buffer_cache: Avoid passing references of shared pointers and misc style changes

Instead of using as template argument a shared pointer, use the
underlying type and manage shared pointers explicitly. This can make
removing shared pointers from the cache more easy.

While we are at it, make some misc style changes and general
improvements (like insert_or_assign instead of operator[] + operator=).

2 files changed, 112 insertions, 114 deletions

diff --git a/src/video_core/buffer_cache/buffer_block.h b/src/video_core/buffer_cache/buffer_block.h
index e35ee0b67..e64170e66 100644
--- a/src/video_core/buffer_cache/buffer_block.h
+++ b/src/video_core/buffer_cache/buffer_block.h
@@ -15,48 +15,47 @@ namespace VideoCommon {
 
 class BufferBlock {
 public:
-    bool Overlaps(const VAddr start, const VAddr end) const {
+    bool Overlaps(VAddr start, VAddr end) const {
         return (cpu_addr < end) && (cpu_addr_end > start);
     }
 
-    bool IsInside(const VAddr other_start, const VAddr other_end) const {
+    bool IsInside(VAddr other_start, VAddr other_end) const {
         return cpu_addr <= other_start && other_end <= cpu_addr_end;
     }
 
-    std::size_t GetOffset(const VAddr in_addr) {
+    std::size_t Offset(VAddr in_addr) const {
         return static_cast<std::size_t>(in_addr - cpu_addr);
     }
 
-    VAddr GetCpuAddr() const {
+    VAddr CpuAddr() const {
         return cpu_addr;
     }
 
-    VAddr GetCpuAddrEnd() const {
+    VAddr CpuAddrEnd() const {
         return cpu_addr_end;
     }
 
-    void SetCpuAddr(const VAddr new_addr) {
+    void SetCpuAddr(VAddr new_addr) {
         cpu_addr = new_addr;
         cpu_addr_end = new_addr + size;
     }
 
-    std::size_t GetSize() const {
+    std::size_t Size() const {
         return size;
     }
 
-    void SetEpoch(u64 new_epoch) {
-        epoch = new_epoch;
+    u64 Epoch() const {
+        return epoch;
     }
 
-    u64 GetEpoch() {
-        return epoch;
+    void SetEpoch(u64 new_epoch) {
+        epoch = new_epoch;
     }
 
 protected:
-    explicit BufferBlock(VAddr cpu_addr, const std::size_t size) : size{size} {
-        SetCpuAddr(cpu_addr);
+    explicit BufferBlock(VAddr cpu_addr_, std::size_t size_) : size{size_} {
+        SetCpuAddr(cpu_addr_);
     }
-    ~BufferBlock() = default;
 
 private:
     VAddr cpu_addr{};
diff --git a/src/video_core/buffer_cache/buffer_cache.h b/src/video_core/buffer_cache/buffer_cache.h
index b88fce2cd..efc480d08 100644
--- a/src/video_core/buffer_cache/buffer_cache.h
+++ b/src/video_core/buffer_cache/buffer_cache.h
@@ -30,12 +30,16 @@
 
 namespace VideoCommon {
 
-template <typename OwnerBuffer, typename BufferType, typename StreamBuffer>
+template <typename Buffer, typename BufferType, typename StreamBuffer>
 class BufferCache {
     using IntervalSet = boost::icl::interval_set<VAddr>;
     using IntervalType = typename IntervalSet::interval_type;
     using VectorMapInterval = boost::container::small_vector<MapInterval*, 1>;
 
+    static constexpr u64 WRITE_PAGE_BIT = 11;
+    static constexpr u64 BLOCK_PAGE_BITS = 21;
+    static constexpr u64 BLOCK_PAGE_SIZE = 1ULL << BLOCK_PAGE_BITS;
+
 public:
     using BufferInfo = std::pair<BufferType, u64>;
 
@@ -82,7 +86,7 @@ public:
             }
         }
 
-        OwnerBuffer block = GetBlock(cpu_addr, size);
+        Buffer* const block = GetBlock(cpu_addr, size);
         MapInterval* const map = MapAddress(block, gpu_addr, cpu_addr, size);
         if (!map) {
             return {GetEmptyBuffer(size), 0};
@@ -98,7 +102,7 @@ public:
             }
         }
 
