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authorPéter Szilágyi <peterke@gmail.com>2015-11-06 05:57:57 +0800
committerPéter Szilágyi <peterke@gmail.com>2015-11-27 17:06:12 +0800
commit9e1d9bff3b18cfa09ba96cd027fa653daae10816 (patch)
tree95d74007caa613ba0c6a62962efcda2e96b273af /node
parent168d0e9e45939b7282204f3f52fe86fc8110cfc7 (diff)
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node: customizable protocol and service stacks
Diffstat (limited to 'node')
-rw-r--r--node/config.go171
-rw-r--r--node/config_test.go120
-rw-r--r--node/errors.go31
-rw-r--r--node/node.go252
-rw-r--r--node/node_example_test.go87
-rw-r--r--node/node_test.go492
-rw-r--r--node/service.go67
-rw-r--r--node/service_test.go60
-rw-r--r--node/utils.go33
9 files changed, 1313 insertions, 0 deletions
diff --git a/node/config.go b/node/config.go
new file mode 100644
index 000000000..93f0ba79d
--- /dev/null
+++ b/node/config.go
@@ -0,0 +1,171 @@
+// Copyright 2015 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 node
+
+import (
+ "crypto/ecdsa"
+ "encoding/json"
+ "io/ioutil"
+ "net"
+ "os"
+ "path/filepath"
+
+ "github.com/ethereum/go-ethereum/crypto"
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/ethereum/go-ethereum/logger/glog"
+ "github.com/ethereum/go-ethereum/p2p/discover"
+ "github.com/ethereum/go-ethereum/p2p/nat"
+)
+
+var (
+ datadirPrivateKey = "nodekey" // Path within the datadir to the node's private key
+ datadirStaticNodes = "static-nodes.json" // Path within the datadir to the static node list
+ datadirTrustedNodes = "trusted-nodes.json" // Path within the datadir to the trusted node list
+ datadirNodeDatabase = "nodes" // Path within the datadir to store the node infos
+)
+
+// Config represents a small collection of configuration values to fine tune the
+// P2P network layer of a protocol stack. These values can be further extended by
+// all registered services.
+type Config struct {
+ // DataDir is the file system folder the node should use for any data storage
+ // requirements. The configured data directory will not be directly shared with
+ // registered services, instead those can use utility methods to create/access
+ // databases or flat files. This enables ephemeral nodes which can fully reside
+ // in memory.
+ DataDir string
+
+ // This field should be a valid secp256k1 private key that will be used for both
+ // remote peer identification as well as network traffic encryption. If no key
+ // is configured, the preset one is loaded from the data dir, generating it if
+ // needed.
+ PrivateKey *ecdsa.PrivateKey
+
+ // Name sets the node name of this server. Use common.MakeName to create a name
+ // that follows existing conventions.
+ Name string
+
+ // NoDiscovery specifies whether the peer discovery mechanism should be started
+ // or not. Disabling is usually useful for protocol debugging (manual topology).
+ NoDiscovery bool
+
+ // Bootstrap nodes used to establish connectivity with the rest of the network.
+ BootstrapNodes []*discover.Node
+
+ // Network interface address on which the node should listen for inbound peers.
+ ListenAddr string
+
+ // If set to a non-nil value, the given NAT port mapper is used to make the
+ // listening port available to the Internet.
+ NAT nat.Interface
+
+ // If Dialer is set to a non-nil value, the given Dialer is used to dial outbound
+ // peer connections.
+ Dialer *net.Dialer
+
+ // If NoDial is true, the node will not dial any peers.
+ NoDial bool
+
+ // MaxPeers is the maximum number of peers that can be connected. If this is
+ // set to zero, then only the configured static and trusted peers can connect.
+ MaxPeers int
+
+ // MaxPendingPeers is the maximum number of peers that can be pending in the
+ // handshake phase, counted separately for inbound and outbound connections.
+ // Zero defaults to preset values.
+ MaxPendingPeers int
+}
+
+// NodeKey retrieves the currently configured private key of the node, checking
+// first any manually set key, falling back to the one found in the configured
+// data folder. If no key can be found, a new one is generated.
+func (c *Config) NodeKey() *ecdsa.PrivateKey {
+ // Use any specifically configured key
+ if c.PrivateKey != nil {
+ return c.PrivateKey
+ }
+ // Generate ephemeral key if no datadir is being used
+ if c.DataDir == "" {
+ key, err := crypto.GenerateKey()
+ if err != nil {
+ glog.Fatalf("Failed to generate ephemeral node key: %v", err)
+ }
+ return key
+ }
+ // Fall back to persistent key from the data directory
+ keyfile := filepath.Join(c.DataDir, datadirPrivateKey)
+ if key, err := crypto.LoadECDSA(keyfile); err == nil {
+ return key
+ }
+ // No persistent key found, generate and store a new one
+ key, err := crypto.GenerateKey()
+ if err != nil {
+ glog.Fatalf("Failed to generate node key: %v", err)
+ }
+ if err := crypto.SaveECDSA(keyfile, key); err != nil {
+ glog.V(logger.Error).Infof("Failed to persist node key: %v", err)
+ }
+ return key
+}
+
+// StaticNodes returns a list of node enode URLs configured as static nodes.
