method to subscribe to the service
Subscribe(id rpc.ID, sub chan<- SubscriptionPayload, quitChan chan<- bool, params shared.SubscriptionSettings)
// Method to unsubscribe from the service
Unsubscribe(id rpc.ID)
// Method to access the node info for the service
Node() *node.Node
// Method to access chain type
Chain() shared.ChainType
}
// Service is the underlying struct for the watcher
type Service struct {
// Used to sync access to the Subscriptions
sync.Mutex
// Interface for streaming payloads over an rpc subscription
Streamer shared.PayloadStreamer
// Interface for converting raw payloads into IPLD object payloads
Converter shared.PayloadConverter
// Interface for publishing and indexing the PG-IPLD payloads
Publisher shared.IPLDPublisher
// Interface for filtering and serving data according to subscribed clients according to their specification
Filterer shared.ResponseFilterer
// Interface for fetching IPLD objects from IPFS
IPLDFetcher shared.IPLDFetcher
// Interface for searching and retrieving CIDs from Postgres index
Retriever shared.CIDRetriever
// Chan the processor uses to subscribe to payloads from the Streamer
PayloadChan chan shared.RawChainData
// Used to signal shutdown of the service
QuitChan chan bool
// A mapping of rpc.IDs to their subscription channels, mapped to their subscription type (hash of the StreamFilters)
Subscriptions map[common.Hash]map[rpc.ID]Subscription
// A mapping of subscription params hash to the corresponding subscription params
SubscriptionTypes map[common.Hash]shared.SubscriptionSettings
// Info for the Geth node that this watcher is working with
NodeInfo *node.Node
// Number of publish workers
WorkerPoolSize int
// chain type for this service
chain shared.ChainType
// Underlying db
db *postgres.DB
// wg for syncing serve processes
serveWg *sync.WaitGroup
}
// NewWatcher creates a new Watcher using an underlying Service struct
func NewWatcher(settings *Config) (Watcher, error) {
sn := new(Service)
var err error
// If we are syncing, initialize the needed interfaces
if settings.Sync {
sn.Streamer, sn.PayloadChan, err = builders.NewPayloadStreamer(settings.Chain, settings.WSClient)
if err != nil {
return nil, err
}
sn.Converter, err = builders.NewPayloadConverter(settings.Chain, settings.NodeInfo.ChainID)
if err != nil {
return nil, err
}
sn.Publisher, err = builders.NewIPLDPublisher(settings.Chain, settings.SyncDBConn)
if err != nil {
return nil, err
}
sn.Filterer, err = builders.NewResponseFilterer(settings.Chain)
if err != nil {
return nil, err
}
}
// If we are serving, initialize the needed interfaces
if settings.Serve {
sn.Retriever, err = builders.NewCIDRetriever(settings.Chain, settings.ServeDBConn)
if err != nil {
return nil, err
}
sn.IPLDFetcher, err = builders.NewIPLDFetcher(settings.Chain, settings.ServeDBConn)
if err != nil {
return nil, err
}
sn.db = settings.ServeDBConn
}
sn.QuitChan = make(chan bool)
sn.Subscriptions = make(map[common.Hash]map[rpc.ID]Subscription)
sn.SubscriptionTypes = make(map[common.Hash]shared.SubscriptionSettings)
sn.WorkerPoolSize = settings.Workers
sn.NodeInfo = &settings.NodeInfo
sn.chain = settings.Chain
return sn, nil
}
// Protocols exports the services p2p protocols, this service has none
func (sap *Service) Protocols() []p2p.Protocol {
return []p2p.Protocol{}
}
// APIs returns the RPC descriptors the watcher service offers
func (sap *Service) APIs() []rpc.API {
infoAPI := NewInfoAPI()
apis := []rpc.API{
{
Namespace: APIName,
Version: APIVersion,
Service: NewPublicWatcherAPI(sap),
Public: true,
},
{
Namespace: "rpc",
Version: APIVersion,
Service: infoAPI,
Public: true,
},
{
Namespace: "net",
Version: APIVersion,
Service: infoAPI,
Public: true,
},
{
Namespace: "admin",
Version: APIVersion,
Service: infoAPI,
Public: true,
},
}
chainAPI, err := builders.NewPublicAPI(sap.chain, sap.db)
