Auto merge of #31 - nipunn1313:bench, r=jdm

Add benchmarks for push, insert, extend, and pushpop

Want to add these benchmarks so that we can more effectively detect regressions/improvements from PR's like #28 and #29.

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Author: bors-servo

.travis.yml

@@ -3,5 +3,10 @@ rust:
   - nightly
   - beta
   - stable
+script: |
+  cargo build --verbose &&
+  cargo test --verbose &&
+  ([ $TRAVIS_RUST_VERSION != nightly ] || cargo test --verbose --features benchmarks) &&
+  ([ $TRAVIS_RUST_VERSION != nightly ] || cargo bench --verbose --features benchmarks bench)
 notifications:
   webhooks: http://build.servo.org:54856/travis

Cargo.toml

@@ -13,3 +13,6 @@ documentation = "http://doc.servo.org/smallvec/"
 name = "smallvec"
 path = "lib.rs"
 doctest = false
+
+[features]
+benchmarks = []

lib.rs

@@ -5,6 +5,8 @@
 //! Small vectors in various sizes. These store a certain number of elements inline and fall back
 //! to the heap for larger allocations.
 
+#![cfg_attr(feature = "benchmarks", feature(test))]
+
 use std::borrow::{Borrow, BorrowMut};
 use std::cmp;
 use std::fmt;
@@ -1008,3 +1010,53 @@ pub mod tests {
         assert_eq!(vec.drain().len(), 3);
     }
 }
+
+#[cfg(all(feature = "benchmarks", test))]
+mod bench {
+    extern crate test;
+    use SmallVec;
+    use self::test::Bencher;
+
+    #[bench]
+    fn bench_push(b: &mut Bencher) {
+        b.iter(|| {
+            let mut vec: SmallVec<[u64; 16]> = SmallVec::new();
+            for x in 0..100 {
+                vec.push(x);
+            }
+            vec
+        });
+    }
+
+    #[bench]
+    fn bench_insert(b: &mut Bencher) {
+        b.iter(|| {
+            let mut vec: SmallVec<[u64; 16]> = SmallVec::new();
+            for x in 0..100 {
+                vec.insert(0, x);
+            }
+            vec
+        });
+    }
+
+    #[bench]
+    fn bench_extend(b: &mut Bencher) {
+        b.iter(|| {
+            let mut vec: SmallVec<[u64; 16]> = SmallVec::new();
+            vec.extend(0..100);
+            vec
+        });
+    }
+
+    #[bench]
+    fn bench_pushpop(b: &mut Bencher) {
+        b.iter(|| {
+            let mut vec: SmallVec<[u64; 16]> = SmallVec::new();
+            for x in 0..100 {
+                vec.push(x);
+                vec.pop();
+            }
+            vec
+        });
+    }
+}