node: customizable protocol and service stacks

1 files changed, 492 insertions, 0 deletions

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)
+			}
+		}
+	}
+}