Introduce RawVarData and associated classes for serializing PP_Vars

ppapi/proxy/raw_var_data_unittest.cc

+// Copyright (c) 2012 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 "ppapi/proxy/raw_var_data.h"
+
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/values.h"
+#include "ppapi/c/pp_bool.h"
+#include "ppapi/c/pp_var.h"
+#include "ppapi/shared_impl/array_var.h"
+#include "ppapi/shared_impl/dictionary_var.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/proxy_lock.h"
+#include "ppapi/shared_impl/scoped_pp_var.h"
+#include "ppapi/shared_impl/test_globals.h"
+#include "ppapi/shared_impl/var.h"
+#include "ppapi/shared_impl/var_tracker.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace ppapi {
+namespace proxy {
+
+namespace {
+
+class RawVarDataTest : public testing::Test {
+ public:
+  RawVarDataTest() {}
+  ~RawVarDataTest() {}
+
+  // testing::Test implementation.
+  virtual void SetUp() {
+    ProxyLock::Acquire();
+  }
+  virtual void TearDown() {
+    ASSERT_TRUE(PpapiGlobals::Get()->GetVarTracker()->GetLiveVars().empty());
+    ProxyLock::Release();
+  }
+
+ private:
+  TestGlobals globals_;
+};
+
+// Compares two vars for equality. When two vars are found to be equal, an entry
+// is inserted into |visited_map| with (expected id, actual id). This avoids
+// following reference cycles.

[dmichael (off chromium), 2013/04/16 18:41:20]

It also ensures that id X in expected always maps to id Y in expected, right?
Which seems like a good property. If you just did value comparisons all the way
down, you might see two things as equal that contain the same data but are
actually topographically very different.

[raymes, 2013/04/16 20:34:19]

Yes exactly :) This was tricky to say concisely though but I think you did a
good job so I adopted your wording :)