if err != nil {
log.Error(err)
return apis
}
return append(apis, chainAPI)
}
// Sync streams incoming raw chain data and converts it for further processing
// It forwards the converted data to the publish process(es) it spins up
// If forwards the converted data to a ScreenAndServe process if it there is one listening on the passed screenAndServePayload channel
// This continues on no matter if or how many subscribers there are
func (sap *Service) Sync(wg *sync.WaitGroup, screenAndServePayload chan<- shared.ConvertedData) error {
sub, err := sap.Streamer.Stream(sap.PayloadChan)
if err != nil {
return err
}
// spin up publish worker goroutines
publishPayload := make(chan shared.ConvertedData, PayloadChanBufferSize)
for i := 1; i <= sap.WorkerPoolSize; i++ {
go sap.publish(wg, i, publishPayload)
log.Debugf("%s publish worker %d successfully spun up", sap.chain.String(), i)
}
go func() {
wg.Add(1)
defer wg.Done()
for {
select {
case payload := <-sap.PayloadChan:
ipldPayload, err := sap.Converter.Convert(payload)
if err != nil {
log.Errorf("watcher conversion error for chain %s: %v", sap.chain.String(), err)
continue
}
log.Infof("%s data streamed at head height %d", sap.chain.String(), ipldPayload.Height())
// If we have a ScreenAndServe process running, forward the iplds to it
select {
case screenAndServePayload <- ipldPayload:
default:
}
// Forward the payload to the publish workers
// this channel acts as a ring buffer
select {
case publishPayload <- ipldPayload:
default:
<-publishPayload
publishPayload <- ipldPayload
}
case err := <-sub.Err():
log.Errorf("watcher subscription error for chain %s: %v", sap.chain.String(), err)
case <-sap.QuitChan:
log.Infof("quiting %s Sync process", sap.chain.String())
return
}
}
}()
log.Infof("%s Sync goroutine successfully spun up", sap.chain.String())
return nil
}
// publish is spun up by SyncAndConvert and receives converted chain data from that process
// it publishes this data to IPFS and indexes their CIDs with useful metadata in Postgres
func (sap *Service) publish(wg *sync.WaitGroup, id int, publishPayload <-chan shared.ConvertedData) {
wg.Add(1)
defer wg.Done()
for {
select {
case payload := <-publishPayload:
log.Debugf("%s watcher sync worker %d publishing and indexing data streamed at head height %d", sap.chain.String(), id, payload.Height())
if err := sap.Publisher.Publish(payload); err != nil {
log.Errorf("%s watcher publish worker %d publishing error: %v", sap.chain.String(), id, err)
continue
}
case <-sap.QuitChan:
log.Infof("%s watcher publish worker %d shutting down", sap.chain.String(), id)
return
}
}
}
// Serve listens for incoming converter data off the screenAndServePayload from the Sync process
// It filters and sends this data to any subscribers to the service
// This process can also be stood up alone, without an screenAndServePayload attached to a Sync process
// and it will hang on the WaitGroup indefinitely, allowing the Service to serve historical data requests only
func (sap *Service) Serve(wg *sync.WaitGroup, screenAndServePayload <-chan shared.ConvertedData) {
sap.serveWg = wg
go func() {
wg.Add(1)
defer wg.Done()
for {
select {
case payload := <-screenAndServePayload:
sap.filterAndServe(payload)
case <-sap.QuitChan:
log.Infof("quiting %s Serve process", sap.chain.String())
return
}
}
}()
log.Infof("%s Serve goroutine successfully spun up", sap.chain.String())
}
// filterAndServe filters the payload according to each subscription type and sends to the subscriptions
func (sap *Service) filterAndServe(payload shared.ConvertedData) {
log.Debugf("sending %s payload to subscriptions", sap.chain.String())
sap.Lock()
sap.serveWg.Add(1)
defer sap.Unlock()
defer sap.serveWg.Done()
for ty, subs := range sap.Subscriptions {
// Retrieve the subscription parameters for this subscription type
subConfig, ok := sap.SubscriptionTypes[ty]
