add metrics and tracing

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

handler/graphql/graphql.go

@@ -0,0 +1,77 @@
+//go:build ignore
+
+package graphql_handler
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/99designs/gqlgen/graphql"
+	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v3/store"
+)
+
+var _ graphql.Cache = (*cacheWrapper)(nil)
+
+type Handler struct {
+	opts Options
+}
+
+type Option func(*Options)
+
+type Options struct {
+	cache *cacheWrapper
+	Path  string
+}
+
+type cacheWrapper struct {
+	s store.Store
+	l logger.Logger
+}
+
+func (c *cacheWrapper) Get(ctx context.Context, key string) (interface{}, bool) {
+	var val interface{}
+	if err := c.s.Read(ctx, key, val); err != nil && err != store.ErrNotFound {
+		c.l.Error(ctx, fmt.Sprintf("cache.Get %s failed", key), err)
+		return nil, false
+	}
+	return val, true
+}
+
+func (c *cacheWrapper) Add(ctx context.Context, key string, val interface{}) {
+	if err := c.s.Write(ctx, key, val); err != nil {
+		c.l.Error(ctx, fmt.Sprintf("cache.Add %s failed", key), err)
+	}
+}
+
+func Store(s store.Store) Option {
+	return func(o *Options) {
+		if o.cache == nil {
+			o.cache = &cacheWrapper{}
+		}
+		o.cache.s = s
+	}
+}
+
+func Logger(l logger.Logger) Option {
+	return func(o *Options) {
+		if o.cache == nil {
+			o.cache = &cacheWrapper{}
+		}
+		o.cache.l = l
+	}
+}
+
+func Path(path string) Option {
+	return func(o *Options) {
+		o.Path = path
+	}
+}
+
+func NewHandler(opts ...Option) *Handler {
+	options := Options{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &Handler{opts: options}
+}