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authorJeffrey Wilcke <jeffrey@ethereum.org>2016-04-05 15:43:32 +0800
committerJeffrey Wilcke <jeffrey@ethereum.org>2016-04-05 15:43:32 +0800
commited92f116f72646e73613afc2f2e7b83472a61434 (patch)
tree6c6d3cf414e21ee37d93e30e782ec028ff0144f8
parent6a185531d2cd2003bb4352c391f9dca023894d5a (diff)
parentf7328c5ecbd1076582a71ef7bf436485f3868b1f (diff)
downloadgo-tangerine-ed92f116f72646e73613afc2f2e7b83472a61434.tar.gz
go-tangerine-ed92f116f72646e73613afc2f2e7b83472a61434.tar.zst
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Merge pull request #2407 from bas-vk/rpc-notifications
RPC pub sub
-rw-r--r--eth/api.go206
-rw-r--r--eth/backend.go2
-rw-r--r--eth/downloader/api.go75
-rw-r--r--eth/filters/api.go79
-rw-r--r--node/node.go2
-rw-r--r--rpc/doc.go28
-rw-r--r--rpc/http.go2
-rw-r--r--rpc/inproc.go2
-rw-r--r--rpc/json.go24
-rw-r--r--rpc/notification.go288
-rw-r--r--rpc/notification_test.go119
-rw-r--r--rpc/server.go228
-rw-r--r--rpc/server_test.go16
-rw-r--r--rpc/types.go54
-rw-r--r--rpc/utils.go26
-rw-r--r--rpc/websocket.go3
16 files changed, 844 insertions, 310 deletions
diff --git a/eth/api.go b/eth/api.go
index a257639ba..676191fc2 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -28,6 +28,8 @@ import (
"sync"
"time"
+ "golang.org/x/net/context"
+
"github.com/ethereum/ethash"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/common"
@@ -457,16 +459,46 @@ func (s *PrivateAccountAPI) LockAccount(addr common.Address) bool {
// It offers only methods that operate on public data that is freely available to anyone.
type PublicBlockChainAPI struct {
config *core.ChainConfig
- bc *core.BlockChain
- chainDb ethdb.Database
- eventMux *event.TypeMux
- am *accounts.Manager
- miner *miner.Miner
+ bc *core.BlockChain
+ chainDb ethdb.Database
+ eventMux *event.TypeMux
+ muNewBlockSubscriptions sync.Mutex // protects newBlocksSubscriptions
+ newBlockSubscriptions map[string]func(core.ChainEvent) error // callbacks for new block subscriptions
+ am *accounts.Manager
+ miner *miner.Miner
}
// NewPublicBlockChainAPI creates a new Etheruem blockchain API.
func NewPublicBlockChainAPI(config *core.ChainConfig, bc *core.BlockChain, m *miner.Miner, chainDb ethdb.Database, eventMux *event.TypeMux, am *accounts.Manager) *PublicBlockChainAPI {
- return &PublicBlockChainAPI{config: config, bc: bc, miner: m, chainDb: chainDb, eventMux: eventMux, am: am}
+ api := &PublicBlockChainAPI{
+ config: config,
+ bc: bc,
+ miner: m,
+ chainDb: chainDb,
+ eventMux: eventMux,
+ am: am,
+ newBlockSubscriptions: make(map[string]func(core.ChainEvent) error),
+ }
+
+ go api.subscriptionLoop()
+
+ return api
+}
+
+// subscriptionLoop reads events from the global event mux and creates notifications for the matched subscriptions.
+func (s *PublicBlockChainAPI) subscriptionLoop() {
+ sub := s.eventMux.Subscribe(core.ChainEvent{})
+ for event := range sub.Chan() {
+ if chainEvent, ok := event.Data.(core.ChainEvent); ok {
+ s.muNewBlockSubscriptions.Lock()
+ for id, notifyOf := range s.newBlockSubscriptions {
+ if notifyOf(chainEvent) == rpc.ErrNotificationNotFound {
+ delete(s.newBlockSubscriptions, id)
+ }
+ }
+ s.muNewBlockSubscriptions.Unlock()
+ }
+ }
}
// BlockNumber returns the block number of the chain head.
@@ -564,20 +596,36 @@ type NewBlocksArgs struct {
// NewBlocks triggers a new block event each time a block is appended to the chain. It accepts an argument which allows
// the caller to specify whether the output should contain transactions and in what format.
-func (s *PublicBlockChainAPI) NewBlocks(args NewBlocksArgs) (rpc.Subscription, error) {
- sub := s.eventMux.Subscribe(core.ChainEvent{})
+func (s *PublicBlockChainAPI) NewBlocks(ctx context.Context, args NewBlocksArgs) (rpc.Subscription, error) {
+ notifier, supported := ctx.Value(rpc.NotifierContextKey).(rpc.Notifier)
+ if !supported {
+ return nil, rpc.ErrNotificationsUnsupported
+ }
- output := func(rawBlock interface{}) interface{} {
- if event, ok := rawBlock.(core.ChainEvent); ok {
- notification, err := s.rpcOutputBlock(event.Block, args.IncludeTransactions, args.TransactionDetails)
- if err == nil {
- return notification
- }
+ // create a subscription that will remove itself when unsubscribed/cancelled
+ subscription, err := notifier.NewSubscription(func(subId string) {
+ s.muNewBlockSubscriptions.Lock()
+ delete(s.newBlockSubscriptions, subId)
+ s.muNewBlockSubscriptions.Unlock()
+ })
+
+ if err != nil {
+ return nil, err
+ }
+
+ // add a callback that is called on chain events which will format the block and notify the client
+ s.muNewBlockSubscriptions.Lock()
+ s.newBlockSubscriptions[subscription.ID()] = func(e core.ChainEvent) error {
+ if notification, err := s.rpcOutputBlock(e.Block, args.IncludeTransactions, args.TransactionDetails); err == nil {
+ return subscription.Notify(notification)
+ } else {
+ glog.V(logger.Warn).Info("unable to format block %v\n", err)
}
- return rawBlock
+ return nil
}
+ s.muNewBlockSubscriptions.Unlock()
- return rpc.NewSubscriptionWithOutputFormat(sub, output), nil
+ return subscription, nil
}
// GetCode returns the code stored at the given address in the state for the given block number.
@@ -821,26 +869,75 @@ func newRPCTransaction(b *types.Block, txHash common.Hash) (*RPCTransaction, err
// PublicTransactionPoolAPI exposes methods for the RPC interface
type PublicTransactionPoolAPI struct {
- eventMux *event.TypeMux
- chainDb ethdb.Database
- gpo *GasPriceOracle
- bc *core.BlockChain
- miner *miner.Miner
- am *accounts.Manager
- txPool *core.TxPool
- txMu sync.Mutex
+ eventMux *event.TypeMux
+ chainDb ethdb.Database
+ gpo *GasPriceOracle
+ bc *core.BlockChain
+ miner *miner.Miner
+ am *accounts.Manager
+ txPool *core.TxPool
+ txMu sync.Mutex
+ muPendingTxSubs sync.Mutex
+ pendingTxSubs map[string]rpc.Subscription
}
// NewPublicTransactionPoolAPI creates a new RPC service with methods specific for the transaction pool.
func NewPublicTransactionPoolAPI(e *Ethereum) *PublicTransactionPoolAPI {
- return &PublicTransactionPoolAPI{
- eventMux: e.EventMux(),
- gpo: NewGasPriceOracle(e),
- chainDb: e.ChainDb(),
- bc: e.BlockChain(),
- am: e.AccountManager(),
- txPool: e.TxPool(),
- miner: e.Miner(),
+ api := &PublicTransactionPoolAPI{
+ eventMux: e.EventMux(),
+ gpo: NewGasPriceOracle(e),
+ chainDb: e.ChainDb(),
+ bc: e.BlockChain(),
+ am: e.AccountManager(),
+ txPool: e.TxPool(),
+ miner: e.Miner(),
+ pendingTxSubs: make(map[string]rpc.Subscription),
+ }
+
+ go api.subscriptionLoop()
+
+ return api
+}
+
+// subscriptionLoop listens for events on the global event mux and creates notifications for subscriptions.
