158 lines
3.9 KiB
Go
158 lines
3.9 KiB
Go
// Copyright 2017 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 simulations
|
|
|
|
import (
|
|
"context"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/p2p/discover"
|
|
)
|
|
|
|
// Simulation provides a framework for running actions in a simulated network
|
|
// and then waiting for expectations to be met
|
|
type Simulation struct {
|
|
network *Network
|
|
}
|
|
|
|
// NewSimulation returns a new simulation which runs in the given network
|
|
func NewSimulation(network *Network) *Simulation {
|
|
return &Simulation{
|
|
network: network,
|
|
}
|
|
}
|
|
|
|
// Run performs a step of the simulation by performing the step's action and
|
|
// then waiting for the step's expectation to be met
|
|
func (s *Simulation) Run(ctx context.Context, step *Step) (result *StepResult) {
|
|
result = newStepResult()
|
|
|
|
result.StartedAt = time.Now()
|
|
defer func() { result.FinishedAt = time.Now() }()
|
|
|
|
// watch network events for the duration of the step
|
|
stop := s.watchNetwork(result)
|
|
defer stop()
|
|
|
|
// perform the action
|
|
if err := step.Action(ctx); err != nil {
|
|
result.Error = err
|
|
return
|
|
}
|
|
|
|
// wait for all node expectations to either pass, error or timeout
|
|
nodes := make(map[discover.NodeID]struct{}, len(step.Expect.Nodes))
|
|
for _, id := range step.Expect.Nodes {
|
|
nodes[id] = struct{}{}
|
|
}
|
|
for len(result.Passes) < len(nodes) {
|
|
select {
|
|
case id := <-step.Trigger:
|
|
// skip if we aren't checking the node
|
|
if _, ok := nodes[id]; !ok {
|
|
continue
|
|
}
|
|
|
|
// skip if the node has already passed
|
|
if _, ok := result.Passes[id]; ok {
|
|
continue
|
|
}
|
|
|
|
// run the node expectation check
|
|
pass, err := step.Expect.Check(ctx, id)
|
|
if err != nil {
|
|
result.Error = err
|
|
return
|
|
}
|
|
if pass {
|
|
result.Passes[id] = time.Now()
|
|
}
|
|
case <-ctx.Done():
|
|
result.Error = ctx.Err()
|
|
return
|
|
}
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
func (s *Simulation) watchNetwork(result *StepResult) func() {
|
|
stop := make(chan struct{})
|
|
done := make(chan struct{})
|
|
events := make(chan *Event)
|
|
sub := s.network.Events().Subscribe(events)
|
|
go func() {
|
|
defer close(done)
|
|
defer sub.Unsubscribe()
|
|
for {
|
|
select {
|
|
case event := <-events:
|
|
result.NetworkEvents = append(result.NetworkEvents, event)
|
|
case <-stop:
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
return func() {
|
|
close(stop)
|
|
<-done
|
|
}
|
|
}
|
|
|
|
type Step struct {
|
|
// Action is the action to perform for this step
|
|
Action func(context.Context) error
|
|
|
|
// Trigger is a channel which receives node ids and triggers an
|
|
// expectation check for that node
|
|
Trigger chan discover.NodeID
|
|
|
|
// Expect is the expectation to wait for when performing this step
|
|
Expect *Expectation
|
|
}
|
|
|
|
type Expectation struct {
|
|
// Nodes is a list of nodes to check
|
|
Nodes []discover.NodeID
|
|
|
|
// Check checks whether a given node meets the expectation
|
|
Check func(context.Context, discover.NodeID) (bool, error)
|
|
}
|
|
|
|
func newStepResult() *StepResult {
|
|
return &StepResult{
|
|
Passes: make(map[discover.NodeID]time.Time),
|
|
}
|
|
}
|
|
|
|
type StepResult struct {
|
|
// Error is the error encountered whilst running the step
|
|
Error error
|
|
|
|
// StartedAt is the time the step started
|
|
StartedAt time.Time
|
|
|
|
// FinishedAt is the time the step finished
|
|
FinishedAt time.Time
|
|
|
|
// Passes are the timestamps of the successful node expectations
|
|
Passes map[discover.NodeID]time.Time
|
|
|
|
// NetworkEvents are the network events which occurred during the step
|
|
NetworkEvents []*Event
|
|
}
|