/*
 * Copyright 2021 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "src/gpu/ganesh/vk/GrVkBuffer.h"

#include "include/gpu/GrDirectContext.h"
#include "src/gpu/ganesh/GrDirectContextPriv.h"
#include "src/gpu/ganesh/GrResourceProvider.h"
#include "src/gpu/ganesh/vk/GrVkDescriptorSet.h"
#include "src/gpu/ganesh/vk/GrVkGpu.h"
#include "src/gpu/ganesh/vk/GrVkUtil.h"
#include "src/gpu/vk/VulkanMemory.h"

#define VK_CALL(GPU, X) GR_VK_CALL(GPU->vkInterface(), X)

GrVkBuffer::GrVkBuffer(GrVkGpu* gpu,
                       size_t sizeInBytes,
                       GrGpuBufferType bufferType,
                       GrAccessPattern accessPattern,
                       VkBuffer buffer,
                       const skgpu::VulkanAlloc& alloc,
                       const GrVkDescriptorSet* uniformDescriptorSet,
                       std::string_view label)
        : GrGpuBuffer(gpu, sizeInBytes, bufferType, accessPattern, label)
        , fBuffer(buffer)
        , fAlloc(alloc)
        , fUniformDescriptorSet(uniformDescriptorSet) {
    // We always require dynamic buffers to be mappable
    SkASSERT(accessPattern != kDynamic_GrAccessPattern || this->isVkMappable());
    SkASSERT(bufferType != GrGpuBufferType::kUniform || uniformDescriptorSet);
    this->registerWithCache(skgpu::Budgeted::kYes);
}

static const GrVkDescriptorSet* make_uniform_desc_set(GrVkGpu* gpu, VkBuffer buffer, size_t size) {
    const GrVkDescriptorSet* descriptorSet = gpu->resourceProvider().getUniformDescriptorSet();
    if (!descriptorSet) {
        return nullptr;
    }

    VkDescriptorBufferInfo bufferInfo;
    memset(&bufferInfo, 0, sizeof(VkDescriptorBufferInfo));
    bufferInfo.buffer = buffer;
    bufferInfo.offset = 0;
    bufferInfo.range = size;

    VkWriteDescriptorSet descriptorWrite;
    memset(&descriptorWrite, 0, sizeof(VkWriteDescriptorSet));
    descriptorWrite.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    descriptorWrite.pNext = nullptr;
    descriptorWrite.dstSet = *descriptorSet->descriptorSet();
    descriptorWrite.dstBinding = GrVkUniformHandler::kUniformBinding;
    descriptorWrite.dstArrayElement = 0;
    descriptorWrite.descriptorCount = 1;
    descriptorWrite.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    descriptorWrite.pImageInfo = nullptr;
    descriptorWrite.pBufferInfo = &bufferInfo;
    descriptorWrite.pTexelBufferView = nullptr;

    GR_VK_CALL(gpu->vkInterface(),
               UpdateDescriptorSets(gpu->device(), 1, &descriptorWrite, 0, nullptr));
    return descriptorSet;
}

sk_sp<GrVkBuffer> GrVkBuffer::Make(GrVkGpu* gpu,
                                   size_t size,
                                   GrGpuBufferType bufferType,
                                   GrAccessPattern accessPattern) {
    VkBuffer buffer;
    skgpu::VulkanAlloc alloc;

    // The only time we don't require mappable buffers is when we have a static access pattern and
    // we're on a device where gpu only memory has faster reads on the gpu than memory that is also
    // mappable on the cpu. Protected memory always uses mappable buffers.
    bool requiresMappable = gpu->protectedContext() ||
                            accessPattern == kDynamic_GrAccessPattern ||
                            accessPattern == kStream_GrAccessPattern ||
                            !gpu->vkCaps().gpuOnlyBuffersMorePerformant();

    using BufferUsage = skgpu::VulkanMemoryAllocator::BufferUsage;
    BufferUsage allocUsage;

    // create the buffer object
    VkBufferCreateInfo bufInfo;
    memset(&bufInfo, 0, sizeof(VkBufferCreateInfo));
    bufInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
    bufInfo.flags = 0;
    bufInfo.size = size;
    // To support SkMesh buffer updates we make Vertex and Index buffers capable of being transfer
    // dsts.
    switch (bufferType) {
        case GrGpuBufferType::kVertex:
            bufInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
            allocUsage = requiresMappable ? BufferUsage::kCpuWritesGpuReads : BufferUsage::kGpuOnly;
            break;
        case GrGpuBufferType::kIndex:
            bufInfo.usage = VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
            allocUsage = requiresMappable ? BufferUsage::kCpuWritesGpuReads : BufferUsage::kGpuOnly;
            break;
        case GrGpuBufferType::kDrawIndirect:
            bufInfo.usage = VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT;
            allocUsage = requiresMappable ? BufferUsage::kCpuWritesGpuReads : BufferUsage::kGpuOnly;
            break;
        case GrGpuBufferType::kUniform:
            bufInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;
            allocUsage = BufferUsage::kCpuWritesGpuReads;
            break;
        case GrGpuBufferType::kXferCpuToGpu:
            bufInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
            allocUsage = BufferUsage::kTransfersFromCpuToGpu;
            break;
        case GrGpuBufferType::kXferGpuToCpu:
            bufInfo.usage = VK_BUFFER_USAGE_TRANSFER_DST_BIT;
            allocUsage = BufferUsage::kTransfersFromGpuToCpu;
            break;
    }
    // We may not always get a mappable buffer for non dynamic access buffers. Thus we set the
    // transfer dst usage bit in case we need to do a copy to write data.
    // TODO: It doesn't really hurt setting this extra usage flag, but maybe we can narrow the scope
    // of buffers we set it on more than just not dynamic.
    if (!requiresMappable) {
        bufInfo.usage |= VK_BUFFER_USAGE_TRANSFER_DST_BIT;
    }

    bufInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    bufInfo.queueFamilyIndexCount = 0;
    bufInfo.pQueueFamilyIndices = nullptr;

    VkResult err;
    err = VK_CALL(gpu, CreateBuffer(gpu->device(), &bufInfo, nullptr, &buffer));
    if (err) {
        return nullptr;
    }

    auto checkResult = [gpu](VkResult result) {
        return gpu->checkVkResult(result);
    };
    auto allocator = gpu->memoryAllocator();
    bool shouldPersistentlyMapCpuToGpu = gpu->vkCaps().shouldPersistentlyMapCpuToGpuBuffers();
    if (!skgpu::VulkanMemory::AllocBufferMemory(allocator,
                                                buffer,
                                                allocUsage,
                                                shouldPersistentlyMapCpuToGpu,
                                                checkResult,
                                                &alloc)) {
        VK_CALL(gpu, DestroyBuffer(gpu->device(), buffer, nullptr));
        return nullptr;
    }

    // Bind buffer
    GR_VK_CALL_RESULT(gpu, err, BindBufferMemory(gpu->device(),
                                                 buffer,
                                                 alloc.fMemory,
                                                 alloc.fOffset));
    if (err) {
        skgpu::VulkanMemory::FreeBufferMemory(allocator, alloc);
        VK_CALL(gpu, DestroyBuffer(gpu->device(), buffer, nullptr));
        return nullptr;
    }

    // If this is a uniform buffer we must setup a descriptor set
    const GrVkDescriptorSet* uniformDescSet = nullptr;
    if (bufferType == GrGpuBufferType::kUniform) {
        uniformDescSet = make_uniform_desc_set(gpu, buffer, size);
        if (!uniformDescSet) {
            VK_CALL(gpu, DestroyBuffer(gpu->device(), buffer, nullptr));
            skgpu::VulkanMemory::FreeBufferMemory(allocator, alloc);
            return nullptr;
        }
    }

    return sk_sp<GrVkBuffer>(new GrVkBuffer(
            gpu, size, bufferType, accessPattern, buffer, alloc, uniformDescSet,
            /*label=*/"MakeVkBuffer"));
}

void GrVkBuffer::vkMap(size_t readOffset, size_t readSize) {
    SkASSERT(!fMapPtr);
    if (this->isVkMappable()) {
        // Not every buffer will use command buffer usage refs and instead the command buffer just
        // holds normal refs. Systems higher up in Ganesh should be making sure not to reuse a
        // buffer that currently has a ref held by something else. However, we do need to make sure
        // there isn't a buffer with just a command buffer usage that is trying to be mapped.
        SkASSERT(this->internalHasNoCommandBufferUsages());
        SkASSERT(fAlloc.fSize > 0);
        SkASSERT(fAlloc.fSize >= readOffset + readSize);

        GrVkGpu* gpu = this->getVkGpu();
        auto checkResult = [gpu](VkResult result) {
            return gpu->checkVkResult(result);
        };
        auto allocator = gpu->memoryAllocator();
        fMapPtr = skgpu::VulkanMemory::MapAlloc(allocator, fAlloc, checkResult);
        if (fMapPtr && readSize != 0) {
            // "Invalidate" here means make device writes visible to the host. That is, it makes
            // sure any GPU writes are finished in the range we might read from.
            skgpu::VulkanMemory::InvalidateMappedAlloc(allocator,
                                                       fAlloc,
                                                       readOffset,
                                                       readSize,
                                                       checkResult);
        }
    }
}

void GrVkBuffer::vkUnmap(size_t flushOffset, size_t flushSize) {
    SkASSERT(fMapPtr && this->isVkMappable());

    SkASSERT(fAlloc.fSize > 0);
    SkASSERT(fAlloc.fSize >= flushOffset + flushSize);

    GrVkGpu* gpu = this->getVkGpu();
    auto checkResult = [gpu](VkResult result) {
        return gpu->checkVkResult(result);
    };
    auto allocator = this->getVkGpu()->memoryAllocator();
    skgpu::VulkanMemory::FlushMappedAlloc(allocator, fAlloc, flushOffset, flushSize, checkResult);
    skgpu::VulkanMemory::UnmapAlloc(allocator, fAlloc);
}

void GrVkBuffer::copyCpuDataToGpuBuffer(const void* src, size_t offset, size_t size) {
    SkASSERT(src);