+func (c *Config) StaticNodes() []*discover.Node {
+ return c.parsePersistentNodes(datadirStaticNodes)
+}
+
+// TrusterNodes returns a list of node enode URLs configured as trusted nodes.
+func (c *Config) TrusterNodes() []*discover.Node {
+ return c.parsePersistentNodes(datadirTrustedNodes)
+}
+
+// parsePersistentNodes parses a list of discovery node URLs loaded from a .json
+// file from within the data directory.
+func (c *Config) parsePersistentNodes(file string) []*discover.Node {
+ // Short circuit if no node config is present
+ if c.DataDir == "" {
+ return nil
+ }
+ path := filepath.Join(c.DataDir, file)
+ if _, err := os.Stat(path); err != nil {
+ return nil
+ }
+ // Load the nodes from the config file
+ blob, err := ioutil.ReadFile(path)
+ if err != nil {
+ glog.V(logger.Error).Infof("Failed to access nodes: %v", err)
+ return nil
+ }
+ nodelist := []string{}
+ if err := json.Unmarshal(blob, &nodelist); err != nil {
+ glog.V(logger.Error).Infof("Failed to load nodes: %v", err)
+ return nil
+ }
+ // Interpret the list as a discovery node array
+ var nodes []*discover.Node
+ for _, url := range nodelist {
+ if url == "" {
+ continue
+ }
+ node, err := discover.ParseNode(url)
+ if err != nil {
+ glog.V(logger.Error).Infof("Node URL %s: %v\n", url, err)
+ continue
+ }
+ nodes = append(nodes, node)
+ }
+ return nodes
+}
diff --git a/node/config_test.go b/node/config_test.go
new file mode 100644
index 000000000..f59f3c0fe
--- /dev/null
+++ b/node/config_test.go
@@ -0,0 +1,120 @@
+// Copyright 2015 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 node
+
+import (
+ "bytes"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+ "testing"
+
+ "github.com/ethereum/go-ethereum/crypto"
+)
+
+// Tests that datadirs can be successfully created, be them manually configured
+// ones or automatically generated temporary ones.
+func TestDatadirCreation(t *testing.T) {
+ // Create a temporary data dir and check that it can be used by a node
+ dir, err := ioutil.TempDir("", "")
+ if err != nil {
+ t.Fatalf("failed to create manual data dir: %v", err)
+ }
+ defer os.RemoveAll(dir)
+
+ if _, err := New(&Config{DataDir: dir}); err != nil {
+ t.Fatalf("failed to create stack with existing datadir: %v", err)
+ }
+ // Generate a long non-existing datadir path and check that it gets created by a node
+ dir = filepath.Join(dir, "a", "b", "c", "d", "e", "f")
+ if _, err := New(&Config{DataDir: dir}); err != nil {
+ t.Fatalf("failed to create stack with creatable datadir: %v", err)
+ }
+ if _, err := os.Stat(dir); err != nil {
+ t.Fatalf("freshly created datadir not accessible: %v", err)
+ }
+ // Verify that an impossible datadir fails creation
+ file, err := ioutil.TempFile("", "")
+ if err != nil {
+ t.Fatalf("failed to create temporary file: %v", err)
+ }
+ defer os.Remove(file.Name())
+
+ dir = filepath.Join(file.Name(), "invalid/path")
+ if _, err := New(&Config{DataDir: dir}); err == nil {
+ t.Fatalf("protocol stack created with an invalid datadir")
+ }
+}
+
+// Tests that node keys can be correctly created, persisted, loaded and/or made
+// ephemeral.
+func TestNodeKeyPersistency(t *testing.T) {
+ // Create a temporary folder and make sure no key is present
+ dir, err := ioutil.TempDir("", "")
+ if err != nil {
+ t.Fatalf("failed to create temporary data directory: %v", err)
+ }
+ defer os.RemoveAll(dir)
+
+ if _, err := os.Stat(filepath.Join(dir, datadirPrivateKey)); err == nil {
+ t.Fatalf("non-created node key already exists")
+ }
+ // Configure a node with a preset key and ensure it's not persisted
+ key, err := crypto.GenerateKey()
+ if err != nil {
+ t.Fatalf("failed to generate one-shot node key: %v", err)
+ }
+ if _, err := New(&Config{DataDir: dir, PrivateKey: key}); err != nil {
+ t.Fatalf("failed to create empty stack: %v", err)
+ }
+ if _, err := os.Stat(filepath.Join(dir, datadirPrivateKey)); err == nil {
+ t.Fatalf("one-shot node key persisted to data directory")
+ }
+ // Configure a node with no preset key and ensure it is persisted this time
+ if _, err := New(&Config{DataDir: dir}); err != nil {
+ t.Fatalf("failed to create newly keyed stack: %v", err)
+ }
+ if _, err := os.Stat(filepath.Join(dir, datadirPrivateKey)); err != nil {
+ t.Fatalf("node key not persisted to data directory: %v", err)
+ }
+ key, err = crypto.LoadECDSA(filepath.Join(dir, datadirPrivateKey))
+ if err != nil {
+ t.Fatalf("failed to load freshly persisted node key: %v", err)
+ }
+ blob1, err := ioutil.ReadFile(filepath.Join(dir, datadirPrivateKey))
+ if err != nil {
+ t.Fatalf("failed to read freshly persisted node key: %v", err)
+ }
+ // Configure a new node and ensure the previously persisted key is loaded
+ if _, err := New(&Config{DataDir: dir}); err != nil {
+ t.Fatalf("failed to create previously keyed stack: %v", err)
+ }
+ blob2, err := ioutil.ReadFile(filepath.Join(dir, datadirPrivateKey))
+ if err != nil {
+ t.Fatalf("failed to read previously persisted node key: %v", err)
+ }
+ if bytes.Compare(blob1, blob2) != 0 {
+ t.Fatalf("persisted node key mismatch: have %x, want %x", blob2, blob1)
+ }
+ // Configure ephemeral node and ensure no key is dumped locally
+ if _, err := New(&Config{DataDir: ""}); err != nil {
+ t.Fatalf("failed to create ephemeral stack: %v", err)
+ }
+ if _, err := os.Stat(filepath.Join(".", datadirPrivateKey)); err == nil {
+ t.Fatalf("ephemeral node key persisted to disk")
+ }
+}
diff --git a/node/errors.go b/node/errors.go
new file mode 100644
index 000000000..f8eece06d
--- /dev/null
+++ b/node/errors.go
@@ -0,0 +1,31 @@
+// Copyright 2015 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 node
+
+import "fmt"
+
+// StopError is returned if a node fails to stop either any of its registered
+// services or itself.
