1 files changed, 197 insertions, 0 deletions
diff --git a/libs/ui/tests/FlattenableHelpers_test.cpp b/libs/ui/tests/FlattenableHelpers_test.cpp
new file mode 100644
index 0000000000..44e20b504d
--- /dev/null
+++ b/libs/ui/tests/FlattenableHelpers_test.cpp
@@ -0,0 +1,197 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "FlattenableHelpersTest"
+
+#include <ui/FlattenableHelpers.h>
+
+#include <gtest/gtest.h>
+#include <utils/Flattenable.h>
+#include <cstdint>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace android {
+
+namespace {
+
+struct TestLightFlattenable : LightFlattenable<TestLightFlattenable> {
+    std::unique_ptr<int32_t> ptr;
+
+    bool isFixedSize() const { return true; }
+    size_t getFlattenedSize() const { return sizeof(int32_t); }
+
+    status_t flatten(void* buffer, size_t size) const {
+        FlattenableUtils::write(buffer, size, *ptr);
+        return OK;
+    }
+
+    status_t unflatten(void const* buffer, size_t size) {
+        int32_t value;
+        FlattenableUtils::read(buffer, size, value);
+        ptr = std::make_unique<int32_t>(value);
+        return OK;
+    }
+};
+
+class FlattenableHelpersTest : public testing::Test {
+public:
+    template <class T>
+    void testWriteThenRead(const T& value, size_t bufferSize) {
+        std::vector<int8_t> buffer(bufferSize);
+        auto rawBuffer = reinterpret_cast<void*>(buffer.data());
+        size_t size = buffer.size();
+        ASSERT_EQ(OK, FlattenableHelpers::flatten(&rawBuffer, &size, value));
+
+        auto rawReadBuffer = reinterpret_cast<const void*>(buffer.data());
+        size = buffer.size();
+        T valueRead;
+        ASSERT_EQ(OK, FlattenableHelpers::unflatten(&rawReadBuffer, &size, &valueRead));
+        EXPECT_EQ(value, valueRead);
+    }
+
+    template <class T>
+    void testTriviallyCopyable(const T& value) {
+        testWriteThenRead(value, sizeof(T));
+    }
+
+    template <class T>
+    void testWriteThenRead(const T& value) {
+        testWriteThenRead(value, FlattenableHelpers::getFlattenedSize(value));
+    }
+};
+
+TEST_F(FlattenableHelpersTest, TriviallyCopyable) {
+    testTriviallyCopyable(42);
+    testTriviallyCopyable(1LL << 63);
+    testTriviallyCopyable(false);
+    testTriviallyCopyable(true);
+    testTriviallyCopyable(std::optional<int>());
+    testTriviallyCopyable(std::optional<int>(4));
+}
+
+TEST_F(FlattenableHelpersTest, String) {
+    testWriteThenRead(std::string("Android"));
+    testWriteThenRead(std::string());
+}
+
+TEST_F(FlattenableHelpersTest, Vector) {
+    testWriteThenRead(std::vector<int>({1, 2, 3}));
+    testWriteThenRead(std::vector<int>());
+}
+
+TEST_F(FlattenableHelpersTest, OptionalOfLightFlattenable) {
+    std::vector<size_t> buffer;
+    constexpr int kInternalValue = 16;
+    {
+        std::optional<TestLightFlattenable> value =
+                TestLightFlattenable{.ptr = std::make_unique<int32_t>(kInternalValue)};
+        buffer.assign(FlattenableHelpers::getFlattenedSize(value), 0);
+        void* rawBuffer = reinterpret_cast<void*>(buffer.data());
+        size_t size = buffer.size();
+        ASSERT_EQ(OK, FlattenableHelpers::flatten(&rawBuffer, &size, value));
+    }
+
+    const void* rawReadBuffer = reinterpret_cast<const void*>(buffer.data());
+    size_t size = buffer.size();
