/* Copyright 2015 The TensorFlow Authors. All Rights Reserved.

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.
==============================================================================*/

#include "tensorflow/core/framework/variant.h"

#include <cstddef>
#if defined(__x86_64__)
#include <xmmintrin.h>
#endif
#include <vector>

#include "tensorflow/core/framework/tensor.h"
#include "tensorflow/core/framework/tensor.pb.h"
#include "tensorflow/core/framework/tensor_shape.pb.h"
#include "tensorflow/core/framework/variant_encode_decode.h"
#include "tensorflow/core/framework/variant_tensor_data.h"
#include "tensorflow/core/kernels/ops_testutil.h"
#include "tensorflow/core/lib/core/coding.h"
#include "tensorflow/core/platform/test.h"

namespace tensorflow {

namespace {

template <typename T, bool BIG>
struct Wrapper {
  T value;
  char big[BIG ? 256 : 1];
  std::string TypeName() const { return "POD"; }
};

template <bool BIG>
using Int = Wrapper<int, BIG>;

template <bool BIG>
using Float = Wrapper<float, BIG>;

template <bool BIG>
class MaybeAlive {
 public:
  MaybeAlive() : alive_(false) {}

  explicit MaybeAlive(bool alive) : alive_(alive) {
    if (alive) ++live_counter_;
  }

  ~MaybeAlive() {
    if (alive_) --live_counter_;
  }

  MaybeAlive(const MaybeAlive& rhs) : alive_(rhs.alive_) {
    if (alive_) ++live_counter_;
  }

  MaybeAlive& operator=(const MaybeAlive& rhs) {
    if (this == &rhs) return *this;
    if (alive_) --live_counter_;
    alive_ = rhs.alive_;
    if (alive_) ++live_counter_;
    return *this;
  }

  MaybeAlive(MaybeAlive&& rhs) : alive_(false) {
    alive_ = std::move(rhs.alive_);
    if (alive_) ++live_counter_;
  }

  MaybeAlive& operator=(MaybeAlive&& rhs) {
    if (this == &rhs) return *this;
    if (alive_) --live_counter_;
    alive_ = std::move(rhs.alive_);
    if (alive_) ++live_counter_;
    return *this;
  }

  static int LiveCounter() { return live_counter_; }

  std::string TypeName() const { return "MaybeAlive"; }
  void Encode(VariantTensorData* data) const {}
  bool Decode(VariantTensorData data) { return false; }

 private:
  bool alive_;
  char big_[BIG ? 256 : 1];
  static int live_counter_;
};

template <>
int MaybeAlive<false>::live_counter_ = 0;
template <>
int MaybeAlive<true>::live_counter_ = 0;

template <bool BIG>
class DeleteCounter {
 public:
  DeleteCounter() : big_{}, counter_(nullptr) {}
  explicit DeleteCounter(int* counter) : big_{}, counter_(counter) {}
  ~DeleteCounter() {
    if (counter_) ++*counter_;
  }
  // Need custom move operations because int* just gets copied on move, but we
  // need to clear counter_ on move.
  DeleteCounter& operator=(const DeleteCounter& rhs) = default;
  DeleteCounter& operator=(DeleteCounter&& rhs) {
    if (this == &rhs) return *this;
    counter_ = rhs.counter_;
    rhs.counter_ = nullptr;
    return *this;
  }
  DeleteCounter(DeleteCounter&& rhs) {
    counter_ = rhs.counter_;
    rhs.counter_ = nullptr;
  }
  DeleteCounter(const DeleteCounter& rhs) = default;
  char big_[BIG ? 256 : 1];
  int* counter_;

  std::string TypeName() const { return "DeleteCounter"; }
  void Encode(VariantTensorData* data) const {}
  bool Decode(VariantTensorData data) { return false; }
};