+type StopError struct {
+ Server error
+ Services map[string]error
+}
+
+// Error generates a textual representation of the stop error.
+func (e *StopError) Error() string {
+ return fmt.Sprintf("server: %v, services: %v", e.Server, e.Services)
+}
diff --git a/node/node.go b/node/node.go
new file mode 100644
index 000000000..ad4e69414
--- /dev/null
+++ b/node/node.go
@@ -0,0 +1,252 @@
+// Copyright 2015 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 node represents the Ethereum protocol stack container.
+package node
+
+import (
+ "errors"
+ "os"
+ "path/filepath"
+ "sync"
+ "syscall"
+
+ "github.com/ethereum/go-ethereum/event"
+ "github.com/ethereum/go-ethereum/p2p"
+)
+
+var (
+ ErrDatadirUsed = errors.New("datadir already used")
+ ErrNodeStopped = errors.New("node not started")
+ ErrNodeRunning = errors.New("node already running")
+ ErrServiceUnknown = errors.New("service not registered")
+ ErrServiceRegistered = errors.New("service already registered")
+
+ datadirInUseErrnos = map[uint]bool{11: true, 32: true, 35: true}
+)
+
+// Node represents a P2P node into which arbitrary services might be registered.
+type Node struct {
+ datadir string // Path to the currently used data directory
+ config *p2p.Server // Configuration of the underlying P2P networking layer
+ stack map[string]ServiceConstructor // Protocol stack registered into this node
+ emux *event.TypeMux // Event multiplexer used between the services of a stack
+
+ running *p2p.Server // Currently running P2P networking layer
+ services map[string]Service // Currently running services
+
+ lock sync.RWMutex
+}
+
+// New creates a new P2P node, ready for protocol registration.
+func New(conf *Config) (*Node, error) {
+ // Ensure the data directory exists, failing if it cannot be created
+ if conf.DataDir != "" {
+ if err := os.MkdirAll(conf.DataDir, 0700); err != nil {
+ return nil, err
+ }
+ }
+ // Assemble the networking layer and the node itself
+ nodeDbPath := ""
+ if conf.DataDir != "" {
+ nodeDbPath = filepath.Join(conf.DataDir, datadirNodeDatabase)
+ }
+ return &Node{
+ datadir: conf.DataDir,
+ config: &p2p.Server{
+ PrivateKey: conf.NodeKey(),
+ Name: conf.Name,
+ Discovery: !conf.NoDiscovery,
+ BootstrapNodes: conf.BootstrapNodes,
+ StaticNodes: conf.StaticNodes(),
+ TrustedNodes: conf.TrusterNodes(),
+ NodeDatabase: nodeDbPath,
+ ListenAddr: conf.ListenAddr,
+ NAT: conf.NAT,
+ Dialer: conf.Dialer,
+ NoDial: conf.NoDial,
+ MaxPeers: conf.MaxPeers,
+ MaxPendingPeers: conf.MaxPendingPeers,
+ },
+ stack: make(map[string]ServiceConstructor),
+ emux: new(event.TypeMux),
+ }, nil
+}
+
+// Register injects a new service into the node's stack.
+func (n *Node) Register(id string, constructor ServiceConstructor) error {
+ n.lock.Lock()
+ defer n.lock.Unlock()
+
+ // Short circuit if the node is running or if the id is taken
+ if n.running != nil {
+ return ErrNodeRunning
+ }
+ if _, ok := n.stack[id]; ok {
+ return ErrServiceRegistered
+ }
+ // Otherwise register the service and return
+ n.stack[id] = constructor
+
+ return nil
+}
+
+// Unregister removes a service from a node's stack. If the node is currently
+// running, an error will be returned.
+func (n *Node) Unregister(id string) error {
+ n.lock.Lock()
+ defer n.lock.Unlock()
+
+ // Short circuit if the node is running, or if the service is unknown
+ if n.running != nil {
+ return ErrNodeRunning
+ }
+ if _, ok := n.stack[id]; !ok {
+ return ErrServiceUnknown
+ }
+ // Otherwise drop the service and return
+ delete(n.stack, id)
+ return nil
+}
+
+// Start create a live P2P node and starts running it.