-        return {ToHandle(block), static_cast<u64>(block->GetOffset(cpu_addr))};
+        return {block->Handle(), static_cast<u64>(block->Offset(cpu_addr))};
     }
 
     /// Uploads from a host memory. Returns the OpenGL buffer where it's located and its offset.
@@ -125,16 +129,18 @@ public:
         return std::exchange(invalidated, false);
     }
 
+    /// Function called at the end of each frame, inteded for deferred operations
     void TickFrame() {
         ++epoch;
+
         while (!pending_destruction.empty()) {
             // Delay at least 4 frames before destruction.
             // This is due to triple buffering happening on some drivers.
             static constexpr u64 epochs_to_destroy = 5;
-            if (pending_destruction.front()->GetEpoch() + epochs_to_destroy > epoch) {
+            if (pending_destruction.front()->Epoch() + epochs_to_destroy > epoch) {
                 break;
             }
-            pending_destruction.pop_front();
+            pending_destruction.pop();
         }
     }
 
@@ -249,23 +255,21 @@ public:
 
 protected:
     explicit BufferCache(VideoCore::RasterizerInterface& rasterizer, Core::System& system,
-                         std::unique_ptr<StreamBuffer> stream_buffer)
-        : rasterizer{rasterizer}, system{system}, stream_buffer{std::move(stream_buffer)},
-          stream_buffer_handle{this->stream_buffer->GetHandle()} {}
+                         std::unique_ptr<StreamBuffer> stream_buffer_)
+        : rasterizer{rasterizer}, system{system}, stream_buffer{std::move(stream_buffer_)},
+          stream_buffer_handle{stream_buffer->Handle()} {}
 
     ~BufferCache() = default;
 
-    virtual BufferType ToHandle(const OwnerBuffer& storage) = 0;
+    virtual std::shared_ptr<Buffer> CreateBlock(VAddr cpu_addr, std::size_t size) = 0;
 
-    virtual OwnerBuffer CreateBlock(VAddr cpu_addr, std::size_t size) = 0;
-
-    virtual void UploadBlockData(const OwnerBuffer& buffer, std::size_t offset, std::size_t size,
+    virtual void UploadBlockData(const Buffer& buffer, std::size_t offset, std::size_t size,
                                  const u8* data) = 0;
 
-    virtual void DownloadBlockData(const OwnerBuffer& buffer, std::size_t offset, std::size_t size,
+    virtual void DownloadBlockData(const Buffer& buffer, std::size_t offset, std::size_t size,
                                    u8* data) = 0;
 
-    virtual void CopyBlock(const OwnerBuffer& src, const OwnerBuffer& dst, std::size_t src_offset,
+    virtual void CopyBlock(const Buffer& src, const Buffer& dst, std::size_t src_offset,
                            std::size_t dst_offset, std::size_t size) = 0;
 
     virtual BufferInfo ConstBufferUpload(const void* raw_pointer, std::size_t size) {
@@ -321,7 +325,7 @@ protected:
     }
 
 private:
-    MapInterval* MapAddress(const OwnerBuffer& block, GPUVAddr gpu_addr, VAddr cpu_addr,
+    MapInterval* MapAddress(const Buffer* block, GPUVAddr gpu_addr, VAddr cpu_addr,
                             std::size_t size) {
         const VectorMapInterval overlaps = GetMapsInRange(cpu_addr, size);
         if (overlaps.empty()) {
@@ -329,11 +333,11 @@ private:
             const VAddr cpu_addr_end = cpu_addr + size;
             if (memory_manager.IsGranularRange(gpu_addr, size)) {
                 u8* host_ptr = memory_manager.GetPointer(gpu_addr);
-                UploadBlockData(block, block->GetOffset(cpu_addr), size, host_ptr);
+                UploadBlockData(*block, block->Offset(cpu_addr), size, host_ptr);
             } else {
                 staging_buffer.resize(size);
                 memory_manager.ReadBlockUnsafe(gpu_addr, staging_buffer.data(), size);
-                UploadBlockData(block, block->GetOffset(cpu_addr), size, staging_buffer.data());
+                UploadBlockData(*block, block->Offset(cpu_addr), size, staging_buffer.data());
             }
             return Register(MapInterval(cpu_addr, cpu_addr_end, gpu_addr));
         }
@@ -376,7 +380,7 @@ private:
         return map;
     }
 
