//
// Copyright 2022 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// Suballocation.h:
//    Defines class interface for BufferBlock and Suballocation and other related classes.
//

#ifndef LIBANGLE_RENDERER_VULKAN_SUBALLOCATION_H_
#define LIBANGLE_RENDERER_VULKAN_SUBALLOCATION_H_

#include "common/SimpleMutex.h"
#include "common/debug.h"
#include "common/unsafe_buffers.h"
#include "libANGLE/angletypes.h"
#include "libANGLE/renderer/serial_utils.h"
#include "libANGLE/renderer/vulkan/vk_cache_utils.h"
#include "libANGLE/renderer/vulkan/vk_resource.h"
#include "libANGLE/renderer/vulkan/vk_utils.h"
#include "libANGLE/renderer/vulkan/vk_wrapper.h"

namespace rx
{
enum class MemoryAllocationType;

namespace vk
{
class ErrorContext;

// BufferBlock
class BufferBlock final : angle::NonCopyable
{
  public:
    BufferBlock();
    BufferBlock(BufferBlock &&other);
    ~BufferBlock();

    void destroy(Renderer *renderer);
    VkResult init(ErrorContext *context,
                  Buffer &buffer,
                  uint32_t memoryTypeIndex,
                  vma::VirtualBlockCreateFlags flags,
                  DeviceMemory &deviceMemory,
                  VkMemoryPropertyFlags memoryPropertyFlags,
                  VkDeviceSize size);
    void initWithoutVirtualBlock(ErrorContext *context,
                                 Buffer &buffer,
                                 MemoryAllocationType memoryAllocationType,
                                 uint32_t memoryTypeIndex,
                                 DeviceMemory &deviceMemory,
                                 VkMemoryPropertyFlags memoryPropertyFlags,
                                 VkDeviceSize size,
                                 VkDeviceSize allocatedBufferSize);

    BufferBlock &operator=(BufferBlock &&other);

    const Buffer &getBuffer() const { return mBuffer; }
    const DeviceMemory &getDeviceMemory() const { return mDeviceMemory; }
    DeviceMemory &getDeviceMemory() { return mDeviceMemory; }
    BufferSerial getBufferSerial() const { return mSerial; }

    VkMemoryPropertyFlags getMemoryPropertyFlags() const;
    VkDeviceSize getMemorySize() const;
    VkDeviceSize getAllocatedBufferSize() const;

    VkResult allocate(VkDeviceSize size,
                      VkDeviceSize alignment,
                      VmaVirtualAllocation *allocationOut,
                      VkDeviceSize *offsetOut);
    void free(VmaVirtualAllocation allocation, VkDeviceSize offset);
    VkBool32 isEmpty();

    bool hasVirtualBlock() const { return mVirtualBlock.valid(); }
    bool isHostVisible() const;
    bool isCoherent() const;
    bool isCached() const;
    bool isMapped() const;
    VkResult map(const VkDevice device);
    void unmap(const VkDevice device);
    uint8_t *getMappedMemory() const;

    // This should be called whenever this found to be empty. The total number of count of empty is
    // returned.
    int32_t getAndIncrementEmptyCounter();
    void calculateStats(vma::StatInfo *pStatInfo) const;

  private:
    mutable angle::SimpleMutex mVirtualBlockMutex;
    VirtualBlock mVirtualBlock;

    Buffer mBuffer;
    DeviceMemory mDeviceMemory;
    VkMemoryPropertyFlags mMemoryPropertyFlags;

    // Memory size that user of this object thinks we have.
    VkDeviceSize mSize;
    // Memory size that was actually allocated for this object.
    VkDeviceSize mAllocatedBufferSize;
    // Memory allocation type used for this object.
    MemoryAllocationType mMemoryAllocationType;
    // Memory type index used for the allocation. It can be used to determine the heap index.
    uint32_t mMemoryTypeIndex;