+func (n *Node) Start() error {
+ n.lock.Lock()
+ defer n.lock.Unlock()
+
+ // Short circuit if the node's already running
+ if n.running != nil {
+ return ErrNodeRunning
+ }
+ // Otherwise copy and specialize the P2P configuration
+ running := new(p2p.Server)
+ *running = *n.config
+
+ ctx := &ServiceContext{
+ dataDir: n.datadir,
+ EventMux: n.emux,
+ }
+ services := make(map[string]Service)
+ for id, constructor := range n.stack {
+ service, err := constructor(ctx)
+ if err != nil {
+ return err
+ }
+ services[id] = service
+ }
+ // Gather the protocols and start the freshly assembled P2P server
+ for _, service := range services {
+ running.Protocols = append(running.Protocols, service.Protocols()...)
+ }
+ if err := running.Start(); err != nil {
+ if errno, ok := err.(syscall.Errno); ok && datadirInUseErrnos[uint(errno)] {
+ return ErrDatadirUsed
+ }
+ return err
+ }
+ // Start each of the services
+ started := []string{}
+ for id, service := range services {
+ // Start the next service, stopping all previous upon failure
+ if err := service.Start(); err != nil {
+ for _, id := range started {
+ services[id].Stop()
+ }
+ return err
+ }
+ // Mark the service started for potential cleanup
+ started = append(started, id)
+ }
+ // Finish initializing the startup
+ n.services = services
+ n.running = running
+
+ return nil
+}
+
+// Stop terminates a running node along with all it's services. In the node was
+// not started, an error is returned.
+func (n *Node) Stop() error {
+ n.lock.Lock()
+ defer n.lock.Unlock()
+
+ // Short circuit if the node's not running
+ if n.running == nil {
+ return ErrNodeStopped
+ }
+ // Otherwise terminate all the services and the P2P server too
+ failure := &StopError{
+ Services: make(map[string]error),
+ }
+ for id, service := range n.services {
+ if err := service.Stop(); err != nil {
+ failure.Services[id] = err
+ }
+ }
+ n.running.Stop()
+
+ n.services = nil
+ n.running = nil
+
+ if len(failure.Services) > 0 {
+ return failure
+ }
+ return nil
+}
+
+// Restart terminates a running node and boots up a new one in its place. If the
+// node isn't running, an error is returned.
+func (n *Node) Restart() error {
+ if err := n.Stop(); err != nil {
+ return err
+ }
+ if err := n.Start(); err != nil {
+ return err
+ }
+ return nil
+}
+
+// Server retrieves the currently running P2P network layer. This method is meant
+// only to inspect fields of the currently running server, life cycle management
+// should be left to this Node entity.
+func (n *Node) Server() *p2p.Server {
+ n.lock.RLock()
+ defer n.lock.RUnlock()
+
+ return n.running
+}
+
+// Service retrieves a currently running services registered under a given id.
+func (n *Node) Service(id string) Service {
+ n.lock.RLock()
+ defer n.lock.RUnlock()
+
+ if n.services == nil {
+ return nil
+ }
+ return n.services[id]
+}
+
+// DataDir retrieves the current datadir used by the protocol stack.
+func (n *Node) DataDir() string {
+ return n.datadir
+}
+
+// EventMux retrieves the event multiplexer used by all the network services in
+// the current protocol stack.
+func (n *Node) EventMux() *event.TypeMux {
+ return n.emux
+}
diff --git a/node/node_example_test.go b/node/node_example_test.go
new file mode 100644
index 000000000..f2bd014b0
--- /dev/null
+++ b/node/node_example_test.go
@@ -0,0 +1,87 @@
+// Copyright 2015 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 node_test
+
+import (
+ "fmt"
+ "log"
+
+ "github.com/ethereum/go-ethereum/node"
+ "github.com/ethereum/go-ethereum/p2p"
+ "github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+// SampleService is a trivial network service that can be attached to a node for
+// life cycle management.
+//
+// The following methods are needed to implement a node.Service:
+// - Protocols() []p2p.Protocol - devp2p protocols the service can communicate on
+// - Start() error - method invoked when the node is ready to start the service
+// - Stop() error - method invoked when the node terminates the service
+type SampleService struct{}
+
+func (s *SampleService) Protocols() []p2p.Protocol { return nil }
+func (s *SampleService) Start() error { fmt.Println("Sample service starting..."); return nil }
+func (s *SampleService) Stop() error { fmt.Println("Sample service stopping..."); return nil }
+
+func ExampleUsage() {
+ // Create a network node to run protocols with the default values. The below list
+ // is only used to display each of the configuration options. All of these could
+ // have been ommited if the default behavior is desired.
+ nodeConfig := &node.Config{
+ DataDir: "", // Empty uses ephemeral storage
+ PrivateKey: nil, // Nil generates a node key on the fly
+ Name: "", // Any textual node name is allowed
+ NoDiscovery: false, // Can disable discovering remote nodes
+ BootstrapNodes: []*discover.Node{}, // List of bootstrap nodes to use
+ ListenAddr: ":0", // Network interface to listen on
+ NAT: nil, // UPnP port mapper to use for crossing firewalls
+ Dialer: nil, // Custom dialer to use for establishing peer connections
+ NoDial: false, // Can prevent this node from dialing out
+ MaxPeers: 0, // Number of peers to allow
+ MaxPendingPeers: 0, // Number of peers allowed to handshake concurrently
+ }
+ stack, err := node.New(nodeConfig)
+ if err != nil {
+ log.Fatalf("Failed to create network node: %v", err)
+ }
+ // Create and register a simple network service. This is done through the definition
+ // of a node.ServiceConstructor that will instantiate a node.Service. The reason for
+ // the factory method approach is to support service restarts without relying on the
+ // individual implementations' support for such operations.