+func (s *PublicTransactionPoolAPI) subscriptionLoop() {
+ sub := s.eventMux.Subscribe(core.TxPreEvent{})
+ accountTimeout := time.NewTicker(10 * time.Second)
+
+ // only publish pending tx signed by one of the accounts in the node
+ accountSet := set.New()
+ accounts, _ := s.am.Accounts()
+ for _, acc := range accounts {
+ accountSet.Add(acc.Address)
+ }
+
+ for {
+ select {
+ case event := <-sub.Chan():
+ if event == nil {
+ continue
+ }
+ tx := event.Data.(core.TxPreEvent)
+ if from, err := tx.Tx.FromFrontier(); err == nil {
+ if accountSet.Has(from) {
+ s.muPendingTxSubs.Lock()
+ for id, sub := range s.pendingTxSubs {
+ if sub.Notify(tx.Tx.Hash()) == rpc.ErrNotificationNotFound {
+ delete(s.pendingTxSubs, id)
+ }
+ }
+ s.muPendingTxSubs.Unlock()
+ }
+ }
+ case <-accountTimeout.C:
+ // refresh account list when accounts are added/removed from the node.
+ if accounts, err := s.am.Accounts(); err == nil {
+ accountSet.Clear()
+ for _, acc := range accounts {
+ accountSet.Add(acc.Address)
+ }
+ }
+ }
}
}
@@ -1275,40 +1372,27 @@ func (s *PublicTransactionPoolAPI) PendingTransactions() ([]*RPCTransaction, err
// NewPendingTransaction creates a subscription that is triggered each time a transaction enters the transaction pool
// and is send from one of the transactions this nodes manages.
-func (s *PublicTransactionPoolAPI) NewPendingTransactions() (rpc.Subscription, error) {
- sub := s.eventMux.Subscribe(core.TxPreEvent{})
-
- accounts, err := s.am.Accounts()
- if err != nil {
- return rpc.Subscription{}, err
+func (s *PublicTransactionPoolAPI) NewPendingTransactions(ctx context.Context) (rpc.Subscription, error) {
+ notifier, supported := ctx.Value(rpc.NotifierContextKey).(rpc.Notifier)
+ if !supported {
+ return nil, rpc.ErrNotificationsUnsupported
}
- accountSet := set.New()
- for _, account := range accounts {
- accountSet.Add(account.Address)
- }
- accountSetLastUpdates := time.Now()
- output := func(transaction interface{}) interface{} {
- if time.Since(accountSetLastUpdates) > (time.Duration(2) * time.Second) {
- if accounts, err = s.am.Accounts(); err != nil {
- accountSet.Clear()
- for _, account := range accounts {
- accountSet.Add(account.Address)
- }
- accountSetLastUpdates = time.Now()
- }
- }
+ subscription, err := notifier.NewSubscription(func(id string) {
+ s.muPendingTxSubs.Lock()
+ delete(s.pendingTxSubs, id)
+ s.muPendingTxSubs.Unlock()
+ })
- tx := transaction.(core.TxPreEvent)
- if from, err := tx.Tx.FromFrontier(); err == nil {
- if accountSet.Has(from) {
- return tx.Tx.Hash()
- }
- }
- return nil
+ if err != nil {
+ return nil, err
}
- return rpc.NewSubscriptionWithOutputFormat(sub, output), nil
+ s.muPendingTxSubs.Lock()
+ s.pendingTxSubs[subscription.ID()] = subscription
+ s.muPendingTxSubs.Unlock()
+
+ return subscription, nil
}
// Resend accepts an existing transaction and a new gas price and limit. It will remove the given transaction from the
diff --git a/eth/backend.go b/eth/backend.go
index 26af7ff91..20f516610 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -306,7 +306,7 @@ func (s *Ethereum) APIs() []rpc.API {
}, {
Namespace: "eth",
Version: "1.0",
- Service: downloader.NewPublicDownloaderAPI(s.Downloader()),
+ Service: downloader.NewPublicDownloaderAPI(s.Downloader(), s.EventMux()),
Public: true,
}, {
Namespace: "miner",
diff --git a/eth/downloader/api.go b/eth/downloader/api.go
index 13d0ed46e..576b33f1d 100644
--- a/eth/downloader/api.go
+++ b/eth/downloader/api.go
@@ -17,18 +17,55 @@
package downloader
import (
+ "sync"
+
+ "golang.org/x/net/context"
+
+ "github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/rpc"
)
// PublicDownloaderAPI provides an API which gives information about the current synchronisation status.
// It offers only methods that operates on data that can be available to anyone without security risks.
type PublicDownloaderAPI struct {
- d *Downloader
+ d *Downloader
+ mux *event.TypeMux
+ muSyncSubscriptions sync.Mutex
+ syncSubscriptions map[string]rpc.Subscription
}
// NewPublicDownloaderAPI create a new PublicDownloaderAPI.
-func NewPublicDownloaderAPI(d *Downloader) *PublicDownloaderAPI {
- return &PublicDownloaderAPI{d}
+func NewPublicDownloaderAPI(d *Downloader, m *event.TypeMux) *PublicDownloaderAPI {
+ api := &PublicDownloaderAPI{d: d, mux: m, syncSubscriptions: make(map[string]rpc.Subscription)}
+
+ go api.run()
+
+ return api
+}
+
+func (api *PublicDownloaderAPI) run() {
+ sub := api.mux.Subscribe(StartEvent{}, DoneEvent{}, FailedEvent{})
+
+ for event := range sub.Chan() {
+ var notification interface{}
+
+ switch event.Data.(type) {
+ case StartEvent:
+ result := &SyncingResult{Syncing: true}
+ result.Status.Origin, result.Status.Current, result.Status.Height, result.Status.Pulled, result.Status.Known = api.d.Progress()
+ notification = result
+ case DoneEvent, FailedEvent:
+ notification = false
+ }
+
+ api.muSyncSubscriptions.Lock()
+ for id, sub := range api.syncSubscriptions {
+ if sub.Notify(notification) == rpc.ErrNotificationNotFound {
+ delete(api.syncSubscriptions, id)
+ }
+ }
+ api.muSyncSubscriptions.Unlock()
+ }
}
// Progress gives progress indications when the node is synchronising with the Ethereum network.
@@ -47,19 +84,25 @@ type SyncingResult struct {
}
// Syncing provides information when this nodes starts synchronising with the Ethereum network and when it's finished.
-func (s *PublicDownloaderAPI) Syncing() (rpc.Subscription, error) {
- sub := s.d.mux.Subscribe(StartEvent{}, DoneEvent{}, FailedEvent{})
+func (api *PublicDownloaderAPI) Syncing(ctx context.Context) (rpc.Subscription, error) {
+ notifier, supported := ctx.Value(rpc.NotifierContextKey).(rpc.Notifier)
+ if !supported {
+ return nil, rpc.ErrNotificationsUnsupported
+ }
- output := func(event interface{}) interface{} {
- switch event.(type) {
- case StartEvent:
- result := &SyncingResult{Syncing: true}
- result.Status.Origin, result.Status.Current, result.Status.Height, result.Status.Pulled, result.Status.Known = s.d.Progress()
- return result
- case DoneEvent, FailedEvent:
- return false
- }
- return nil
+ subscription, err := notifier.NewSubscription(func(id string) {
+ api.muSyncSubscriptions.Lock()
+ delete(api.syncSubscriptions, id)
+ api.muSyncSubscriptions.Unlock()
+ })
+
+ if err != nil {
+ return nil, err
}
- return rpc.NewSubscriptionWithOutputFormat(sub, output), nil
+
+ api.muSyncSubscriptions.Lock()
+ api.syncSubscriptions[subscription.ID()] = subscription
+ api.muSyncSubscriptions.Unlock()
+
+ return subscription, nil
}
diff --git a/eth/filters/api.go b/eth/filters/api.go
index e6a1ce3ab..956660363 100644
--- a/eth/filters/api.go
+++ b/eth/filters/api.go
@@ -17,15 +17,13 @@
package filters
import (
- "sync"
- "time"
-
"crypto/rand"
"encoding/hex"
- "errors"
-
"encoding/json"
+ "errors"
"fmt"
+ "sync"
+ "time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
@@ -33,6 +31,8 @@ import (
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/rpc"
+
+ "golang.org/x/net/context"
)
var (
@@ -202,7 +202,7 @@ func (s *PublicFilterAPI) NewPendingTransactionFilter() (string, error) {
}
// newLogFilter creates a new log filter.
