Add Equals() to mojom structs and related types.

BUG=

Review URL: https://codereview.chromium.org/649633003

Cr-Commit-Position: refs/heads/master@{#299614}

11 files changed, 214 insertions, 1 deletions

diff --git a/mojo/edk/mojo_edk.gyp b/mojo/edk/mojo_edk.gyp
index 98c493b..58dae52 100644
--- a/mojo/edk/mojo_edk.gyp
+++ b/mojo/edk/mojo_edk.gyp
@@ -85,6 +85,7 @@
         '../public/cpp/bindings/tests/buffer_unittest.cc',
         '../public/cpp/bindings/tests/connector_unittest.cc',
         '../public/cpp/bindings/tests/container_test_util.cc',
+        '../public/cpp/bindings/tests/equals_unittest.cc',
         '../public/cpp/bindings/tests/handle_passing_unittest.cc',
         '../public/cpp/bindings/tests/interface_ptr_unittest.cc',
         '../public/cpp/bindings/tests/map_unittest.cc',
diff --git a/mojo/public/cpp/bindings/array.h b/mojo/public/cpp/bindings/array.h
index 966cf31..2544abb 100644
--- a/mojo/public/cpp/bindings/array.h
+++ b/mojo/public/cpp/bindings/array.h
@@ -12,6 +12,7 @@
 #include <vector>
 
 #include "mojo/public/cpp/bindings/lib/array_internal.h"
+#include "mojo/public/cpp/bindings/lib/bindings_internal.h"
 #include "mojo/public/cpp/bindings/lib/template_util.h"
 #include "mojo/public/cpp/bindings/type_converter.h"
 
@@ -107,6 +108,18 @@ class Array {
     return result.Pass();
   }
 
+  bool Equals(const Array& other) const {
+    if (is_null() != other.is_null())
+      return false;
+    if (size() != other.size())
+      return false;
+    for (size_t i = 0; i < size(); ++i) {
+      if (!internal::ValueTraits<T>::Equals(at(i), other.at(i)))
+        return false;
+    }
+    return true;
+  }
+
  private:
   typedef std::vector<StorageType> Array::*Testable;
 
diff --git a/mojo/public/cpp/bindings/lib/bindings_internal.h b/mojo/public/cpp/bindings/lib/bindings_internal.h
index df3c620..ec70d37 100644
--- a/mojo/public/cpp/bindings/lib/bindings_internal.h
+++ b/mojo/public/cpp/bindings/lib/bindings_internal.h
@@ -12,6 +12,12 @@
 namespace mojo {
 class String;
 
+template <typename T>
+class Array;
+
+template <typename K, typename V>
+class Map;
+
 namespace internal {
 template <typename T>
 class Array_Data;
@@ -94,6 +100,29 @@ struct WrapperTraits<S, true> {
   typedef typename S::Data_* DataType;
 };
 
+template <typename T, typename Enable = void>
+struct ValueTraits {
+  static bool Equals(const T& a, const T& b) { return a == b; }
+};
+
+template <typename T>
+struct ValueTraits<
+    T,
+    typename EnableIf<IsSpecializationOf<Array, T>::value ||
+                      IsSpecializationOf<Map, T>::value ||
+                      IsSpecializationOf<StructPtr, T>::value ||
+                      IsSpecializationOf<InlinedStructPtr, T>::value>::type> {
+  static bool Equals(const T& a, const T& b) { return a.Equals(b); }
+};
+
+template <typename T>
+struct ValueTraits<ScopedHandleBase<T>> {
+  static bool Equals(const ScopedHandleBase<T>& a,
+                     const ScopedHandleBase<T>& b) {
+    return a.get().value() == b.get().value();
+  }
+};
+
 }  // namespace internal
 }  // namespace mojo
 
diff --git a/mojo/public/cpp/bindings/lib/map_internal.h b/mojo/public/cpp/bindings/lib/map_internal.h
index ce6e9d6..aa0fe7e 100644
--- a/mojo/public/cpp/bindings/lib/map_internal.h
+++ b/mojo/public/cpp/bindings/lib/map_internal.h
@@ -8,7 +8,7 @@
 #include <map>
 
 #include "mojo/public/cpp/bindings/array.h"
-#include "mojo/public/cpp/bindings/lib/bindings_internal.h"
+#include "mojo/public/cpp/bindings/lib/template_util.h"
 
 namespace mojo {
 namespace internal {
diff --git a/mojo/public/cpp/bindings/lib/template_util.h b/mojo/public/cpp/bindings/lib/template_util.h
index c4aeb43..6767acf 100644
--- a/mojo/public/cpp/bindings/lib/template_util.h
+++ b/mojo/public/cpp/bindings/lib/template_util.h
@@ -104,6 +104,15 @@ struct RemovePointer<T*> {
   typedef T type;
 };
 
