规则引擎

pkg/rule_engine/instance.go

@@ -0,0 +1,89 @@
+package rule_engine
+
+import (
+	"context"
+	"fmt"
+	"github.com/sirupsen/logrus"
+	"pandax/pkg/rule_engine/manifest"
+	"pandax/pkg/rule_engine/message"
+	"pandax/pkg/rule_engine/nodes"
+)
+
+// ruleChainInstance is rulechain's runtime instance that manage all nodes in this chain,
+type ruleChainInstance struct {
+	firstRuleNodeId string
+	nodes           map[string]nodes.Node
+}
+
+func newRuleChainInstance(data []byte) (*ruleChainInstance, []error) {
+	errors := []error{}
+
+	manifest, err := manifest.New(data)
+	if err != nil {
+		errors = append(errors, err)
+		logrus.WithError(err).Errorf("invalidi manifest file")
+		return nil, errors
+	}
+	return newInstanceWithManifest(manifest)
+}
+
+// newWithManifest create rule chain by user's manifest file
+func newInstanceWithManifest(m *manifest.Manifest) (*ruleChainInstance, []error) {
+	errs := []error{}
+	r := &ruleChainInstance{
+		firstRuleNodeId: m.FirstRuleNodeId,
+		nodes:           make(map[string]nodes.Node),
+	}
+	// Create All nodes
+	for _, n := range m.Nodes {
+		metadata := nodes.NewMetadataWithValues(n.Properties)
+		node, err := nodes.NewNode(n.Type, n.Id, metadata)
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		if _, found := r.nodes[n.Id]; found {
+			err := fmt.Errorf("node '%s' already exist in rulechain", n.Id)
+			errs = append(errs, err)
+			continue
+		}
+		r.nodes[n.Id] = node
+	}
+
+	for _, edge := range m.Edges {
+		originalNode, found := r.nodes[edge.SourceNodeId]
+		if !found {
+			err := fmt.Errorf("original node '%s' no exist in", originalNode.Name())
+			errs = append(errs, err)
+			continue
+		}
+		targetNode, found := r.nodes[edge.TargetNodeId]
+		if !found {
+			err := fmt.Errorf("target node '%s' no exist in rulechain", targetNode.Name())
+			errs = append(errs, err)
+			continue
+		}
+		originalNode.AddLinkedNode(edge.Type, targetNode)
+	}
+	for name, node := range r.nodes {
+		targetNodes := node.GetLinkedNodes()
+		mustLabels := node.MustLabels()
+		for _, label := range mustLabels {
+			if _, found := targetNodes[label]; !found {
+				err := fmt.Errorf("the label '%s' in node '%s' no exist'", label, name)
+				errs = append(errs, err)
+				continue
+			}
+		}
+	}
+
+	return r, errs
+}
+
+// StartRuleChain TODO 是否需要添加context
+func (c *ruleChainInstance) StartRuleChain(context context.Context, message message.Message) error {
+	if node, found := c.nodes[c.firstRuleNodeId]; found {
+		go node.Handle(message)
+	}
+	return nil
+}