-func (s *PublicFilterAPI) newLogFilter(earliest, latest int64, addresses []common.Address, topics [][]common.Hash) (int, error) {
+func (s *PublicFilterAPI) newLogFilter(earliest, latest int64, addresses []common.Address, topics [][]common.Hash, callback func(log *vm.Log, removed bool)) (int, error) {
s.logMu.Lock()
defer s.logMu.Unlock()
@@ -219,17 +219,70 @@ func (s *PublicFilterAPI) newLogFilter(earliest, latest int64, addresses []commo
filter.SetAddresses(addresses)
filter.SetTopics(topics)
filter.LogCallback = func(log *vm.Log, removed bool) {
- s.logMu.Lock()
- defer s.logMu.Unlock()
-
- if queue := s.logQueue[id]; queue != nil {
- queue.add(vmlog{log, removed})
+ if callback != nil {
+ callback(log, removed)
+ } else {
+ s.logMu.Lock()
+ defer s.logMu.Unlock()
+ if queue := s.logQueue[id]; queue != nil {
+ queue.add(vmlog{log, removed})
+ }
}
}
return id, nil
}
+func (s *PublicFilterAPI) Logs(ctx context.Context, args NewFilterArgs) (rpc.Subscription, error) {
+ notifier, supported := ctx.Value(rpc.NotifierContextKey).(rpc.Notifier)
+ if !supported {
+ return nil, rpc.ErrNotificationsUnsupported
+ }
+
+ var (
+ externalId string
+ subscription rpc.Subscription
+ err error
+ )
+
+ if externalId, err = newFilterId(); err != nil {
+ return nil, err
+ }
+
+ // uninstall filter when subscription is unsubscribed/cancelled
+ if subscription, err = notifier.NewSubscription(func(string) {
+ s.UninstallFilter(externalId)
+ }); err != nil {
+ return nil, err
+ }
+
+ notifySubscriber := func(log *vm.Log, removed bool) {
+ rpcLog := toRPCLogs(vm.Logs{log}, removed)
+ if err := subscription.Notify(rpcLog); err != nil {
+ subscription.Cancel()
+ }
+ }
+
+ // from and to block number are not used since subscriptions don't allow you to travel to "time"
+ var id int
+ if len(args.Addresses) > 0 {
+ id, err = s.newLogFilter(-1, -1, args.Addresses, args.Topics, notifySubscriber)
+ } else {
+ id, err = s.newLogFilter(-1, -1, nil, args.Topics, notifySubscriber)
+ }
+
+ if err != nil {
+ subscription.Cancel()
+ return nil, err
+ }
+
+ s.filterMapMu.Lock()
+ s.filterMapping[externalId] = id
+ s.filterMapMu.Unlock()
+
+ return subscription, err
+}
+
// NewFilterArgs represents a request to create a new filter.
type NewFilterArgs struct {
FromBlock rpc.BlockNumber
@@ -364,9 +417,9 @@ func (s *PublicFilterAPI) NewFilter(args NewFilterArgs) (string, error) {
var id int
if len(args.Addresses) > 0 {
- id, err = s.newLogFilter(args.FromBlock.Int64(), args.ToBlock.Int64(), args.Addresses, args.Topics)
+ id, err = s.newLogFilter(args.FromBlock.Int64(), args.ToBlock.Int64(), args.Addresses, args.Topics, nil)
} else {
- id, err = s.newLogFilter(args.FromBlock.Int64(), args.ToBlock.Int64(), nil, args.Topics)
+ id, err = s.newLogFilter(args.FromBlock.Int64(), args.ToBlock.Int64(), nil, args.Topics, nil)
}
if err != nil {
return "", err
diff --git a/node/node.go b/node/node.go
index 7d3a10874..62cc3895b 100644
--- a/node/node.go
+++ b/node/node.go
@@ -303,7 +303,7 @@ func (n *Node) startIPC(apis []rpc.API) error {
glog.V(logger.Error).Infof("IPC accept failed: %v", err)
continue
}
- go handler.ServeCodec(rpc.NewJSONCodec(conn))
+ go handler.ServeCodec(rpc.NewJSONCodec(conn), rpc.OptionMethodInvocation | rpc.OptionSubscriptions)
}
}()
// All listeners booted successfully
diff --git a/rpc/doc.go b/rpc/doc.go
index a2506ad58..c9dba3270 100644
--- a/rpc/doc.go
+++ b/rpc/doc.go
@@ -68,35 +68,19 @@ The package also supports the publish subscribe pattern through the use of subsc
A method that is considered eligible for notifications must satisfy the following criteria:
- object must be exported
- method must be exported
+ - first method argument type must be context.Context
- method argument(s) must be exported or builtin types
- method must return the tuple Subscription, error
-
An example method:
- func (s *BlockChainService) Head() (Subscription, error) {
- sub := s.bc.eventMux.Subscribe(ChainHeadEvent{})
- return v2.NewSubscription(sub), nil
- }
-
-This method will push all raised ChainHeadEvents to subscribed clients. If the client is only
-interested in every N'th block it is possible to add a criteria.
-
- func (s *BlockChainService) HeadFiltered(nth uint64) (Subscription, error) {
- sub := s.bc.eventMux.Subscribe(ChainHeadEvent{})
-
- criteria := func(event interface{}) bool {
- chainHeadEvent := event.(ChainHeadEvent)
- if chainHeadEvent.Block.NumberU64() % nth == 0 {
- return true
- }
- return false
- }
-
- return v2.NewSubscriptionFiltered(sub, criteria), nil
+ func (s *BlockChainService) NewBlocks(ctx context.Context) (Subscription, error) {
+ ...
}
Subscriptions are deleted when:
- the user sends an unsubscribe request
- - the connection which was used to create the subscription is closed
+ - the connection which was used to create the subscription is closed. This can be initiated
+ by the client and server. The server will close the connection on an write error or when
+ the queue of buffered notifications gets too big.