-    void UpdateBlock(const OwnerBuffer& block, VAddr start, VAddr end,
+    void UpdateBlock(const Buffer* block, VAddr start, VAddr end,
                      const VectorMapInterval& overlaps) {
         const IntervalType base_interval{start, end};
         IntervalSet interval_set{};
@@ -386,13 +390,13 @@ private:
             interval_set.subtract(subtract);
         }
         for (auto& interval : interval_set) {
-            std::size_t size = interval.upper() - interval.lower();
-            if (size > 0) {
-                staging_buffer.resize(size);
-                system.Memory().ReadBlockUnsafe(interval.lower(), staging_buffer.data(), size);
-                UploadBlockData(block, block->GetOffset(interval.lower()), size,
-                                staging_buffer.data());
+            const std::size_t size = interval.upper() - interval.lower();
+            if (size == 0) {
+                continue;
             }
+            staging_buffer.resize(size);
+            system.Memory().ReadBlockUnsafe(interval.lower(), staging_buffer.data(), size);
+            UploadBlockData(*block, block->Offset(interval.lower()), size, staging_buffer.data());
         }
     }
 
@@ -422,10 +426,14 @@ private:
     }
 
     void FlushMap(MapInterval* map) {
+        const auto it = blocks.find(map->start >> BLOCK_PAGE_BITS);
+        ASSERT_OR_EXECUTE(it != blocks.end(), return;);
+
+        std::shared_ptr<Buffer> block = it->second;
+
         const std::size_t size = map->end - map->start;
-        OwnerBuffer block = blocks[map->start >> block_page_bits];
         staging_buffer.resize(size);
-        DownloadBlockData(block, block->GetOffset(map->start), size, staging_buffer.data());
+        DownloadBlockData(*block, block->Offset(map->start), size, staging_buffer.data());
         system.Memory().WriteBlockUnsafe(map->start, staging_buffer.data(), size);
         map->MarkAsModified(false, 0);
     }
@@ -448,97 +456,89 @@ private:
         buffer_offset = offset_aligned;
     }
 
-    OwnerBuffer EnlargeBlock(OwnerBuffer buffer) {
-        const std::size_t old_size = buffer->GetSize();
-        const std::size_t new_size = old_size + block_page_size;
-        const VAddr cpu_addr = buffer->GetCpuAddr();
-        OwnerBuffer new_buffer = CreateBlock(cpu_addr, new_size);
-        CopyBlock(buffer, new_buffer, 0, 0, old_size);
-        buffer->SetEpoch(epoch);
-        pending_destruction.push_back(buffer);
+    std::shared_ptr<Buffer> EnlargeBlock(std::shared_ptr<Buffer> buffer) {
+        const std::size_t old_size = buffer->Size();
+        const std::size_t new_size = old_size + BLOCK_PAGE_SIZE;
+        const VAddr cpu_addr = buffer->CpuAddr();
+        std::shared_ptr<Buffer> new_buffer = CreateBlock(cpu_addr, new_size);
+        CopyBlock(*buffer, *new_buffer, 0, 0, old_size);
+        QueueDestruction(std::move(buffer));
+
         const VAddr cpu_addr_end = cpu_addr + new_size - 1;
-        u64 page_start = cpu_addr >> block_page_bits;
-        const u64 page_end = cpu_addr_end >> block_page_bits;
-        while (page_start <= page_end) {
-            blocks[page_start] = new_buffer;
-            ++page_start;
+        const u64 page_end = cpu_addr_end >> BLOCK_PAGE_BITS;
+        for (u64 page_start = cpu_addr >> BLOCK_PAGE_BITS; page_start <= page_end; ++page_start) {
+            blocks.insert_or_assign(page_start, new_buffer);
         }
+
         return new_buffer;
     }
 
