WIP: flow rewrite #138

Draft
vtolstov wants to merge 3 commits from dag into v3
5 changed files with 236 additions and 262 deletions
Showing only changes of commit 79d4318d42 - Show all commits

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@ -1,3 +1,5 @@
//go:build ignore
package flow
import (

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@ -1,21 +0,0 @@
package flow
type node struct {
name string
}
func (n *node) ID() string {
return n.name
}
func (n *node) Name() string {
return n.name
}
func (n *node) String() string {
return n.name
}
func (n *node) Hashcode() interface{} {
return n.name
}

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@ -1,68 +0,0 @@
package flow
import (
"fmt"
"testing"
"github.com/silas/dag"
)
func checkErr(t *testing.T, err error) {
if err != nil {
t.Fatal(err)
}
}
func TestDag(t *testing.T) {
d1 := &dag.AcyclicGraph{}
d2 := &dag.AcyclicGraph{}
d2v1 := d2.Add(&node{"Substep.Create"})
v1 := d1.Add(&node{"AccountService.Create"})
v2 := d1.Add(&node{"AuthzService.Create"})
v3 := d1.Add(&node{"AuthnService.Create"})
v4 := d1.Add(&node{"ProjectService.Create"})
v5 := d1.Add(&node{"ContactService.Create"})
v6 := d1.Add(&node{"NetworkService.Create"})
v7 := d1.Add(&node{"MailerService.Create"})
v8 := d1.Add(&node{"NestedService.Create"})
v9 := d1.Add(d2v1)
d1.Connect(dag.BasicEdge(v1, v2))
d1.Connect(dag.BasicEdge(v1, v3))
d1.Connect(dag.BasicEdge(v1, v4))
d1.Connect(dag.BasicEdge(v1, v5))
d1.Connect(dag.BasicEdge(v1, v6))
d1.Connect(dag.BasicEdge(v1, v7))
d1.Connect(dag.BasicEdge(v7, v8))
d1.Connect(dag.BasicEdge(v8, v9))
if err := d1.Validate(); err != nil {
t.Fatal(err)
}
d1.TransitiveReduction()
var steps [][]string
fn := func(n dag.Vertex, idx int) error {
if idx == 0 {
steps = make([][]string, 1)
steps[0] = make([]string, 0, 1)
} else if idx >= len(steps) {
tsteps := make([][]string, idx+1)
copy(tsteps, steps)
steps = tsteps
steps[idx] = make([]string, 0, 1)
}
steps[idx] = append(steps[idx], fmt.Sprintf("%s", n))
return nil
}
start := &node{"AccountService.Create"}
err := d1.SortedDepthFirstWalk([]dag.Vertex{start}, fn)
checkErr(t, err)
if len(steps) != 4 {
t.Fatalf("invalid steps: %#+v", steps)
}
if steps[3][0] != "Substep.Create" {
t.Fatalf("invalid last step: %#+v", steps)
}
}