*/
package rpc
diff --git a/rpc/http.go b/rpc/http.go
index af3d29014..dd1ec2c01 100644
--- a/rpc/http.go
+++ b/rpc/http.go
@@ -126,7 +126,7 @@ func newJSONHTTPHandler(srv *Server) http.HandlerFunc {
// a single request.
codec := NewJSONCodec(&httpReadWriteNopCloser{r.Body, w})
defer codec.Close()
- srv.ServeSingleRequest(codec)
+ srv.ServeSingleRequest(codec, OptionMethodInvocation)
}
}
diff --git a/rpc/inproc.go b/rpc/inproc.go
index 3cfbea71c..250f5c787 100644
--- a/rpc/inproc.go
+++ b/rpc/inproc.go
@@ -39,7 +39,7 @@ func (c *inProcClient) Close() {
// RPC server.
func NewInProcRPCClient(handler *Server) Client {
p1, p2 := net.Pipe()
- go handler.ServeCodec(NewJSONCodec(p1))
+ go handler.ServeCodec(NewJSONCodec(p1), OptionMethodInvocation|OptionSubscriptions)
return &inProcClient{handler, p2, json.NewEncoder(p2), json.NewDecoder(p2)}
}
diff --git a/rpc/json.go b/rpc/json.go
index 1ed943c00..a0bfcac04 100644
--- a/rpc/json.go
+++ b/rpc/json.go
@@ -22,7 +22,7 @@ import (
"io"
"reflect"
"strings"
- "sync/atomic"
+ "sync"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
@@ -81,19 +81,20 @@ type jsonNotification struct {
// jsonCodec reads and writes JSON-RPC messages to the underlying connection. It also has support for parsing arguments
// and serializing (result) objects.
type jsonCodec struct {
- closed chan interface{}
- isClosed int32
- d *json.Decoder
- e *json.Encoder
- req JSONRequest
- rw io.ReadWriteCloser
+ closed chan interface{}
+ closer sync.Once
+ d *json.Decoder
+ muEncoder sync.Mutex
+ e *json.Encoder
+ req JSONRequest
+ rw io.ReadWriteCloser
}
// NewJSONCodec creates a new RPC server codec with support for JSON-RPC 2.0
func NewJSONCodec(rwc io.ReadWriteCloser) ServerCodec {
d := json.NewDecoder(rwc)
d.UseNumber()
- return &jsonCodec{closed: make(chan interface{}), d: d, e: json.NewEncoder(rwc), rw: rwc, isClosed: 0}
+ return &jsonCodec{closed: make(chan interface{}), d: d, e: json.NewEncoder(rwc), rw: rwc}
}
// isBatch returns true when the first non-whitespace characters is '['
@@ -326,15 +327,18 @@ func (c *jsonCodec) CreateNotification(subid string, event interface{}) interfac
// Write message to client
func (c *jsonCodec) Write(res interface{}) error {
+ c.muEncoder.Lock()
+ defer c.muEncoder.Unlock()
+
return c.e.Encode(res)
}
// Close the underlying connection
func (c *jsonCodec) Close() {
- if atomic.CompareAndSwapInt32(&c.isClosed, 0, 1) {
+ c.closer.Do(func() {
close(c.closed)
c.rw.Close()
- }
+ })
}
// Closed returns a channel which will be closed when Close is called
diff --git a/rpc/notification.go b/rpc/notification.go
new file mode 100644
index 000000000..146d785c9
--- /dev/null
+++ b/rpc/notification.go
@@ -0,0 +1,288 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+ "errors"
+ "sync"
+ "time"
+
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/ethereum/go-ethereum/logger/glog"
+)
+
+var (
+ // ErrNotificationsUnsupported is returned when the connection doesn't support notifications
+ ErrNotificationsUnsupported = errors.New("notifications not supported")
+
+ // ErrNotificationNotFound is returned when the notification for the given id is not found
+ ErrNotificationNotFound = errors.New("notification not found")
+
+ // errNotifierStopped is returned when the notifier is stopped (e.g. codec is closed)
+ errNotifierStopped = errors.New("unable to send notification")
+
+ // errNotificationQueueFull is returns when there are too many notifications in the queue
+ errNotificationQueueFull = errors.New("too many pending notifications")
+)
+
+// unsubSignal is a signal that the subscription is unsubscribed. It is used to flush buffered
+// notifications that might be pending in the internal queue.
+var unsubSignal = new(struct{})
+
+// UnsubscribeCallback defines a callback that is called when a subcription ends.
+// It receives the subscription id as argument.
+type UnsubscribeCallback func(id string)
+
+// notification is a helper object that holds event data for a subscription
+type notification struct {
+ sub *bufferedSubscription // subscription id
+ data interface{} // event data
+}
+
+// A Notifier type describes the interface for objects that can send create subscriptions
+type Notifier interface {
+ // Create a new subscription. The given callback is called when this subscription
+ // is cancelled (e.g. client send an unsubscribe, connection closed).
+ NewSubscription(UnsubscribeCallback) (Subscription, error)
+ // Cancel subscription
+ Unsubscribe(id string) error
+}
+
+// Subscription defines the interface for objects that can notify subscribers
+type Subscription interface {
+ // Inform client of an event
+ Notify(data interface{}) error
+ // Unique identifier
+ ID() string
+ // Cancel subscription
+ Cancel() error
+}
+
+// bufferedSubscription is a subscription that uses a bufferedNotifier to send
+// notifications to subscribers.
+type bufferedSubscription struct {
+ id string
+ unsubOnce sync.Once // call unsub method once
+ unsub UnsubscribeCallback // called on Unsubscribed
+ notifier *bufferedNotifier // forward notifications to
+ pending chan interface{} // closed when active
+ flushed chan interface{} // closed when all buffered notifications are send
+ lastNotification time.Time // last time a notification was send
+}
+
+// ID returns the subscription identifier that the client uses to refer to this instance.
+func (s *bufferedSubscription) ID() string {
+ return s.id
+}
+
+// Cancel informs the notifier that this subscription is cancelled by the API
+func (s *bufferedSubscription) Cancel() error {
+ return s.notifier.Unsubscribe(s.id)
+}
+
+// Notify the subscriber of a particular event.
+func (s *bufferedSubscription) Notify(data interface{}) error {
+ return s.notifier.send(s.id, data)
+}
+
+// bufferedNotifier is a notifier that queues notifications in an internal queue and
+// send them as fast as possible to the client from this queue. It will stop if the
+// queue grows past a given size.
+type bufferedNotifier struct {
+ codec ServerCodec // underlying connection
+ mu sync.Mutex // guard internal state
+ subscriptions map[string]*bufferedSubscription // keep track of subscriptions associated with codec
+ queueSize int // max number of items in queue
+ queue chan *notification // notification queue
+ stopped bool // indication if this notifier is ordered to stop
+}
+
+// newBufferedNotifier returns a notifier that queues notifications in an internal queue
+// from which notifications are send as fast as possible to the client. If the queue size
+// limit is reached (client is unable to keep up) it will stop and closes the codec.
+func newBufferedNotifier(codec ServerCodec, size int) *bufferedNotifier {
+ notifier := &bufferedNotifier{
+ codec: codec,
+ subscriptions: make(map[string]*bufferedSubscription),
+ queue: make(chan *notification, size),
+ queueSize: size,
+ }
+
+ go notifier.run()
+
+ return notifier
+}
+
+// NewSubscription creates a new subscription that forwards events to this instance internal
+// queue. The given callback is called when the subscription is unsubscribed/cancelled.
+func (n *bufferedNotifier) NewSubscription(callback UnsubscribeCallback) (Subscription, error) {
+ id, err := newSubscriptionID()
+ if err != nil {
+ return nil, err
+ }
+
+ n.mu.Lock()
+ defer n.mu.Unlock()
+
+ if n.stopped {
+ return nil, errNotifierStopped
+ }
+
+ sub := &bufferedSubscription{
+ id: id,
+ unsub: callback,
+ notifier: n,
+ pending: make(chan interface{}),
+ flushed: make(chan interface{}),
+ lastNotification: time.Now(),
+ }
+
+ n.subscriptions[id] = sub
+
+ return sub, nil
+}
+
+// Remove the given subscription. If subscription is not found notificationNotFoundErr is returned.
+func (n *bufferedNotifier) Unsubscribe(subid string) error {
+ n.mu.Lock()
+ sub, found := n.subscriptions[subid]
+ n.mu.Unlock()
+
+ if found {
+ // send the unsubscribe signal, this will cause the notifier not to accept new events
+ // for this subscription and will close the flushed channel after the last (buffered)
+ // notification was send to the client.
+ if err := n.send(subid, unsubSignal); err != nil {
+ return err
+ }
+
+ // wait for confirmation that all (buffered) events are send for this subscription.