+ constructor := func(context *node.ServiceContext) (node.Service, error) {
+ return new(SampleService), nil
+ }
+ if err := stack.Register("my sample service", constructor); err != nil {
+ log.Fatalf("Failed to register service: %v", err)
+ }
+ // Boot up the entire protocol stack, do a restart and terminate
+ if err := stack.Start(); err != nil {
+ log.Fatalf("Failed to start the protocol stack: %v", err)
+ }
+ if err := stack.Restart(); err != nil {
+ log.Fatalf("Failed to restart the protocol stack: %v", err)
+ }
+ if err := stack.Stop(); err != nil {
+ log.Fatalf("Failed to stop the protocol stack: %v", err)
+ }
+ // Output:
+ // Sample service starting...
+ // Sample service stopping...
+ // Sample service starting...
+ // Sample service stopping...
+}
diff --git a/node/node_test.go b/node/node_test.go
new file mode 100644
index 000000000..7201276b5
--- /dev/null
+++ b/node/node_test.go
@@ -0,0 +1,492 @@
+// Copyright 2015 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 node
+
+import (
+ "errors"
+ "io/ioutil"
+ "os"
+ "testing"
+
+ "github.com/ethereum/go-ethereum/crypto"
+ "github.com/ethereum/go-ethereum/p2p"
+)
+
+var (
+ testNodeKey, _ = crypto.GenerateKey()
+
+ testNodeConfig = &Config{
+ PrivateKey: testNodeKey,
+ Name: "test node",
+ }
+)
+
+// Tests that an empty protocol stack can be started, restarted and stopped.
+func TestNodeLifeCycle(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Ensure that a stopped node can be stopped again
+ for i := 0; i < 3; i++ {
+ if err := stack.Stop(); err != ErrNodeStopped {
+ t.Fatalf("iter %d: stop failure mismatch: have %v, want %v", i, err, ErrNodeStopped)
+ }
+ }
+ // Ensure that a node can be successfully started, but only once
+ if err := stack.Start(); err != nil {
+ t.Fatalf("failed to start node: %v", err)
+ }
+ if err := stack.Start(); err != ErrNodeRunning {
+ t.Fatalf("start failure mismatch: have %v, want %v ", err, ErrNodeRunning)
+ }
+ // Ensure that a node can be restarted arbitrarily many times
+ for i := 0; i < 3; i++ {
+ if err := stack.Restart(); err != nil {
+ t.Fatalf("iter %d: failed to restart node: %v", i, err)
+ }
+ }
+ // Ensure that a node can be stopped, but only once
+ if err := stack.Stop(); err != nil {
+ t.Fatalf("failed to stop node: %v", err)
+ }
+ if err := stack.Stop(); err != ErrNodeStopped {
+ t.Fatalf("stop failure mismatch: have %v, want %v ", err, ErrNodeStopped)
+ }
+}
+
+// Tests that if the data dir is already in use, an appropriate error is returned.
+func TestNodeUsedDataDir(t *testing.T) {
+ // Create a temporary folder to use as the data directory
+ dir, err := ioutil.TempDir("", "")
+ if err != nil {
+ t.Fatalf("failed to create temporary data directory: %v", err)
+ }
+ defer os.RemoveAll(dir)
+
+ // Create a new node based on the data directory
+ original, err := New(&Config{DataDir: dir})
+ if err != nil {
+ t.Fatalf("failed to create original protocol stack: %v", err)
+ }
+ if err := original.Start(); err != nil {
+ t.Fatalf("failed to start original protocol stack: %v", err)
+ }
+ defer original.Stop()
+
+ // Create a second node based on the same data directory and ensure failure
+ duplicate, err := New(&Config{DataDir: dir})
+ if err != nil {
+ t.Fatalf("failed to create duplicate protocol stack: %v", err)
+ }
+ if err := duplicate.Start(); err != ErrDatadirUsed {
+ t.Fatalf("duplicate datadir failure mismatch: have %v, want %v", err, ErrDatadirUsed)
+ }
+}
+
+// NoopService is a trivial implementation of the Service interface.
+type NoopService struct{}
+
+func (s *NoopService) Protocols() []p2p.Protocol { return nil }
+func (s *NoopService) Start() error { return nil }
+func (s *NoopService) Stop() error { return nil }
+
+func NewNoopService(*ServiceContext) (Service, error) { return new(NoopService), nil }
+
+// Tests whether services can be registered and unregistered.
