Add example usages and tests to scoped_ptr.h and tuple.h.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@1305 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 346 insertions, 5 deletions

diff --git a/base/SConscript b/base/SConscript
index e6723e7..e5682ca2 100644
--- a/base/SConscript
+++ b/base/SConscript
@@ -254,6 +254,7 @@ test_files = [
     'pr_time_test.cc',
     'ref_counted_unittest.cc',
     'run_all_unittests.cc',
+    'scoped_ptr_unittest.cc',
     'sha2_unittest.cc',
     'singleton_unittest.cc',
     'stack_container_unittest.cc',
@@ -264,6 +265,7 @@ test_files = [
     'thread_unittest.cc',
     'time_unittest.cc',
     'tracked_objects_test.cc',
+    'tuple_unittest.cc',
     'values_unittest.cc',
     'waitable_event_unittest.cc',
     'word_iterator_unittest.cc',
diff --git a/base/build/base_unittests.vcproj b/base/build/base_unittests.vcproj
index fa32036..8eb9a94 100644
--- a/base/build/base_unittests.vcproj
+++ b/base/build/base_unittests.vcproj
@@ -252,6 +252,10 @@
 				>
 			</File>
 			<File
+				RelativePath="..\scoped_ptr_unittest.cc"
+				>
+			</File>
+			<File
 				RelativePath="..\sha2_unittest.cc"
 				>
 			</File>
@@ -316,6 +320,10 @@
 				>
 			</File>
 			<File
+				RelativePath="..\tuple_unittest.cc"
+				>
+			</File>
+			<File
 				RelativePath="..\values_unittest.cc"
 				>
 			</File>
diff --git a/base/scoped_ptr.h b/base/scoped_ptr.h
index 3abaec8..4489f2da 100644
--- a/base/scoped_ptr.h
+++ b/base/scoped_ptr.h
@@ -1,10 +1,40 @@
 // Copyright (c) 2006-2008 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.
-// All Rights Reserved.
 
-#ifndef BASE_SCOPED_PTR_H__
-#define BASE_SCOPED_PTR_H__
+// Scopers help you manage ownership of a pointer, helping you easily manage the
+// a pointer within a scope, and automatically destroying the pointer at the
+// end of a scope.  There are two main classes you will use, which coorespond
+// to the operators new/delete and new[]/delete[].
+//
+// Example usage (scoped_ptr):
+//   {
+//     scoped_ptr<Foo> foo(new Foo("wee"));
+//   }  // foo goes out of scope, releasing the pointer with it.
+//
+//   {
+//     scoped_ptr<Foo> foo;          // No pointer managed.
+//     foo.reset(new Foo("wee"));    // Now a pointer is managed.
+//     foo.reset(new Foo("wee2"));   // Foo("wee") was destroyed.
+//     foo.reset(new Foo("wee3"));   // Foo("wee2") was destroyed.
+//     foo->Method();                // Foo::Method() called.
+//     foo.get()->Method();          // Foo::Method() called.
+//     SomeFunc(foo.Release());      // SomeFunc takes owernship, foo no longer
+//                                   // manages a pointer.
+//     foo.reset(new Foo("wee4"));   // foo manages a pointer again.
+//     foo.reset();                  // Foo("wee4") destroyed, foo no longer
+//                                   // manages a pointer.
+//   }  // foo wasn't managing a pointer, so nothing was destroyed.
+//
+// Example usage (scoped_array):
+//   {
+//     scoped_array<Foo> foo(new Foo[100]);
+//     foo.get()->Method();  // Foo::Method on the 0th element.
+//     foo[10].Method();     // Foo::Method on the 10th element.
+//   }
+
+#ifndef BASE_SCOPED_PTR_H_
+#define BASE_SCOPED_PTR_H_
 
 // This is an implementation designed to match the anticipated future TR2
 // implementation of the scoped_ptr class, and its closely-related brethren,
@@ -347,5 +377,4 @@ bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
   return p != b.get();
 }
 