+ // this ensures that the unsubscribe method response is not send before all buffered
+ // events for this subscription are send.
+ <-sub.flushed
+
+ return nil
+ }
+
+ return ErrNotificationNotFound
+}
+
+// Send enques the given data for the subscription with public ID on the internal queue. t returns
+// an error when the notifier is stopped or the queue is full. If data is the unsubscribe signal it
+// will remove the subscription with the given id from the subscription collection.
+func (n *bufferedNotifier) send(id string, data interface{}) error {
+ n.mu.Lock()
+ defer n.mu.Unlock()
+
+ if n.stopped {
+ return errNotifierStopped
+ }
+
+ var (
+ subscription *bufferedSubscription
+ found bool
+ )
+
+ // check if subscription is associated with this connection, it might be cancelled
+ // (subscribe/connection closed)
+ if subscription, found = n.subscriptions[id]; !found {
+ glog.V(logger.Error).Infof("received notification for unknown subscription %s\n", id)
+ return ErrNotificationNotFound
+ }
+
+ // received the unsubscribe signal. Add it to the queue to make sure any pending notifications
+ // for this subscription are send. When the run loop receives this singal it will signal that
+ // all pending subscriptions are flushed and that the confirmation of the unsubscribe can be
+ // send to the user. Remove the subscriptions to make sure new notifications are not accepted.
+ if data == unsubSignal {
+ delete(n.subscriptions, id)
+ if subscription.unsub != nil {
+ subscription.unsubOnce.Do(func() { subscription.unsub(id) })
+ }
+ }
+
+ subscription.lastNotification = time.Now()
+
+ if len(n.queue) >= n.queueSize {
+ glog.V(logger.Warn).Infoln("too many buffered notifications -> close connection")
+ n.codec.Close()
+ return errNotificationQueueFull
+ }
+
+ n.queue <- &notification{subscription, data}
+ return nil
+}
+
+// run reads notifications from the internal queue and sends them to the client. In case of an
+// error, or when the codec is closed it will cancel all active subscriptions and returns.
+func (n *bufferedNotifier) run() {
+ defer func() {
+ n.mu.Lock()
+ defer n.mu.Unlock()
+
+ n.stopped = true
+ close(n.queue)
+
+ // on exit call unsubscribe callback
+ for id, sub := range n.subscriptions {
+ if sub.unsub != nil {
+ sub.unsubOnce.Do(func() { sub.unsub(id) })
+ }
+ close(sub.flushed)
+ delete(n.subscriptions, id)
+ }
+ }()
+
+ for {
+ select {
+ case notification := <-n.queue:
+ // It can happen that an event is raised before the RPC server was able to send the sub
+ // id to the client. Therefore subscriptions are marked as pending until the sub id was
+ // send. The RPC server will activate the subscription by closing the pending chan.
+ <-notification.sub.pending
+
+ if notification.data == unsubSignal {
+ // unsubSignal is the last accepted message for this subscription. Raise the signal
+ // that all buffered notifications are sent by closing the flushed channel. This
+ // indicates that the response for the unsubscribe can be send to the client.
+ close(notification.sub.flushed)
+ } else {
+ msg := n.codec.CreateNotification(notification.sub.id, notification.data)
+ if err := n.codec.Write(msg); err != nil {
+ n.codec.Close()
+ // unable to send notification to client, unsubscribe all subscriptions
+ glog.V(logger.Warn).Infof("unable to send notification - %v\n", err)
+ return
+ }
+ }
+ case <-n.codec.Closed(): // connection was closed
+ glog.V(logger.Debug).Infoln("codec closed, stop subscriptions")
+ return
+ }
+ }
+}
+
+// Marks the subscription as active. This will causes the notifications for this subscription to be
+// forwarded to the client.
+func (n *bufferedNotifier) activate(subid string) {
+ n.mu.Lock()
+ defer n.mu.Unlock()
+
+ if sub, found := n.subscriptions[subid]; found {
+ close(sub.pending)
+ }
+}
diff --git a/rpc/notification_test.go b/rpc/notification_test.go
new file mode 100644
index 000000000..8d2add81c
--- /dev/null
+++ b/rpc/notification_test.go
@@ -0,0 +1,119 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+package rpc
+
+import (
+ "encoding/json"
+ "net"
+ "testing"
+ "time"
+
+ "golang.org/x/net/context"
+)
+
+type NotificationTestService struct{}
+
+var (
+ unsubCallbackCalled = false
+)
+
+func (s *NotificationTestService) Unsubscribe(subid string) {
+ unsubCallbackCalled = true
+}
+
+func (s *NotificationTestService) SomeSubscription(ctx context.Context, n, val int) (Subscription, error) {
+ notifier, supported := ctx.Value(NotifierContextKey).(Notifier)
+ if !supported {
+ return nil, ErrNotificationsUnsupported
+ }
+
+ // by explicitly creating an subscription we make sure that the subscription id is send back to the client
+ // before the first subscription.Notify is called. Otherwise the events might be send before the response
+ // for the eth_subscribe method.
+ subscription, err := notifier.NewSubscription(s.Unsubscribe)
+ if err != nil {
+ return nil, err
+ }
+
+ go func() {
+ for i := 0; i < n; i++ {
+ if err := subscription.Notify(val + i); err != nil {
+ return
+ }
+ }
+ }()
+
+ return subscription, nil
+}
+
+func TestNotifications(t *testing.T) {
+ server := NewServer()
+ service := &NotificationTestService{}
+
+ if err := server.RegisterName("eth", service); err != nil {
+ t.Fatalf("unable to register test service %v", err)
+ }
+
+ clientConn, serverConn := net.Pipe()
+
+ go server.ServeCodec(NewJSONCodec(serverConn), OptionMethodInvocation|OptionSubscriptions)
+
+ out := json.NewEncoder(clientConn)
+ in := json.NewDecoder(clientConn)
+
+ n := 5
+ val := 12345
+ request := map[string]interface{}{
+ "id": 1,
+ "method": "eth_subscribe",
+ "version": "2.0",
+ "params": []interface{}{"someSubscription", n, val},
+ }
+
+ // create subscription
+ if err := out.Encode(request); err != nil {
+ t.Fatal(err)
+ }
+
+ var subid string
+ response := JSONSuccessResponse{Result: subid}
+ if err := in.Decode(&response); err != nil {
+ t.Fatal(err)
+ }
+
+ var ok bool
+ if subid, ok = response.Result.(string); !ok {
+ t.Fatalf("expected subscription id, got %T", response.Result)
+ }
+
+ for i := 0; i < n; i++ {
+ var notification jsonNotification
+ if err := in.Decode(&notification); err != nil {
+ t.Fatalf("%v", err)
+ }
+
+ if int(notification.Params.Result.(float64)) != val+i {
+ t.Fatalf("expected %d, got %d", val+i, notification.Params.Result)
+ }
+ }
+
+ clientConn.Close() // causes notification unsubscribe callback to be called
+ time.Sleep(1 * time.Second)
+
+ if !unsubCallbackCalled {
+ t.Error("unsubscribe callback not called after closing connection")
+ }
+}
diff --git a/rpc/server.go b/rpc/server.go
index 22448f8e3..cf90eba02 100644
--- a/rpc/server.go
+++ b/rpc/server.go
@@ -23,7 +23,6 @@ import (
"sync/atomic"
"time"
- "github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"golang.org/x/net/context"
@@ -33,10 +32,26 @@ import (
const (
stopPendingRequestTimeout = 3 * time.Second // give pending requests stopPendingRequestTimeout the time to finish when the server is stopped
+ // NotifierContextKey is the key where the notifier associated with the codec is stored in the context
+ NotifierContextKey = 1
+
+ notificationBufferSize = 10000 // max buffered notifications before codec is closed
+
DefaultIPCApis = "admin,eth,debug,miner,net,shh,txpool,personal,web3"
DefaultHTTPApis = "eth,net,web3"
)
+// CodecOption specifies which type of messages this codec supports
+type CodecOption int
+
+const (
+ // OptionMethodInvocation is an indication that the codec supports RPC method calls
+ OptionMethodInvocation CodecOption = 1 << iota
+
+ // OptionSubscriptions is an indication that the codec suports RPC notifications
+ OptionSubscriptions = 1 << iota // support pub sub
+)
+
// NewServer will create a new server instance with no registered handlers.