+func TestServiceRegistry(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Create a batch of dummy services and ensure they don't exist
+ ids := []string{"A", "B", "C"}
+ for i, id := range ids {
+ if err := stack.Unregister(id); err != ErrServiceUnknown {
+ t.Fatalf("service %d: pre-unregistration failure mismatch: have %v, want %v", i, err, ErrServiceUnknown)
+ }
+ }
+ // Register the services, checking that the operation succeeds only once
+ for i, id := range ids {
+ if err := stack.Register(id, NewNoopService); err != nil {
+ t.Fatalf("service %d: registration failed: %v", i, err)
+ }
+ if err := stack.Register(id, NewNoopService); err != ErrServiceRegistered {
+ t.Fatalf("service %d: registration failure mismatch: have %v, want %v", i, err, ErrServiceRegistered)
+ }
+ }
+ // Unregister the services, checking that the operation succeeds only once
+ for i, id := range ids {
+ if err := stack.Unregister(id); err != nil {
+ t.Fatalf("service %d: unregistration failed: %v", i, err)
+ }
+ if err := stack.Unregister(id); err != ErrServiceUnknown {
+ t.Fatalf("service %d: unregistration failure mismatch: have %v, want %v", i, err, ErrServiceUnknown)
+ }
+ }
+}
+
+// InstrumentedService is an implementation of Service for which all interface
+// methods can be instrumented both return value as well as event hook wise.
+type InstrumentedService struct {
+ protocols []p2p.Protocol
+ start error
+ stop error
+
+ protocolsHook func()
+ startHook func()
+ stopHook func()
+}
+
+func (s *InstrumentedService) Protocols() []p2p.Protocol {
+ if s.protocolsHook != nil {
+ s.protocolsHook()
+ }
+ return s.protocols
+}
+
+func (s *InstrumentedService) Start() error {
+ if s.startHook != nil {
+ s.startHook()
+ }
+ return s.start
+}
+
+func (s *InstrumentedService) Stop() error {
+ if s.stopHook != nil {
+ s.stopHook()
+ }
+ return s.stop
+}
+
+// Tests that registered services get started and stopped correctly.
+func TestServiceLifeCycle(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Register a batch of life-cycle instrumented services
+ ids := []string{"A", "B", "C"}
+
+ started := make(map[string]bool)
+ stopped := make(map[string]bool)
+
+ for i, id := range ids {
+ id := id // Closure for the constructor
+ constructor := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ startHook: func() { started[id] = true },
+ stopHook: func() { stopped[id] = true },
+ }, nil
+ }
+ if err := stack.Register(id, constructor); err != nil {
+ t.Fatalf("service %d: registration failed: %v", i, err)
+ }
+ }
+ // Start the node and check that all services are running
+ if err := stack.Start(); err != nil {
+ t.Fatalf("failed to start protocol stack: %v", err)
+ }
+ for i, id := range ids {
+ if !started[id] {
+ t.Fatalf("service %d: freshly started service not running", i)
+ }
+ if stopped[id] {
+ t.Fatalf("service %d: freshly started service already stopped", i)
+ }
+ if stack.Service(id) == nil {
+ t.Fatalf("service %d: freshly started service unaccessible", i)
+ }
+ }
+ // Stop the node and check that all services have been stopped
+ if err := stack.Stop(); err != nil {
+ t.Fatalf("failed to stop protocol stack: %v", err)
+ }
+ for i, id := range ids {
+ if !stopped[id] {
+ t.Fatalf("service %d: freshly terminated service still running", i)
+ }
+ if service := stack.Service(id); service != nil {
+ t.Fatalf("service %d: freshly terminated service still accessible: %v", i, service)
+ }
+ }
+}
+
+// Tests that services are restarted cleanly as new instances.
+func TestServiceRestarts(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Define a service that does not support restarts
+ var (
+ running bool
+ started int
+ )
+ constructor := func(*ServiceContext) (Service, error) {
+ running = false
+
+ return &InstrumentedService{
+ startHook: func() {
+ if running {
+ panic("already running")
+ }
+ running = true
+ started++
+ },
+ }, nil
+ }
+ // Register the service and start the protocol stack
+ if err := stack.Register("service", constructor); err != nil {
+ t.Fatalf("failed to register the service: %v", err)
+ }
+ if err := stack.Start(); err != nil {
+ t.Fatalf("failed to start protocol stack: %v", err)
+ }
+ defer stack.Stop()
+
+ if running != true || started != 1 {
+ t.Fatalf("running/started mismatch: have %v/%d, want true/1", running, started)
+ }
+ // Restart the stack a few times and check successful service restarts
+ for i := 0; i < 3; i++ {
+ if err := stack.Restart(); err != nil {
+ t.Fatalf("iter %d: failed to restart stack: %v", i, err)
+ }
+ }
+ if running != true || started != 4 {
+ t.Fatalf("running/started mismatch: have %v/%d, want true/4", running, started)
+ }
+}
+
+// Tests that if a service fails to initialize itself, none of the other services
+// will be allowed to even start.
+func TestServiceConstructionAbortion(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Define a batch of good services
+ ids := []string{"A", "B", "C", "D", "E", "F"}
+
+ started := make(map[string]bool)
+ for i, id := range ids {
+ id := id // Closure for the constructor
+ constructor := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ startHook: func() { started[id] = true },
+ }, nil
+ }
+ if err := stack.Register(id, constructor); err != nil {
+ t.Fatalf("service %d: registration failed: %v", i, err)
+ }
+ }
+ // Register a service that fails to construct itself
+ failure := errors.New("fail")
+ failer := func(*ServiceContext) (Service, error) {
+ return nil, failure
+ }
+ if err := stack.Register("failer", failer); err != nil {
+ t.Fatalf("failer registration failed: %v", err)
+ }
+ // Start the protocol stack and ensure none of the services get started
+ for i := 0; i < 100; i++ {
+ if err := stack.Start(); err != failure {
+ t.Fatalf("iter %d: stack startup failure mismatch: have %v, want %v", i, err, failure)
+ }
+ for i, id := range ids {
+ if started[id] {
+ t.Fatalf("service %d: started should not have", i)
+ }
+ delete(started, id)
+ }
+ }
+}
+
+// Tests that if a service fails to start, all others started before it will be
+// shut down.