+    std::optional<TestLightFlattenable> valueRead;
+    ASSERT_EQ(OK, FlattenableHelpers::unflatten(&rawReadBuffer, &size, &valueRead));
+    ASSERT_TRUE(valueRead.has_value());
+    EXPECT_EQ(kInternalValue, *valueRead->ptr);
+}
+
+TEST_F(FlattenableHelpersTest, NullOptionalOfLightFlattenable) {
+    std::vector<size_t> buffer;
+    {
+        std::optional<TestLightFlattenable> value;
+        buffer.assign(FlattenableHelpers::getFlattenedSize(value), 0);
+        void* rawBuffer = reinterpret_cast<void*>(buffer.data());
+        size_t size = buffer.size();
+        ASSERT_EQ(OK, FlattenableHelpers::flatten(&rawBuffer, &size, value));
+    }
+
+    const void* rawReadBuffer = reinterpret_cast<const void*>(buffer.data());
+    size_t size = buffer.size();
+    std::optional<TestLightFlattenable> valueRead;
+    ASSERT_EQ(OK, FlattenableHelpers::unflatten(&rawReadBuffer, &size, &valueRead));
+    ASSERT_FALSE(valueRead.has_value());
+}
+
+// If a struct is both trivially copyable and light flattenable we should treat it
+// as LigthFlattenable.
+TEST_F(FlattenableHelpersTest, TriviallyCopyableAndLightFlattenableIsFlattenedAsLightFlattenable) {
+    static constexpr int32_t kSizeTag = 1234567;
+    static constexpr int32_t kFlattenTag = 987654;
+    static constexpr int32_t kUnflattenTag = 5926582;
+
+    struct LightFlattenableAndTriviallyCopyable
+          : LightFlattenable<LightFlattenableAndTriviallyCopyable> {
+        int32_t value;
+
+        bool isFixedSize() const { return true; }
+        size_t getFlattenedSize() const { return kSizeTag; }
+
+        status_t flatten(void* buffer, size_t size) const {
+            FlattenableUtils::write(buffer, size, kFlattenTag);
+            return OK;
+        }
+
+        status_t unflatten(void const*, size_t) {
+            value = kUnflattenTag;
+            return OK;
+        }
+    };
+
+    {
+        // Verify that getFlattenedSize uses the LightFlattenable overload
+        LightFlattenableAndTriviallyCopyable foo;
+        EXPECT_EQ(kSizeTag, FlattenableHelpers::getFlattenedSize(foo));
+    }
+
+    {
+        // Verify that flatten uses the LightFlattenable overload
+        std::vector<int8_t> buffer(sizeof(int32_t));
+        auto rawBuffer = reinterpret_cast<void*>(buffer.data());
+        size_t size = buffer.size();
+        LightFlattenableAndTriviallyCopyable foo;
+        ASSERT_EQ(OK, FlattenableHelpers::flatten(&rawBuffer, &size, foo));
+
+        auto rawReadBuffer = reinterpret_cast<const void*>(buffer.data());
+        int32_t value;
+        FlattenableHelpers::unflatten(&rawReadBuffer, &size, &value);
+        EXPECT_EQ(kFlattenTag, value);
+    }
+
+    {
+        // Verify that unflatten uses the LightFlattenable overload
+        std::vector<int8_t> buffer(sizeof(int32_t));
+        auto rawBuffer = reinterpret_cast<void*>(buffer.data());
+        size_t size = buffer.size();
+        int32_t value = 4;
+        ASSERT_EQ(OK, FlattenableHelpers::flatten(&rawBuffer, &size, value));
+
+        auto rawReadBuffer = reinterpret_cast<const void*>(buffer.data());
+
+        LightFlattenableAndTriviallyCopyable foo;
+        FlattenableHelpers::unflatten(&rawReadBuffer, &size, &foo);
+        EXPECT_EQ(kUnflattenTag, foo.value);
+    }
+}
+
+} // namespace
+} // namespace android