func NewServer() *Server {
server := &Server{
@@ -63,7 +78,7 @@ type RPCService struct {
// Modules returns the list of RPC services with their version number
func (s *RPCService) Modules() map[string]string {
modules := make(map[string]string)
- for name, _ := range s.server.services {
+ for name := range s.server.services {
modules[name] = "1.0"
}
return modules
@@ -92,7 +107,7 @@ func (s *Server) RegisterName(name string, rcvr interface{}) error {
if regsvc, present := s.services[name]; present {
methods, subscriptions := suitableCallbacks(rcvrVal, svc.typ)
if len(methods) == 0 && len(subscriptions) == 0 {
- return fmt.Errorf("Service doesn't have any suitable methods/subscriptions to expose")
+ return fmt.Errorf("Service %T doesn't have any suitable methods/subscriptions to expose", rcvr)
}
for _, m := range methods {
@@ -109,7 +124,7 @@ func (s *Server) RegisterName(name string, rcvr interface{}) error {
svc.callbacks, svc.subscriptions = suitableCallbacks(rcvrVal, svc.typ)
if len(svc.callbacks) == 0 && len(svc.subscriptions) == 0 {
- return fmt.Errorf("Service doesn't have any suitable methods/subscriptions to expose")
+ return fmt.Errorf("Service %T doesn't have any suitable methods/subscriptions to expose", rcvr)
}
s.services[svc.name] = svc
@@ -117,12 +132,23 @@ func (s *Server) RegisterName(name string, rcvr interface{}) error {
return nil
}
+// hasOption returns true if option is included in options, otherwise false
+func hasOption(option CodecOption, options []CodecOption) bool {
+ for _, o := range options {
+ if option == o {
+ return true
+ }
+ }
+ return false
+}
+
// serveRequest will reads requests from the codec, calls the RPC callback and
// writes the response to the given codec.
+//
// If singleShot is true it will process a single request, otherwise it will handle
// requests until the codec returns an error when reading a request (in most cases
// an EOF). It executes requests in parallel when singleShot is false.
-func (s *Server) serveRequest(codec ServerCodec, singleShot bool) error {
+func (s *Server) serveRequest(codec ServerCodec, singleShot bool, options CodecOption) error {
defer func() {
if err := recover(); err != nil {
const size = 64 << 10
@@ -141,6 +167,12 @@ func (s *Server) serveRequest(codec ServerCodec, singleShot bool) error {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
+ // if the codec supports notification include a notifier that callbacks can use
+ // to send notification to clients. It is thight to the codec/connection. If the
+ // connection is closed the notifier will stop and cancels all active subscriptions.
+ if options&OptionSubscriptions == OptionSubscriptions {
+ ctx = context.WithValue(ctx, NotifierContextKey, newBufferedNotifier(codec, notificationBufferSize))
+ }
s.codecsMu.Lock()
if atomic.LoadInt32(&s.run) != 1 { // server stopped
s.codecsMu.Unlock()
@@ -193,20 +225,16 @@ func (s *Server) serveRequest(codec ServerCodec, singleShot bool) error {
// ServeCodec reads incoming requests from codec, calls the appropriate callback and writes the
// response back using the given codec. It will block until the codec is closed or the server is
// stopped. In either case the codec is closed.
-//
-// This server will:
-// 1. allow for asynchronous and parallel request execution
-// 2. supports notifications (pub/sub)
-// 3. supports request batches
-func (s *Server) ServeCodec(codec ServerCodec) {
+func (s *Server) ServeCodec(codec ServerCodec, options CodecOption) {
defer codec.Close()
- s.serveRequest(codec, false)
+ s.serveRequest(codec, false, options)
}
// ServeSingleRequest reads and processes a single RPC request from the given codec. It will not
-// close the codec unless a non-recoverable error has occurred.
-func (s *Server) ServeSingleRequest(codec ServerCodec) {
- s.serveRequest(codec, true)
+// close the codec unless a non-recoverable error has occurred. Note, this method will return after
+// a single request has been processed!
+func (s *Server) ServeSingleRequest(codec ServerCodec, options CodecOption) {
+ s.serveRequest(codec, true, options)
}
// Stop will stop reading new requests, wait for stopPendingRequestTimeout to allow pending requests to finish,
@@ -225,122 +253,64 @@ func (s *Server) Stop() {
}
}
-// sendNotification will create a notification from the given event by serializing member fields of the event.
-// It will then send the notification to the client, when it fails the codec is closed. When the event has multiple
-// fields an array of values is returned.
-func sendNotification(codec ServerCodec, subid string, event interface{}) {
- notification := codec.CreateNotification(subid, event)
-
- if err := codec.Write(notification); err != nil {
- codec.Close()
- }
-}
-
-// createSubscription will register a new subscription and waits for raised events. When an event is raised it will:
-// 1. test if the event is raised matches the criteria the user has (optionally) specified
-// 2. create a notification of the event and send it the client when it matches the criteria
-// It will unsubscribe the subscription when the socket is closed or the subscription is unsubscribed by the user.
-func (s *Server) createSubscription(c ServerCodec, req *serverRequest) (string, error) {
- args := []reflect.Value{req.callb.rcvr}
- if len(req.args) > 0 {
- args = append(args, req.args...)
- }
-
- subid, err := newSubscriptionId()
- if err != nil {
- return "", err
- }
-
+// createSubscription will call the subscription callback and returns the subscription id or error.
+func (s *Server) createSubscription(ctx context.Context, c ServerCodec, req *serverRequest) (string, error) {
+ // subscription have as first argument the context following optional arguments
+ args := []reflect.Value{req.callb.rcvr, reflect.ValueOf(ctx)}
+ args = append(args, req.args...)
reply := req.callb.method.Func.Call(args)
- if reply[1].IsNil() { // no error
- if subscription, ok := reply[0].Interface().(Subscription); ok {
- s.muSubcriptions.Lock()
- s.subscriptions[subid] = subscription
- s.muSubcriptions.Unlock()
- go func() {
- cases := []reflect.SelectCase{
- reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(subscription.Chan())}, // new event
- reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(c.Closed())}, // connection closed
- }
-
- for {
- idx, notification, recvOk := reflect.Select(cases)
- switch idx {
- case 0: // new event, or channel closed
- if recvOk { // send notification
- if event, ok := notification.Interface().(*event.Event); ok {
- if subscription.match == nil || subscription.match(event.Data) {
- sendNotification(c, subid, subscription.format(event.Data))
- }
- }
- } else { // user send an eth_unsubscribe request
- return
- }
- case 1: // connection closed
- s.unsubscribe(subid)
- return
- }
- }
- }()
- } else { // unable to create subscription
- s.muSubcriptions.Lock()
- delete(s.subscriptions, subid)
- s.muSubcriptions.Unlock()
- }
- } else {
- return "", fmt.Errorf("Unable to create subscription")
+ if !reply[1].IsNil() { // subscription creation failed
+ return "", reply[1].Interface().(error)
}
- return subid, nil
-}
-
-// unsubscribe calls the Unsubscribe method on the subscription and removes a subscription from the subscription
-// registry.
-func (s *Server) unsubscribe(subid string) bool {
- s.muSubcriptions.Lock()
- defer s.muSubcriptions.Unlock()
- if sub, ok := s.subscriptions[subid]; ok {
- sub.Unsubscribe()
- delete(s.subscriptions, subid)
- return true
- }
- return false
+ return reply[0].Interface().(Subscription).ID(), nil
}
// handle executes a request and returns the response from the callback.