    uint8_t *mMappedMemory;
    BufferSerial mSerial;
    // Heuristic information for pruneEmptyBuffer. This tracks how many times (consecutively) this
    // buffer block is found to be empty when pruneEmptyBuffer is called. This gets reset whenever
    // it becomes non-empty.
    int32_t mCountRemainsEmpty;
};
using BufferBlockPointer       = std::unique_ptr<BufferBlock>;
using BufferBlockPointerVector = std::vector<BufferBlockPointer>;

class BufferBlockGarbageList final : angle::NonCopyable
{
  public:
    BufferBlockGarbageList() : mBufferBlockQueue(kInitialQueueCapacity) {}
    ~BufferBlockGarbageList() { ASSERT(mBufferBlockQueue.empty()); }

    void add(BufferBlock *bufferBlock)
    {
        std::unique_lock<angle::SimpleMutex> lock(mMutex);
        if (mBufferBlockQueue.full())
        {
            size_t newCapacity = mBufferBlockQueue.capacity() << 1;
            mBufferBlockQueue.updateCapacity(newCapacity);
        }
        mBufferBlockQueue.push(bufferBlock);
    }

    // Number of buffer blocks destroyed is returned.
    size_t pruneEmptyBufferBlocks(Renderer *renderer)
    {
        size_t blocksDestroyed = 0;
        if (!mBufferBlockQueue.empty())
        {
            std::unique_lock<angle::SimpleMutex> lock(mMutex);
            size_t count = mBufferBlockQueue.size();
            for (size_t i = 0; i < count; i++)
            {
                BufferBlock *block = mBufferBlockQueue.front();
                mBufferBlockQueue.pop();
                if (block->isEmpty())
                {
                    block->destroy(renderer);
                    ++blocksDestroyed;
                }
                else
                {
                    mBufferBlockQueue.push(block);
                }
            }
        }
        return blocksDestroyed;
    }

    bool empty() const { return mBufferBlockQueue.empty(); }

  private:
    static constexpr size_t kInitialQueueCapacity = 4;
    angle::SimpleMutex mMutex;
    angle::FixedQueue<BufferBlock *> mBufferBlockQueue;
};

// BufferSuballocation
class BufferSuballocation final : angle::NonCopyable
{
  public:
    BufferSuballocation();

    BufferSuballocation(BufferSuballocation &&other);
    BufferSuballocation &operator=(BufferSuballocation &&other);

    void destroy(Renderer *renderer);

    void init(BufferBlock *block,
              VmaVirtualAllocation allocation,
              VkDeviceSize offset,
              VkDeviceSize size);
    void initWithEntireBuffer(ErrorContext *context,
                              Buffer &buffer,
                              MemoryAllocationType memoryAllocationType,
                              uint32_t memoryTypeIndex,
                              DeviceMemory &deviceMemory,
                              VkMemoryPropertyFlags memoryPropertyFlags,
                              VkDeviceSize size,
                              VkDeviceSize allocatedBufferSize);

    const Buffer &getBuffer() const;
    VkDeviceSize getSize() const;
    const DeviceMemory &getDeviceMemory() const;
    VkMemoryMapFlags getMemoryPropertyFlags() const;
    bool isHostVisible() const;
    bool isCoherent() const;
    bool isCached() const;
    bool isMapped() const;
    uint8_t *getMappedMemory() const;
    void flush(Renderer *renderer);
    void invalidate(Renderer *renderer);
    VkDeviceSize getOffset() const;
    bool valid() const;
    VkResult map(ErrorContext *context);
    BufferSerial getBlockSerial() const;
    uint8_t *getBlockMemory() const;
    VkDeviceSize getBlockMemorySize() const;
    bool isSuballocated() const { return mBufferBlock->hasVirtualBlock(); }
    BufferBlock *getBufferBlock() const { return mBufferBlock; }

  private:
    // Only used by DynamicBuffer where DynamicBuffer does the actual suballocation and pass the
    // offset/size to this object. Since DynamicBuffer does not have a VMA virtual allocator, they
    // will be ignored at destroy time. The offset/size is set here mainly for easy retrieval when
    // the BufferHelper object is passed around.
    friend class BufferHelper;
    void setOffsetAndSize(VkDeviceSize offset, VkDeviceSize size);

