settings

1 files changed, 53 insertions, 0 deletions

diff --git a/helpers/queue.js b/helpers/queue.js
new file mode 100644
index 0000000..69e708a
--- /dev/null
+++ b/helpers/queue.js
@@ -0,0 +1,53 @@
+class Queue {
+  static queue = [];
+  static pendingPromise = false;
+  static stop = false;
+
+  static enqueue(promise) {
+    return new Promise((resolve, reject) => {
+      this.queue.push({
+        promise,
+        resolve,
+        reject
+      });
+      this.dequeue();
+    });
+  }
+
+  static dequeue() {
+    if (this.workingOnPromise) {
+      return false;
+    }
+    if (this.stop) {
+      this.queue = [];
+      this.stop = false;
+      return;
+    }
+    const item = this.queue.shift();
+    if (!item) {
+      return false;
+    }
+    try {
+      this.workingOnPromise = true;
+      item
+        .promise()
+        .then((value) => {
+          this.workingOnPromise = false;
+          item.resolve(value);
+          this.dequeue();
+        })
+        .catch((err) => {
+          this.workingOnPromise = false;
+          item.reject(err);
+          this.dequeue();
+        });
+    } catch (err) {
+      this.workingOnPromise = false;
+      item.reject(err);
+      this.dequeue();
+    }
+    return true;
+  }
+}
+
+export default Queue