-func (s *Server) handle(ctx context.Context, codec ServerCodec, req *serverRequest) interface{} {
+func (s *Server) handle(ctx context.Context, codec ServerCodec, req *serverRequest) (interface{}, func()) {
if req.err != nil {
- return codec.CreateErrorResponse(&req.id, req.err)
+ return codec.CreateErrorResponse(&req.id, req.err), nil
}
- if req.isUnsubscribe { // first param must be the subscription id
+ if req.isUnsubscribe { // cancel subscription, first param must be the subscription id
if len(req.args) >= 1 && req.args[0].Kind() == reflect.String {
+ notifier, supported := ctx.Value(NotifierContextKey).(*bufferedNotifier)
+ if !supported { // interface doesn't support subscriptions (e.g. http)
+ return codec.CreateErrorResponse(&req.id, &callbackError{ErrNotificationsUnsupported.Error()}), nil
+ }
+
subid := req.args[0].String()
- if s.unsubscribe(subid) {
- return codec.CreateResponse(req.id, true)
- } else {
- return codec.CreateErrorResponse(&req.id,
- &callbackError{fmt.Sprintf("subscription '%s' not found", subid)})
+ if err := notifier.Unsubscribe(subid); err != nil {
+ return codec.CreateErrorResponse(&req.id, &callbackError{err.Error()}), nil
}
+
+ return codec.CreateResponse(req.id, true), nil
}
- return codec.CreateErrorResponse(&req.id, &invalidParamsError{"Expected subscription id as argument"})
+ return codec.CreateErrorResponse(&req.id, &invalidParamsError{"Expected subscription id as first argument"}), nil
}
if req.callb.isSubscribe {
- subid, err := s.createSubscription(codec, req)
+ subid, err := s.createSubscription(ctx, codec, req)
if err != nil {
- return codec.CreateErrorResponse(&req.id, &callbackError{err.Error()})
+ return codec.CreateErrorResponse(&req.id, &callbackError{err.Error()}), nil
+ }
+
+ // active the subscription after the sub id was successful sent to the client
+ activateSub := func() {
+ notifier, _ := ctx.Value(NotifierContextKey).(*bufferedNotifier)
+ notifier.activate(subid)
}
- return codec.CreateResponse(req.id, subid)
+
+ return codec.CreateResponse(req.id, subid), activateSub
}
- // regular RPC call
+ // regular RPC call, prepare arguments
if len(req.args) != len(req.callb.argTypes) {
rpcErr := &invalidParamsError{fmt.Sprintf("%s%s%s expects %d parameters, got %d",
req.svcname, serviceMethodSeparator, req.callb.method.Name,
len(req.callb.argTypes), len(req.args))}
- return codec.CreateErrorResponse(&req.id, rpcErr)
+ return codec.CreateErrorResponse(&req.id, rpcErr), nil
}
arguments := []reflect.Value{req.callb.rcvr}
@@ -351,45 +321,56 @@ func (s *Server) handle(ctx context.Context, codec ServerCodec, req *serverReque
arguments = append(arguments, req.args...)
}
+ // execute RPC method and return result
reply := req.callb.method.Func.Call(arguments)
-
if len(reply) == 0 {
- return codec.CreateResponse(req.id, nil)
+ return codec.CreateResponse(req.id, nil), nil
}
if req.callb.errPos >= 0 { // test if method returned an error
if !reply[req.callb.errPos].IsNil() {
e := reply[req.callb.errPos].Interface().(error)
res := codec.CreateErrorResponse(&req.id, &callbackError{e.Error()})
- return res
+ return res, nil
}
}
- return codec.CreateResponse(req.id, reply[0].Interface())
+ return codec.CreateResponse(req.id, reply[0].Interface()), nil
}
// exec executes the given request and writes the result back using the codec.
func (s *Server) exec(ctx context.Context, codec ServerCodec, req *serverRequest) {
var response interface{}
+ var callback func()
if req.err != nil {
response = codec.CreateErrorResponse(&req.id, req.err)
} else {
- response = s.handle(ctx, codec, req)
+ response, callback = s.handle(ctx, codec, req)
}
+
if err := codec.Write(response); err != nil {
glog.V(logger.Error).Infof("%v\n", err)
codec.Close()
}
+
+ // when request was a subscribe request this allows these subscriptions to be actived
+ if callback != nil {
+ callback()
+ }
}
-// execBatch executes the given requests and writes the result back using the codec. It will only write the response
-// back when the last request is processed.
+// execBatch executes the given requests and writes the result back using the codec.
+// It will only write the response back when the last request is processed.
func (s *Server) execBatch(ctx context.Context, codec ServerCodec, requests []*serverRequest) {
responses := make([]interface{}, len(requests))
+ var callbacks []func()
for i, req := range requests {
if req.err != nil {
responses[i] = codec.CreateErrorResponse(&req.id, req.err)
} else {
- responses[i] = s.handle(ctx, codec, req)
+ var callback func()
+ if responses[i], callback = s.handle(ctx, codec, req); callback != nil {
+ callbacks = append(callbacks, callback)
+ }
}
}
@@ -397,11 +378,16 @@ func (s *Server) execBatch(ctx context.Context, codec ServerCodec, requests []*s
glog.V(logger.Error).Infof("%v\n", err)
codec.Close()
}
+
+ // when request holds one of more subscribe requests this allows these subscriptions to be actived
+ for _, c := range callbacks {
+ c()
+ }
}
-// readRequest requests the next (batch) request from the codec. It will return the collection of requests, an
-// indication if the request was a batch, the invalid request identifier and an error when the request could not be
-// read/parsed.
+// readRequest requests the next (batch) request from the codec. It will return the collection
+// of requests, an indication if the request was a batch, the invalid request identifier and an
+// error when the request could not be read/parsed.