-    OwnerBuffer MergeBlocks(OwnerBuffer first, OwnerBuffer second) {
-        const std::size_t size_1 = first->GetSize();
-        const std::size_t size_2 = second->GetSize();
-        const VAddr first_addr = first->GetCpuAddr();
-        const VAddr second_addr = second->GetCpuAddr();
+    std::shared_ptr<Buffer> MergeBlocks(std::shared_ptr<Buffer> first,
+                                        std::shared_ptr<Buffer> second) {
+        const std::size_t size_1 = first->Size();
+        const std::size_t size_2 = second->Size();
+        const VAddr first_addr = first->CpuAddr();
+        const VAddr second_addr = second->CpuAddr();
         const VAddr new_addr = std::min(first_addr, second_addr);
         const std::size_t new_size = size_1 + size_2;
-        OwnerBuffer new_buffer = CreateBlock(new_addr, new_size);
-        CopyBlock(first, new_buffer, 0, new_buffer->GetOffset(first_addr), size_1);
-        CopyBlock(second, new_buffer, 0, new_buffer->GetOffset(second_addr), size_2);
-        first->SetEpoch(epoch);
-        second->SetEpoch(epoch);
-        pending_destruction.push_back(first);
-        pending_destruction.push_back(second);
+
+        std::shared_ptr<Buffer> new_buffer = CreateBlock(new_addr, new_size);
+        CopyBlock(*first, *new_buffer, 0, new_buffer->Offset(first_addr), size_1);
+        CopyBlock(*second, *new_buffer, 0, new_buffer->Offset(second_addr), size_2);
+        QueueDestruction(std::move(first));
+        QueueDestruction(std::move(second));
+
         const VAddr cpu_addr_end = new_addr + new_size - 1;
-        u64 page_start = new_addr >> block_page_bits;
-        const u64 page_end = cpu_addr_end >> block_page_bits;
-        while (page_start <= page_end) {
-            blocks[page_start] = new_buffer;
-            ++page_start;
+        const u64 page_end = cpu_addr_end >> BLOCK_PAGE_BITS;
+        for (u64 page_start = new_addr >> BLOCK_PAGE_BITS; page_start <= page_end; ++page_start) {
+            blocks.insert_or_assign(page_start, new_buffer);
         }
         return new_buffer;
     }
 
-    OwnerBuffer GetBlock(const VAddr cpu_addr, const std::size_t size) {
-        OwnerBuffer found;
+    Buffer* GetBlock(VAddr cpu_addr, std::size_t size) {
+        std::shared_ptr<Buffer> found;
+
         const VAddr cpu_addr_end = cpu_addr + size - 1;
-        u64 page_start = cpu_addr >> block_page_bits;
-        const u64 page_end = cpu_addr_end >> block_page_bits;
-        while (page_start <= page_end) {
+        const u64 page_end = cpu_addr_end >> BLOCK_PAGE_BITS;
+        for (u64 page_start = cpu_addr >> BLOCK_PAGE_BITS; page_start <= page_end; ++page_start) {
             auto it = blocks.find(page_start);
             if (it == blocks.end()) {
                 if (found) {
                     found = EnlargeBlock(found);
-                } else {
-                    const VAddr start_addr = (page_start << block_page_bits);
-                    found = CreateBlock(start_addr, block_page_size);
-                    blocks[page_start] = found;
-                }
-            } else {
-                if (found) {
-                    if (found == it->second) {
-                        ++page_start;
-                        continue;
-                    }
-                    found = MergeBlocks(found, it->second);
-                } else {
-                    found = it->second;
+                    continue;
                 }
+                const VAddr start_addr = page_start << BLOCK_PAGE_BITS;
+                found = CreateBlock(start_addr, BLOCK_PAGE_SIZE);
+                blocks.insert_or_assign(page_start, found);
+                continue;
+            }
+            if (!found) {
+                found = it->second;
+                continue;
+            }
+            if (found != it->second) {
+                found = MergeBlocks(std::move(found), it->second);
             }
-            ++page_start;
         }
-        return found;
+        return found.get();
     }
 