+// TODO(raymes): Add logging in this function to make debugging easier.
+bool Equals(const PP_Var& expected,
+            const PP_Var& actual,
+            base::hash_map<int64_t, int64_t>* visited_map) {
+  if (expected.type != actual.type)
+    return false;
+  if (VarTracker::IsVarTypeRefcounted(expected.type)) {
+    base::hash_map<int64_t, int64_t>::iterator it =
+        visited_map->find(expected.value.as_id);
+    if (it != visited_map->end())
+      return it->second == actual.value.as_id;
+    else
+      (*visited_map)[expected.value.as_id] = actual.value.as_id;
+  }
+  switch (expected.type) {
+    case PP_VARTYPE_UNDEFINED:
+      return true;
+    case PP_VARTYPE_NULL:
+      return true;
+    case PP_VARTYPE_BOOL:
+      return expected.value.as_bool == actual.value.as_bool;
+    case PP_VARTYPE_INT32:
+      return expected.value.as_int == actual.value.as_int;
+    case PP_VARTYPE_DOUBLE:
+      return expected.value.as_double == actual.value.as_double;
+    case PP_VARTYPE_OBJECT:
+      return expected.value.as_id == actual.value.as_id;
+    case PP_VARTYPE_STRING: {
+      StringVar* expected_var = StringVar::FromPPVar(expected);
+      StringVar* actual_var = StringVar::FromPPVar(actual);
+      DCHECK(expected_var && actual_var);
+      return expected_var->value() == expected_var->value();
+    }
+    case PP_VARTYPE_ARRAY_BUFFER: {
+      ArrayBufferVar* expected_var = ArrayBufferVar::FromPPVar(expected);
+      ArrayBufferVar* actual_var = ArrayBufferVar::FromPPVar(actual);
+      DCHECK(expected_var && actual_var);
+      if (expected_var->ByteLength() != actual_var->ByteLength())
+        return false;
+      return memcmp(expected_var->Map(), actual_var->Map(),
+                    expected_var->ByteLength()) == 0;
+    }
+    case PP_VARTYPE_ARRAY: {
+      ArrayVar* expected_var = ArrayVar::FromPPVar(expected);
+      ArrayVar* actual_var = ArrayVar::FromPPVar(actual);
+      DCHECK(expected_var && actual_var);
+      if (expected_var->elements().size() != actual_var->elements().size())
+        return false;
+      for (size_t i = 0; i < expected_var->elements().size(); ++i) {
+        if (!Equals(expected_var->elements()[i].get(),
+                    actual_var->elements()[i].get(),
+                    visited_map)) {
+          return false;
+        }
+      }
+      return true;
+    }
+    case PP_VARTYPE_DICTIONARY: {
+      DictionaryVar* expected_var = DictionaryVar::FromPPVar(expected);
+      DictionaryVar* actual_var = DictionaryVar::FromPPVar(actual);
+      DCHECK(expected_var && actual_var);
+      if (expected_var->key_value_map().size() !=
+          actual_var->key_value_map().size())
+        return false;
+      DictionaryVar::KeyValueMap::const_iterator expected_iter =
+          expected_var->key_value_map().begin();
+      DictionaryVar::KeyValueMap::const_iterator actual_iter =
+          actual_var->key_value_map().begin();
+      for ( ; expected_iter != expected_var->key_value_map().end();
+           ++expected_iter, ++actual_iter) {
+           if (expected_iter->first != actual_iter->first)
+             return false;
+        if (!Equals(expected_iter->second.get(),
+                    actual_iter->second.get(),
+                    visited_map)) {
+          return false;
+        }
+      }
+      return true;
+    }
+  }
+  NOTREACHED();
+  return false;
+}
+
+bool Equals(const PP_Var& expected,
+            const PP_Var& actual) {
+  base::hash_map<int64_t, int64_t> visited_map;
+  return Equals(expected, actual, &visited_map);
+}
+
+PP_Var WriteAndRead(const PP_Var& var) {
+  PP_Instance dummy_instance = 1234;
+  scoped_ptr<RawVarDataGraph> expected_data(RawVarDataGraph::Create(
+      var, dummy_instance));
+  IPC::Message m;
+  expected_data->Write(&m);
+  PickleIterator iter(m);
+  scoped_ptr<RawVarDataGraph> actual_data(RawVarDataGraph::Read(&m, &iter));
+  return actual_data->CreatePPVar(dummy_instance);
+}
+
+// Assumes a ref for var.
+bool WriteReadAndCompare(const PP_Var& var) {
+  ScopedPPVar expected(ScopedPPVar::PassRef(), var);
+  ScopedPPVar actual(ScopedPPVar::PassRef(), WriteAndRead(expected.get()));
+  return Equals(expected.get(), actual.get());
+}
+
+}  // namespace
+
+TEST_F(RawVarDataTest, SimpleTest) {
+  EXPECT_TRUE(WriteReadAndCompare(PP_MakeUndefined()));
+  EXPECT_TRUE(WriteReadAndCompare(PP_MakeNull()));
+  EXPECT_TRUE(WriteReadAndCompare(PP_MakeInt32(100)));
+  EXPECT_TRUE(WriteReadAndCompare(PP_MakeBool(PP_TRUE)));
+  EXPECT_TRUE(WriteReadAndCompare(PP_MakeDouble(53.75)));
+  PP_Var object;
+  object.type = PP_VARTYPE_OBJECT;
+  object.value.as_id = 10;
+  EXPECT_TRUE(WriteReadAndCompare(object));
+}
+
+TEST_F(RawVarDataTest, StringTest) {
+  EXPECT_TRUE(WriteReadAndCompare(StringVar::StringToPPVar("")));
+  EXPECT_TRUE(WriteReadAndCompare(StringVar::StringToPPVar("hello world!")));
+}
+
+TEST_F(RawVarDataTest, ArrayBufferTest) {
+  std::string data = "hello world!";
+  PP_Var var = PpapiGlobals::Get()->GetVarTracker()->MakeArrayBufferPPVar(
+      data.size(), data.data());
+  EXPECT_TRUE(WriteReadAndCompare(var));
+  var = PpapiGlobals::Get()->GetVarTracker()->MakeArrayBufferPPVar(
+      0, static_cast<void*>(NULL));
+  EXPECT_TRUE(WriteReadAndCompare(var));
+  // TODO(raymes): add tests for shmem type array buffers.
+}
+
+TEST_F(RawVarDataTest, DictionaryArrayTest) {
+  // Empty array.
+  scoped_refptr<ArrayVar> array(new ArrayVar);
+  ScopedPPVar release_array(ScopedPPVar::PassRef(), array->GetPPVar());
+  EXPECT_TRUE(WriteReadAndCompare(array->GetPPVar()));
+
+  size_t index = 0;
+
+  // Array with primitives.
+  array->Set(index++, PP_MakeUndefined());
+  array->Set(index++, PP_MakeNull());
+  array->Set(index++, PP_MakeInt32(100));
+  array->Set(index++, PP_MakeBool(PP_FALSE));
+  array->Set(index++, PP_MakeDouble(0.123));
+  EXPECT_TRUE(WriteReadAndCompare(array->GetPPVar()));
+
+  // Array with 2 references to the same string.
+  ScopedPPVar release_string(
+      ScopedPPVar::PassRef(), StringVar::StringToPPVar("abc"));
+  array->Set(index++, release_string.get());
+  array->Set(index++, release_string.get());
+  EXPECT_TRUE(WriteReadAndCompare(array->GetPPVar()));
+

[dmichael (off chromium), 2013/04/16 18:41:20]

Do you want to somehow clear the array out between tests? You're actually
growing it with each new test. Seems okay, but what you're actually testing is a
bit more than what the comment says.