func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, RPCError) {
reqs, batch, err := codec.ReadRequestHeaders()
if err != nil {
@@ -417,7 +403,7 @@ func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, RPCErro
if r.isPubSub && r.method == unsubscribeMethod {
requests[i] = &serverRequest{id: r.id, isUnsubscribe: true}
- argTypes := []reflect.Type{reflect.TypeOf("")}
+ argTypes := []reflect.Type{reflect.TypeOf("")} // expect subscription id as first arg
if args, err := codec.ParseRequestArguments(argTypes, r.params); err == nil {
requests[i].args = args
} else {
@@ -426,12 +412,12 @@ func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, RPCErro
continue
}
- if svc, ok = s.services[r.service]; !ok {
+ if svc, ok = s.services[r.service]; !ok { // rpc method isn't available
requests[i] = &serverRequest{id: r.id, err: &methodNotFoundError{r.service, r.method}}
continue
}
- if r.isPubSub { // eth_subscribe
+ if r.isPubSub { // eth_subscribe, r.method contains the subscription method name
if callb, ok := svc.subscriptions[r.method]; ok {
requests[i] = &serverRequest{id: r.id, svcname: svc.name, callb: callb}
if r.params != nil && len(callb.argTypes) > 0 {
@@ -449,7 +435,7 @@ func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, RPCErro
continue
}
- if callb, ok := svc.callbacks[r.method]; ok {
+ if callb, ok := svc.callbacks[r.method]; ok { // lookup RPC method
requests[i] = &serverRequest{id: r.id, svcname: svc.name, callb: callb}
if r.params != nil && len(callb.argTypes) > 0 {
if args, err := codec.ParseRequestArguments(callb.argTypes, r.params); err == nil {
diff --git a/rpc/server_test.go b/rpc/server_test.go
index 5b91fe42a..c60db38df 100644
--- a/rpc/server_test.go
+++ b/rpc/server_test.go
@@ -65,8 +65,12 @@ func (s *Service) InvalidRets3() (string, string, error) {
return "", "", nil
}
-func (s *Service) Subscription() (Subscription, error) {
- return NewSubscription(nil), nil
+func (s *Service) Subscription(ctx context.Context) (Subscription, error) {
+ return nil, nil
+}
+
+func (s *Service) SubsriptionWithArgs(ctx context.Context, a, b int) (Subscription, error) {
+ return nil, nil
}
func TestServerRegisterName(t *testing.T) {
@@ -90,8 +94,8 @@ func TestServerRegisterName(t *testing.T) {
t.Errorf("Expected 4 callbacks for service 'calc', got %d", len(svc.callbacks))
}
- if len(svc.subscriptions) != 1 {
- t.Errorf("Expected 1 subscription for service 'calc', got %d", len(svc.subscriptions))
+ if len(svc.subscriptions) != 2 {
+ t.Errorf("Expected 2 subscriptions for service 'calc', got %d", len(svc.subscriptions))
}
}
@@ -229,7 +233,7 @@ func TestServerMethodExecution(t *testing.T) {
input, _ := json.Marshal(&req)
codec := &ServerTestCodec{input: input, closer: make(chan interface{})}
- go server.ServeCodec(codec)
+ go server.ServeCodec(codec, OptionMethodInvocation)
<-codec.closer
@@ -259,7 +263,7 @@ func TestServerMethodWithCtx(t *testing.T) {
input, _ := json.Marshal(&req)
codec := &ServerTestCodec{input: input, closer: make(chan interface{})}
- go server.ServeCodec(codec)
+ go server.ServeCodec(codec, OptionMethodInvocation)
<-codec.closer
diff --git a/rpc/types.go b/rpc/types.go
index f268d84db..596fdf264 100644
--- a/rpc/types.go
+++ b/rpc/types.go
@@ -24,7 +24,6 @@ import (
"strings"
"sync"
- "github.com/ethereum/go-ethereum/event"
"gopkg.in/fatih/set.v0"
)
@@ -66,10 +65,10 @@ type serverRequest struct {
err RPCError
}
-type serviceRegistry map[string]*service // collection of services
-type callbacks map[string]*callback // collection of RPC callbacks
-type subscriptions map[string]*callback // collection of subscription callbacks
-type subscriptionRegistry map[string]Subscription // collection of subscriptions
+type serviceRegistry map[string]*service // collection of services
+type callbacks map[string]*callback // collection of RPC callbacks
+type subscriptions map[string]*callback // collection of subscription callbacks
+type subscriptionRegistry map[string]*callback // collection of subscription callbacks
// Server represents a RPC server
type Server struct {
@@ -123,51 +122,6 @@ type ServerCodec interface {
Closed() <-chan interface{}
}
-// SubscriptionMatcher returns true if the given value matches the criteria specified by the user
-type SubscriptionMatcher func(interface{}) bool
-
-// SubscriptionOutputFormat accepts event data and has the ability to format the data before it is send to the client
-type SubscriptionOutputFormat func(interface{}) interface{}
-
-// defaultSubscriptionOutputFormatter returns data and is used as default output format for notifications
-func defaultSubscriptionOutputFormatter(data interface{}) interface{} {
- return data
-}
-
-// Subscription is used by the server to send notifications to the client
-type Subscription struct {
- sub event.Subscription
- match SubscriptionMatcher
- format SubscriptionOutputFormat
-}
-
-// NewSubscription create a new RPC subscription
-func NewSubscription(sub event.Subscription) Subscription {
- return Subscription{sub, nil, defaultSubscriptionOutputFormatter}
-}
-
-// NewSubscriptionWithOutputFormat create a new RPC subscription which a custom notification output format
-func NewSubscriptionWithOutputFormat(sub event.Subscription, formatter SubscriptionOutputFormat) Subscription {
- return Subscription{sub, nil, formatter}
-}
-
-// NewSubscriptionFiltered will create a new subscription. For each raised event the given matcher is
-// called. If it returns true the event is send as notification to the client, otherwise it is ignored.
-func NewSubscriptionFiltered(sub event.Subscription, match SubscriptionMatcher) Subscription {
- return Subscription{sub, match, defaultSubscriptionOutputFormatter}
-}
-
-// Chan returns the channel where new events will be published. It's up the user to call the matcher to
-// determine if the events are interesting for the client.
-func (s *Subscription) Chan() <-chan *event.Event {
- return s.sub.Chan()
-}
-
-// Unsubscribe will end the subscription and closes the event channel
-func (s *Subscription) Unsubscribe() {
- s.sub.Unsubscribe()
-}
-
// HexNumber serializes a number to hex format using the "%#x" format
type HexNumber big.Int
diff --git a/rpc/utils.go b/rpc/utils.go
index fa114284d..d43c50495 100644
--- a/rpc/utils.go
+++ b/rpc/utils.go
@@ -45,6 +45,16 @@ func isExportedOrBuiltinType(t reflect.Type) bool {
return isExported(t.Name()) || t.PkgPath() == ""
}
+var contextType = reflect.TypeOf((*context.Context)(nil)).Elem()
+
+// isContextType returns an indication if the given t is of context.Context or *context.Context type
+func isContextType(t reflect.Type) bool {
+ for t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+ return t == contextType
+}
+
var errorType = reflect.TypeOf((*error)(nil)).Elem()
// Implements this type the error interface
@@ -57,6 +67,7 @@ func isErrorType(t reflect.Type) bool {
var subscriptionType = reflect.TypeOf((*Subscription)(nil)).Elem()
+// isSubscriptionType returns an indication if the given t is of Subscription or *Subscription type
func isSubscriptionType(t reflect.Type) bool {
for t.Kind() == reflect.Ptr {
t = t.Elem()
@@ -64,12 +75,17 @@ func isSubscriptionType(t reflect.Type) bool {
return t == subscriptionType
}
-// isPubSub tests whether the given method return the pair (v2.Subscription, error)
+// isPubSub tests whether the given method has as as first argument a context.Context
+// and returns the pair (Subscription, error)
func isPubSub(methodType reflect.Type) bool {
- if methodType.NumOut() != 2 {
+ // numIn(0) is the receiver type
+ if methodType.NumIn() < 2 || methodType.NumOut() != 2 {
return false
}
- return isSubscriptionType(methodType.Out(0)) && isErrorType(methodType.Out(1))
+
+ return isContextType(methodType.In(1)) &&
+ isSubscriptionType(methodType.Out(0)) &&
+ isErrorType(methodType.Out(1))
}
// formatName will convert to first character to lower case
@@ -110,8 +126,6 @@ func isBlockNumber(t reflect.Type) bool {
return t == blockNumberType
}
-var contextType = reflect.TypeOf(new(context.Context)).Elem()
-
// suitableCallbacks iterates over the methods of the given type. It will determine if a method satisfies the criteria
// for a RPC callback or a subscription callback and adds it to the collection of callbacks or subscriptions. See server
// documentation for a summary of these criteria.
@@ -205,7 +219,7 @@ METHODS:
return callbacks, subscriptions
}
-func newSubscriptionId() (string, error) {
+func newSubscriptionID() (string, error) {
var subid [16]byte
n, _ := rand.Read(subid[:])
if n != 16 {
diff --git a/rpc/websocket.go b/rpc/websocket.go
index 92615494e..499eedabe 100644
--- a/rpc/websocket.go
+++ b/rpc/websocket.go
@@ -93,7 +93,8 @@ func NewWSServer(cors string, handler *Server) *http.Server {
Handler: websocket.Server{
Handshake: wsHandshakeValidator(strings.Split(cors, ",")),
Handler: func(conn *websocket.Conn) {
- handler.ServeCodec(NewJSONCodec(&wsReaderWriterCloser{conn}))
+ handler.ServeCodec(NewJSONCodec(&wsReaderWriterCloser{conn}),
+ OptionMethodInvocation|OptionSubscriptions)
},
},
}