adding iterator benches to tree-based maps for comparison purposes

Author: Gankra

src/libcollections/btree/map.rs

@@ -1145,9 +1145,12 @@ mod test {
 
 #[cfg(test)]
 mod bench {
-    use test::Bencher;
+    use std::prelude::*;
+    use std::rand::{weak_rng, Rng};
+    use test::{Bencher, black_box};
 
     use super::BTreeMap;
+    use MutableMap;
     use deque::bench::{insert_rand_n, insert_seq_n, find_rand_n, find_seq_n};
 
     #[bench]
@@ -1200,4 +1203,34 @@ mod bench {
         let mut m : BTreeMap<uint,uint> = BTreeMap::new();
         find_seq_n(10_000, &mut m, b);
     }
+
+    fn bench_iter(b: &mut Bencher, size: uint) {
+        let mut map = BTreeMap::<uint, uint>::new();
+        let mut rng = weak_rng();
+
+        for _ in range(0, size) {
+            map.swap(rng.gen(), rng.gen());
+        }
+
+        b.iter(|| {
+            for entry in map.iter() {
+                black_box(entry);
+            }
+        });
+    }
+
+    #[bench]
+    pub fn iter_20(b: &mut Bencher) {
+        bench_iter(b, 20);
+    }
+
+    #[bench]
+    pub fn iter_1000(b: &mut Bencher) {
+        bench_iter(b, 1000);
+    }
+
+    #[bench]
+    pub fn iter_100000(b: &mut Bencher) {
+        bench_iter(b, 100000);
+    }
 }

src/libcollections/treemap.rs

@@ -2232,9 +2232,12 @@ mod test_treemap {
 
 #[cfg(test)]
 mod bench {
-    use test::Bencher;
+    use std::prelude::*;
+    use std::rand::{weak_rng, Rng};
+    use test::{Bencher, black_box};
 
     use super::TreeMap;
+    use MutableMap;
     use deque::bench::{insert_rand_n, insert_seq_n, find_rand_n, find_seq_n};
 
     // Find seq
@@ -2288,6 +2291,36 @@ mod bench {
         let mut m : TreeMap<uint,uint> = TreeMap::new();
         find_seq_n(10_000, &mut m, b);
     }
+
+    fn bench_iter(b: &mut Bencher, size: uint) {
+        let mut map = TreeMap::<uint, uint>::new();
+        let mut rng = weak_rng();
+
+        for _ in range(0, size) {
+            map.swap(rng.gen(), rng.gen());
+        }
+
+        b.iter(|| {
+            for entry in map.iter() {
+                black_box(entry);
+            }
+        });
+    }
+
+    #[bench]
+    pub fn iter_20(b: &mut Bencher) {
+        bench_iter(b, 20);
+    }
+
+    #[bench]
+    pub fn iter_1000(b: &mut Bencher) {
+        bench_iter(b, 1000);
+    }
+
+    #[bench]
+    pub fn iter_100000(b: &mut Bencher) {
+        bench_iter(b, 100000);
+    }
 }
 
 #[cfg(test)]

src/libcollections/trie.rs

@@ -948,8 +948,8 @@ macro_rules! iterator_impl {
                 // rules, and are just manipulating raw pointers like there's no
                 // such thing as invalid pointers and memory unsafety. The
                 // reason is performance, without doing this we can get the
-                // bench_iter_large microbenchmark down to about 30000 ns/iter
-                // (using .unsafe_get to index self.stack directly, 38000
+                // (now replaced) bench_iter_large microbenchmark down to about
+                // 30000 ns/iter (using .unsafe_get to index self.stack directly, 38000
                 // ns/iter with [] checked indexing), but this smashes that down
                 // to 13500 ns/iter.
                 //
@@ -1458,31 +1458,39 @@ mod test_map {
 mod bench_map {
     use std::prelude::*;
     use std::rand::{weak_rng, Rng};
-    use test::Bencher;
+    use test::{Bencher, black_box};
 
     use MutableMap;
     use super::TrieMap;
 
-    #[bench]
-    fn bench_iter_small(b: &mut Bencher) {
-        let mut m = TrieMap::<uint>::new();
+    fn bench_iter(b: &mut Bencher, size: uint) {
+        let mut map = TrieMap::<uint>::new();
         let mut rng = weak_rng();
-        for _ in range(0u, 20) {
-            m.insert(rng.gen(), rng.gen());
+
+        for _ in range(0, size) {
+            map.swap(rng.gen(), rng.gen());
         }
 
-        b.iter(|| for _ in m.iter() {})
+        b.iter(|| {
+            for entry in map.iter() {
+                black_box(entry);
+            }
+        });
     }
 
     #[bench]
-    fn bench_iter_large(b: &mut Bencher) {
-        let mut m = TrieMap::<uint>::new();
-        let mut rng = weak_rng();
-        for _ in range(0u, 1000) {
-            m.insert(rng.gen(), rng.gen());
-        }
+    pub fn iter_20(b: &mut Bencher) {
+        bench_iter(b, 20);
+    }
 
-        b.iter(|| for _ in m.iter() {})
+    #[bench]
+    pub fn iter_1000(b: &mut Bencher) {
+        bench_iter(b, 1000);
+    }
+
+    #[bench]
+    pub fn iter_100000(b: &mut Bencher) {
+        bench_iter(b, 100000);
     }
 
     #[bench]