1 files changed, 51 insertions, 0 deletions
diff --git a/workhorse/internal/queueing/requests.go b/workhorse/internal/queueing/requests.go
new file mode 100644
index 00000000000..409a7656fa4
--- /dev/null
+++ b/workhorse/internal/queueing/requests.go
@@ -0,0 +1,51 @@
+package queueing
+
+import (
+	"net/http"
+	"time"
+
+	"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
+)
+
+const (
+	DefaultTimeout            = 30 * time.Second
+	httpStatusTooManyRequests = 429
+)
+
+// QueueRequests creates a new request queue
+// name specifies the name of queue, used to label Prometheus metrics
+//      Don't call QueueRequests twice with the same name argument!
+// h specifies a http.Handler which will handle the queue requests
+// limit specifies number of requests run concurrently
+// queueLimit specifies maximum number of requests that can be queued
+// queueTimeout specifies the time limit of storing the request in the queue
+func QueueRequests(name string, h http.Handler, limit, queueLimit uint, queueTimeout time.Duration) http.Handler {
+	if limit == 0 {
+		return h
+	}
+	if queueTimeout == 0 {
+		queueTimeout = DefaultTimeout
+	}
+
+	queue := newQueue(name, limit, queueLimit, queueTimeout)
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		err := queue.Acquire()
+
+		switch err {
+		case nil:
+			defer queue.Release()
+			h.ServeHTTP(w, r)
+
+		case ErrTooManyRequests:
+			http.Error(w, "Too Many Requests", httpStatusTooManyRequests)
+
+		case ErrQueueingTimedout:
+			http.Error(w, "Service Unavailable", http.StatusServiceUnavailable)
+
+		default:
+			helper.Fail500(w, r, err)
+		}
+
+	})
+}