+template <template <typename...> class Template, typename T>
+struct IsSpecializationOf : FalseType {};
+
+template <template <typename...> class Template, typename... Args>
+struct IsSpecializationOf<Template, Template<Args...>> : TrueType {};
+
+template <class A, class B>
+struct LogicalOr : IntegralConstant<bool, A::value || B::value> {};
+
 }  // namespace internal
 }  // namespace mojo
 
diff --git a/mojo/public/cpp/bindings/map.h b/mojo/public/cpp/bindings/map.h
index 0ee66fb..f09937a 100644
--- a/mojo/public/cpp/bindings/map.h
+++ b/mojo/public/cpp/bindings/map.h
@@ -117,6 +117,24 @@ class Map {
     return result.Pass();
   }
 
+  bool Equals(const Map& other) const {
+    if (is_null() != other.is_null())
+      return false;
+    if (size() != other.size())
+      return false;
+    auto i = begin();
+    auto j = other.begin();
+    while (i != end()) {
+      if (i.GetKey() != j.GetKey())
+        return false;
+      if (!internal::ValueTraits<Value>::Equals(i.GetValue(), j.GetValue()))
+        return false;
+      ++i;
+      ++j;
+    }
+    return true;
+  }
+
   class ConstMapIterator {
    public:
     ConstMapIterator(
diff --git a/mojo/public/cpp/bindings/struct_ptr.h b/mojo/public/cpp/bindings/struct_ptr.h
index 5d08364..efcf255 100644
--- a/mojo/public/cpp/bindings/struct_ptr.h
+++ b/mojo/public/cpp/bindings/struct_ptr.h
@@ -71,6 +71,12 @@ class StructPtr {
   // that it contains Mojo handles).
   StructPtr Clone() const { return is_null() ? StructPtr() : ptr_->Clone(); }
 
+  bool Equals(const StructPtr& other) const {
+    if (is_null() || other.is_null())
+      return is_null() && other.is_null();
+    return ptr_->Equals(*other.ptr_);
+  }
+
  private:
   typedef Struct* StructPtr::*Testable;
 
@@ -139,6 +145,11 @@ class InlinedStructPtr {
   InlinedStructPtr Clone() const {
     return is_null() ? InlinedStructPtr() : value_.Clone();
   }
+  bool Equals(const InlinedStructPtr& other) const {
+    if (is_null() || other.is_null())
+      return is_null() && other.is_null();
+    return value_.Equals(other.value_);
+  }
 