    BufferBlock *mBufferBlock;
    VmaVirtualAllocation mAllocation;
    VkDeviceSize mOffset;
    VkDeviceSize mSize;
};

class BufferSuballocationGarbage
{
  public:
    BufferSuballocationGarbage() = default;
    BufferSuballocationGarbage(BufferSuballocationGarbage &&other)
        : mLifetime(other.mLifetime),
          mSuballocation(std::move(other.mSuballocation)),
          mBuffer(std::move(other.mBuffer))
    {}
    BufferSuballocationGarbage &operator=(BufferSuballocationGarbage &&other)
    {
        mLifetime      = other.mLifetime;
        mSuballocation = std::move(other.mSuballocation);
        mBuffer        = std::move(other.mBuffer);
        return *this;
    }
    BufferSuballocationGarbage(const ResourceUse &use,
                               BufferSuballocation &&suballocation,
                               Buffer &&buffer)
        : mLifetime(use), mSuballocation(std::move(suballocation)), mBuffer(std::move(buffer))
    {}
    ~BufferSuballocationGarbage() = default;

    bool destroyIfComplete(Renderer *renderer);
    bool hasResourceUseSubmitted(Renderer *renderer) const;
    VkDeviceSize getSize() const { return mSuballocation.getSize(); }
    bool isSuballocated() const { return mSuballocation.isSuballocated(); }

  private:
    ResourceUse mLifetime;
    BufferSuballocation mSuballocation;
    Buffer mBuffer;
};

// BufferBlock implementation.
ANGLE_INLINE VkMemoryPropertyFlags BufferBlock::getMemoryPropertyFlags() const
{
    return mMemoryPropertyFlags;
}

ANGLE_INLINE VkDeviceSize BufferBlock::getMemorySize() const
{
    return mSize;
}

ANGLE_INLINE VkDeviceSize BufferBlock::getAllocatedBufferSize() const
{
    return mAllocatedBufferSize;
}

ANGLE_INLINE VkBool32 BufferBlock::isEmpty()
{
    std::unique_lock<angle::SimpleMutex> lock(mVirtualBlockMutex);
    return vma::IsVirtualBlockEmpty(mVirtualBlock.getHandle());
}

ANGLE_INLINE bool BufferBlock::isHostVisible() const
{
    return (mMemoryPropertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0;
}

ANGLE_INLINE bool BufferBlock::isCoherent() const
{
    return (mMemoryPropertyFlags & VK_MEMORY_PROPERTY_HOST_COHERENT_BIT) != 0;
}

ANGLE_INLINE bool BufferBlock::isCached() const
{
    return (mMemoryPropertyFlags & VK_MEMORY_PROPERTY_HOST_CACHED_BIT) != 0;
}

ANGLE_INLINE bool BufferBlock::isMapped() const
{
    return mMappedMemory != nullptr;
}

ANGLE_INLINE uint8_t *BufferBlock::getMappedMemory() const
{
    ASSERT(mMappedMemory != nullptr);
    return mMappedMemory;
}

// BufferSuballocation implementation.
ANGLE_INLINE BufferSuballocation::BufferSuballocation()
    : mBufferBlock(nullptr), mAllocation(VK_NULL_HANDLE), mOffset(0), mSize(0)
{}

ANGLE_INLINE BufferSuballocation::BufferSuballocation(BufferSuballocation &&other)
    : BufferSuballocation()
{
    *this = std::move(other);
}

ANGLE_INLINE BufferSuballocation &BufferSuballocation::operator=(BufferSuballocation &&other)
{
    std::swap(mBufferBlock, other.mBufferBlock);
    std::swap(mSize, other.mSize);
    std::swap(mAllocation, other.mAllocation);
    std::swap(mOffset, other.mOffset);
    return *this;
}

ANGLE_INLINE bool BufferSuballocation::valid() const
{
    return mBufferBlock != nullptr;
}