}  // end namespace

TEST(VariantTest, MoveAndCopyBetweenBigAndSmall) {
  Variant x;
  int deleted_big = 0;
  int deleted_small = 0;
  x = DeleteCounter</*BIG=*/true>(&deleted_big);
  EXPECT_EQ(deleted_big, 0);
  x = DeleteCounter</*BIG=*/false>(&deleted_small);
  EXPECT_EQ(deleted_big, 1);
  EXPECT_EQ(deleted_small, 0);
  x = DeleteCounter</*BIG=*/true>(&deleted_big);
  EXPECT_EQ(deleted_big, 1);
  EXPECT_EQ(deleted_small, 1);
  x.clear();
  EXPECT_EQ(deleted_big, 2);
  EXPECT_EQ(deleted_small, 1);
  DeleteCounter</*BIG=*/true> big(&deleted_big);
  DeleteCounter</*BIG=*/false> small(&deleted_small);
  EXPECT_EQ(deleted_big, 2);
  EXPECT_EQ(deleted_small, 1);
  x = big;
  EXPECT_EQ(deleted_big, 2);
  EXPECT_EQ(deleted_small, 1);
  x = small;
  EXPECT_EQ(deleted_big, 3);
  EXPECT_EQ(deleted_small, 1);
  x = std::move(big);
  EXPECT_EQ(deleted_big, 3);
  EXPECT_EQ(deleted_small, 2);
  x = std::move(small);
  EXPECT_EQ(deleted_big, 4);
  EXPECT_EQ(deleted_small, 2);
  x.clear();
  EXPECT_EQ(deleted_big, 4);
  EXPECT_EQ(deleted_small, 3);
}

TEST(VariantTest, MoveAndCopyBetweenBigAndSmallVariants) {
  int deleted_big = 0;
  int deleted_small = 0;
  {
    Variant x = DeleteCounter</*BIG=*/true>(&deleted_big);
    Variant y = DeleteCounter</*BIG=*/false>(&deleted_small);
    EXPECT_EQ(deleted_big, 0);
    EXPECT_EQ(deleted_small, 0);
    x = y;
    EXPECT_EQ(deleted_big, 1);
    EXPECT_EQ(deleted_small, 0);
    x = x;
    EXPECT_EQ(deleted_big, 1);
    EXPECT_EQ(deleted_small, 0);
    EXPECT_NE(x.get<DeleteCounter<false>>(), nullptr);
    EXPECT_NE(y.get<DeleteCounter<false>>(), nullptr);
    x = std::move(y);
    EXPECT_EQ(deleted_small, 1);
    EXPECT_NE(x.get<DeleteCounter<false>>(), nullptr);
  }
  EXPECT_EQ(deleted_big, 1);
  EXPECT_EQ(deleted_small, 2);

  deleted_big = 0;
  deleted_small = 0;
  {
    Variant x = DeleteCounter</*BIG=*/false>(&deleted_small);
    Variant y = DeleteCounter</*BIG=*/true>(&deleted_big);
    EXPECT_EQ(deleted_big, 0);
    EXPECT_EQ(deleted_small, 0);
    x = y;
    EXPECT_EQ(deleted_big, 0);
    EXPECT_EQ(deleted_small, 1);
    x = x;
    EXPECT_EQ(deleted_big, 0);
    EXPECT_EQ(deleted_small, 1);
    EXPECT_NE(x.get<DeleteCounter<true>>(), nullptr);
    EXPECT_NE(y.get<DeleteCounter<true>>(), nullptr);
    x = std::move(y);
    EXPECT_EQ(deleted_big, 1);
    EXPECT_NE(x.get<DeleteCounter<true>>(), nullptr);
  }
  EXPECT_EQ(deleted_big, 2);
  EXPECT_EQ(deleted_small, 1);
}

namespace {

template <bool BIG>
class MoveAndCopyCounter {
 public:
  MoveAndCopyCounter()
      : big_{}, move_counter_(nullptr), copy_counter_(nullptr) {}
  explicit MoveAndCopyCounter(int* move_counter, int* copy_counter)
      : big_{}, move_counter_(move_counter), copy_counter_(copy_counter) {}