  private:
   typedef Struct InlinedStructPtr::*Testable;
diff --git a/mojo/public/cpp/bindings/tests/BUILD.gn b/mojo/public/cpp/bindings/tests/BUILD.gn
index 918a3db..9e6deab 100644
--- a/mojo/public/cpp/bindings/tests/BUILD.gn
+++ b/mojo/public/cpp/bindings/tests/BUILD.gn
@@ -10,6 +10,7 @@ test("mojo_public_bindings_unittests") {
     "buffer_unittest.cc",
     "connector_unittest.cc",
     "container_test_util.cc",
+    "equals_unittest.cc",
     "handle_passing_unittest.cc",
     "interface_ptr_unittest.cc",
     "map_unittest.cc",
diff --git a/mojo/public/cpp/bindings/tests/equals_unittest.cc b/mojo/public/cpp/bindings/tests/equals_unittest.cc
new file mode 100644
index 0000000..38c78cb
--- /dev/null
+++ b/mojo/public/cpp/bindings/tests/equals_unittest.cc
@@ -0,0 +1,120 @@
+// Copyright 2014 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 "mojo/public/cpp/environment/environment.h"
+#include "mojo/public/interfaces/bindings/tests/test_structs.mojom.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace test {
+
+namespace {
+
+RectPtr CreateRect() {
+  RectPtr r = Rect::New();
+  r->x = 1;
+  r->y = 2;
+  r->width = 3;
+  r->height = 4;
+  return r.Pass();
+}
+
+class EqualsTest : public testing::Test {
+ public:
+  virtual ~EqualsTest() {}
+
+ private:
+  Environment env_;
+};
+}
+
+TEST_F(EqualsTest, Null) {
+  RectPtr r1;
+  RectPtr r2;
+  EXPECT_TRUE(r1.Equals(r2));
+  EXPECT_TRUE(r2.Equals(r1));
+
+  r1 = CreateRect();
+  EXPECT_FALSE(r1.Equals(r2));
+  EXPECT_FALSE(r2.Equals(r1));
+}
+
+TEST_F(EqualsTest, EqualsStruct) {
+  RectPtr r1(CreateRect());
+  RectPtr r2(r1.Clone());
+  EXPECT_TRUE(r1.Equals(r2));
+  r2->y = 1;
+  EXPECT_FALSE(r1.Equals(r2));
+  r2.reset();
+  EXPECT_FALSE(r1.Equals(r2));
+}
+
+TEST_F(EqualsTest, EqualsStructNested) {
+  RectPairPtr p1(RectPair::New());
+  p1->first = CreateRect();
+  p1->second = CreateRect();
+  RectPairPtr p2(p1.Clone());
+  EXPECT_TRUE(p1.Equals(p2));
+  p2->second->width = 0;
+  EXPECT_FALSE(p1.Equals(p2));
+  p2->second.reset();
+  EXPECT_FALSE(p1.Equals(p2));
+}
+
+TEST_F(EqualsTest, EqualsArray) {
+  NamedRegionPtr n1(NamedRegion::New());
+  n1->name = "n1";
+  n1->rects.push_back(CreateRect());
+  NamedRegionPtr n2(n1.Clone());
+  EXPECT_TRUE(n1.Equals(n2));
+
+  n2->rects.reset();
+  EXPECT_FALSE(n1.Equals(n2));
+  n2->rects.resize(0);
+  EXPECT_FALSE(n1.Equals(n2));
+
+  n2->rects.push_back(CreateRect());
+  n2->rects.push_back(CreateRect());
+  EXPECT_FALSE(n1.Equals(n2));
+
+  n2->rects.resize(1);
+  n2->rects[0]->width = 0;
+  EXPECT_FALSE(n1.Equals(n2));
+
+  n2->rects[0] = CreateRect();
+  EXPECT_TRUE(n1.Equals(n2));
+}
+
+TEST_F(EqualsTest, EqualsMap) {
+  auto n1(NamedRegion::New());
+  n1->name = "foo";
+  n1->rects.push_back(CreateRect());
+
+  Map<std::string, NamedRegionPtr> m1;
+  m1.insert("foo", n1.Pass());
+
+  decltype(m1) m2;
+  EXPECT_FALSE(m1.Equals(m2));
+
+  m2.insert("bar", m1.at("foo").Clone());
+  EXPECT_FALSE(m1.Equals(m2));
+
+  m2 = m1.Clone();
+  m2.at("foo")->name = "monkey";
+  EXPECT_FALSE(m1.Equals(m2));
+
+  m2 = m1.Clone();
+  m2.at("foo")->rects.push_back(Rect::New());
+  EXPECT_FALSE(m1.Equals(m2));
+
+  m2.at("foo")->rects.resize(1);
+  m2.at("foo")->rects[0]->width = 1;
+  EXPECT_FALSE(m1.Equals(m2));
+
+  m2 = m1.Clone();
+  EXPECT_TRUE(m1.Equals(m2));
+}
+
+}  // test
+}  // mojo
diff --git a/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl b/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
index 21f2968..f6bea2c 100644
--- a/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
+++ b/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
@@ -21,9 +21,11 @@ class {{struct.name}} {
 
   {{struct.name}}();
   ~{{struct.name}}();
+
 {%  if struct|is_cloneable_kind %}
   {{struct.name}}Ptr Clone() const;
 {%- endif %}
+  bool Equals(const {{struct.name}}& other) const;
 
 {#--- Getters #}
 {%  for field in struct.fields %}
diff --git a/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_definition.tmpl b/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_definition.tmpl
index 1ba7235..cb5a5fa 100644
--- a/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_definition.tmpl
+++ b/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_definition.tmpl
@@ -13,6 +13,7 @@
 
 {{struct.name}}::~{{struct.name}}() {
 }
+
 {%  if struct|is_cloneable_kind %}
 {{struct.name}}Ptr {{struct.name}}::Clone() const {
   {{struct.name}}Ptr rv(New());
@@ -26,3 +27,11 @@
   return rv.Pass();
 }
 {%  endif %}
+
+bool {{struct.name}}::Equals(const {{struct.name}}& other) const {
+{%-  for field in struct.fields %}
+  if (!mojo::internal::ValueTraits<{{field.kind|cpp_wrapper_type}}>::Equals({{field.name}}, other.{{field.name}}))
+    return false;
+{%-  endfor %}
+  return true;
+}