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Merge pull request #120 from unistack-org/fsm

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fsm: run steps in order
This commit is contained in:
Василий Толстов 2022-04-19 17:36:05 +03:00 committed by GitHub
commit 12f188e3ad
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2 changed files with 44 additions and 22 deletions
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28
fsm/fsm.go
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@ -23,10 +23,10 @@ type Options struct {
}
// HookBeforeFunc func signature
type HookBeforeFunc func(ctx context.Context, state string, args map[string]interface{})
type HookBeforeFunc func(ctx context.Context, state string, args interface{})
// HookAfterFunc func signature
type HookAfterFunc func(ctx context.Context, state string, args map[string]interface{})
type HookAfterFunc func(ctx context.Context, state string, args interface{})
// Option func signature
type Option func(*Options)
@ -53,12 +53,13 @@ func StateHookAfter(fns ...HookAfterFunc) Option {
}
// StateFunc called on state transition and return next step and error
type StateFunc func(ctx context.Context, args map[string]interface{}) (string, map[string]interface{}, error)
type StateFunc func(ctx context.Context, args interface{}) (string, interface{}, error)
// FSM is a finite state machine
type FSM struct {
mu sync.Mutex
states map[string]StateFunc
statesMap map[string]StateFunc
statesOrder []string
opts *Options
current string
}
@ -73,7 +74,7 @@ func New(opts ...Option) *FSM {
}
return &FSM{
states: map[string]StateFunc{},
statesMap: map[string]StateFunc{},
opts: options,
}
}
@ -95,12 +96,13 @@ func (f *FSM) Reset() {
// State adds state to fsm
func (f *FSM) State(state string, fn StateFunc) {
f.mu.Lock()
f.states[state] = fn
f.statesMap[state] = fn
f.statesOrder = append(f.statesOrder, state)
f.mu.Unlock()
}
// Start runs state machine with provided data
func (f *FSM) Start(ctx context.Context, args map[string]interface{}, opts ...Option) (map[string]interface{}, error) {
func (f *FSM) Start(ctx context.Context, args interface{}, opts ...Option) (interface{}, error) {
var err error
var ok bool
var fn StateFunc
@ -114,8 +116,8 @@ func (f *FSM) Start(ctx context.Context, args map[string]interface{}, opts ...Op
}
cstate := options.Initial
states := make(map[string]StateFunc, len(f.states))
for k, v := range f.states {
states := make(map[string]StateFunc, len(f.statesMap))
for k, v := range f.statesMap {
states[k] = v
}
f.current = cstate
@ -142,8 +144,14 @@ func (f *FSM) Start(ctx context.Context, args map[string]interface{}, opts ...Op
}
if err != nil {
return args, err
} else if nstate == "" || nstate == StateEnd {
} else if nstate == StateEnd {
return args, nil
} else if nstate == "" {
for idx := range f.statesOrder {
if f.statesOrder[idx] == cstate && len(f.statesOrder) > idx+1 {
nstate = f.statesOrder[idx+1]
}
}
}
cstate = nstate
}

30
fsm/fsm_test.go
View File

@ -10,40 +10,54 @@ import (
func TestFSMStart(t *testing.T) {
ctx := context.TODO()
buf := bytes.NewBuffer(nil)
pfb := func(_ context.Context, state string, _ map[string]interface{}) {
pfb := func(_ context.Context, state string, _ interface{}) {
fmt.Fprintf(buf, "before state %s\n", state)
}
pfa := func(_ context.Context, state string, _ map[string]interface{}) {
pfa := func(_ context.Context, state string, _ interface{}) {
fmt.Fprintf(buf, "after state %s\n", state)
}
f := New(StateInitial("1"), StateHookBefore(pfb), StateHookAfter(pfa))
f1 := func(_ context.Context, args map[string]interface{}) (string, map[string]interface{}, error) {
f1 := func(_ context.Context, req interface{}) (string, interface{}, error) {
args := req.(map[string]interface{})
if v, ok := args["request"].(string); !ok || v == "" {
return "", nil, fmt.Errorf("empty request")
}
return "2", map[string]interface{}{"response": "test2"}, nil
}
f2 := func(_ context.Context, args map[string]interface{}) (string, map[string]interface{}, error) {
f2 := func(_ context.Context, req interface{}) (string, interface{}, error) {
args := req.(map[string]interface{})
if v, ok := args["response"].(string); !ok || v == "" {
return "", nil, fmt.Errorf("empty response")
}
return "", map[string]interface{}{"response": "test"}, nil
}
f3 := func(_ context.Context, req interface{}) (string, interface{}, error) {
args := req.(map[string]interface{})
if v, ok := args["response"].(string); !ok || v == "" {
return "", nil, fmt.Errorf("empty response")
}
return StateEnd, map[string]interface{}{"response": "test_last"}, nil
}
f.State("1", f1)
f.State("2", f2)
args, err := f.Start(ctx, map[string]interface{}{"request": "test1"})
f.State("3", f3)
rsp, err := f.Start(ctx, map[string]interface{}{"request": "test1"})
if err != nil {
t.Fatal(err)
} else if v, ok := args["response"].(string); !ok || v == "" {
}
args := rsp.(map[string]interface{})
if v, ok := args["response"].(string); !ok || v == "" {
t.Fatalf("nil rsp: %#+v", args)
} else if v != "test" {
} else if v != "test_last" {
t.Fatalf("invalid rsp %#+v", args)
}
if !bytes.Contains(buf.Bytes(), []byte(`before state 1`)) ||
!bytes.Contains(buf.Bytes(), []byte(`before state 2`)) ||
!bytes.Contains(buf.Bytes(), []byte(`after state 1`)) ||
!bytes.Contains(buf.Bytes(), []byte(`after state 2`)) {
!bytes.Contains(buf.Bytes(), []byte(`after state 2`)) ||
!bytes.Contains(buf.Bytes(), []byte(`after state 3`)) ||
!bytes.Contains(buf.Bytes(), []byte(`after state 3`)) {
t.Fatalf("fsm not works properly or hooks error, buf: %s", buf.Bytes())
}
}