ANGLE_INLINE void BufferSuballocation::destroy(Renderer *renderer)
{
    if (valid())
    {
        ASSERT(mBufferBlock);
        if (mBufferBlock->hasVirtualBlock())
        {
            mBufferBlock->free(mAllocation, mOffset);
            mBufferBlock = nullptr;
        }
        else
        {
            // When virtual block is invalid, this is the standalone buffer that are created by
            // BufferSuballocation::initWithEntireBuffer call. In this case, vmaBufferSuballocation
            // owns block, we must properly delete the block object.
            mBufferBlock->destroy(renderer);
            SafeDelete(mBufferBlock);
        }
        mAllocation = VK_NULL_HANDLE;
        mOffset     = 0;
        mSize       = 0;
    }
}

ANGLE_INLINE void BufferSuballocation::init(BufferBlock *block,
                                            VmaVirtualAllocation allocation,
                                            VkDeviceSize offset,
                                            VkDeviceSize size)
{
    ASSERT(!valid());
    ASSERT(block != nullptr);
    ASSERT(allocation != VK_NULL_HANDLE);
    ASSERT(offset != VK_WHOLE_SIZE);
    mBufferBlock = block;
    mAllocation  = allocation;
    mOffset      = offset;
    mSize        = size;
}

ANGLE_INLINE void BufferSuballocation::initWithEntireBuffer(
    ErrorContext *context,
    Buffer &buffer,
    MemoryAllocationType memoryAllocationType,
    uint32_t memoryTypeIndex,
    DeviceMemory &deviceMemory,
    VkMemoryPropertyFlags memoryPropertyFlags,
    VkDeviceSize size,
    VkDeviceSize allocatedBufferSize)
{
    ASSERT(!valid());

    std::unique_ptr<BufferBlock> block = std::make_unique<BufferBlock>();
    block->initWithoutVirtualBlock(context, buffer, memoryAllocationType, memoryTypeIndex,
                                   deviceMemory, memoryPropertyFlags, size, allocatedBufferSize);

    mBufferBlock = block.release();
    mAllocation  = VK_NULL_HANDLE;
    mOffset      = 0;
    mSize        = mBufferBlock->getMemorySize();
}

ANGLE_INLINE const Buffer &BufferSuballocation::getBuffer() const
{
    return mBufferBlock->getBuffer();
}

ANGLE_INLINE VkDeviceSize BufferSuballocation::getSize() const
{
    return mSize;
}

ANGLE_INLINE const DeviceMemory &BufferSuballocation::getDeviceMemory() const
{
    return mBufferBlock->getDeviceMemory();
}

ANGLE_INLINE VkMemoryMapFlags BufferSuballocation::getMemoryPropertyFlags() const
{
    return mBufferBlock->getMemoryPropertyFlags();
}

ANGLE_INLINE bool BufferSuballocation::isHostVisible() const
{
    return mBufferBlock->isHostVisible();
}
ANGLE_INLINE bool BufferSuballocation::isCoherent() const
{
    return mBufferBlock->isCoherent();
}
ANGLE_INLINE bool BufferSuballocation::isCached() const
{
    return mBufferBlock->isCached();
}
ANGLE_INLINE bool BufferSuballocation::isMapped() const
{
    return mBufferBlock->isMapped();
}
ANGLE_INLINE uint8_t *BufferSuballocation::getMappedMemory() const
{
    return ANGLE_UNSAFE_TODO(mBufferBlock->getMappedMemory() + getOffset());
}

ANGLE_INLINE VkDeviceSize BufferSuballocation::getOffset() const
{
    return mOffset;
}

ANGLE_INLINE void BufferSuballocation::setOffsetAndSize(VkDeviceSize offset, VkDeviceSize size)
{
    mOffset = offset;
    mSize   = size;
}

ANGLE_INLINE uint8_t *BufferSuballocation::getBlockMemory() const
{
    return mBufferBlock->getMappedMemory();
}
ANGLE_INLINE VkDeviceSize BufferSuballocation::getBlockMemorySize() const
{
    return mBufferBlock->getMemorySize();
}
ANGLE_INLINE BufferSerial BufferSuballocation::getBlockSerial() const
{
    ASSERT(valid());
    return mBufferBlock->getBufferSerial();
}
}  // namespace vk
}  // namespace rx

#endif  // LIBANGLE_RENDERER_VULKAN_SUBALLOCATION_H_
