1 files changed, 88 insertions, 0 deletions
diff --git a/benches/stack.rs b/benches/stack.rs
new file mode 100644
index 0000000..59efae5
--- /dev/null
+++ b/benches/stack.rs
@@ -0,0 +1,88 @@
+// pest. The Elegant Parser
+// Copyright (c) 2018 Dragoș Tiselice
+//
+// Licensed under the Apache License, Version 2.0
+// <LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0> or the MIT
+// license <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. All files in the project carrying such notice may not be copied,
+// modified, or distributed except according to those terms.
+
+use criterion::{criterion_group, criterion_main, Criterion};
+use pest::Stack;
+
+fn snapshot_push_restore<T: Clone>(elements: impl Iterator<Item = T> + Clone) {
+    let mut stack = Stack::<T>::new();
+    for elem in elements {
+        stack.snapshot();
+        stack.push(elem.clone());
+        stack.restore();
+        stack.push(elem);
+    }
+}
+
+fn snapshot_push_clear_snapshot<T: Clone>(elements: impl Iterator<Item = T> + Clone) {
+    let mut stack = Stack::<T>::new();
+    for elem in elements {
+        stack.snapshot();
+        stack.push(elem);
+        stack.clear_snapshot();
+    }
+}
+
+fn snapshot_pop_restore<T: Clone>(elements: impl Iterator<Item = T>) {
+    let mut stack = Stack::<T>::new();
+    for elem in elements {
+        stack.push(elem);
+    }
+    while !stack.is_empty() {
+        stack.snapshot();
+        stack.pop();
+        stack.restore();
+        stack.pop();
+    }
+}
+
+fn snapshot_pop_clear<T: Clone>(elements: impl Iterator<Item = T>) {
+    let mut stack = Stack::<T>::new();
+    for elem in elements {
+        stack.push(elem);
+    }
+    while !stack.is_empty() {
+        stack.snapshot();
+        stack.pop();
+        stack.clear_snapshot();
+    }
+}
+
+fn benchmark(b: &mut Criterion) {
+    use core::iter::repeat;
+    // use criterion::black_box;
+    let times = 10000usize;
+    let small = 0..times;
+    let medium = ("", 0usize, 1usize);
+    let medium = repeat(medium).take(times);
+    let large = [""; 64];
+    let large = repeat(large).take(times);
+    macro_rules! test_series {
+        ($kind:ident) => {
+            b.bench_function(stringify!(push - restore - $kind), |b| {
+                b.iter(|| snapshot_push_restore($kind.clone()))
+            })
+            .bench_function(stringify!(push - clear - $kind), |b| {
+                b.iter(|| snapshot_push_clear_snapshot($kind.clone()))
+            })
+            .bench_function(stringify!(pop - restore - $kind), |b| {
+                b.iter(|| snapshot_pop_restore($kind.clone()))
+            })
+            .bench_function(stringify!(pop - clear - $kind), |b| {
+                b.iter(|| snapshot_pop_clear($kind.clone()))
+            })
+        };
+    }
+    test_series!(small);
+    test_series!(medium);
+    test_series!(large);
+}
+
+criterion_group!(benchmarks, benchmark);
+criterion_main!(benchmarks);