Initial QSfera import

Server/vendor/go-micro.dev/v4/client/cache.go

@@ -0,0 +1,70 @@
+package client
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"hash/fnv"
+	"time"
+
+	cache "github.com/patrickmn/go-cache"
+
+	"go-micro.dev/v4/metadata"
+	"go-micro.dev/v4/transport/headers"
+)
+
+// NewCache returns an initialized cache.
+func NewCache() *Cache {
+	return &Cache{
+		cache: cache.New(cache.NoExpiration, 30*time.Second),
+	}
+}
+
+// Cache for responses.
+type Cache struct {
+	cache *cache.Cache
+}
+
+// Get a response from the cache.
+func (c *Cache) Get(ctx context.Context, req *Request) (interface{}, bool) {
+	return c.cache.Get(key(ctx, req))
+}
+
+// Set a response in the cache.
+func (c *Cache) Set(ctx context.Context, req *Request, rsp interface{}, expiry time.Duration) {
+	c.cache.Set(key(ctx, req), rsp, expiry)
+}
+
+// List the key value pairs in the cache.
+func (c *Cache) List() map[string]string {
+	items := c.cache.Items()
+
+	rsp := make(map[string]string, len(items))
+
+	for k, v := range items {
+		bytes, _ := json.Marshal(v.Object)
+		rsp[k] = string(bytes)
+	}
+
+	return rsp
+}
+
+// key returns a hash for the context and request.
+func key(ctx context.Context, req *Request) string {
+	ns, _ := metadata.Get(ctx, headers.Namespace)
+
+	bytes, _ := json.Marshal(map[string]interface{}{
+		"namespace": ns,
+		"request": map[string]interface{}{
+			"service":  (*req).Service(),
+			"endpoint": (*req).Endpoint(),
+			"method":   (*req).Method(),
+			"body":     (*req).Body(),
+		},
+	})
+
+	h := fnv.New64()
+	h.Write(bytes)
+
+	return fmt.Sprintf("%x", h.Sum(nil))
+}