  MoveAndCopyCounter& operator=(const MoveAndCopyCounter& rhs) {
    copy_counter_ = rhs.copy_counter_;
    if (copy_counter_) ++*copy_counter_;
    return *this;
  }
  MoveAndCopyCounter& operator=(MoveAndCopyCounter&& rhs) {
    move_counter_ = rhs.move_counter_;
    if (move_counter_) ++*move_counter_;
    return *this;
  }
  MoveAndCopyCounter(MoveAndCopyCounter&& rhs) {
    move_counter_ = rhs.move_counter_;
    if (move_counter_) ++*move_counter_;
  }
  MoveAndCopyCounter(const MoveAndCopyCounter& rhs) {
    copy_counter_ = rhs.copy_counter_;
    if (copy_counter_) ++*copy_counter_;
  }
  char big_[BIG ? 256 : 1];
  int* move_counter_;
  int* copy_counter_;

  std::string TypeName() const { return "MoveAndCopyCounter"; }
  void Encode(VariantTensorData* data) const {}
  bool Decode(VariantTensorData data) { return false; }
};

}  // namespace

TEST(VariantTest, EmplaceBigAndSmallVariants) {
  {
    int moved_big = 0;
    int moved_small = 0;
    int copied_big = 0;
    int copied_small = 0;
    Variant x = MoveAndCopyCounter</*BIG=*/true>(&moved_big, &copied_big);
    EXPECT_EQ(moved_big, 1);
    EXPECT_EQ(copied_big, 0);
    Variant y = MoveAndCopyCounter</*BIG=*/false>(&moved_small, &copied_small);
    EXPECT_EQ(moved_small, 1);
    EXPECT_EQ(copied_small, 0);
  }

  {
    int moved_big = 0;
    int moved_small = 0;
    int copied_big = 0;
    int copied_small = 0;
    Variant x(MoveAndCopyCounter</*BIG=*/true>(&moved_big, &copied_big));
    EXPECT_EQ(moved_big, 1);
    EXPECT_EQ(copied_big, 0);
    Variant y(MoveAndCopyCounter</*BIG=*/false>(&moved_small, &copied_small));
    EXPECT_EQ(moved_small, 1);
    EXPECT_EQ(copied_small, 0);
  }

  {
    int moved_big = 0;
    int moved_small = 0;
    int copied_big = 0;
    int copied_small = 0;
    Variant x;
    x.emplace<MoveAndCopyCounter</*BIG=*/true>>(&moved_big, &copied_big);
    EXPECT_EQ(moved_big, 0);
    EXPECT_EQ(copied_big, 0);
    Variant y;
    y.emplace<MoveAndCopyCounter</*BIG=*/false>>(&moved_small, &copied_small);
    EXPECT_EQ(moved_small, 0);
    EXPECT_EQ(copied_small, 0);
  }
}

template <bool BIG>
void TestDestructOnVariantMove() {
  CHECK_EQ(MaybeAlive<BIG>::LiveCounter(), 0);
  {
    Variant a = MaybeAlive<BIG>(true);
    Variant b = std::move(a);
  }
  EXPECT_EQ(MaybeAlive<BIG>::LiveCounter(), 0);
}

TEST(VariantTest, RHSDestructOnVariantMoveBig) {
  TestDestructOnVariantMove</*BIG=*/true>();
}

TEST(VariantTest, RHSDestructOnVariantMoveSmall) {
  TestDestructOnVariantMove</*BIG=*/false>();
}

TEST(VariantTest, Int) {
  Variant x;
  EXPECT_EQ(x.get<void>(), nullptr);
  x = 3;
  EXPECT_NE(x.get<void>(), nullptr);
  EXPECT_EQ(*x.get<int>(), 3);
  EXPECT_EQ(x.TypeName(), "int");
}
#if defined(__x86_64__)
struct MayCreateAlignmentDifficulties {
  int a;
  __m128 b;
};

bool M128AllEqual(const __m128& a, const __m128& b) {
  return _mm_movemask_ps(_mm_cmpeq_ps(a, b)) == 0xf;
}

TEST(VariantTest, NotAlignable) {
  Variant x;
  EXPECT_EQ(x.get<void>(), nullptr);
  __m128 v = _mm_set_ps(1.0, 2.0, 3.0, 4.0);
  x = MayCreateAlignmentDifficulties{-1, v};
  EXPECT_NE(x.get<void>(), nullptr);
  auto* x_val = x.get<MayCreateAlignmentDifficulties>();
  // check that *x_val == x
  Variant y = x;
  EXPECT_EQ(x_val->a, -1);
  EXPECT_TRUE(M128AllEqual(x_val->b, v));
  auto* y_val = y.get<MayCreateAlignmentDifficulties>();
  EXPECT_EQ(y_val->a, -1);
  EXPECT_TRUE(M128AllEqual(y_val->b, v));
  Variant z = std::move(y);
  auto* z_val = z.get<MayCreateAlignmentDifficulties>();
  EXPECT_EQ(z_val->a, -1);
  EXPECT_TRUE(M128AllEqual(z_val->b, v));
}
#endif
template <bool BIG>
void TestBasic() {
  Variant x;
  EXPECT_EQ(x.get<void>(), nullptr);

  x = Int<BIG>{42};

