/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/

#include "src/gpu/vk/GrVkMemory.h"

#include "include/gpu/vk/GrVkMemoryAllocator.h"
#include "src/gpu/vk/GrVkGpu.h"
#include "src/gpu/vk/GrVkUtil.h"

using AllocationPropertyFlags = GrVkMemoryAllocator::AllocationPropertyFlags;
using BufferUsage = GrVkMemoryAllocator::BufferUsage;

static void report_memory_usage(GrVkMemoryAllocator* allocator) {
#if SK_HISTOGRAMS_ENABLED
    uint64_t allocatedMemory = allocator->totalAllocatedMemory();
    uint64_t usedMemory = allocator->totalUsedMemory();
    SkASSERT(usedMemory <= allocatedMemory);
    SK_HISTOGRAM_PERCENTAGE("VulkanMemoryAllocator.PercentUsed",
                            (usedMemory * 100) / allocatedMemory);
    // allocatedMemory is in bytes and need to be reported it in kilobytes. SK_HISTOGRAM_MEMORY_KB
    // supports samples up to around 500MB which should support the amounts of memory we allocate.
    SK_HISTOGRAM_MEMORY_KB("VulkanMemoryAllocator.AmountAllocated", allocatedMemory >> 10);
#endif
}

static BufferUsage get_buffer_usage(GrVkBuffer::Type type, bool dynamic) {
    switch (type) {
        case GrVkBuffer::kVertex_Type: // fall through
        case GrVkBuffer::kIndex_Type: // fall through
        case GrVkBuffer::kIndirect_Type: // fall through
        case GrVkBuffer::kTexel_Type:
            return dynamic ? BufferUsage::kCpuWritesGpuReads : BufferUsage::kGpuOnly;
        case GrVkBuffer::kUniform_Type:
            SkASSERT(dynamic);
            return BufferUsage::kCpuWritesGpuReads;
        case GrVkBuffer::kCopyRead_Type: // fall through
        case GrVkBuffer::kCopyWrite_Type:
            return BufferUsage::kCpuOnly;
    }
    SK_ABORT("Invalid GrVkBuffer::Type");
}

bool GrVkMemory::AllocAndBindBufferMemory(GrVkGpu* gpu,
                                          VkBuffer buffer,
                                          GrVkBuffer::Type type,
                                          bool dynamic,
                                          GrVkAlloc* alloc) {
    GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
    GrVkBackendMemory memory = 0;

    GrVkMemoryAllocator::BufferUsage usage = get_buffer_usage(type, dynamic);

    AllocationPropertyFlags propFlags;
    if (usage == GrVkMemoryAllocator::BufferUsage::kCpuWritesGpuReads) {
        // In general it is always fine (and often better) to keep buffers always mapped.
        // TODO: According to AMDs guide for the VulkanMemoryAllocator they suggest there are two
        // cases when keeping it mapped can hurt. The first is when running on Win7 or Win8 (Win 10
        // is fine). In general, by the time Vulkan ships it is probably less likely to be running
        // on non Win10 or newer machines. The second use case is if running on an AMD card and you
        // are using the special GPU local and host mappable memory. However, in general we don't
        // pick this memory as we've found it slower than using the cached host visible memory. In
        // the future if we find the need to special case either of these two issues we can add
        // checks for them here.
        propFlags = AllocationPropertyFlags::kPersistentlyMapped;
    } else {
        propFlags = AllocationPropertyFlags::kNone;
    }

    VkResult result = allocator->allocateBufferMemory(buffer, usage, propFlags, &memory);
    if (!gpu->checkVkResult(result)) {
        return false;
    }
    allocator->getAllocInfo(memory, alloc);

    // Bind buffer
    VkResult err;
    GR_VK_CALL_RESULT(gpu, err, BindBufferMemory(gpu->device(), buffer, alloc->fMemory,
                                                 alloc->fOffset));
    if (err) {
        FreeBufferMemory(gpu, type, *alloc);
        return false;
    }

    report_memory_usage(allocator);

    return true;
}

void GrVkMemory::FreeBufferMemory(const GrVkGpu* gpu, GrVkBuffer::Type type,
                                  const GrVkAlloc& alloc) {
    SkASSERT(alloc.fBackendMemory);
    GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
    allocator->freeMemory(alloc.fBackendMemory);
}

bool GrVkMemory::AllocAndBindImageMemory(GrVkGpu* gpu,
                                         VkImage image,
                                         bool linearTiling,
                                         GrVkAlloc* alloc) {
    SkASSERT(!linearTiling);
    GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
    GrVkBackendMemory memory = 0;