if !ok {
log.Errorf("watcher %s subscription configuration for subscription type %s not available", sap.chain.String(), ty.Hex())
sap.closeType(ty)
continue
}
if subConfig.EndingBlock().Int64() > 0 && subConfig.EndingBlock().Int64() < payload.Height() {
// We are not out of range for this subscription type
// close it, and continue to the next
sap.closeType(ty)
continue
}
response, err := sap.Filterer.Filter(subConfig, payload)
if err != nil {
log.Errorf("watcher filtering error for chain %s: %v", sap.chain.String(), err)
sap.closeType(ty)
continue
}
responseRLP, err := rlp.EncodeToBytes(response)
if err != nil {
log.Errorf("watcher rlp encoding error for chain %s: %v", sap.chain.String(), err)
continue
}
for id, sub := range subs {
select {
case sub.PayloadChan <- SubscriptionPayload{Data: responseRLP, Err: "", Flag: EmptyFlag, Height: response.Height()}:
log.Debugf("sending watcher %s payload to subscription %s", sap.chain.String(), id)
default:
log.Infof("unable to send %s payload to subscription %s; channel has no receiver", sap.chain.String(), id)
}
}
}
}
// Subscribe is used by the API to remotely subscribe to the service loop
// The params must be rlp serializable and satisfy the SubscriptionSettings() interface
func (sap *Service) Subscribe(id rpc.ID, sub chan<- SubscriptionPayload, quitChan chan<- bool, params shared.SubscriptionSettings) {
sap.serveWg.Add(1)
defer sap.serveWg.Done()
log.Infof("New %s subscription %s", sap.chain.String(), id)
subscription := Subscription{
ID: id,
PayloadChan: sub,
QuitChan: quitChan,
}
if params.ChainType() != sap.chain {
sendNonBlockingErr(subscription, fmt.Errorf("subscription %s is for chain %s, service supports chain %s", id, params.ChainType().String(), sap.chain.String()))
sendNonBlockingQuit(subscription)
return
}
// Subscription type is defined as the hash of the rlp-serialized subscription settings
by, err := rlp.EncodeToBytes(params)
if err != nil {
sendNonBlockingErr(subscription, err)
sendNonBlockingQuit(subscription)
return
}
subscriptionType := crypto.Keccak256Hash(by)
if !params.HistoricalDataOnly() {
// Add subscriber
sap.Lock()
if sap.Subscriptions[subscriptionType] == nil {
sap.Subscriptions[subscriptionType] = make(map[rpc.ID]Subscription)
}
sap.Subscriptions[subscriptionType][id] = subscription
sap.SubscriptionTypes[subscriptionType] = params
sap.Unlock()
}
// If the subscription requests a backfill, use the Postgres index to lookup and retrieve historical data
// Otherwise we only filter new data as it is streamed in from the state diffing geth node
if params.HistoricalData() || params.HistoricalDataOnly() {
if err := sap.sendHistoricalData(subscription, id, params); err != nil {
sendNonBlockingErr(subscription, fmt.Errorf("%s watcher subscriber backfill error: %v", sap.chain.String(), err))
sendNonBlockingQuit(subscription)
return
}
}
}
// sendHistoricalData sends historical data to the requesting subscription
func (sap *Service) sendHistoricalData(sub Subscription, id rpc.ID, params shared.SubscriptionSettings) error {
log.Infof("Sending %s historical data to subscription %s", sap.chain.String(), id)
// Retrieve cached CIDs relevant to this subscriber
var endingBlock int64
var startingBlock int64
var err error
startingBlock, err = sap.Retriever.RetrieveFirstBlockNumber()
if err != nil {
return err
}
if startingBlock < params.StartingBlock().Int64() {
startingBlock = params.StartingBlock().Int64()
}
endingBlock, err = sap.Retriever.RetrieveLastBlockNumber()
if err != nil {
return err
}
if endingBlock > params.EndingBlock().Int64() && params.EndingBlock().Int64() > 0 && params.EndingBlock().Int64() > startingBlock {
endingBlock = params.EndingBlock().Int64()
}
log.Debugf("%s historical data starting block: %d", sap.chain.String(), params.StartingBlock().Int64())
