Function-type templated CallbackRegistry

base/callback_registry_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/callback_registry.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace {
 
 class Listener {
  public:
   Listener() : total_(0), scaler_(1) {}
   explicit Listener(int scaler) : total_(0), scaler_(scaler) {}
   void IncrementTotal() { total_++; }
-  void IncrementByMultipleOfScaler(const int& x) { total_ += x * scaler_; }
+  void IncrementByMultipleOfScaler(int x) { total_ += x * scaler_; }
 
   int total_;
 
  private:
   int scaler_;
   DISALLOW_COPY_AND_ASSIGN(Listener);
 };
 
 class Remover {
  public:
   Remover() : total_(0) {}
   void IncrementTotalAndRemove() {
     total_++;
     removal_subscription_.reset();
   }
   void SetSubscriptionToRemove(
-      scoped_ptr<CallbackRegistry<void>::Subscription> sub) {
+      scoped_ptr<CallbackRegistry<void(void)>::Subscription> sub) {
     removal_subscription_ = sub.Pass();
   }
 
   int total_;
 
  private:
-  scoped_ptr<CallbackRegistry<void>::Subscription> removal_subscription_;
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> removal_subscription_;
   DISALLOW_COPY_AND_ASSIGN(Remover);
 };
 
 class Adder {
  public:
-  explicit Adder(CallbackRegistry<void>* cb_reg)
+  explicit Adder(CallbackRegistry<void(void)>* cb_reg)
       : added_(false),
         total_(0),
         cb_reg_(cb_reg) {}
   void AddCallback() {
     if (!added_) {
       added_ = true;
       subscription_ =
           cb_reg_->Add(Bind(&Adder::IncrementTotal, Unretained(this)));
     }
   }
   void IncrementTotal() { total_++; }
 
   bool added_;
   int total_;
 
  private:
-  CallbackRegistry<void>* cb_reg_;
-  scoped_ptr<CallbackRegistry<void>::Subscription> subscription_;
+  CallbackRegistry<void(void)>* cb_reg_;
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> subscription_;
   DISALLOW_COPY_AND_ASSIGN(Adder);
 };
 
+class Summer {
+ public:
+  Summer() : value_(0) {}
+
+  void AddOneParam(int a) { value_ = a; }
+  void AddTwoParam(int a, int b) { value_ = a + b; }
+  void AddThreeParam(int a, int b, int c) { value_ = a + b + c; }
+  void AddFourParam(int a, int b, int c, int d) { value_ = a + b + c + d; }
+  void AddFiveParam(int a, int b, int c, int d, int e) {
+    value_ = a + b + c + d + e;
+  }
+  void AddSixParam(int a, int b, int c, int d, int e , int f) {
+    value_ = a + b + c + d + e + f;
+  }
+
+  int value_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Summer);
+};
+
+// Sanity check that we can instantiate a CallbackRegistry for each arity.
+TEST(CallbackRegistryTest, ArityTest) {
+  Summer s;
+
+  CallbackRegistry<void(int)> c1;
+  scoped_ptr<CallbackRegistry<void(int)>::Subscription> subscription1 =
+      c1.Add(Bind(&Summer::AddOneParam, Unretained(&s)));
+
+  c1.Notify(1);
+  EXPECT_EQ(1, s.value_);
+
+  CallbackRegistry<void(int, int)> c2;
+  scoped_ptr<CallbackRegistry<void(int, int)>::Subscription> subscription2 =
+      c2.Add(Bind(&Summer::AddTwoParam, Unretained(&s)));
+
+  c2.Notify(1, 2);
+  EXPECT_EQ(3, s.value_);
+
+  CallbackRegistry<void(int, int, int)> c3;
+  scoped_ptr<CallbackRegistry<void(int, int, int)>::Subscription>
+      subscription3 = c3.Add(Bind(&Summer::AddThreeParam, Unretained(&s)));
+
+  c3.Notify(1, 2, 3);
+  EXPECT_EQ(6, s.value_);
+
+  CallbackRegistry<void(int, int, int, int)> c4;
+  scoped_ptr<CallbackRegistry<void(int, int, int, int)>::Subscription>
+      subscription4 = c4.Add(Bind(&Summer::AddFourParam, Unretained(&s)));
+
+  c4.Notify(1, 2, 3, 4);
+  EXPECT_EQ(10, s.value_);
+
+  CallbackRegistry<void(int, int, int, int, int)> c5;
+  scoped_ptr<CallbackRegistry<void(int, int, int, int, int)>::Subscription>
+      subscription5 = c5.Add(Bind(&Summer::AddFiveParam, Unretained(&s)));
+
+  c5.Notify(1, 2, 3, 4, 5);
+  EXPECT_EQ(15, s.value_);
+
+  CallbackRegistry<void(int, int, int, int, int, int)> c6;
+  scoped_ptr<CallbackRegistry<void(int, int, int, int, int, int)>::Subscription>
+      subscription6 = c6.Add(Bind(&Summer::AddSixParam, Unretained(&s)));
+
+  c6.Notify(1, 2, 3, 4, 5, 6);
+  EXPECT_EQ(21, s.value_);
+}
+
 // Sanity check that closures added to the list will be run, and those removed
 // from the list will not be run.
 TEST(CallbackRegistryTest, BasicTest) {
-  CallbackRegistry<void> cb_reg;
+  CallbackRegistry<void(void)> cb_reg;
   Listener a, b, c;
 