+func TestServiceStartupAbortion(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Register a batch of good services
+ ids := []string{"A", "B", "C", "D", "E", "F"}
+
+ started := make(map[string]bool)
+ stopped := make(map[string]bool)
+
+ for i, id := range ids {
+ id := id // Closure for the constructor
+ constructor := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ startHook: func() { started[id] = true },
+ stopHook: func() { stopped[id] = true },
+ }, nil
+ }
+ if err := stack.Register(id, constructor); err != nil {
+ t.Fatalf("service %d: registration failed: %v", i, err)
+ }
+ }
+ // Register a service that fails to start
+ failure := errors.New("fail")
+ failer := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ start: failure,
+ }, nil
+ }
+ if err := stack.Register("failer", failer); err != nil {
+ t.Fatalf("failer registration failed: %v", err)
+ }
+ // Start the protocol stack and ensure all started services stop
+ for i := 0; i < 100; i++ {
+ if err := stack.Start(); err != failure {
+ t.Fatalf("iter %d: stack startup failure mismatch: have %v, want %v", i, err, failure)
+ }
+ for i, id := range ids {
+ if started[id] && !stopped[id] {
+ t.Fatalf("service %d: started but not stopped", i)
+ }
+ delete(started, id)
+ delete(stopped, id)
+ }
+ }
+}
+
+// Tests that even if a registered service fails to shut down cleanly, it does
+// not influece the rest of the shutdown invocations.
+func TestServiceTerminationGuarantee(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Register a batch of good services
+ ids := []string{"A", "B", "C", "D", "E", "F"}
+
+ started := make(map[string]bool)
+ stopped := make(map[string]bool)
+
+ for i, id := range ids {
+ id := id // Closure for the constructor
+ constructor := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ startHook: func() { started[id] = true },
+ stopHook: func() { stopped[id] = true },
+ }, nil
+ }
+ if err := stack.Register(id, constructor); err != nil {
+ t.Fatalf("service %d: registration failed: %v", i, err)
+ }
+ }
+ // Register a service that fails to shot down cleanly
+ failure := errors.New("fail")
+ failer := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ stop: failure,
+ }, nil
+ }
+ if err := stack.Register("failer", failer); err != nil {
+ t.Fatalf("failer registration failed: %v", err)
+ }
+ // Start the protocol stack, and ensure that a failing shut down terminates all
+ for i := 0; i < 100; i++ {
+ // Start the stack and make sure all is online
+ if err := stack.Start(); err != nil {
+ t.Fatalf("iter %d: failed to start protocol stack: %v", i, err)
+ }
+ for j, id := range ids {
+ if !started[id] {
+ t.Fatalf("iter %d, service %d: service not running", i, j)
+ }
+ if stopped[id] {
+ t.Fatalf("iter %d, service %d: service already stopped", i, j)
+ }
+ }
+ // Stop the stack, verify failure and check all terminations
+ err := stack.Stop()
+ if err, ok := err.(*StopError); !ok {
+ t.Fatalf("iter %d: termination failure mismatch: have %v, want StopError", i, err)
+ } else {
+ if err.Services["failer"] != failure {
+ t.Fatalf("iter %d: failer termination failure mismatch: have %v, want %v", i, err.Services["failer"], failure)
+ }
+ if len(err.Services) != 1 {
+ t.Fatalf("iter %d: failure count mismatch: have %d, want %d", i, len(err.Services), 1)
+ }
+ }
+ for j, id := range ids {
+ if !stopped[id] {
+ t.Fatalf("iter %d, service %d: service not terminated", i, j)
+ }
+ delete(started, id)
+ delete(stopped, id)
+ }
+ }
+}
+
+// Tests that all protocols defined by individual services get launched.