log.Debugf("%s historical data ending block: %d", sap.chain.String(), endingBlock)
go func() {
sap.serveWg.Add(1)
defer sap.serveWg.Done()
for i := startingBlock; i <= endingBlock; i++ {
select {
case <-sap.QuitChan:
log.Infof("%s watcher historical data feed to subscription %s closed", sap.chain.String(), id)
return
default:
}
cidWrappers, empty, err := sap.Retriever.Retrieve(params, i)
if err != nil {
sendNonBlockingErr(sub, fmt.Errorf(" %s watcher CID Retrieval error at block %d\r%s", sap.chain.String(), i, err.Error()))
continue
}
if empty {
continue
}
for _, cids := range cidWrappers {
response, err := sap.IPLDFetcher.Fetch(cids)
if err != nil {
sendNonBlockingErr(sub, fmt.Errorf("%s watcher IPLD Fetching error at block %d\r%s", sap.chain.String(), i, err.Error()))
continue
}
responseRLP, err := rlp.EncodeToBytes(response)
if err != nil {
log.Error(err)
continue
}
select {
case sub.PayloadChan <- SubscriptionPayload{Data: responseRLP, Err: "", Flag: EmptyFlag, Height: response.Height()}:
log.Debugf("sending watcher historical data payload to %s subscription %s", sap.chain.String(), id)
default:
log.Infof("unable to send backFill payload to %s subscription %s; channel has no receiver", sap.chain.String(), id)
}
}
}
// when we are done backfilling send an empty payload signifying so in the msg
select {
case sub.PayloadChan <- SubscriptionPayload{Data: nil, Err: "", Flag: BackFillCompleteFlag}:
log.Debugf("sending backFill completion notice to %s subscription %s", sap.chain.String(), id)
default:
log.Infof("unable to send backFill completion notice to %s subscription %s", sap.chain.String(), id)
}
}()
return nil
}
// Unsubscribe is used by the API to remotely unsubscribe to the StateDiffingService loop
func (sap *Service) Unsubscribe(id rpc.ID) {
log.Infof("Unsubscribing %s from the %s watcher service", id, sap.chain.String())
sap.Lock()
for ty := range sap.Subscriptions {
delete(sap.Subscriptions[ty], id)
if len(sap.Subscriptions[ty]) == 0 {
// If we removed the last subscription of this type, remove the subscription type outright
delete(sap.Subscriptions, ty)
delete(sap.SubscriptionTypes, ty)
}
}
sap.Unlock()
}
// Start is used to begin the service
// This is mostly just to satisfy the node.Service interface
func (sap *Service) Start(*p2p.Server) error {
log.Infof("Starting %s watcher service", sap.chain.String())
wg := new(sync.WaitGroup)
payloadChan := make(chan shared.ConvertedData, PayloadChanBufferSize)
if err := sap.Sync(wg, payloadChan); err != nil {
return err
}
sap.Serve(wg, payloadChan)
return nil
}
// Stop is used to close down the service
// This is mostly just to satisfy the node.Service interface
func (sap *Service) Stop() error {
log.Infof("Stopping %s watcher service", sap.chain.String())
sap.Lock()
close(sap.QuitChan)
sap.close()
sap.Unlock()
return nil
}
// Node returns the node info for this service
func (sap *Service) Node() *node.Node {
return sap.NodeInfo
}
// Chain returns the chain type for this service
func (sap *Service) Chain() shared.ChainType {
return sap.chain
}
// close is used to close all listening subscriptions
// close needs to be called with subscription access locked
func (sap *Service) close() {
log.Infof("Closing all %s subscriptions", sap.chain.String())
for subType, subs := range sap.Subscriptions {
for _, sub := range subs {
sendNonBlockingQuit(sub)
}
delete(sap.Subscriptions, subType)
delete(sap.SubscriptionTypes, subType)
}
}
// closeType is used to close all subscriptions of given type
// closeType needs to be called with subscription access locked
func (sap *Service) closeType(subType common.Hash) {
log.Infof("Closing all %s subscriptions of type %s", sap.chain.String(), subType.String())
subs := sap.Subscriptions[subType]
for _, sub := range subs {
sendNonBlockingQuit(sub)
}
delete(sap.Subscriptions, subType)
delete(sap.SubscriptionTypes, subType)
}