-  scoped_ptr<CallbackRegistry<void>::Subscription> a_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> a_subscription =
       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&a)));
-  scoped_ptr<CallbackRegistry<void>::Subscription> b_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> b_subscription =
       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&b)));
 
   EXPECT_TRUE(a_subscription.get());
   EXPECT_TRUE(b_subscription.get());
 
   cb_reg.Notify();
 
   EXPECT_EQ(1, a.total_);
   EXPECT_EQ(1, b.total_);
 
   b_subscription.reset();
 
-  scoped_ptr<CallbackRegistry<void>::Subscription> c_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> c_subscription =
       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&c)));
 
   cb_reg.Notify();
 
   EXPECT_EQ(2, a.total_);
   EXPECT_EQ(1, b.total_);
   EXPECT_EQ(1, c.total_);
 
   a_subscription.reset();
   b_subscription.reset();
   c_subscription.reset();
 }
 
 // Sanity check that callbacks with details added to the list will be run, with
 // the correct details, and those removed from the list will not be run.
 TEST(CallbackRegistryTest, BasicTestWithParams) {
-  CallbackRegistry<int> cb_reg;
+  CallbackRegistry<void(int)> cb_reg;
   Listener a(1), b(-1), c(1);
 
-  scoped_ptr<CallbackRegistry<int>::Subscription> a_subscription =
+  scoped_ptr<CallbackRegistry<void(int)>::Subscription> a_subscription =
       cb_reg.Add(Bind(&Listener::IncrementByMultipleOfScaler, Unretained(&a)));
-  scoped_ptr<CallbackRegistry<int>::Subscription> b_subscription =
+  scoped_ptr<CallbackRegistry<void(int)>::Subscription> b_subscription =
       cb_reg.Add(Bind(&Listener::IncrementByMultipleOfScaler, Unretained(&b)));
 
   EXPECT_TRUE(a_subscription.get());
   EXPECT_TRUE(b_subscription.get());
 
   cb_reg.Notify(10);
 
   EXPECT_EQ(10, a.total_);
   EXPECT_EQ(-10, b.total_);
 
   b_subscription.reset();
 
-  scoped_ptr<CallbackRegistry<int>::Subscription> c_subscription =
+  scoped_ptr<CallbackRegistry<void(int)>::Subscription> c_subscription =
       cb_reg.Add(Bind(&Listener::IncrementByMultipleOfScaler, Unretained(&c)));
 
   cb_reg.Notify(10);
 
