1 files changed, 65 insertions, 0 deletions
diff --git a/cli/js/streams/queue.ts b/cli/js/streams/queue.ts
new file mode 100644
index 000000000..264851baf
--- /dev/null
+++ b/cli/js/streams/queue.ts
@@ -0,0 +1,65 @@
+// Forked from https://github.com/stardazed/sd-streams/tree/8928cf04b035fd02fb1340b7eb541c76be37e546
+// Copyright (c) 2018-Present by Arthur Langereis - @zenmumbler MIT
+
+/**
+ * streams/queue - simple queue type with chunked array backing
+ * Part of Stardazed
+ * (c) 2018-Present by Arthur Langereis - @zenmumbler
+ * https://github.com/stardazed/sd-streams
+ */
+
+const CHUNK_SIZE = 16384;
+
+export interface Queue<T> {
+  push(t: T): void;
+  shift(): T | undefined;
+  front(): T | undefined;
+  readonly length: number;
+}
+
+export class QueueImpl<T> implements Queue<T> {
+  private readonly chunks_: T[][];
+  private readChunk_: T[];
+  private writeChunk_: T[];
+  private length_: number;
+
+  constructor() {
+    this.chunks_ = [[]];
+    this.readChunk_ = this.writeChunk_ = this.chunks_[0];
+    this.length_ = 0;
+  }
+
+  push(t: T): void {
+    this.writeChunk_.push(t);
+    this.length_ += 1;
+    if (this.writeChunk_.length === CHUNK_SIZE) {
+      this.writeChunk_ = [];
+      this.chunks_.push(this.writeChunk_);
+    }
+  }
+
+  front(): T | undefined {
+    if (this.length_ === 0) {
+      return undefined;
+    }
+    return this.readChunk_[0];
+  }
+
+  shift(): T | undefined {
+    if (this.length_ === 0) {
+      return undefined;
+    }
+    const t = this.readChunk_.shift();
+
+    this.length_ -= 1;
+    if (this.readChunk_.length === 0 && this.readChunk_ !== this.writeChunk_) {
+      this.chunks_.shift();
+      this.readChunk_ = this.chunks_[0];
+    }
+    return t;
+  }
+
+  get length(): number {
+    return this.length_;
+  }
+}