lib: FixedQueue add a benchmark

Author: gurgunday

benchmark/util/fixed-queue-oscillate.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const common = require('../common');
+
+// Oscillates the FixedQueue between N and N+1 segments repeatedly to
+// exercise the spare-segment reuse path: push k items to force a new segment,
+// then shift k items to empty one segment; repeat.
+const bench = common.createBenchmark(main, {
+  cycles: [5e3],
+}, { flags: ['--expose-internals'] });
+
+function main({ cycles }) {
+  const FixedQueue = require('internal/fixed_queue');
+  const q = new FixedQueue();
+  // Derive the internal segment size (kSize) from the current head.
+  const k = q.head.list.length;
+
+  bench.start();
+  for (let c = 0; c < cycles; c++) {
+    // Grow to N+1 by pushing k items: k-1 fills the current segment,
+    // the k-th push creates/uses the next segment.
+    for (let i = 0; i < k; i++) q.push(i);
+    // Shrink back to N by shifting k items: empties one segment and advances.
+    for (let i = 0; i < k; i++) q.shift();
+  }
+  // Report total operations (push + shift) to normalize throughput.
+  bench.end(cycles * 2 * k);
+}

benchmark/util/fixed-queue.js

@@ -0,0 +1,18 @@
+'use strict';
+
+const common = require('../common');
+
+const bench = common.createBenchmark(main, {
+  n: [1e5],
+}, { flags: ['--expose-internals'] });
+
+function main({ n }) {
+  const FixedQueue = require('internal/fixed_queue');
+  const queue = new FixedQueue();
+  bench.start();
+  for (let i = 0; i < n; i++)
+    queue.push(i);
+  for (let i = 0; i < n; i++)
+    queue.shift();
+  bench.end(n);
+}