flow/dag.go

@@ -0,0 +1,21 @@
+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
+}

flow/dag_test.go

@@ -0,0 +1,68 @@
+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, 1)
+			steps[0] = make([]string, 0, 1)
+		} else if idx >= len(steps) {
+			tsteps := make([][]string, idx+1, 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)
+	}
+}

flow/flow.go

@@ -0,0 +1,7 @@
+// Package flow is an interface used for saga pattern messaging
+package flow
+
+type Step interface {
+	// Endpoint returns service_name.service_method
+	Endpoint() string
+}

go.mod

@@ -6,10 +6,12 @@ require (
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
 	github.com/ef-ds/deque v1.0.4
 	github.com/google/uuid v1.2.0
+	github.com/heimdalr/dag v1.0.1 // indirect
 	github.com/imdario/mergo v0.3.11
 	github.com/kr/text v0.2.0 // indirect
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
 	github.com/patrickmn/go-cache v2.1.0+incompatible
+	github.com/silas/dag v0.0.0-20210121180416-41cf55125c34 // indirect
 	golang.org/x/net v0.0.0-20210119194325-5f4716e94777
 	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
 )

go.sum

@@ -3,8 +3,13 @@ github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumC
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/ef-ds/deque v1.0.4 h1:iFAZNmveMT9WERAkqLJ+oaABF9AcVQ5AjXem/hroniI=
 github.com/ef-ds/deque v1.0.4/go.mod h1:gXDnTC3yqvBcHbq2lcExjtAcVrOnJCbMcZXmuj8Z4tg=
+github.com/go-test/deep v1.0.7 h1:/VSMRlnY/JSyqxQUzQLKVMAskpY/NZKFA5j2P+0pP2M=
+github.com/go-test/deep v1.0.7/go.mod h1:QV8Hv/iy04NyLBxAdO9njL0iVPN1S4d/A3NVv1V36o8=
+github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.2.0 h1:qJYtXnJRWmpe7m/3XlyhrsLrEURqHRM2kxzoxXqyUDs=
 github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/heimdalr/dag v1.0.1 h1:iR2K3DSUFDYx0GeV7iXBnZkedWS1xePSGrylQ197uxg=
+github.com/heimdalr/dag v1.0.1/go.mod h1:t+ZkR+sjKL4xhlE1B9rwpvwfo+x+2R0363efS+Oghns=
 github.com/imdario/mergo v0.3.11 h1:3tnifQM4i+fbajXKBHXWEH+KvNHqojZ778UH75j3bGA=
 github.com/imdario/mergo v0.3.11/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
@@ -15,13 +20,12 @@ github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWb
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
-github.com/unistack-org/micro v1.18.0 h1:EbFiII0bKV0Xcua7o6J30MFmm4/g0Hv3ECOKzsUBihU=
+github.com/silas/dag v0.0.0-20210121180416-41cf55125c34 h1:vBfVmA5mZhsQa2jr1FOL9nfA37N/jnbBmi5XUfviVTI=
+github.com/silas/dag v0.0.0-20210121180416-41cf55125c34/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777 h1:003p0dJM77cxMSyCPFphvZf/Y5/NXf5fzg6ufd1/Oew=
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=