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@ -33,10 +33,6 @@ func (w *microWorkflow) ID() string {
return w.id
}
func (w *microWorkflow) Steps() ([][]Step, error) {
return w.getSteps("", false)
}
func (w *microWorkflow) Status() Status {
return w.status
}
@ -44,11 +40,11 @@ func (w *microWorkflow) Status() Status {
func (w *microWorkflow) AppendSteps(steps ...Step) error {
var err error
w.Lock()
defer w.Unlock()
for _, s := range steps {
w.steps[s.String()] = s
if _, err = w.g.AddVertex(s); err != nil {
w.Unlock()
return err
}
}
@ -57,11 +53,9 @@ func (w *microWorkflow) AppendSteps(steps ...Step) error {
for _, req := range dst.Requires() {
src, ok := w.steps[req]
if !ok {
w.Unlock()
return ErrStepNotExists
}
if err = w.g.AddEdge(src.String(), dst.String()); err != nil {
w.Unlock()
return err
}
}
@ -69,8 +63,6 @@ func (w *microWorkflow) AppendSteps(steps ...Step) error {
w.g.ReduceTransitively()
w.Unlock()
return nil
}
@ -78,6 +70,7 @@ func (w *microWorkflow) RemoveSteps(steps ...Step) error {
// TODO: handle case when some step requires or required by removed step
w.Lock()
defer w.Unlock()
for _, s := range steps {
delete(w.steps, s.String())
@ -88,7 +81,6 @@ func (w *microWorkflow) RemoveSteps(steps ...Step) error {
for _, req := range dst.Requires() {
src, ok := w.steps[req]
if !ok {
w.Unlock()
return ErrStepNotExists
}
w.g.AddEdge(src.String(), dst.String())
@ -97,54 +89,9 @@ func (w *microWorkflow) RemoveSteps(steps ...Step) error {
w.g.ReduceTransitively()
w.Unlock()
return nil
}
func (w *microWorkflow) getSteps(start string) ([][]Step, error) {
var steps [][]Step
var root dag.Vertex
var err error
fn := func(n dag.Vertex, idx int) error {
if idx == 0 {
steps = make([][]Step, 1)
steps[0] = make([]Step, 0, 1)
} else if idx >= len(steps) {
tsteps := make([][]Step, idx+1)
copy(tsteps, steps)
steps = tsteps
steps[idx] = make([]Step, 0, 1)
}
steps[idx] = append(steps[idx], n.(Step))
return nil
}
if start != "" {
var ok bool
w.RLock()
root, ok = w.steps[start]
w.RUnlock()
if !ok {
return nil, ErrStepNotExists
}
} else {
root, err = w.g.Root()
if err != nil {
return nil, err
}
}
err = w.g.SortedDepthFirstWalk(root, fn)
if err != nil {
return nil, err
}
return steps, nil
}
func (w *microWorkflow) Abort(ctx context.Context, id string) error {
workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", id))
return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusAborted.String())})
@ -173,26 +120,11 @@ func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...Execu
return "", err
}
stepStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("steps", eid))
// stepStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("steps", eid))
workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
options := NewExecuteOptions(opts...)
steps, err := w.getSteps(options.Start)
if err != nil {
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
}
return "", err
}
var wg sync.WaitGroup
cherr := make(chan error, 1)
chstatus := make(chan Status, 1)
nctx, cancel := context.WithCancel(ctx)
defer cancel()
nopts := make([]ExecuteOption, 0, len(opts)+5)
nopts = append(nopts,
@ -202,143 +134,274 @@ func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...Execu
ExecuteMeter(w.opts.Meter),
)
nopts = append(nopts, opts...)
done := make(chan struct{})
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
return eid, werr
}
for idx := range steps {
for nidx := range steps[idx] {
cstep := steps[idx][nidx]
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
return eid, werr
var startID string
if options.Start == "" {
mp := w.g.GetRoots()
if len(mp) != 1 {
return eid, ErrStepNotExists
}
for k := range mp {
startID = k
}
} else {
for k, v := range w.g.GetVertices() {
if v == options.Start {
startID = k
}
}
}
go func() {
for idx := range steps {
for nidx := range steps[idx] {
wStatus := &codec.Frame{}
if werr := workflowStore.Read(w.opts.Context, "status", wStatus); werr != nil {
cherr <- werr
return
if startID == "" {
return eid, ErrStepNotExists
}
if options.Async {
go w.handleWorkflow(startID, nopts...)
return eid, nil
}
return eid, w.handleWorkflow(startID, nopts...)
}
func (w *microWorkflow) handleWorkflow(startID string, opts ...ExecuteOption) error {
w.RLock()
defer w.RUnlock()
// stepStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("steps", eid))
// workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
// Get IDs of all descendant vertices.
flowIDs, errDes := w.g.GetDescendants(startID)
if errDes != nil {
return errDes
}
// inputChannels provides for input channels for each of the descendant vertices (+ the start-vertex).
inputChannels := make(map[string]chan FlowResult, len(flowIDs)+1)
// Iterate vertex IDs and create an input channel for each of them and a single
// output channel for leaves. Note, this "pre-flight" is needed to ensure we
// really have an input channel regardless of how we traverse the tree and spawn
// workers.
leafCount := 0
for id := range flowIDs {
// Get all parents of this vertex.
parents, errPar := w.g.GetParents(id)
if errPar != nil {
return errPar
}
// Create a buffered input channel that has capacity for all parent results.
inputChannels[id] = make(chan FlowResult, len(parents))
if w.g.isLeaf(id) {
leafCount += 1
}
}
// outputChannel caries the results of leaf vertices.
outputChannel := make(chan FlowResult, leafCount)
// To also process the start vertex and to have its results being passed to its
// children, add it to the vertex IDs. Also add an input channel for the start
// vertex and feed the inputs to this channel.
flowIDs[startID] = struct{}{}
inputChannels[startID] = make(chan FlowResult, len(inputs))
for _, i := range inputs {
inputChannels[startID] <- i
}
wg := sync.WaitGroup{}
// Iterate all vertex IDs (now incl. start vertex) and handle each worker (incl.
// inputs and outputs) in a separate goroutine.
for id := range flowIDs {
// Get all children of this vertex that later need to be notified. Note, we