-#endif  // BASE_SCOPED_PTR_H__
-
+#endif  // BASE_SCOPED_PTR_H_
diff --git a/base/scoped_ptr_unittest.cc b/base/scoped_ptr_unittest.cc
new file mode 100644
index 0000000..9ea2289
--- /dev/null
+++ b/base/scoped_ptr_unittest.cc
@@ -0,0 +1,169 @@
+// Copyright (c) 2006-2008 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/basictypes.h"
+#include "base/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class ConDecLogger {
+ public:
+  ConDecLogger() : ptr_(NULL) { }
+  explicit ConDecLogger(int* ptr) { set_ptr(ptr); }
+  ~ConDecLogger() { --*ptr_; }
+
+  void set_ptr(int* ptr) { ptr_ = ptr; ++*ptr_; }
+
+  int SomeMeth(int x) { return x; }
+
+ private:
+  int* ptr_;
+  DISALLOW_COPY_AND_ASSIGN(ConDecLogger);
+};
+
+}  // namespace
+
+TEST(ScopedPtrTest, ScopedPtr) {
+  int constructed = 0;
+
+  {
+    scoped_ptr<ConDecLogger> scoper(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    EXPECT_EQ(10, scoper->SomeMeth(10));
+    EXPECT_EQ(10, scoper.get()->SomeMeth(10));
+    EXPECT_EQ(10, (*scoper).SomeMeth(10));
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test reset() and release()
+  {
+    scoped_ptr<ConDecLogger> scoper(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    scoper.reset(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    scoper.reset();
+    EXPECT_EQ(0, constructed);
+    EXPECT_FALSE(scoper.get());
+
+    scoper.reset(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    ConDecLogger* take = scoper.release();
+    EXPECT_EQ(1, constructed);
+    EXPECT_FALSE(scoper.get());
+    delete take;
+    EXPECT_EQ(0, constructed);
+
+    scoper.reset(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test swap(), == and !=
+  {
+    scoped_ptr<ConDecLogger> scoper1;
+    scoped_ptr<ConDecLogger> scoper2;
+    EXPECT_TRUE(scoper1 == scoper2.get());
+    EXPECT_FALSE(scoper1 != scoper2.get());
+
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    scoper1.reset(logger);
+    EXPECT_EQ(logger, scoper1.get());
+    EXPECT_FALSE(scoper2.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+
+    scoper2.swap(scoper1);
+    EXPECT_EQ(logger, scoper2.get());
+    EXPECT_FALSE(scoper1.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+TEST(ScopedPtrTest, ScopedArray) {
+  static const int kNumLoggers = 12;
+
+  int constructed = 0;
+
+  {
+    scoped_array<ConDecLogger> scoper(new ConDecLogger[kNumLoggers]);
+    EXPECT_TRUE(scoper.get());
+    EXPECT_EQ(&scoper[0], scoper.get());
+    for (int i = 0; i < kNumLoggers; ++i) {
+      scoper[i].set_ptr(&constructed);
+    }
+    EXPECT_EQ(12, constructed);
+
+    EXPECT_EQ(10, scoper.get()->SomeMeth(10));
+    EXPECT_EQ(10, scoper[2].SomeMeth(10));
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test reset() and release()
+  {
+    scoped_array<ConDecLogger> scoper;
+    EXPECT_FALSE(scoper.get());
+    scoper.release();
+    EXPECT_FALSE(scoper.get());
+    scoper.reset();
+    EXPECT_FALSE(scoper.get());
+
+    scoper.reset(new ConDecLogger[kNumLoggers]);
+    for (int i = 0; i < kNumLoggers; ++i) {
+      scoper[i].set_ptr(&constructed);
+    }
+    EXPECT_EQ(12, constructed);
+    scoper.reset();
+    EXPECT_EQ(0, constructed);
+
+    scoper.reset(new ConDecLogger[kNumLoggers]);
+    for (int i = 0; i < kNumLoggers; ++i) {
+      scoper[i].set_ptr(&constructed);
+    }
+    EXPECT_EQ(12, constructed);
+    ConDecLogger* ptr = scoper.release();
+    EXPECT_EQ(12, constructed);
+    delete[] ptr;
+    EXPECT_EQ(0, constructed);
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test swap(), == and !=
+  {
+    scoped_array<ConDecLogger> scoper1;
+    scoped_array<ConDecLogger> scoper2;
+    EXPECT_TRUE(scoper1 == scoper2.get());
+    EXPECT_FALSE(scoper1 != scoper2.get());
+
+    ConDecLogger* loggers = new ConDecLogger[kNumLoggers];
+    for (int i = 0; i < kNumLoggers; ++i) {
+      loggers[i].set_ptr(&constructed);
+    }
+    scoper1.reset(loggers);
+    EXPECT_EQ(loggers, scoper1.get());
+    EXPECT_FALSE(scoper2.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+
+    scoper2.swap(scoper1);
+    EXPECT_EQ(loggers, scoper2.get());
+    EXPECT_FALSE(scoper1.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+// TODO scoped_ptr_malloc
diff --git a/base/tuple.h b/base/tuple.h
index 08ba1e5..c54b579 100644
--- a/base/tuple.h
+++ b/base/tuple.h
@@ -2,6 +2,30 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// A Tuple is a generic templatized container, similar in concept to std::pair.
+// There are classes Tuple0 to Tuple5, cooresponding to the number of elements
+// it contains.  The convenient MakeTuple() function takes 0 to 5 arguments,
+// and will construct and return the appropriate Tuple object.  The functions
+// DispatchToMethod and DispatchToFunction take a function pointer or instance
+// and method pointer, and unpack a tuple into arguments to the call.
+//
+// Tuple elements are copied by value, and stored in the tuple.  See the unit
+// tests for more details of how/when the values are copied.
+//
+// Example usage:
+//   // These two methods of creating a Tuple are identical.
+//   Tuple2<int, const char*> tuple_a(1, "wee");
+//   Tuple2<int, const char*> tuple_b = MakeTuple(1, "wee");
+//
+//   void SomeFunc(int a, const char* b) { }
+//   DispatchToFunction(&SomeFunc, tuple_a);  // SomeFunc(1, "wee")
+//   DispatchToFunction(
+//       &SomeFunc, MakeTuple(10, "foo"));    // SomeFunc(10, "foo")
+//
+//   struct { void SomeMeth(int a, int b, int c) { } } foo;
+//   DispatchToMethod(&foo, &Foo::SomeMeth, MakeTuple(1, 2, 3));
+//   // foo->SomeMeth(1, 2, 3);
+
 #ifndef BASE_TUPLE_H__
 #define BASE_TUPLE_H__
 