    GrVkGpu* gpu = this->getVkGpu();

    // We should never call this method in protected contexts.
    SkASSERT(!gpu->protectedContext());

    // The vulkan api restricts the use of vkCmdUpdateBuffer to updates that are less than or equal
    // to 65536 bytes and a size and offset that are both 4 byte aligned.
    if ((size <= 65536) && SkIsAlign4(size) && SkIsAlign4(offset) &&
        !gpu->vkCaps().avoidUpdateBuffers()) {
        gpu->updateBuffer(sk_ref_sp(this), src, offset, size);
    } else {
        GrResourceProvider* resourceProvider = gpu->getContext()->priv().resourceProvider();
        sk_sp<GrGpuBuffer> transferBuffer = resourceProvider->createBuffer(
                src,
                size,
                GrGpuBufferType::kXferCpuToGpu,
                kDynamic_GrAccessPattern);
        if (!transferBuffer) {
            return;
        }

        gpu->transferFromBufferToBuffer(std::move(transferBuffer),
                                        /*srcOffset=*/0,
                                        sk_ref_sp(this),
                                        offset,
                                        size);
    }
}

void GrVkBuffer::addMemoryBarrier(VkAccessFlags srcAccessMask,
                                  VkAccessFlags dstAccesMask,
                                  VkPipelineStageFlags srcStageMask,
                                  VkPipelineStageFlags dstStageMask,
                                  bool byRegion) const {
    VkBufferMemoryBarrier bufferMemoryBarrier = {
            VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER,  // sType
            nullptr,                                  // pNext
            srcAccessMask,                            // srcAccessMask
            dstAccesMask,                             // dstAccessMask
            VK_QUEUE_FAMILY_IGNORED,                  // srcQueueFamilyIndex
            VK_QUEUE_FAMILY_IGNORED,                  // dstQueueFamilyIndex
            fBuffer,                                  // buffer
            0,                                        // offset
            this->size(),                             // size
    };

    // TODO: restrict to area of buffer we're interested in
    this->getVkGpu()->addBufferMemoryBarrier(srcStageMask, dstStageMask, byRegion,
                                             &bufferMemoryBarrier);
}

void GrVkBuffer::vkRelease() {
    if (this->wasDestroyed()) {
        return;
    }

    if (fMapPtr) {
        this->vkUnmap(0, this->size());
        fMapPtr = nullptr;
    }

    if (fUniformDescriptorSet) {
        fUniformDescriptorSet->recycle();
        fUniformDescriptorSet = nullptr;
    }

    SkASSERT(fBuffer);
    SkASSERT(fAlloc.fMemory && fAlloc.fBackendMemory);
    VK_CALL(this->getVkGpu(), DestroyBuffer(this->getVkGpu()->device(), fBuffer, nullptr));
    fBuffer = VK_NULL_HANDLE;

    skgpu::VulkanMemory::FreeBufferMemory(this->getVkGpu()->memoryAllocator(), fAlloc);
    fAlloc.fMemory = VK_NULL_HANDLE;
    fAlloc.fBackendMemory = 0;
}

void GrVkBuffer::onRelease() {
    this->vkRelease();
    this->GrGpuBuffer::onRelease();
}

void GrVkBuffer::onAbandon() {
    this->vkRelease();
    this->GrGpuBuffer::onAbandon();
}

void GrVkBuffer::onMap(MapType type) {
    this->vkMap(0, type == MapType::kRead ? this->size() : 0);
}

void GrVkBuffer::onUnmap(MapType type) {
    this->vkUnmap(0, type == MapType::kWriteDiscard ? this->size() : 0);
}

bool GrVkBuffer::onClearToZero() { return this->getVkGpu()->zeroBuffer(sk_ref_sp(this)); }

bool GrVkBuffer::onUpdateData(const void* src, size_t offset, size_t size, bool /*preserve*/) {
    if (this->isVkMappable()) {
        // We won't be reading the mapped memory so pass an empty range.
        this->vkMap(0, 0);
        if (!fMapPtr) {
            return false;
        }
        memcpy(SkTAddOffset<void>(fMapPtr, offset), src, size);
        // We only need to flush the updated portion so pass the true range here.
        this->vkUnmap(offset, size);
        fMapPtr = nullptr;
    } else {
        this->copyCpuDataToGpuBuffer(src, offset, size);
    }
    return true;
}

GrVkGpu* GrVkBuffer::getVkGpu() const {
    SkASSERT(!this->wasDestroyed());
    return static_cast<GrVkGpu*>(this->getGpu());
}

const VkDescriptorSet* GrVkBuffer::uniformDescriptorSet() const {
    SkASSERT(fUniformDescriptorSet);
    return fUniformDescriptorSet->descriptorSet();
}

