[benchmark] Add DictionaryRemoveOfObjects

Another dictionary benchmark with objects as key and value types.

Author: aschwaighofer

benchmark/single-source/DictionaryRemove.swift

@@ -41,3 +41,50 @@ public func run_DictionaryRemove(N: Int) {
     CheckResults(tmpDict.isEmpty,
                  "tmpDict should be empty: \(tmpDict.count) != 0.")
 }
+
+class Box<T : Hashable where T : Equatable> : Hashable {
+  var value: T
+
+  init(_ v: T) {
+    value = v
+  }
+
+  var hashValue : Int {
+    return value.hashValue
+  }
+}
+
+extension Box : Equatable {
+}
+
+func ==<T: Equatable>(lhs: Box<T>,  rhs: Box<T>) -> Bool {
+  return lhs.value == rhs.value
+}
+
+@inline(never)
+public func run_DictionaryRemoveOfObjects(N: Int) {
+    let size = 100
+    var dict = Dictionary<Box<Int>, Box<Int>>(minimumCapacity: size)
+
+    // Fill dictionary
+    for i in 1...size {
+        dict[Box(i)] = Box(i)
+    }
+    CheckResults(dict.count == size,
+                 "Incorrect dict count: \(dict.count) != \(size).")
+
+    var tmpDict = dict
+    for _ in 1...1000*N {
+        tmpDict = dict
+        // Empty dictionary
+        for i in 1...size {
+            tmpDict.removeValue(forKey: Box(i))
+        }
+        if !tmpDict.isEmpty {
+            break
+        }
+    }
+
+    CheckResults(tmpDict.isEmpty,
+                 "tmpDict should be empty: \(tmpDict.count) != 0.")
+}

benchmark/utils/main.swift

@@ -127,6 +127,7 @@ precommitTests = [
   "DictionaryBridge": run_DictionaryBridge,
   "DictionaryLiteral": run_DictionaryLiteral,
   "DictionaryRemove": run_DictionaryRemove,
+  "DictionaryRemoveOfObjects": run_DictionaryRemoveOfObjects,
   "DictionarySwap": run_DictionarySwap,
   "ErrorHandling": run_ErrorHandling,
   "GlobalClass": run_GlobalClass,