  EXPECT_NE(x.get<void>(), nullptr);
  EXPECT_NE(x.get<Int<BIG>>(), nullptr);
  EXPECT_EQ(x.get<Int<BIG>>()->value, 42);
  EXPECT_EQ(x.TypeName(), "POD");
}

TEST(VariantTest, Basic) { TestBasic<false>(); }

TEST(VariantTest, BasicBig) { TestBasic<true>(); }

template <bool BIG>
void TestConstGet() {
  Variant x;
  EXPECT_EQ(x.get<void>(), nullptr);

  x = Int<BIG>{42};

  const Variant y = x;

  EXPECT_NE(y.get<void>(), nullptr);
  EXPECT_NE(y.get<Int<BIG>>(), nullptr);
  EXPECT_EQ(y.get<Int<BIG>>()->value, 42);
}

TEST(VariantTest, ConstGet) { TestConstGet<false>(); }

TEST(VariantTest, ConstGetBig) { TestConstGet<true>(); }

template <bool BIG>
void TestClear() {
  Variant x;
  EXPECT_EQ(x.get<void>(), nullptr);

  x = Int<BIG>{42};

  EXPECT_NE(x.get<void>(), nullptr);
  EXPECT_NE(x.get<Int<BIG>>(), nullptr);
  EXPECT_EQ(x.get<Int<BIG>>()->value, 42);

  x.clear();
  EXPECT_EQ(x.get<void>(), nullptr);
}

TEST(VariantTest, Clear) { TestClear<false>(); }

TEST(VariantTest, ClearBig) { TestClear<true>(); }

template <bool BIG>
void TestClearDeletes() {
  Variant x;
  EXPECT_EQ(x.get<void>(), nullptr);

  int deleted_count = 0;
  using DC = DeleteCounter<BIG>;
  DC dc(&deleted_count);
  EXPECT_EQ(deleted_count, 0);
  x = dc;
  EXPECT_EQ(deleted_count, 0);

  EXPECT_NE(x.get<void>(), nullptr);
  EXPECT_NE(x.get<DC>(), nullptr);

  x.clear();
  EXPECT_EQ(x.get<void>(), nullptr);
  EXPECT_EQ(deleted_count, 1);

  x = dc;
  EXPECT_EQ(deleted_count, 1);

  Variant y = x;
  EXPECT_EQ(deleted_count, 1);

  x.clear();
  EXPECT_EQ(deleted_count, 2);

  y.clear();
  EXPECT_EQ(deleted_count, 3);
}

TEST(VariantTest, ClearDeletesOnHeap) { TestClearDeletes</*BIG=*/true>(); }

TEST(VariantTest, ClearDeletesOnStack) { TestClearDeletes</*BIG=*/false>(); }

TEST(VariantTest, Tensor) {
  Variant x;
  Tensor t(DT_FLOAT, {});
  t.flat<float>()(0) = 42.0f;
  x = t;

  EXPECT_NE(x.get<Tensor>(), nullptr);
  EXPECT_EQ(x.get<Tensor>()->flat<float>()(0), 42.0f);
  x.get<Tensor>()->flat<float>()(0) += 1.0f;
  EXPECT_EQ(x.get<Tensor>()->flat<float>()(0), 43.0f);
  EXPECT_EQ(x.TypeName(), "tensorflow::Tensor");

  Tensor& foo_t = x.emplace<Tensor>("foo");
  EXPECT_NE(x.get<Tensor>(), nullptr);
  EXPECT_EQ(x.get<Tensor>()->scalar<tstring>()(), "foo");
  EXPECT_EQ(&foo_t, x.get<Tensor>());
  EXPECT_EQ(x.TypeName(), "tensorflow::Tensor");