diff --git a/base/tuple_unittest.cc b/base/tuple_unittest.cc
new file mode 100644
index 0000000..36ea560
--- /dev/null
+++ b/base/tuple_unittest.cc
@@ -0,0 +1,109 @@
+// Copyright (c) 2006-2008 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/tuple.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+void DoAdd(int a, int b, int c, int* res) {
+  *res = a + b + c;
+}
+
+struct Addy {
+  Addy() { }
+  void DoAdd(int a, int b, int c, int d, int* res) {
+    *res = a + b + c + d;
+  }
+};
+
+}  // namespace
+
+TEST(TupleTest, Basic) {
+  Tuple0 t0 = MakeTuple();
+  Tuple1<int> t1(1);
+  Tuple2<int, const char*> t2 = MakeTuple(1, static_cast<const char*>("wee"));
+  Tuple3<int, int, int> t3(1, 2, 3);
+  Tuple4<int, int, int, int*> t4(1, 2, 3, &t1.a);
+  Tuple5<int, int, int, int, int*> t5(1, 2, 3, 4, &t4.a);
+
+  EXPECT_EQ(1, t1.a);
+  EXPECT_EQ(1, t2.a);
+  EXPECT_EQ(1, t3.a);
+  EXPECT_EQ(2, t3.b);
+  EXPECT_EQ(3, t3.c);
+  EXPECT_EQ(1, t4.a);
+  EXPECT_EQ(2, t4.b);
+  EXPECT_EQ(3, t4.c);
+  EXPECT_EQ(1, t5.a);
+  EXPECT_EQ(2, t5.b);
+  EXPECT_EQ(3, t5.c);
+  EXPECT_EQ(4, t5.d);
+
+
+  EXPECT_EQ(1, t1.a);
+  DispatchToFunction(&DoAdd, t4);
+  EXPECT_EQ(6, t1.a);
+
+  int res = 0;
+  DispatchToFunction(&DoAdd, MakeTuple(9, 8, 7, &res));
+  EXPECT_EQ(24, res);
+
+  Addy addy;
+  EXPECT_EQ(1, t4.a);
+  DispatchToMethod(&addy, &Addy::DoAdd, t5);
+  EXPECT_EQ(10, t4.a);
+}
+
+namespace {
+
+struct CopyLogger {
+  CopyLogger() { ++TimesConstructed; }
+  CopyLogger(const CopyLogger& tocopy) { ++TimesConstructed; ++TimesCopied; }
+  ~CopyLogger() { }
+
+  static int TimesCopied;
+  static int TimesConstructed;
+};
+
+void SomeLoggerMethRef(const CopyLogger& logy, const CopyLogger* ptr, bool* b) {
+  *b = &logy == ptr;
+}
+
+void SomeLoggerMethCopy(CopyLogger logy, const CopyLogger* ptr, bool* b) {
+  *b = &logy == ptr;
+}
+
+int CopyLogger::TimesCopied = 0;
+int CopyLogger::TimesConstructed = 0;
+
+}  // namespace
+
+TEST(TupleTest, Copying) {
+  CopyLogger logger;
+  EXPECT_EQ(0, CopyLogger::TimesCopied);
+  EXPECT_EQ(1, CopyLogger::TimesConstructed);
+
+  bool res = false;
+
+  // Creating the tuple should copy the class to store internally in the tuple.
+  Tuple3<CopyLogger, CopyLogger*, bool*> tuple(logger, &logger, &res);
+  tuple.b = &tuple.a;
+  EXPECT_EQ(2, CopyLogger::TimesConstructed);
+  EXPECT_EQ(1, CopyLogger::TimesCopied);
+
+  // Our internal Logger and the one passed to the function should be the same.
+  res = false;
+  DispatchToFunction(&SomeLoggerMethRef, tuple);
+  EXPECT_TRUE(res);
+  EXPECT_EQ(2, CopyLogger::TimesConstructed);
+  EXPECT_EQ(1, CopyLogger::TimesCopied);
+
+  // Now they should be different, since the function call will make a copy.
+  res = false;
+  DispatchToFunction(&SomeLoggerMethCopy, tuple);
+  EXPECT_FALSE(res);
+  EXPECT_EQ(3, CopyLogger::TimesConstructed);
+  EXPECT_EQ(2, CopyLogger::TimesCopied);
+}