Merge pull request #78 from sfackler/master

Implement HeapSizeOf for LinkedHashMap

Author: Gankra

.travis.yml

@@ -3,9 +3,9 @@ sudo: false
 matrix:
     include:
         - rust: beta
-          env: FEATURES="serde_impl"
+          env: FEATURES="serde_impl heapsize_impl"
         - rust: nightly
-          env: FEATURES="serde_impl nightly clippy"
+          env: FEATURES="serde_impl nightly clippy heapsize_impl"
         - rust: stable
 script:
     - cargo build --features "$FEATURES"

Cargo.toml

@@ -18,8 +18,10 @@ readme = "README.md"
 [features]
 nightly = []
 serde_impl = ["serde", "serde_test"]
+heapsize_impl = ["heapsize"]
 
 [dependencies]
 clippy = { version = "0.*", optional = true }
 serde = { version = "0.9", optional = true }
 serde_test = { version = "0.9", optional = true }
+heapsize = { version = "0.3.9", optional = true }

src/heapsize.rs

@@ -0,0 +1,49 @@
+extern crate heapsize;
+
+use self::heapsize::{HeapSizeOf, heap_size_of};
+use std::hash::{Hash, BuildHasher};
+
+use {LinkedHashMap, KeyRef, Node};
+
+impl<K> HeapSizeOf for KeyRef<K> {
+    fn heap_size_of_children(&self) -> usize {
+        0
+    }
+}
+
+impl<K, V> HeapSizeOf for Node<K, V>
+    where K: HeapSizeOf,
+          V: HeapSizeOf
+{
+    fn heap_size_of_children(&self) -> usize {
+        self.key.heap_size_of_children() + self.value.heap_size_of_children()
+    }
+}
+
+impl<K, V, S> HeapSizeOf for LinkedHashMap<K, V, S>
+    where K: HeapSizeOf + Hash + Eq,
+          V: HeapSizeOf,
+          S: BuildHasher
+{
+    fn heap_size_of_children(&self) -> usize {
+        unsafe {
+            let mut size = self.map.heap_size_of_children();
+            for &value in self.map.values() {
+                size += (*value).heap_size_of_children();
+                size += heap_size_of(value as *const _ as *const _);
+            }
+
+            if !self.head.is_null() {
+                size += heap_size_of(self.head as *const _ as *const _);
+            }
+
+            let mut free = self.free;
+            while !free.is_null() {
+                size += heap_size_of(free as *const _ as *const _);
+                free = (*free).next
+            }
+
+            size
+        }
+    }
+}

src/lib.rs

@@ -37,6 +37,9 @@
 // Optional Serde support
 #[cfg(feature = "serde_impl")]
 pub mod serde;
+// Optional Heapsize support
+#[cfg(feature = "heapsize_impl")]
+mod heapsize;
 
 use std::borrow::Borrow;
 use std::cmp::Ordering;

tests/heapsize.rs

@@ -0,0 +1,23 @@
+#![cfg(feature = "heapsize_impl")]
+
+extern crate heapsize;
+extern crate linked_hash_map;
+
+use linked_hash_map::LinkedHashMap;
+use heapsize::HeapSizeOf;
+
+#[test]
+fn empty() {
+    assert_eq!(LinkedHashMap::<String, String>::new().heap_size_of_children(), 0);
+}
+
+#[test]
+fn nonempty() {
+    let mut map = LinkedHashMap::new();
+    map.insert("hello".to_string(), "world".to_string());
+    map.insert("hola".to_string(), "mundo".to_string());
+    map.insert("bonjour".to_string(), "monde".to_string());
+    map.remove("hello");
+
+    assert!(map.heap_size_of_children() != 0);
+}