[raymes, 2013/04/16 20:34:19]

Yeah the state builds up cumulatively. I'd prefer to leave it for better
coverage for now. I think the comments are still accurate, like you said it just
tests a superset of that. I guess if I were to be really thorough I would have
tests for each of those things individually and then a complex test which mixes
them.

+  // Array with nested array that references the same string.
+  scoped_refptr<ArrayVar> array2(new ArrayVar);
+  ScopedPPVar release_array2(ScopedPPVar::PassRef(), array2->GetPPVar());
+  array2->Set(0, release_string.get());
+  array->Set(index++, release_array2.get());
+  EXPECT_TRUE(WriteReadAndCompare(array->GetPPVar()));
+
+  // Empty dictionary.
+  scoped_refptr<DictionaryVar> dictionary(new DictionaryVar);
+  ScopedPPVar release_dictionary(ScopedPPVar::PassRef(),
+                                 dictionary->GetPPVar());
+  EXPECT_TRUE(WriteReadAndCompare(dictionary->GetPPVar()));
+
+  // Dictionary with primitives.
+  dictionary->SetWithStringKey("1", PP_MakeUndefined());
+  dictionary->SetWithStringKey("2", PP_MakeNull());
+  dictionary->SetWithStringKey("3", PP_MakeInt32(-100));
+  dictionary->SetWithStringKey("4", PP_MakeBool(PP_TRUE));
+  dictionary->SetWithStringKey("5", PP_MakeDouble(-103.52));
+  EXPECT_TRUE(WriteReadAndCompare(dictionary->GetPPVar()));
+
+  // Dictionary with 2 references to the same string.
+  dictionary->SetWithStringKey("6", release_string.get());
+  dictionary->SetWithStringKey("7", release_string.get());
+  EXPECT_TRUE(WriteReadAndCompare(dictionary->GetPPVar()));
+
+  // Dictionary with nested dictionary that references the same string.
+  scoped_refptr<DictionaryVar> dictionary2(new DictionaryVar);
+  ScopedPPVar release_dictionary2(ScopedPPVar::PassRef(),
+                                  dictionary2->GetPPVar());
+  dictionary2->SetWithStringKey("abc", release_string.get());
+  dictionary->SetWithStringKey("8", release_dictionary2.get());
+  EXPECT_TRUE(WriteReadAndCompare(dictionary->GetPPVar()));
+
+  // Array with dictionary.
+  array->Set(index++, release_dictionary.get());
+  EXPECT_TRUE(WriteReadAndCompare(array->GetPPVar()));
+
+  // Array with dictionary with array.
+  array2->Set(0, PP_MakeInt32(100));
+  dictionary->SetWithStringKey("9", release_array2.get());
+  EXPECT_TRUE(WriteReadAndCompare(array->GetPPVar()));
+
+  // Array <-> dictionary cycle.
+  dictionary->SetWithStringKey("10", release_array.get());
+  ScopedPPVar result = ScopedPPVar(ScopedPPVar::PassRef(),
+                                   WriteAndRead(release_dictionary.get()));
+  EXPECT_TRUE(Equals(release_dictionary.get(), result.get()));
+  // Break the cycle.
+  // TODO(raymes): We need some better machinery for releasing vars with
+  // cycles. Remove the code below once we have that.
+  dictionary->DeleteWithStringKey("10");
+  DictionaryVar* result_dictionary = DictionaryVar::FromPPVar(result.get());
+  result_dictionary->DeleteWithStringKey("10");
+
+  // Array with self references.
+  array->Set(index, release_array.get());
+  result = ScopedPPVar(ScopedPPVar::PassRef(),
+                       WriteAndRead(release_array.get()));
+  EXPECT_TRUE(Equals(release_array.get(), result.get()));
+  // Break the self reference.
+  array->Set(index, PP_MakeUndefined());
+  ArrayVar* result_array = ArrayVar::FromPPVar(result.get());
+  result_array->Set(index, PP_MakeUndefined());
+}
+
+}  // namespace proxy
+}  // namespace ppapi