add graphql

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

graphql/registry.go

@@ -0,0 +1,139 @@
+package generator
+
+import (
+	"sync"
+
+	"github.com/jhump/protoreflect/desc"
+	"github.com/vektah/gqlparser/v2/ast"
+)
+
+type Registry interface {
+	FindMethodByName(op ast.Operation, name string) *desc.MethodDescriptor
+	FindObjectByName(name string) *desc.MessageDescriptor
+
+	// FindObjectByFullyQualifiedName TODO maybe find a better way to get ast definition
+	FindObjectByFullyQualifiedName(fqn string) (*desc.MessageDescriptor, *ast.Definition)
+
+	// FindFieldByName given the proto Descriptor and the graphql field name get the the proto FieldDescriptor
+	FindFieldByName(msg desc.Descriptor, name string) *desc.FieldDescriptor
+
+	// FindUnionFieldByMessageFQNAndName given the proto Descriptor and the graphql field name get the the proto FieldDescriptor
+	FindUnionFieldByMessageFQNAndName(fqn, name string) *desc.FieldDescriptor
+
+	FindGraphqlFieldByProtoField(msg *ast.Definition, name string) *ast.FieldDefinition
+}
+
+func NewRegistry(files SchemaDescriptorList) Registry {
+	v := &repository{
+		mu:                       &sync.RWMutex{},
+		methodsByName:            map[ast.Operation]map[string]*desc.MethodDescriptor{},
+		objectsByName:            map[string]*desc.MessageDescriptor{},
+		objectsByFQN:             map[string]*ObjectDescriptor{},
+		graphqlFieldsByName:      map[desc.Descriptor]map[string]*desc.FieldDescriptor{},
+		graphqlUnionFieldsByName: map[string]map[string]*desc.FieldDescriptor{},
+		protoFieldsByName:        map[*ast.Definition]map[string]*ast.FieldDefinition{},
+	}
+	for _, f := range files {
+		v.methodsByName[ast.Mutation] = map[string]*desc.MethodDescriptor{}
+		for _, m := range f.GetMutation().Methods() {
+			v.methodsByName[ast.Mutation][m.Name] = m.MethodDescriptor
+		}
+		v.methodsByName[ast.Query] = map[string]*desc.MethodDescriptor{}
+		for _, m := range f.GetQuery().Methods() {
+			v.methodsByName[ast.Query][m.Name] = m.MethodDescriptor
+		}
+		v.methodsByName[ast.Subscription] = map[string]*desc.MethodDescriptor{}
+		for _, m := range f.GetSubscription().Methods() {
+			v.methodsByName[ast.Subscription][m.Name] = m.MethodDescriptor
+		}
+	}
+	for _, f := range files {
+		for _, m := range f.Objects() {
+			switch m.Kind {
+			case ast.Union:
+				fqn := m.Descriptor.GetParent().GetFullyQualifiedName()
+				if _, ok := v.graphqlUnionFieldsByName[fqn]; !ok {
+					v.graphqlUnionFieldsByName[fqn] = map[string]*desc.FieldDescriptor{}
+				}
+				for _, tt := range m.GetTypes() {
+					for _, f := range tt.GetFields() {
+						v.graphqlUnionFieldsByName[fqn][f.Name] = f.FieldDescriptor
+					}
+				}
+			case ast.Object:
+				v.protoFieldsByName[m.Definition] = map[string]*ast.FieldDefinition{}
+				for _, f := range m.GetFields() {
+					if f.FieldDescriptor != nil {
+						v.protoFieldsByName[m.Definition][f.FieldDescriptor.GetName()] = f.FieldDefinition
+					}
+				}
+			case ast.InputObject:
+				v.graphqlFieldsByName[m.Descriptor] = map[string]*desc.FieldDescriptor{}
+				for _, f := range m.GetFields() {
+					v.graphqlFieldsByName[m.Descriptor][f.Name] = f.FieldDescriptor
+				}
+			}
+			switch msgDesc := m.Descriptor.(type) {
+			case *desc.MessageDescriptor:
+				v.objectsByFQN[m.GetFullyQualifiedName()] = m
+				v.objectsByName[m.Name] = msgDesc
+			}
+		}
+	}
+	return v
+}
+
+type repository struct {
+	files SchemaDescriptorList
+	mu    *sync.RWMutex
+
+	methodsByName            map[ast.Operation]map[string]*desc.MethodDescriptor
+	objectsByName            map[string]*desc.MessageDescriptor
+	objectsByFQN             map[string]*ObjectDescriptor
+	graphqlFieldsByName      map[desc.Descriptor]map[string]*desc.FieldDescriptor
+	protoFieldsByName        map[*ast.Definition]map[string]*ast.FieldDefinition
+	graphqlUnionFieldsByName map[string]map[string]*desc.FieldDescriptor
+}
+
+func (r repository) FindMethodByName(op ast.Operation, name string) *desc.MethodDescriptor {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	m, _ := r.methodsByName[op][name]
+	return m
+}
+
+func (r repository) FindObjectByName(name string) *desc.MessageDescriptor {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	o, _ := r.objectsByName[name]
+	return o
+}
+
+func (r repository) FindObjectByFullyQualifiedName(fqn string) (*desc.MessageDescriptor, *ast.Definition) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	o, _ := r.objectsByFQN[fqn]
+	msg, _ := o.Descriptor.(*desc.MessageDescriptor)
+	return msg, o.Definition
+}
+
+func (r repository) FindFieldByName(msg desc.Descriptor, name string) *desc.FieldDescriptor {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	f, _ := r.graphqlFieldsByName[msg][name]
+	return f
+}
+
+func (r repository) FindUnionFieldByMessageFQNAndName(fqn, name string) *desc.FieldDescriptor {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	f, _ := r.graphqlUnionFieldsByName[fqn][name]
+	return f
+}
+
+func (r repository) FindGraphqlFieldByProtoField(msg *ast.Definition, name string) *ast.FieldDefinition {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	f, _ := r.protoFieldsByName[msg][name]
+	return f
+}