-    void MarkRegionAsWritten(const VAddr start, const VAddr end) {
-        u64 page_start = start >> write_page_bit;
-        const u64 page_end = end >> write_page_bit;
-        while (page_start <= page_end) {
+    void MarkRegionAsWritten(VAddr start, VAddr end) {
+        const u64 page_end = end >> WRITE_PAGE_BIT;
+        for (u64 page_start = start >> WRITE_PAGE_BIT; page_start <= page_end; ++page_start) {
             auto it = written_pages.find(page_start);
             if (it != written_pages.end()) {
                 it->second = it->second + 1;
             } else {
-                written_pages[page_start] = 1;
+                written_pages.insert_or_assign(page_start, 1);
             }
-            ++page_start;
         }
     }
 
-    void UnmarkRegionAsWritten(const VAddr start, const VAddr end) {
-        u64 page_start = start >> write_page_bit;
-        const u64 page_end = end >> write_page_bit;
-        while (page_start <= page_end) {
+    void UnmarkRegionAsWritten(VAddr start, VAddr end) {
+        const u64 page_end = end >> WRITE_PAGE_BIT;
+        for (u64 page_start = start >> WRITE_PAGE_BIT; page_start <= page_end; ++page_start) {
             auto it = written_pages.find(page_start);
             if (it != written_pages.end()) {
                 if (it->second > 1) {
@@ -547,22 +547,24 @@ private:
                     written_pages.erase(it);
                 }
             }
-            ++page_start;
         }
     }
 
-    bool IsRegionWritten(const VAddr start, const VAddr end) const {
-        u64 page_start = start >> write_page_bit;
-        const u64 page_end = end >> write_page_bit;
-        while (page_start <= page_end) {
+    bool IsRegionWritten(VAddr start, VAddr end) const {
+        const u64 page_end = end >> WRITE_PAGE_BIT;
+        for (u64 page_start = start >> WRITE_PAGE_BIT; page_start <= page_end; ++page_start) {
             if (written_pages.count(page_start) > 0) {
                 return true;
             }
-            ++page_start;
         }
         return false;
     }
 
+    void QueueDestruction(std::shared_ptr<Buffer> buffer) {
+        buffer->SetEpoch(epoch);
+        pending_destruction.push(std::move(buffer));
+    }
+
     void MarkForAsyncFlush(MapInterval* map) {
         if (!uncommitted_flushes) {
             uncommitted_flushes = std::make_shared<std::unordered_set<MapInterval*>>();
@@ -574,7 +576,7 @@ private:
     Core::System& system;
 
     std::unique_ptr<StreamBuffer> stream_buffer;
-    BufferType stream_buffer_handle{};
+    BufferType stream_buffer_handle;
 
     bool invalidated = false;
 
@@ -586,18 +588,15 @@ private:
     boost::intrusive::set<MapInterval, boost::intrusive::compare<MapIntervalCompare>>
         mapped_addresses;
 
-    static constexpr u64 write_page_bit = 11;
     std::unordered_map<u64, u32> written_pages;
+    std::unordered_map<u64, std::shared_ptr<Buffer>> blocks;
 
-    static constexpr u64 block_page_bits = 21;
-    static constexpr u64 block_page_size = 1ULL << block_page_bits;
-    std::unordered_map<u64, OwnerBuffer> blocks;
-
-    std::list<OwnerBuffer> pending_destruction;
+    std::queue<std::shared_ptr<Buffer>> pending_destruction;
     u64 epoch = 0;
     u64 modified_ticks = 0;
 
     std::vector<u8> staging_buffer;
+
     std::list<MapInterval*> marked_for_unregister;
 
     std::shared_ptr<std::unordered_set<MapInterval*>> uncommitted_flushes;