+func TestProtocolGather(t *testing.T) {
+ stack, err := New(testNodeConfig)
+ if err != nil {
+ t.Fatalf("failed to create protocol stack: %v", err)
+ }
+ // Register a batch of services with some configured number of protocols
+ services := map[string]int{
+ "Zero Protocols": 0,
+ "Single Protocol": 1,
+ "Many Protocols": 25,
+ }
+ for id, count := range services {
+ protocols := make([]p2p.Protocol, count)
+ for i := 0; i < len(protocols); i++ {
+ protocols[i].Name = id
+ protocols[i].Version = uint(i)
+ }
+ constructor := func(*ServiceContext) (Service, error) {
+ return &InstrumentedService{
+ protocols: protocols,
+ }, nil
+ }
+ if err := stack.Register(id, constructor); err != nil {
+ t.Fatalf("service %s: registration failed: %v", id, err)
+ }
+ }
+ // Start the services and ensure all protocols start successfully
+ if err := stack.Start(); err != nil {
+ t.Fatalf("failed to start protocol stack: %v", err)
+ }
+ defer stack.Stop()
+
+ protocols := stack.Server().Protocols
+ if len(protocols) != 26 {
+ t.Fatalf("mismatching number of protocols launched: have %d, want %d", len(protocols), 26)
+ }
+ for id, count := range services {
+ for ver := 0; ver < count; ver++ {
+ launched := false
+ for i := 0; i < len(protocols); i++ {
+ if protocols[i].Name == id && protocols[i].Version == uint(ver) {
+ launched = true
+ break
+ }
+ }
+ if !launched {
+ t.Errorf("configured protocol not launched: %s v%d", id, ver)
+ }
+ }
+ }
+}
diff --git a/node/service.go b/node/service.go
new file mode 100644
index 000000000..ec838dbe8
--- /dev/null
+++ b/node/service.go
@@ -0,0 +1,67 @@
+// Copyright 2015 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 node
+
+import (
+ "path/filepath"
+
+ "github.com/ethereum/go-ethereum/ethdb"
+ "github.com/ethereum/go-ethereum/event"
+ "github.com/ethereum/go-ethereum/p2p"
+)
+
+// ServiceContext is a collection of service independent options inherited from
+// the protocol stack, that is passed to all constructors to be optionally used;
+// as well as utility methods to operate on the service environment.
+type ServiceContext struct {
+ dataDir string // Data directory for protocol persistence
+ EventMux *event.TypeMux // Event multiplexer used for decoupled notifications
+}
+
+// Database opens an existing database with the given name (or creates one if no
+// previous can be found) from within the node's data directory. If the node is
+// an ephemeral one, a memory database is returned.
+func (ctx *ServiceContext) Database(name string, cache int) (ethdb.Database, error) {
+ if ctx.dataDir == "" {
+ return ethdb.NewMemDatabase()
+ }
+ return ethdb.NewLDBDatabase(filepath.Join(ctx.dataDir, name), cache)
+}
+
+// ServiceConstructor is the function signature of the constructors needed to be
+// registered for service instantiation.
+type ServiceConstructor func(ctx *ServiceContext) (Service, error)
+
+// Service is an individual protocol that can be registered into a node.
+//
+// Notes:
+// - Service life-cycle management is delegated to the node. The service is
+// allowed to initialize itself upon creation, but no goroutines should be
+// spun up outside of the Start method.
+// - Restart logic is not required as the node will create a fresh instance
+// every time a service is started.
+type Service interface {
+ // Protocol retrieves the P2P protocols the service wishes to start.
+ Protocols() []p2p.Protocol
+
+ // Start spawns any goroutines required by the service.
+ Start() error
+
+ // Stop terminates all goroutines belonging to the service, blocking until they
+ // are all terminated.
+ Stop() error
+}
diff --git a/node/service_test.go b/node/service_test.go
new file mode 100644
index 000000000..50a4f9715
--- /dev/null
+++ b/node/service_test.go
@@ -0,0 +1,60 @@
+// Copyright 2015 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 node
+
+import (
+ "io/ioutil"
+ "os"
+ "path/filepath"
+ "testing"
+)
+
+// Tests that service context methods work properly.
+func TestServiceContext(t *testing.T) {
+ // Create a temporary folder and ensure no database is contained within
+ dir, err := ioutil.TempDir("", "")
+ if err != nil {
+ t.Fatalf("failed to create temporary data directory: %v", err)
+ }
+ defer os.RemoveAll(dir)
+
+ if _, err := os.Stat(filepath.Join(dir, "database")); err == nil {
+ t.Fatalf("non-created database already exists")
+ }
+ // Request the opening/creation of a database and ensure it persists to disk
+ ctx := &ServiceContext{dataDir: dir}
+ db, err := ctx.Database("persistent", 0)
+ if err != nil {
+ t.Fatalf("failed to open persistent database: %v", err)
+ }
+ db.Close()
+
+ if _, err := os.Stat(filepath.Join(dir, "persistent")); err != nil {
+ t.Fatalf("persistent database doesn't exists: %v", err)
+ }
+ // Request th opening/creation of an ephemeral database and ensure it's not persisted
+ ctx = &ServiceContext{dataDir: ""}
+ db, err = ctx.Database("ephemeral", 0)
+ if err != nil {
+ t.Fatalf("failed to open ephemeral database: %v", err)
+ }
+ db.Close()
+
+ if _, err := os.Stat(filepath.Join(dir, "ephemeral")); err == nil {
+ t.Fatalf("ephemeral database exists")
+ }
+}
diff --git a/node/utils.go b/node/utils.go
new file mode 100644
index 000000000..deaa6c5fb
--- /dev/null
+++ b/node/utils.go
@@ -0,0 +1,33 @@
+// Copyright 2015 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 node
+
+import (
+ "path/filepath"
+
+ "github.com/ethereum/go-ethereum/ethdb"
+)
+
+// openDatabase opens an existing database with the given name from within the
+// specified data directory, creating one if none exists. If the data directory
+// is empty, an ephemeral memory database is returned.
+func openDatabase(dataDir string, name string, cache int) (ethdb.Database, error) {
+ if dataDir == "" {
+ return ethdb.NewMemDatabase()
+ }
+ return ethdb.NewLDBDatabase(filepath.Join(dataDir, name), cache)
+}