  Tensor& bar_t = x.emplace<Tensor>(DT_INT64, TensorShape({1}));
  EXPECT_EQ(&bar_t, x.get<Tensor>());
  bar_t.vec<int64_t>()(0) = 17;
  EXPECT_EQ(x.get<Tensor>()->vec<int64_t>()(0), 17);
  bar_t.vec<int64_t>()(0) += 1;
  EXPECT_EQ(x.get<Tensor>()->vec<int64_t>()(0), 18);
}

TEST(VariantTest, NontrivialTensorVariantCopy) {
  Tensor variants(DT_VARIANT, {});
  Tensor t(true);
  test::FillValues<Variant>(&variants, absl::Span<const Variant>({t}));
  const Tensor* t_c = variants.flat<Variant>()(0).get<Tensor>();
  EXPECT_EQ(t_c->dtype(), t.dtype());
  EXPECT_EQ(t_c->shape(), t.shape());
  EXPECT_EQ(t_c->scalar<bool>()(), t.scalar<bool>()());
}

TEST(VariantTest, TensorProto) {
  Variant x;
  TensorProto t;
  t.set_dtype(DT_FLOAT);
  t.mutable_tensor_shape()->set_unknown_rank(true);
  x = t;

  EXPECT_EQ(x.TypeName(), "tensorflow.TensorProto");
  EXPECT_NE(x.get<TensorProto>(), nullptr);
  EXPECT_EQ(x.get<TensorProto>()->dtype(), DT_FLOAT);
  EXPECT_EQ(x.get<TensorProto>()->tensor_shape().unknown_rank(), true);
}

template <bool BIG>
void TestCopyValue() {
  Variant x, y;
  x = Int<BIG>{10};
  y = x;

  EXPECT_EQ(x.get<Int<BIG>>()->value, 10);
  EXPECT_EQ(x.get<Int<BIG>>()->value, y.get<Int<BIG>>()->value);
}

TEST(VariantTest, CopyValue) { TestCopyValue<false>(); }

TEST(VariantTest, CopyValueBig) { TestCopyValue<true>(); }

template <bool BIG>
void TestMoveValue() {
  Variant x;
  x = []() -> Variant {
    Variant y;
    y = Int<BIG>{10};
    return y;
  }();
  EXPECT_EQ(x.get<Int<BIG>>()->value, 10);
}

TEST(VariantTest, MoveValue) { TestMoveValue<false>(); }

TEST(VariantTest, MoveValueBig) { TestMoveValue<true>(); }

TEST(VariantTest, TypeMismatch) {
  Variant x;
  x = Int<false>{10};
  EXPECT_EQ(x.get<float>(), nullptr);
  EXPECT_EQ(x.get<int>(), nullptr);
  EXPECT_NE(x.get<Int<false>>(), nullptr);
}

struct TensorList {
  void Encode(VariantTensorData* data) const { data->tensors_ = vec; }

  bool Decode(VariantTensorData data) {
    vec = std::move(data.tensors_);
    return true;
  }

  std::string TypeName() const { return "TensorList"; }

  std::vector<Tensor> vec;
};

TEST(VariantTest, TensorListTest) {
  Variant x;

  TensorList vec;
  for (int i = 0; i < 4; ++i) {
    Tensor elem(DT_INT32, {1});
    elem.flat<int>()(0) = i;
    vec.vec.push_back(elem);
  }

  for (int i = 0; i < 4; ++i) {
    Tensor elem(DT_FLOAT, {1});
    elem.flat<float>()(0) = 2 * i;
    vec.vec.push_back(elem);
  }

  x = vec;

  EXPECT_EQ(x.TypeName(), "TensorList");
  EXPECT_EQ(x.DebugString(), "Variant<type: TensorList value: ?>");
  const TensorList& stored_vec = *x.get<TensorList>();
  for (int i = 0; i < 4; ++i) {
    EXPECT_EQ(stored_vec.vec[i].flat<int>()(0), i);
  }
  for (int i = 0; i < 4; ++i) {
    EXPECT_EQ(stored_vec.vec[i + 4].flat<float>()(0), 2 * i);
  }