   EXPECT_EQ(20, a.total_);
   EXPECT_EQ(-10, b.total_);
   EXPECT_EQ(10, c.total_);
 
   a_subscription.reset();
   b_subscription.reset();
   c_subscription.reset();
 }
 
 // Test the a callback can remove itself or a different callback from the list
 // during iteration without invalidating the iterator.
 TEST(CallbackRegistryTest, RemoveCallbacksDuringIteration) {
-  CallbackRegistry<void> cb_reg;
+  CallbackRegistry<void(void)> cb_reg;
   Listener a, b;
   Remover remover_1, remover_2;
 
-  scoped_ptr<CallbackRegistry<void>::Subscription> remover_1_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> remover_1_sub =
       cb_reg.Add(Bind(&Remover::IncrementTotalAndRemove,
           Unretained(&remover_1)));
-  scoped_ptr<CallbackRegistry<void>::Subscription> remover_2_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> remover_2_sub =
       cb_reg.Add(Bind(&Remover::IncrementTotalAndRemove,
           Unretained(&remover_2)));
-  scoped_ptr<CallbackRegistry<void>::Subscription> a_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> a_subscription =
       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&a)));
-  scoped_ptr<CallbackRegistry<void>::Subscription> b_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> b_subscription =
       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&b)));
 
   // |remover_1| will remove itself.
-  remover_1.SetSubscriptionToRemove(remover_1_subscription.Pass());
+  remover_1.SetSubscriptionToRemove(remover_1_sub.Pass());
   // |remover_2| will remove a.
   remover_2.SetSubscriptionToRemove(a_subscription.Pass());
 
   cb_reg.Notify();
 
   // |remover_1| runs once (and removes itself), |remover_2| runs once (and
   // removes a), |a| never runs, and |b| runs once.
   EXPECT_EQ(1, remover_1.total_);
   EXPECT_EQ(1, remover_2.total_);
   EXPECT_EQ(0, a.total_);
   EXPECT_EQ(1, b.total_);
 
   cb_reg.Notify();
 
   // Only |remover_2| and |b| run this time.
   EXPECT_EQ(1, remover_1.total_);
   EXPECT_EQ(2, remover_2.total_);
   EXPECT_EQ(0, a.total_);
   EXPECT_EQ(2, b.total_);
 }
 
 // Test that a callback can add another callback to the list durning iteration
 // without invalidating the iterator. The newly added callback should be run on
 // the current iteration as will all other callbacks in the list.
 TEST(CallbackRegistryTest, AddCallbacksDuringIteration) {
-  CallbackRegistry<void> cb_reg;
+  CallbackRegistry<void(void)> cb_reg;
   Adder a(&cb_reg);
   Listener b;
-  scoped_ptr<CallbackRegistry<void>::Subscription> a_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> a_subscription =
       cb_reg.Add(Bind(&Adder::AddCallback, Unretained(&a)));
-  scoped_ptr<CallbackRegistry<void>::Subscription> b_subscription =
+  scoped_ptr<CallbackRegistry<void(void)>::Subscription> b_subscription =
       cb_reg.Add(Bind(&Listener::IncrementTotal, Unretained(&b)));
 
   cb_reg.Notify();
 
   EXPECT_EQ(1, a.total_);
   EXPECT_EQ(1, b.total_);
   EXPECT_TRUE(a.added_);
 
   cb_reg.Notify();
 
   EXPECT_EQ(2, a.total_);
   EXPECT_EQ(2, b.total_);
 }
 
 // Sanity check: notifying an empty list is a no-op.
 TEST(CallbackRegistryTest, EmptyList) {
-  CallbackRegistry<void> cb_reg;
+  CallbackRegistry<void(void)> cb_reg;
 
   cb_reg.Notify();
 }
 
 }  // namespace
 }  // namespace base