Cs and refactoring

1 files changed, 162 insertions, 0 deletions

diff --git a/service/registry.go b/service/registry.go
new file mode 100644
index 00000000..d4e2ff12
--- /dev/null
+++ b/service/registry.go
@@ -0,0 +1,162 @@
+package service
+
+import (
+	"fmt"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"sync"
+)
+
+// Config provides ability to slice configuration sections and unmarshal configuration data into
+// given structure.
+type Config interface {
+	// Get nested config section (sub-map), returns nil if section not found.
+	Get(service string) Config
+
+	// Unmarshal unmarshal config data into given struct.
+	Unmarshal(out interface{}) error
+}
+
+// Registry controls all internal RR services and provides plugin based system.
+type Registry interface {
+	// Register add new service to the registry under given name.
+	Register(name string, service Service)
+
+	// Configure configures all underlying services with given configuration.
+	Configure(cfg Config) error
+
+	// Check is Service has been registered and configured.
+	Has(service string) bool
+
+	// Get returns Service instance by it's Name or nil if Service not found. Method must return only configured instance.
+	Get(service string) Service
+
+	// Serve all configured services. Non blocking.
+	Serve() error
+
+	// Stop all active services.
+	Stop() error
+}
+
+// Service provides high level functionality for road runner Service.
+type Service interface {
+	// WithConfig must return Service instance configured with the given environment. Must return error in case of
+	// misconfiguration, might return nil as Service if Service is not enabled.
+	WithConfig(cfg Config, reg Registry) (Service, error)
+
+	// Serve serves Service.
+	Serve() error
+
+	// Stop stop Service Service.
+	Stop() error
+}
+
+type registry struct {
+	log        logrus.FieldLogger
+	mu         sync.Mutex
+	candidates []*entry
+	configured []*entry
+}
+
+// entry creates association between service instance and given name.
+type entry struct {
+	// Associated service name
+	Name string
+
+	// Associated service instance
+	Service Service
+
+	// Serving indicates that service is currently serving
+	Serving bool
+}
+
+// NewRegistry creates new registry.
+func NewRegistry(log logrus.FieldLogger) Registry {
+	return &registry{
+		log:        log,
+		candidates: make([]*entry, 0),
+	}
+}
+
+// Register add new service to the registry under given name.
+func (r *registry) Register(name string, service Service) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.candidates = append(r.candidates, &entry{
+		Name:    name,
+		Service: service,
+		Serving: false,
+	})
+
+	r.log.Debugf("%s.service: registered", name)
+}
+
+// Configure configures all underlying services with given configuration.
+func (r *registry) Configure(cfg Config) error {
+	if r.configured != nil {
+		return fmt.Errorf("service bus has been already configured")
+	}
+
+	r.configured = make([]*entry, 0)
+	for _, e := range r.candidates {
+		segment := cfg.Get(e.Name)
+		if segment == nil {
+			r.log.Debugf("%s.service: no config has been provided", e.Name)
+			continue
+		}
+
+		s, err := e.Service.WithConfig(segment, r)
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("%s.service", e.Name))
+		}
+
+		if s != nil {
+			r.configured = append(r.configured, &entry{
+				Name:    e.Name,
+				Service: s,
+				Serving: false,
+			})
+		}
+	}
+
+	return nil
+}
+
+// Check is Service has been registered.
+func (r *registry) Has(service string) bool {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	for _, e := range r.configured {
+		if e.Name == service {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Get returns Service instance by it's Name or nil if Service not found.
+func (r *registry) Get(service string) Service {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	for _, e := range r.configured {
+		if e.Name == service {
+			return e.Service
+		}
+	}
+
+	return nil
+}
+
+// Serve all configured services. Non blocking.
+func (r *registry) Serve() error {
+	return nil
+}
+
+// Stop all active services.
+func (r *registry) Stop() error {
+	return nil
+}