  VariantTensorData serialized;
  x.Encode(&serialized);

  Variant y = TensorList();
  y.Decode(serialized);

  const TensorList& decoded_vec = *y.get<TensorList>();
  for (int i = 0; i < 4; ++i) {
    EXPECT_EQ(decoded_vec.vec[i].flat<int>()(0), i);
  }
  for (int i = 0; i < 4; ++i) {
    EXPECT_EQ(decoded_vec.vec[i + 4].flat<float>()(0), 2 * i);
  }

  VariantTensorDataProto data;
  serialized.ToProto(&data);
  const Variant y_unknown = data;
  EXPECT_EQ(y_unknown.TypeName(), "TensorList");
  EXPECT_EQ(y_unknown.TypeId(), TypeIndex::Make<VariantTensorDataProto>());
  EXPECT_EQ(y_unknown.DebugString(),
            absl::StrCat("Variant<type: TensorList value: ", data.DebugString(),
                         ">"));
}

template <bool BIG>
void TestVariantArray() {
  Variant x[2];
  x[0] = Int<BIG>{2};
  x[1] = Float<BIG>{2.0f};

  EXPECT_EQ(x[0].get<Int<BIG>>()->value, 2);
  EXPECT_EQ(x[1].get<Float<BIG>>()->value, 2.0f);
}

TEST(VariantTest, VariantArray) { TestVariantArray<false>(); }

TEST(VariantTest, VariantArrayBig) { TestVariantArray<true>(); }

template <bool BIG>
void PodUpdateTest() {
  struct Pod {
    int x;
    float y;
    char big[BIG ? 256 : 1];

    std::string TypeName() const { return "POD"; }
  };

  Variant x = Pod{10, 20.f};
  EXPECT_NE(x.get<Pod>(), nullptr);
  EXPECT_EQ(x.TypeName(), "POD");
  EXPECT_EQ(x.DebugString(), "Variant<type: POD value: ?>");

  x.get<Pod>()->x += x.get<Pod>()->y;
  EXPECT_EQ(x.get<Pod>()->x, 30);
}

TEST(VariantTest, PodUpdate) { PodUpdateTest<false>(); }

TEST(VariantTest, PodUpdateBig) { PodUpdateTest<true>(); }

template <bool BIG>
void TestEncodeDecodePod() {
  struct Pod {
    int x;
    float y;
    char big[BIG ? 256 : 1];

    std::string TypeName() const { return "POD"; }
  };

  Variant x;
  Pod p{10, 20.0f};
  x = p;

  VariantTensorData serialized;
  x.Encode(&serialized);

  Variant y = Pod{};
  y.Decode(serialized);

  EXPECT_EQ(p.x, y.get<Pod>()->x);
  EXPECT_EQ(p.y, y.get<Pod>()->y);
}

TEST(VariantTest, EncodeDecodePod) { TestEncodeDecodePod<false>(); }

TEST(VariantTest, EncodeDecodePodBig) { TestEncodeDecodePod<true>(); }

TEST(VariantTest, EncodeDecodeTensor) {
  Variant x;
  Tensor t(DT_INT32, {});
  t.flat<int>()(0) = 42;
  x = t;

  VariantTensorData serialized;
  x.Encode(&serialized);

  Variant y = Tensor();
  y.Decode(serialized);
  EXPECT_EQ(y.DebugString(),
            "Variant<type: tensorflow::Tensor value: Tensor<type: int32 shape: "
            "[] values: 42>>");
  EXPECT_EQ(x.get<Tensor>()->flat<int>()(0), y.get<Tensor>()->flat<int>()(0));
}

TEST(BoolVariantTest, DecodeNonBool) {
  Tensor parsed(DT_VARIANT);
  TensorProto tensor_proto;
  tensor_proto.set_dtype(DT_VARIANT);
  VariantTensorDataProto* variant = tensor_proto.add_variant_val();
  variant->set_type_name("bool");
  variant->set_metadata("-");  // 42
  EXPECT_TRUE(parsed.FromProto(tensor_proto));
  EXPECT_EQ(parsed.NumElements(), 1);
  EXPECT_TRUE(parsed.flat<Variant>()(0).get<bool>());
}

}  // end namespace tensorflow