// collect all children before the goroutine to be able to release the read
// lock as early as possible.
children, errChildren := w.g.GetChildren(id)
if errChildren != nil {
return errChildren
}
// Remember to wait for this goroutine.
wg.Add(1)
go func(id string) {
// Get this vertex's input channel.
// Note, only concurrent read here, which is fine.
c := inputChannels[id]
// Await all parent inputs and stuff them into a slice.
parentCount := cap(c)
parentResults := make([]FlowResult, parentCount)
for i := 0; i < parentCount; i++ {
parentResults[i] = <-c
}
// Execute the worker.
errWorker := callback(w.g, id, parentResults)
if errWorker != nil {
return errWorker
}
// Send this worker's FlowResult onto all children's input channels or, if it is
// a leaf (i.e. no children), send the result onto the output channel.
if len(children) > 0 {
for child := range children {
inputChannels[child] <- flowResult
}
if status := StringStatus[string(wStatus.Data)]; status != StatusRunning {
chstatus <- status
return
}
if w.opts.Logger.V(logger.TraceLevel) {
w.opts.Logger.Tracef(nctx, "will be executed %v", steps[idx][nidx])
}
cstep := steps[idx][nidx]
// nolint: nestif
if len(cstep.Requires()) == 0 {
wg.Add(1)
go func(step Step) {
defer wg.Done()
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "req"), req); werr != nil {
} else {
outputChannel <- flowResult
}
// "Sign off".
wg.Done()
}(id)
}
// Wait for all go routines to finish.
wg.Wait()
// Await all leaf vertex results and stuff them into a slice.
resultCount := cap(outputChannel)
results := make([]FlowResult, resultCount)
for i := 0; i < resultCount; i++ {
results[i] = <-outputChannel
}
/*
go func() {
for idx := range steps {
for nidx := range steps[idx] {
wStatus := &codec.Frame{}
if werr := workflowStore.Read(w.opts.Context, "status", wStatus); werr != nil {
cherr <- werr
return
}
if status := StringStatus[string(wStatus.Data)]; status != StatusRunning {
chstatus <- status
return
}
if w.opts.Logger.V(logger.TraceLevel) {
w.opts.Logger.Tracef(nctx, "will be executed %v", steps[idx][nidx])
}
cstep := steps[idx][nidx]
// nolint: nestif
if len(cstep.Requires()) == 0 {
wg.Add(1)
go func(step Step) {
defer wg.Done()
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "req"), req); werr != nil {
cherr <- werr
return
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
cherr <- werr
return
}
rsp, serr := step.Execute(nctx, req, nopts...)
if serr != nil {
step.SetStatus(StatusFailure)
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
}
cherr <- serr
return
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), rsp); werr != nil {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
cherr <- werr
return
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
cherr <- werr
return
}
}(cstep)
wg.Wait()
} else {
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "req"), req); werr != nil {
cherr <- werr
return
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
cherr <- werr
return
}
rsp, serr := step.Execute(nctx, req, nopts...)
rsp, serr := cstep.Execute(nctx, req, nopts...)
if serr != nil {
step.SetStatus(StatusFailure)
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
cstep.SetStatus(StatusFailure)
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
}
cherr <- serr
return
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), rsp); werr != nil {
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), rsp); werr != nil {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
cherr <- werr
return
}
if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
cherr <- werr
return
}
}(cstep)
wg.Wait()
} else {
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "req"), req); werr != nil {
cherr <- werr
return
}
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
cherr <- werr
return
}
rsp, serr := cstep.Execute(nctx, req, nopts...)
if serr != nil {
cstep.SetStatus(StatusFailure)
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
}
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
}
cherr <- serr
return
}
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), rsp); werr != nil {
w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
cherr <- werr
return
}
if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
cherr <- werr
return
}
}
}
}
close(done)
}()
close(done)
}()
if options.Async {
return eid, nil
}
logger.Tracef(ctx, "wait for finish or error")
select {
case <-nctx.Done():
err = nctx.Err()
case cerr := <-cherr:
err = cerr
case <-done:
close(cherr)
case <-chstatus:
close(chstatus)
return eid, nil
}
switch {
case nctx.Err() != nil:
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusAborted.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
if options.Async {
return eid, nil
}
case err == nil:
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
}
case err != nil:
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
}
}
return eid, err
logger.Tracef(ctx, "wait for finish or error")
select {
case <-nctx.Done():
err = nctx.Err()
case cerr := <-cherr:
err = cerr
case <-done:
close(cherr)
case <-chstatus:
close(chstatus)
return eid, nil
}
switch {
case nctx.Err() != nil:
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusAborted.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
}
case err == nil:
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
}
case err != nil:
if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil {
w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
}
}
*/
return err
}
// NewFlow create new flow

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@ -125,8 +125,6 @@ type Workflow interface {
AppendSteps(steps ...Step) error
// Status returns workflow status
Status() Status
// Steps returns steps slice where parallel steps returned on the same level
Steps() ([][]Step, error)
// Suspend suspends execution
Suspend(ctx context.Context, id string) error
// Resume resumes execution