Slightly faster hash.

Author: itamarst

Cargo.lock

@@ -10,6 +10,7 @@ edition = "2018"
 libc = "0.2"
 itertools = "0.8.2"
 lazy_static = "1.4.0"
+rustc-hash = "1.0.1"
 
 [dependencies.inferno]
 version = "0.9.4"

memapi/Cargo.toml

@@ -1,6 +1,7 @@
 use inferno::flamegraph;
 use itertools::Itertools;
 use libc;
+use rustc_hash;
 use std::cell::RefCell;
 use std::collections;
 use std::sync::Mutex;
@@ -43,17 +44,17 @@ struct Allocation {
 }
 
 struct AllocationTracker {
-    current_allocations: collections::HashMap<usize, Allocation>,
-    peak_allocations: collections::HashMap<usize, Allocation>,
+    current_allocations: rustc_hash::FxHashMap<usize, Allocation>,
+    peak_allocations: rustc_hash::FxHashMap<usize, Allocation>,
     current_allocated_bytes: usize,
     peak_allocated_bytes: usize,
 }
 
 impl AllocationTracker {
     fn new() -> AllocationTracker {
         AllocationTracker {
-            current_allocations: collections::HashMap::default(),
-            peak_allocations: collections::HashMap::default(),
+            current_allocations: rustc_hash::FxHashMap::default(),
+            peak_allocations: rustc_hash::FxHashMap::default(),
             current_allocated_bytes: 0,
             peak_allocated_bytes: 0,
         }