    VkMemoryRequirements memReqs;
    GR_VK_CALL(gpu->vkInterface(), GetImageMemoryRequirements(gpu->device(), image, &memReqs));

    AllocationPropertyFlags propFlags;
    // If we ever find that our allocator is not aggressive enough in using dedicated image
    // memory we can add a size check here to force the use of dedicate memory. However for now,
    // we let the allocators decide. The allocator can query the GPU for each image to see if the
    // GPU recommends or requires the use of dedicated memory.
    if (gpu->vkCaps().shouldAlwaysUseDedicatedImageMemory()) {
        propFlags = AllocationPropertyFlags::kDedicatedAllocation;
    } else {
        propFlags = AllocationPropertyFlags::kNone;
    }

    if (gpu->protectedContext()) {
        propFlags |= AllocationPropertyFlags::kProtected;
    }

    VkResult result = allocator->allocateImageMemory(image, propFlags, &memory);
    if (!gpu->checkVkResult(result)) {
        return false;
    }

    allocator->getAllocInfo(memory, alloc);

    // Bind buffer
    VkResult err;
    GR_VK_CALL_RESULT(gpu, err, BindImageMemory(gpu->device(), image, alloc->fMemory,
                                                alloc->fOffset));
    if (err) {
        FreeImageMemory(gpu, linearTiling, *alloc);
        return false;
    }

    report_memory_usage(allocator);

    return true;
}

void GrVkMemory::FreeImageMemory(const GrVkGpu* gpu, bool linearTiling,
                                 const GrVkAlloc& alloc) {
    SkASSERT(alloc.fBackendMemory);
    GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
    allocator->freeMemory(alloc.fBackendMemory);
}

void* GrVkMemory::MapAlloc(GrVkGpu* gpu, const GrVkAlloc& alloc) {
    SkASSERT(GrVkAlloc::kMappable_Flag & alloc.fFlags);
    SkASSERT(alloc.fBackendMemory);
    GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
    void* mapPtr;
    VkResult result = allocator->mapMemory(alloc.fBackendMemory, &mapPtr);
    if (!gpu->checkVkResult(result)) {
        return nullptr;
    }
    return mapPtr;
}

void GrVkMemory::UnmapAlloc(const GrVkGpu* gpu, const GrVkAlloc& alloc) {
    SkASSERT(alloc.fBackendMemory);
    GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
    allocator->unmapMemory(alloc.fBackendMemory);
}

void GrVkMemory::GetNonCoherentMappedMemoryRange(const GrVkAlloc& alloc, VkDeviceSize offset,
                                                 VkDeviceSize size, VkDeviceSize alignment,
                                                 VkMappedMemoryRange* range) {
    SkASSERT(alloc.fFlags & GrVkAlloc::kNoncoherent_Flag);
    offset = offset + alloc.fOffset;
    VkDeviceSize offsetDiff = offset & (alignment -1);
    offset = offset - offsetDiff;
    size = (size + alignment - 1) & ~(alignment - 1);
#ifdef SK_DEBUG
    SkASSERT(offset >= alloc.fOffset);
    SkASSERT(offset + size <= alloc.fOffset + alloc.fSize);
    SkASSERT(0 == (offset & (alignment-1)));
    SkASSERT(size > 0);
    SkASSERT(0 == (size & (alignment-1)));
#endif

    memset(range, 0, sizeof(VkMappedMemoryRange));
    range->sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
    range->memory = alloc.fMemory;
    range->offset = offset;
    range->size = size;
}

void GrVkMemory::FlushMappedAlloc(GrVkGpu* gpu, const GrVkAlloc& alloc, VkDeviceSize offset,
                                  VkDeviceSize size) {
    if (alloc.fFlags & GrVkAlloc::kNoncoherent_Flag) {
        SkASSERT(offset == 0);
        SkASSERT(size <= alloc.fSize);
        SkASSERT(alloc.fBackendMemory);
        GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
        VkResult result = allocator->flushMemory(alloc.fBackendMemory, offset, size);
        gpu->checkVkResult(result);
    }
}

void GrVkMemory::InvalidateMappedAlloc(GrVkGpu* gpu, const GrVkAlloc& alloc,
                                       VkDeviceSize offset, VkDeviceSize size) {
    if (alloc.fFlags & GrVkAlloc::kNoncoherent_Flag) {
        SkASSERT(offset == 0);
        SkASSERT(size <= alloc.fSize);
        SkASSERT(alloc.fBackendMemory);
        GrVkMemoryAllocator* allocator = gpu->memoryAllocator();
        VkResult result = allocator->invalidateMemory(alloc.fBackendMemory, offset, size);
        gpu->checkVkResult(result);
    }
}